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1583 Commits

Author SHA1 Message Date
Stephen Boyd a098ecd2fa firmware: support loading into a pre-allocated buffer
Some systems are memory constrained but they need to load very large
firmwares.  The firmware subsystem allows drivers to request this
firmware be loaded from the filesystem, but this requires that the
entire firmware be loaded into kernel memory first before it's provided
to the driver.  This can lead to a situation where we map the firmware
twice, once to load the firmware into kernel memory and once to copy the
firmware into the final resting place.

This creates needless memory pressure and delays loading because we have
to copy from kernel memory to somewhere else.  Let's add a
request_firmware_into_buf() API that allows drivers to request firmware
be loaded directly into a pre-allocated buffer.  This skips the
intermediate step of allocating a buffer in kernel memory to hold the
firmware image while it's read from the filesystem.  It also requires
that drivers know how much memory they'll require before requesting the
firmware and negates any benefits of firmware caching because the
firmware layer doesn't manage the buffer lifetime.

For a 16MB buffer, about half the time is spent performing a memcpy from
the buffer to the final resting place.  I see loading times go from
0.081171 seconds to 0.047696 seconds after applying this patch.  Plus
the vmalloc pressure is reduced.

This is based on a patch from Vikram Mulukutla on codeaurora.org:
  https://www.codeaurora.org/cgit/quic/la/kernel/msm-3.18/commit/drivers/base/firmware_class.c?h=rel/msm-3.18&id=0a328c5f6cd999f5c591f172216835636f39bcb5

Link: http://lkml.kernel.org/r/20160607164741.31849-4-stephen.boyd@linaro.org
Signed-off-by: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Vikram Mulukutla <markivx@codeaurora.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-02 19:35:10 -04:00
Linus Torvalds a867d7349e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull userns vfs updates from Eric Biederman:
 "This tree contains some very long awaited work on generalizing the
  user namespace support for mounting filesystems to include filesystems
  with a backing store.  The real world target is fuse but the goal is
  to update the vfs to allow any filesystem to be supported.  This
  patchset is based on a lot of code review and testing to approach that
  goal.

  While looking at what is needed to support the fuse filesystem it
  became clear that there were things like xattrs for security modules
  that needed special treatment.  That the resolution of those concerns
  would not be fuse specific.  That sorting out these general issues
  made most sense at the generic level, where the right people could be
  drawn into the conversation, and the issues could be solved for
  everyone.

  At a high level what this patchset does a couple of simple things:

   - Add a user namespace owner (s_user_ns) to struct super_block.

   - Teach the vfs to handle filesystem uids and gids not mapping into
     to kuids and kgids and being reported as INVALID_UID and
     INVALID_GID in vfs data structures.

  By assigning a user namespace owner filesystems that are mounted with
  only user namespace privilege can be detected.  This allows security
  modules and the like to know which mounts may not be trusted.  This
  also allows the set of uids and gids that are communicated to the
  filesystem to be capped at the set of kuids and kgids that are in the
  owning user namespace of the filesystem.

  One of the crazier corner casees this handles is the case of inodes
  whose i_uid or i_gid are not mapped into the vfs.  Most of the code
  simply doesn't care but it is easy to confuse the inode writeback path
  so no operation that could cause an inode write-back is permitted for
  such inodes (aka only reads are allowed).

  This set of changes starts out by cleaning up the code paths involved
  in user namespace permirted mounts.  Then when things are clean enough
  adds code that cleanly sets s_user_ns.  Then additional restrictions
  are added that are possible now that the filesystem superblock
  contains owner information.

  These changes should not affect anyone in practice, but there are some
  parts of these restrictions that are changes in behavior.

   - Andy's restriction on suid executables that does not honor the
     suid bit when the path is from another mount namespace (think
     /proc/[pid]/fd/) or when the filesystem was mounted by a less
     privileged user.

   - The replacement of the user namespace implicit setting of MNT_NODEV
     with implicitly setting SB_I_NODEV on the filesystem superblock
     instead.

     Using SB_I_NODEV is a stronger form that happens to make this state
     user invisible.  The user visibility can be managed but it caused
     problems when it was introduced from applications reasonably
     expecting mount flags to be what they were set to.

  There is a little bit of work remaining before it is safe to support
  mounting filesystems with backing store in user namespaces, beyond
  what is in this set of changes.

   - Verifying the mounter has permission to read/write the block device
     during mount.

   - Teaching the integrity modules IMA and EVM to handle filesystems
     mounted with only user namespace root and to reduce trust in their
     security xattrs accordingly.

   - Capturing the mounters credentials and using that for permission
     checks in d_automount and the like.  (Given that overlayfs already
     does this, and we need the work in d_automount it make sense to
     generalize this case).

  Furthermore there are a few changes that are on the wishlist:

   - Get all filesystems supporting posix acls using the generic posix
     acls so that posix_acl_fix_xattr_from_user and
     posix_acl_fix_xattr_to_user may be removed.  [Maintainability]

   - Reducing the permission checks in places such as remount to allow
     the superblock owner to perform them.

   - Allowing the superblock owner to chown files with unmapped uids and
     gids to something that is mapped so the files may be treated
     normally.

  I am not considering even obvious relaxations of permission checks
  until it is clear there are no more corner cases that need to be
  locked down and handled generically.

  Many thanks to Seth Forshee who kept this code alive, and putting up
  with me rewriting substantial portions of what he did to handle more
  corner cases, and for his diligent testing and reviewing of my
  changes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits)
  fs: Call d_automount with the filesystems creds
  fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns
  evm: Translate user/group ids relative to s_user_ns when computing HMAC
  dquot: For now explicitly don't support filesystems outside of init_user_ns
  quota: Handle quota data stored in s_user_ns in quota_setxquota
  quota: Ensure qids map to the filesystem
  vfs: Don't create inodes with a uid or gid unknown to the vfs
  vfs: Don't modify inodes with a uid or gid unknown to the vfs
  cred: Reject inodes with invalid ids in set_create_file_as()
  fs: Check for invalid i_uid in may_follow_link()
  vfs: Verify acls are valid within superblock's s_user_ns.
  userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS
  fs: Refuse uid/gid changes which don't map into s_user_ns
  selinux: Add support for unprivileged mounts from user namespaces
  Smack: Handle labels consistently in untrusted mounts
  Smack: Add support for unprivileged mounts from user namespaces
  fs: Treat foreign mounts as nosuid
  fs: Limit file caps to the user namespace of the super block
  userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag
  userns: Remove implicit MNT_NODEV fragility.
  ...
2016-07-29 15:54:19 -07:00
Linus Torvalds 27ae0c41ed Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
 "This fixes error propagation from writeback to fsync/close for
  writeback cache mode as well as adding a missing capability flag to
  the INIT message.  The rest are cleanups.

  (The commits are recent but all the code actually sat in -next for a
  while now.  The recommits are due to conflict avoidance and the
  addition of Cc: stable@...)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: use filemap_check_errors()
  mm: export filemap_check_errors() to modules
  fuse: fix wrong assignment of ->flags in fuse_send_init()
  fuse: fuse_flush must check mapping->flags for errors
  fuse: fsync() did not return IO errors
  fuse: don't mess with blocking signals
  new helper: wait_event_killable_exclusive()
  fuse: improve aio directIO write performance for size extending writes
2016-07-29 12:29:15 -07:00
Miklos Szeredi d72d9e2a5d mm: export filemap_check_errors() to modules
Can be used by fuse, btrfs and f2fs to replace opencoded variants.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29 14:10:57 +02:00
Linus Torvalds 6784725ab0 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Assorted cleanups and fixes.

  Probably the most interesting part long-term is ->d_init() - that will
  have a bunch of followups in (at least) ceph and lustre, but we'll
  need to sort the barrier-related rules before it can get used for
  really non-trivial stuff.

  Another fun thing is the merge of ->d_iput() callers (dentry_iput()
  and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all
  except the one in __d_lookup_lru())"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  fs/dcache.c: avoid soft-lockup in dput()
  vfs: new d_init method
  vfs: Update lookup_dcache() comment
  bdev: get rid of ->bd_inodes
  Remove last traces of ->sync_page
  new helper: d_same_name()
  dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()
  vfs: clean up documentation
  vfs: document ->d_real()
  vfs: merge .d_select_inode() into .d_real()
  unify dentry_iput() and dentry_unlink_inode()
  binfmt_misc: ->s_root is not going anywhere
  drop redundant ->owner initializations
  ufs: get rid of redundant checks
  orangefs: constify inode_operations
  missed comment updates from ->direct_IO() prototype change
  file_inode(f)->i_mapping is f->f_mapping
  trim fsnotify hooks a bit
  9p: new helper - v9fs_parent_fid()
  debugfs: ->d_parent is never NULL or negative
  ...
2016-07-28 12:59:05 -07:00
Linus Torvalds 0e06f5c0de Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - a few misc bits

 - ocfs2

 - most(?) of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
  thp: fix comments of __pmd_trans_huge_lock()
  cgroup: remove unnecessary 0 check from css_from_id()
  cgroup: fix idr leak for the first cgroup root
  mm: memcontrol: fix documentation for compound parameter
  mm: memcontrol: remove BUG_ON in uncharge_list
  mm: fix build warnings in <linux/compaction.h>
  mm, thp: convert from optimistic swapin collapsing to conservative
  mm, thp: fix comment inconsistency for swapin readahead functions
  thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
  shmem: split huge pages beyond i_size under memory pressure
  thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
  khugepaged: add support of collapse for tmpfs/shmem pages
  shmem: make shmem_inode_info::lock irq-safe
  khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
  thp: extract khugepaged from mm/huge_memory.c
  shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
  shmem: add huge pages support
  shmem: get_unmapped_area align huge page
  shmem: prepare huge= mount option and sysfs knob
  mm, rmap: account shmem thp pages
  ...
2016-07-26 19:55:54 -07:00
Minchan Kim bda807d444 mm: migrate: support non-lru movable page migration
We have allowed migration for only LRU pages until now and it was enough
to make high-order pages.  But recently, embedded system(e.g., webOS,
android) uses lots of non-movable pages(e.g., zram, GPU memory) so we
have seen several reports about troubles of small high-order allocation.
For fixing the problem, there were several efforts (e,g,.  enhance
compaction algorithm, SLUB fallback to 0-order page, reserved memory,
vmalloc and so on) but if there are lots of non-movable pages in system,
their solutions are void in the long run.

So, this patch is to support facility to change non-movable pages with
movable.  For the feature, this patch introduces functions related to
migration to address_space_operations as well as some page flags.

If a driver want to make own pages movable, it should define three
functions which are function pointers of struct
address_space_operations.

1. bool (*isolate_page) (struct page *page, isolate_mode_t mode);

What VM expects on isolate_page function of driver is to return *true*
if driver isolates page successfully.  On returing true, VM marks the
page as PG_isolated so concurrent isolation in several CPUs skip the
page for isolation.  If a driver cannot isolate the page, it should
return *false*.

Once page is successfully isolated, VM uses page.lru fields so driver
shouldn't expect to preserve values in that fields.

2. int (*migratepage) (struct address_space *mapping,
		struct page *newpage, struct page *oldpage, enum migrate_mode);

After isolation, VM calls migratepage of driver with isolated page.  The
function of migratepage is to move content of the old page to new page
and set up fields of struct page newpage.  Keep in mind that you should
indicate to the VM the oldpage is no longer movable via
__ClearPageMovable() under page_lock if you migrated the oldpage
successfully and returns 0.  If driver cannot migrate the page at the
moment, driver can return -EAGAIN.  On -EAGAIN, VM will retry page
migration in a short time because VM interprets -EAGAIN as "temporal
migration failure".  On returning any error except -EAGAIN, VM will give
up the page migration without retrying in this time.

Driver shouldn't touch page.lru field VM using in the functions.

3. void (*putback_page)(struct page *);

If migration fails on isolated page, VM should return the isolated page
to the driver so VM calls driver's putback_page with migration failed
page.  In this function, driver should put the isolated page back to the
own data structure.

4. non-lru movable page flags

There are two page flags for supporting non-lru movable page.

* PG_movable

Driver should use the below function to make page movable under
page_lock.

	void __SetPageMovable(struct page *page, struct address_space *mapping)

It needs argument of address_space for registering migration family
functions which will be called by VM.  Exactly speaking, PG_movable is
not a real flag of struct page.  Rather than, VM reuses page->mapping's
lower bits to represent it.

	#define PAGE_MAPPING_MOVABLE 0x2
	page->mapping = page->mapping | PAGE_MAPPING_MOVABLE;

so driver shouldn't access page->mapping directly.  Instead, driver
should use page_mapping which mask off the low two bits of page->mapping
so it can get right struct address_space.

For testing of non-lru movable page, VM supports __PageMovable function.
However, it doesn't guarantee to identify non-lru movable page because
page->mapping field is unified with other variables in struct page.  As
well, if driver releases the page after isolation by VM, page->mapping
doesn't have stable value although it has PAGE_MAPPING_MOVABLE (Look at
__ClearPageMovable).  But __PageMovable is cheap to catch whether page
is LRU or non-lru movable once the page has been isolated.  Because LRU
pages never can have PAGE_MAPPING_MOVABLE in page->mapping.  It is also
good for just peeking to test non-lru movable pages before more
expensive checking with lock_page in pfn scanning to select victim.

For guaranteeing non-lru movable page, VM provides PageMovable function.
Unlike __PageMovable, PageMovable functions validates page->mapping and
mapping->a_ops->isolate_page under lock_page.  The lock_page prevents
sudden destroying of page->mapping.

Driver using __SetPageMovable should clear the flag via
__ClearMovablePage under page_lock before the releasing the page.

* PG_isolated

To prevent concurrent isolation among several CPUs, VM marks isolated
page as PG_isolated under lock_page.  So if a CPU encounters PG_isolated
non-lru movable page, it can skip it.  Driver doesn't need to manipulate
the flag because VM will set/clear it automatically.  Keep in mind that
if driver sees PG_isolated page, it means the page have been isolated by
VM so it shouldn't touch page.lru field.  PG_isolated is alias with
PG_reclaim flag so driver shouldn't use the flag for own purpose.

[opensource.ganesh@gmail.com: mm/compaction: remove local variable is_lru]
  Link: http://lkml.kernel.org/r/20160618014841.GA7422@leo-test
Link: http://lkml.kernel.org/r/1464736881-24886-3-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: John Einar Reitan <john.reitan@foss.arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
Dave Chinner 6c60d2b574 fs/fs-writeback.c: add a new writeback list for sync
wait_sb_inodes() currently does a walk of all inodes in the filesystem
to find dirty one to wait on during sync.  This is highly inefficient
and wastes a lot of CPU when there are lots of clean cached inodes that
we don't need to wait on.

To avoid this "all inode" walk, we need to track inodes that are
currently under writeback that we need to wait for.  We do this by
adding inodes to a writeback list on the sb when the mapping is first
tagged as having pages under writeback.  wait_sb_inodes() can then walk
this list of "inodes under IO" and wait specifically just for the inodes
that the current sync(2) needs to wait for.

Define a couple helpers to add/remove an inode from the writeback list
and call them when the overall mapping is tagged for or cleared from
writeback.  Update wait_sb_inodes() to walk only the inodes under
writeback due to the sync.

With this change, filesystem sync times are significantly reduced for
fs' with largely populated inode caches and otherwise no other work to
do.  For example, on a 16xcpu 2GHz x86-64 server, 10TB XFS filesystem
with a ~10m entry inode cache, sync times are reduced from ~7.3s to less
than 0.1s when the filesystem is fully clean.

Link: http://lkml.kernel.org/r/1466594593-6757-2-git-send-email-bfoster@redhat.com
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Tested-by: Holger Hoffstätte <holger.hoffstaette@applied-asynchrony.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
Christoph Hellwig 70246286e9 block: get rid of bio_rw and READA
These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-07-20 17:37:01 -06:00
Al Viro a4a4f9439c bdev: get rid of ->bd_inodes
Since 2006 we have ->i_bdev pinning bdev in question, so there's no
way to get to bdev ->evict_inode() while there's an aliasing inode
anywhere.  In other words, the only place walking the list of aliases
is guaranteed to do it only when the list is empty...

Remove the detritus; it should've been done in "[PATCH] Fix a race
condition between ->i_mapping and iput()", but nobody had noticed it
back then.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-19 13:16:52 -04:00
Seth Forshee 8175435777 fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns
For filesystems mounted from a user namespace on-disk ids should
be translated relative to s_users_ns rather than init_user_ns.

When an id in the filesystem doesn't exist in s_user_ns the
associated id in the inode will be set to INVALID_[UG]ID, which
turns these into de facto "nobody" ids. This actually maps pretty
well into the way most code already works, and those places where
it didn't were fixed in previous patches. Moving forward vfs code
needs to be careful to handle instances where ids in inodes may
be invalid.

Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-07-05 15:13:21 -05:00
Eric W. Biederman 0bd23d09b8 vfs: Don't modify inodes with a uid or gid unknown to the vfs
When a filesystem outside of init_user_ns is mounted it could have
uids and gids stored in it that do not map to init_user_ns.

The plan is to allow those filesystems to set i_uid to INVALID_UID and
i_gid to INVALID_GID for unmapped uids and gids and then to handle
that strange case in the vfs to ensure there is consistent robust
handling of the weirdness.

Upon a careful review of the vfs and filesystems about the only case
where there is any possibility of confusion or trouble is when the
inode is written back to disk.  In that case filesystems typically
read the inode->i_uid and inode->i_gid and write them to disk even
when just an inode timestamp is being updated.

Which leads to a rule that is very simple to implement and understand
inodes whose i_uid or i_gid is not valid may not be written.

In dealing with access times this means treat those inodes as if the
inode flag S_NOATIME was set.  Reads of the inodes appear safe and
useful, but any write or modification is disallowed.  The only inode
write that is allowed is a chown that sets the uid and gid on the
inode to valid values.  After such a chown the inode is normal and may
be treated as such.

Denying all writes to inodes with uids or gids unknown to the vfs also
prevents several oddball cases where corruption would have occurred
because the vfs does not have complete information.

One problem case that is prevented is attempting to use the gid of a
directory for new inodes where the directories sgid bit is set but the
directories gid is not mapped.

Another problem case avoided is attempting to update the evm hash
after setxattr, removexattr, and setattr.  As the evm hash includeds
the inode->i_uid or inode->i_gid not knowning the uid or gid prevents
a correct evm hash from being computed.  evm hash verification also
fails when i_uid or i_gid is unknown but that is essentially harmless
as it does not cause filesystem corruption.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-07-05 15:06:46 -05:00
Miklos Szeredi 2d902671ce vfs: merge .d_select_inode() into .d_real()
The two methods essentially do the same: find the real dentry/inode
belonging to an overlay dentry.  The difference is in the usage:

vfs_open() uses ->d_select_inode() and expects the function to perform
copy-up if necessary based on the open flags argument.

file_dentry() uses ->d_real() passing in the overlay dentry as well as the
underlying inode.

vfs_rename() uses ->d_select_inode() but passes zero flags.  ->d_real()
with a zero inode would have worked just as well here.

This patch merges the functionality of ->d_select_inode() into ->d_real()
by adding an 'open_flags' argument to the latter.

[Al Viro] Make the signature of d_real() match that of ->d_real() again.
And constify the inode argument, while we are at it.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-06-30 08:53:27 +02:00
Eric W. Biederman cc50a07a24 userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag
Now that SB_I_NODEV controls the nodev behavior devpts can just clear
this flag during mount.  Simplifying the code and making it easier
to audit how the code works.  While still preserving the invariant
that s_iflags is only modified during mount.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23 15:47:31 -05:00
Eric W. Biederman a2982cc922 vfs: Generalize filesystem nodev handling.
Introduce a function may_open_dev that tests MNT_NODEV and a new
superblock flab SB_I_NODEV.  Use this new function in all of the
places where MNT_NODEV was previously tested.

Add the new SB_I_NODEV s_iflag to proc, sysfs, and mqueuefs as those
filesystems should never support device nodes, and a simple superblock
flags makes that very hard to get wrong.  With SB_I_NODEV set if any
device nodes somehow manage to show up on on a filesystem those
device nodes will be unopenable.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23 15:41:57 -05:00
Eric W. Biederman 6e4eab577a fs: Add user namespace member to struct super_block
Start marking filesystems with a user namespace owner, s_user_ns.  In
this change this is only used for permission checks of who may mount a
filesystem.  Ultimately s_user_ns will be used for translating ids and
checking capabilities for filesystems mounted from user namespaces.

The default policy for setting s_user_ns is implemented in sget(),
which arranges for s_user_ns to be set to current_user_ns() and to
ensure that the mounter of the filesystem has CAP_SYS_ADMIN in that
user_ns.

The guts of sget are split out into another function sget_userns().
The function sget_userns calls alloc_super with the specified user
namespace or it verifies the existing superblock that was found
has the expected user namespace, and fails with EBUSY when it is not.
This failing prevents users with the wrong privileges mounting a
filesystem.

The reason for the split of sget_userns from sget is that in some
cases such as mount_ns and kernfs_mount_ns a different policy for
permission checking of mounts and setting s_user_ns is necessary, and
the existence of sget_userns() allows those policies to be
implemented.

The helper mount_ns is expected to be used for filesystems such as
proc and mqueuefs which present per namespace information.  The
function mount_ns is modified to call sget_userns instead of sget to
ensure the user namespace owner of the namespace whose information is
presented by the filesystem is used on the superblock.

For sysfs and cgroup the appropriate permission checks are already in
place, and kernfs_mount_ns is modified to call sget_userns so that
the init_user_ns is the only user namespace used.

For the cgroup filesystem cgroup namespace mounts are bind mounts of a
subset of the full cgroup filesystem and as such s_user_ns must be the
same for all of them as there is only a single superblock.

Mounts of sysfs that vary based on the network namespace could in principle
change s_user_ns but it keeps the analysis and implementation of kernfs
simpler if that is not supported, and at present there appear to be no
benefits from supporting a different s_user_ns on any sysfs mount.

Getting the details of setting s_user_ns correct has been
a long process.  Thanks to Pavel Tikhorirorv who spotted a leak
in sget_userns.  Thanks to Seth Forshee who has kept the work alive.

Thanks-to: Seth Forshee <seth.forshee@canonical.com>
Thanks-to: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2016-06-23 15:41:55 -05:00
Eric W. Biederman d91ee87d8d vfs: Pass data, ns, and ns->userns to mount_ns
Today what is normally called data (the mount options) is not passed
to fill_super through mount_ns.

Pass the mount options and the namespace separately to mount_ns so
that filesystems such as proc that have mount options, can use
mount_ns.

Pass the user namespace to mount_ns so that the standard permission
check that verifies the mounter has permissions over the namespace can
be performed in mount_ns instead of in each filesystems .mount method.
Thus removing the duplication between mqueuefs and proc in terms of
permission checks.  The extra permission check does not currently
affect the rpc_pipefs filesystem and the nfsd filesystem as those
filesystems do not currently allow unprivileged mounts.  Without
unpvileged mounts it is guaranteed that the caller has already passed
capable(CAP_SYS_ADMIN) which guarantees extra permission check will
pass.

Update rpc_pipefs and the nfsd filesystem to ensure that the network
namespace reference is always taken in fill_super and always put in kill_sb
so that the logic is simpler and so that errors originating inside of
fill_super do not cause a network namespace leak.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23 15:41:53 -05:00
Eric W. Biederman 8654df4e2a mnt: Refactor fs_fully_visible into mount_too_revealing
Replace the call of fs_fully_visible in do_new_mount from before the
new superblock is allocated with a call of mount_too_revealing after
the superblock is allocated.   This winds up being a much better location
for maintainability of the code.

The first change this enables is the replacement of FS_USERNS_VISIBLE
with SB_I_USERNS_VISIBLE.  Moving the flag from struct filesystem_type
to sb_iflags on the superblock.

Unfortunately mount_too_revealing fundamentally needs to touch
mnt_flags adding several MNT_LOCKED_XXX flags at the appropriate
times.  If the mnt_flags did not need to be touched the code
could be easily moved into the filesystem specific mount code.

Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-06-23 15:41:46 -05:00
Mike Christie 28a8f0d317 block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH
To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4e1b2d52a8 block, fs, drivers: remove REQ_OP compat defs and related code
This patch drops the compat definition of req_op where it matches
the rq_flag_bits definitions, and drops the related old and compat
code that allowed users to set either the op or flags for the operation.

We also then store the operation in the bi_rw/cmd_flags field similar
to how we used to store the bio ioprio where it sat in the upper bits
of the field.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 8a4c1e42e0 direct-io: use bio set/get op accessors
This patch has the dio code use a REQ_OP for the op and rq_flag_bits
for bi_rw flags. To set/get the op it uses the bio_set_op_attrs/bio_op
accssors.

It also begins to convert btrfs's dio_submit_t because of the dio
submit_io callout use. The next patches will completely convert
this code and the reset of the btrfs code paths.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie f21508211d block: add REQ_OP definitions and helpers
The following patches separate the operation (WRITE, READ, DISCARD,
etc) from the rq_flag_bits flags. This patch adds definitions for
request/bio operations (REQ_OPs) and adds request/bio accessors to
get/set the op.

In this patch the REQ_OPs match the REQ rq_flag_bits ones
for compat reasons while all the code is converted to use the
op accessors in the set. In the last patches the op will become a
number and the accessors and helpers in this patch will be dropped
or updated.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Mike Christie 4e49ea4a3d block/fs/drivers: remove rw argument from submit_bio
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw
instead of passing it in. This makes that use the same as
generic_make_request and how we set the other bio fields.

Signed-off-by: Mike Christie <mchristi@redhat.com>

Fixed up fs/ext4/crypto.c

Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07 13:41:38 -06:00
Linus Torvalds d102a56edb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "Followups to the parallel lookup work:

   - update docs

   - restore killability of the places that used to take ->i_mutex
     killably now that we have down_write_killable() merged

   - Additionally, it turns out that I missed a prerequisite for
     security_d_instantiate() stuff - ->getxattr() wasn't the only thing
     that could be called before dentry is attached to inode; with smack
     we needed the same treatment applied to ->setxattr() as well"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->setxattr() to passing dentry and inode separately
  switch xattr_handler->set() to passing dentry and inode separately
  restore killability of old mutex_lock_killable(&inode->i_mutex) users
  add down_write_killable_nested()
  update D/f/directory-locking
2016-05-27 17:14:05 -07:00
Al Viro 3767e255b3 switch ->setxattr() to passing dentry and inode separately
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64.  Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-27 20:09:16 -04:00
Linus Torvalds 315227f6da DAX error handling for 4.7
- Until now, dax has been disabled if media errors were found on
   any device. This enables the use of DAX in the presence of these
   errors by making all sector-aligned zeroing go through the driver.
 - The driver (already) has the ability to clear errors on writes that
   are sent through the block layer using 'DSMs' defined in ACPI 6.1.
 
 Other misc changes:
 
 - When mounting DAX filesystems, check to make sure the partition
   is page aligned. This is a requirement for DAX, and previously, we
   allowed such unaligned mounts to succeed, but subsequent reads/writes
   would fail.
 
 - Misc/cleanup fixes from Jan that remove unused code from DAX related to
   zeroing, writeback, and some size checks.
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Merge tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull misc DAX updates from Vishal Verma:
 "DAX error handling for 4.7

   - Until now, dax has been disabled if media errors were found on any
     device.  This enables the use of DAX in the presence of these
     errors by making all sector-aligned zeroing go through the driver.

   - The driver (already) has the ability to clear errors on writes that
     are sent through the block layer using 'DSMs' defined in ACPI 6.1.

  Other misc changes:

   - When mounting DAX filesystems, check to make sure the partition is
     page aligned.  This is a requirement for DAX, and previously, we
     allowed such unaligned mounts to succeed, but subsequent
     reads/writes would fail.

   - Misc/cleanup fixes from Jan that remove unused code from DAX
     related to zeroing, writeback, and some size checks"

* tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: fix a comment in dax_zero_page_range and dax_truncate_page
  dax: for truncate/hole-punch, do zeroing through the driver if possible
  dax: export a low-level __dax_zero_page_range helper
  dax: use sb_issue_zerout instead of calling dax_clear_sectors
  dax: enable dax in the presence of known media errors (badblocks)
  dax: fallback from pmd to pte on error
  block: Update blkdev_dax_capable() for consistency
  xfs: Add alignment check for DAX mount
  ext2: Add alignment check for DAX mount
  ext4: Add alignment check for DAX mount
  block: Add bdev_dax_supported() for dax mount checks
  block: Add vfs_msg() interface
  dax: Remove redundant inode size checks
  dax: Remove pointless writeback from dax_do_io()
  dax: Remove zeroing from dax_io()
  dax: Remove dead zeroing code from fault handlers
  ext2: Avoid DAX zeroing to corrupt data
  ext2: Fix block zeroing in ext2_get_blocks() for DAX
  dax: Remove complete_unwritten argument
  DAX: move RADIX_DAX_ definitions to dax.c
2016-05-26 19:34:26 -07:00
Linus Torvalds 1f40c49570 libnvdimm for 4.7
1/ Device DAX for persistent memory:
    Device DAX is the device-centric analogue of Filesystem DAX
    (CONFIG_FS_DAX).  It allows memory ranges to be allocated and mapped
    without need of an intervening file system.  Device DAX is strict,
    precise and predictable.  Specifically this interface:
 
    a) Guarantees fault granularity with respect to a given page size
       (pte, pmd, or pud) set at configuration time.
 
    b) Enforces deterministic behavior by being strict about what fault
       scenarios are supported.
 
    Persistent memory is the first target, but the mechanism is also
    targeted for exclusive allocations of performance/feature differentiated
    memory ranges.
 
 2/ Support for the HPE DSM (device specific method) command formats.
    This enables management of these first generation devices until a
    unified DSM specification materializes.
 
 3/ Further ACPI 6.1 compliance with support for the common dimm
    identifier format.
 
 4/ Various fixes and cleanups across the subsystem.
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Merge tag 'libnvdimm-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this update was stabilized before the merge window and
  appeared in -next.  The "device dax" implementation was revised this
  week in response to review feedback, and to address failures detected
  by the recently expanded ndctl unit test suite.

  Not included in this pull request are two dax topic branches (dax
  error handling, and dax radix-tree locking).  These topics were
  deferred to get a few more days of -next integration testing, and to
  coordinate a branch baseline with Ted and the ext4 tree.  Vishal and
  Ross will send the error handling and locking topics respectively in
  the next few days.

  This branch has received a positive build result from the kbuild robot
  across 226 configs.

  Summary:

   - Device DAX for persistent memory: Device DAX is the device-centric
     analogue of Filesystem DAX (CONFIG_FS_DAX).  It allows memory
     ranges to be allocated and mapped without need of an intervening
     file system.  Device DAX is strict, precise and predictable.
     Specifically this interface:

      a) Guarantees fault granularity with respect to a given page size
         (pte, pmd, or pud) set at configuration time.

      b) Enforces deterministic behavior by being strict about what
         fault scenarios are supported.

     Persistent memory is the first target, but the mechanism is also
     targeted for exclusive allocations of performance/feature
     differentiated memory ranges.

   - Support for the HPE DSM (device specific method) command formats.
     This enables management of these first generation devices until a
     unified DSM specification materializes.

   - Further ACPI 6.1 compliance with support for the common dimm
     identifier format.

   - Various fixes and cleanups across the subsystem"

* tag 'libnvdimm-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (40 commits)
  libnvdimm, dax: fix deletion
  libnvdimm, dax: fix alignment validation
  libnvdimm, dax: autodetect support
  libnvdimm: release ida resources
  Revert "block: enable dax for raw block devices"
  /dev/dax, core: file operations and dax-mmap
  /dev/dax, pmem: direct access to persistent memory
  libnvdimm: stop requiring a driver ->remove() method
  libnvdimm, dax: record the specified alignment of a dax-device instance
  libnvdimm, dax: reserve space to store labels for device-dax
  libnvdimm, dax: introduce device-dax infrastructure
  nfit: add sysfs dimm 'family' and 'dsm_mask' attributes
  tools/testing/nvdimm: ND_CMD_CALL support
  nfit: disable vendor specific commands
  nfit: export subsystem ids as attributes
  nfit: fix format interface code byte order per ACPI6.1
  nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism
  nfit, libnvdimm: clarify "commands" vs "_DSMs"
  libnvdimm: increase max envelope size for ioctl
  acpi/nfit: Add sysfs "id" for NVDIMM ID
  ...
2016-05-23 11:18:01 -07:00
Dan Williams acc93d30d7 Revert "block: enable dax for raw block devices"
This reverts commit 5a023cdba5.

The functionality is superseded by the new "Device DAX" facility.

Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Jan Kara <jack@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-20 22:02:56 -07:00
Linus Torvalds 3aa2fc1667 driver core update for 4.7-rc1
Here's the "big" driver core update for 4.7-rc1.
 
 Mostly just debugfs changes, the long-known and messy races with removing
 debugfs files should be fixed thanks to the great work of Nicolai Stange.  We
 also have some isa updates in here (the x86 maintainers told me to take it
 through this tree), a new warning when we run out of dynamic char major
 numbers, and a few other assorted changes, details in the shortlog.
 
 All have been in linux-next for some time with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here's the "big" driver core update for 4.7-rc1.

  Mostly just debugfs changes, the long-known and messy races with
  removing debugfs files should be fixed thanks to the great work of
  Nicolai Stange.  We also have some isa updates in here (the x86
  maintainers told me to take it through this tree), a new warning when
  we run out of dynamic char major numbers, and a few other assorted
  changes, details in the shortlog.

  All have been in linux-next for some time with no reported issues"

* tag 'driver-core-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (32 commits)
  Revert "base: dd: don't remove driver_data in -EPROBE_DEFER case"
  gpio: ws16c48: Utilize the ISA bus driver
  gpio: 104-idio-16: Utilize the ISA bus driver
  gpio: 104-idi-48: Utilize the ISA bus driver
  gpio: 104-dio-48e: Utilize the ISA bus driver
  watchdog: ebc-c384_wdt: Utilize the ISA bus driver
  iio: stx104: Utilize the module_isa_driver and max_num_isa_dev macros
  iio: stx104: Add X86 dependency to STX104 Kconfig option
  Documentation: Add ISA bus driver documentation
  isa: Implement the max_num_isa_dev macro
  isa: Implement the module_isa_driver macro
  pnp: pnpbios: Add explicit X86_32 dependency to PNPBIOS
  isa: Decouple X86_32 dependency from the ISA Kconfig option
  driver-core: use 'dev' argument in dev_dbg_ratelimited stub
  base: dd: don't remove driver_data in -EPROBE_DEFER case
  kernfs: Move faulting copy_user operations outside of the mutex
  devcoredump: add scatterlist support
  debugfs: unproxify files created through debugfs_create_u32_array()
  debugfs: unproxify files created through debugfs_create_blob()
  debugfs: unproxify files created through debugfs_create_bool()
  ...
2016-05-20 21:26:15 -07:00
Linus Torvalds f4f27d0028 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Highlights:

   - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
     of modules and firmware to be loaded from a specific device (this
     is from ChromeOS, where the device as a whole is verified
     cryptographically via dm-verity).

     This is disabled by default but can be configured to be enabled by
     default (don't do this if you don't know what you're doing).

   - Keys: allow authentication data to be stored in an asymmetric key.
     Lots of general fixes and updates.

   - SELinux: add restrictions for loading of kernel modules via
     finit_module().  Distinguish non-init user namespace capability
     checks.  Apply execstack check on thread stacks"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
  LSM: LoadPin: provide enablement CONFIG
  Yama: use atomic allocations when reporting
  seccomp: Fix comment typo
  ima: add support for creating files using the mknodat syscall
  ima: fix ima_inode_post_setattr
  vfs: forbid write access when reading a file into memory
  fs: fix over-zealous use of "const"
  selinux: apply execstack check on thread stacks
  selinux: distinguish non-init user namespace capability checks
  LSM: LoadPin for kernel file loading restrictions
  fs: define a string representation of the kernel_read_file_id enumeration
  Yama: consolidate error reporting
  string_helpers: add kstrdup_quotable_file
  string_helpers: add kstrdup_quotable_cmdline
  string_helpers: add kstrdup_quotable
  selinux: check ss_initialized before revalidating an inode label
  selinux: delay inode label lookup as long as possible
  selinux: don't revalidate an inode's label when explicitly setting it
  selinux: Change bool variable name to index.
  KEYS: Add KEYCTL_DH_COMPUTE command
  ...
2016-05-19 09:21:36 -07:00
Linus Torvalds c2e7b20705 Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs cleanups from Al Viro:
 "More cleanups from Christoph"

* 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: use RWF_SYNC
  fs: add RWF_DSYNC aand RWF_SYNC
  ceph: use generic_write_sync
  fs: simplify the generic_write_sync prototype
  fs: add IOCB_SYNC and IOCB_DSYNC
  direct-io: remove the offset argument to dio_complete
  direct-io: eliminate the offset argument to ->direct_IO
  xfs: eliminate the pos variable in xfs_file_dio_aio_write
  filemap: remove the pos argument to generic_file_direct_write
  filemap: remove pos variables in generic_file_read_iter
2016-05-17 15:05:23 -07:00
Linus Torvalds c52b76185b Merge branch 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct path' constification update from Al Viro:
 "'struct path' is passed by reference to a bunch of Linux security
  methods; in theory, there's nothing to stop them from modifying the
  damn thing and LSM community being what it is, sooner or later some
  enterprising soul is going to decide that it's a good idea.

  Let's remove the temptation and constify all of those..."

* 'work.const-path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  constify ima_d_path()
  constify security_sb_pivotroot()
  constify security_path_chroot()
  constify security_path_{link,rename}
  apparmor: remove useless checks for NULL ->mnt
  constify security_path_{mkdir,mknod,symlink}
  constify security_path_{unlink,rmdir}
  apparmor: constify common_perm_...()
  apparmor: constify aa_path_link()
  apparmor: new helper - common_path_perm()
  constify chmod_common/security_path_chmod
  constify security_sb_mount()
  constify chown_common/security_path_chown
  tomoyo: constify assorted struct path *
  apparmor_path_truncate(): path->mnt is never NULL
  constify vfs_truncate()
  constify security_path_truncate()
  [apparmor] constify struct path * in a bunch of helpers
2016-05-17 14:41:03 -07:00
Toshi Kani a8078b1fc6 block: Update blkdev_dax_capable() for consistency
blkdev_dax_capable() is similar to bdev_dax_supported(), but needs
to remain as a separate interface for checking dax capability of
a raw block device.

Rename and relocate blkdev_dax_capable() to keep them maintained
consistently, and call bdev_direct_access() for the dax capability
check.

There is no change in the behavior.

Link: https://lkml.org/lkml/2016/5/9/950
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@fb.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-17 00:44:13 -06:00
Jan Kara 02fbd13975 dax: Remove complete_unwritten argument
Fault handlers currently take complete_unwritten argument to convert
unwritten extents after PTEs are updated. However no filesystem uses
this anymore as the code is racy. Remove the unused argument.

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-16 18:11:51 -06:00
Al Viro ae05327a00 ext4: switch to ->iterate_shared()
Note that we need relax_dir() equivalent for directories
locked shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-12 20:36:01 -04:00
Al Viro 6192269444 introduce a parallel variant of ->iterate()
New method: ->iterate_shared().  Same arguments as in ->iterate(),
called with the directory locked only shared.  Once all filesystems
switch, the old one will be gone.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:29 -04:00
Al Viro 9902af79c0 parallel lookups: actual switch to rwsem
ta-da!

The main issue is the lack of down_write_killable(), so the places
like readdir.c switched to plain inode_lock(); once killable
variants of rwsem primitives appear, that'll be dealt with.

lockdep side also might need more work

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:28 -04:00
Al Viro 84e710da2a parallel lookups machinery, part 2
We'll need to verify that there's neither a hashed nor in-lookup
dentry with desired parent/name before adding to in-lookup set.

One possible solution would be to hold the parent's ->d_lock through
both checks, but while the in-lookup set is relatively small at any
time, dcache is not.  And holding the parent's ->d_lock through
something like __d_lookup_rcu() would suck too badly.

So we leave the parent's ->d_lock alone, which means that we watch
out for the following scenario:
	* we verify that there's no hashed match
	* existing in-lookup match gets hashed by another process
	* we verify that there's no in-lookup matches and decide
that everything's fine.

Solution: per-directory kinda-sorta seqlock, bumped around the times
we hash something that used to be in-lookup or move (and hash)
something in place of in-lookup.  Then the above would turn into
	* read the counter
	* do dcache lookup
	* if no matches found, check for in-lookup matches
	* if there had been none of those either, check if the
counter has changed; repeat if it has.

The "kinda-sorta" part is due to the fact that we don't have much spare
space in inode.  There is a spare word (shared with i_bdev/i_cdev/i_pipe),
so the counter part is not a problem, but spinlock is a different story.

We could use the parent's ->d_lock, and it would be less painful in
terms of contention, for __d_add() it would be rather inconvenient to
grab; we could do that (using lock_parent()), but...

Fortunately, we can get serialization on the counter itself, and it
might be a good idea in general; we can use cmpxchg() in a loop to
get from even to odd and smp_store_release() from odd to even.

This commit adds the counter and updating logics; the readers will be
added in the next commit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:26 -04:00
Al Viro 84695ffee7 Merge getxattr prototype change into work.lookups
The rest of work.xattr stuff isn't needed for this branch
2016-05-02 19:45:47 -04:00
Christoph Hellwig e259221763 fs: simplify the generic_write_sync prototype
The kiocb already has the new position, so use that.  The only interesting
case is AIO, where we currently don't bother updating ki_pos.  We're about
to free the kiocb after we're done, so we might as well update it to make
everyone's life simpler.

While we're at it also return the bytes written argument passed in if
we were successful so that the boilerplate error switch code in the
callers can go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig dde0c2e798 fs: add IOCB_SYNC and IOCB_DSYNC
This will allow us to do per-I/O sync file writes, as required by a lot
of fileservers or storage targets.

XXX: Will need a few additional audits for O_DSYNC

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig c8b8e32d70 direct-io: eliminate the offset argument to ->direct_IO
Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig 1af5bb491f filemap: remove the pos argument to generic_file_direct_write
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Kees Cook da20dfe6b5 fs: fix over-zealous use of "const"
When I was fixing up const recommendations from checkpatch.pl, I went
overboard. This fixes the warning (during a W=1 build):

include/linux/fs.h:2627:74: warning: type qualifiers ignored on function return type [-Wignored-qualifiers]
static inline const char * const kernel_read_file_id_str(enum kernel_read_file_id id)

Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-04-27 17:25:02 +10:00
Mimi Zohar 1284ab5b2d fs: define a string representation of the kernel_read_file_id enumeration
A string representation of the kernel_read_file_id enumeration is
needed for displaying messages (eg. pr_info, auditing) that can be
used by multiple LSMs and the integrity subsystem.  To simplify
keeping the list of strings up to date with the enumeration, this
patch defines two new preprocessing macros named __fid_enumify and
__fid_stringify to create the enumeration and an array of strings.
kernel_read_file_id_str() returns a string based on the enumeration.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
[kees: removed removal of my old version, constified pointer values]
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-04-21 10:47:26 +10:00
Greg Kroah-Hartman 5614e77258 Merge 4.6-rc4 into driver-core-next
We want those fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-19 04:28:28 +09:00
Al Viro ce23e64013 ->getxattr(): pass dentry and inode as separate arguments
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-11 00:48:00 -04:00
Linus Torvalds 93061f390f These changes contains a fix for overlayfs interacting with some
(badly behaved) dentry code in various file systems.  These have been
 reviewed by Al and the respective file system mtinainers and are going
 through the ext4 tree for convenience.
 
 This also has a few ext4 encryption bug fixes that were discovered in
 Android testing (yes, we will need to get these sync'ed up with the
 fs/crypto code; I'll take care of that).  It also has some bug fixes
 and a change to ignore the legacy quota options to allow for xfstests
 regression testing of ext4's internal quota feature and to be more
 consistent with how xfs handles this case.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "These changes contains a fix for overlayfs interacting with some
  (badly behaved) dentry code in various file systems.  These have been
  reviewed by Al and the respective file system mtinainers and are going
  through the ext4 tree for convenience.

  This also has a few ext4 encryption bug fixes that were discovered in
  Android testing (yes, we will need to get these sync'ed up with the
  fs/crypto code; I'll take care of that).  It also has some bug fixes
  and a change to ignore the legacy quota options to allow for xfstests
  regression testing of ext4's internal quota feature and to be more
  consistent with how xfs handles this case"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: ignore quota mount options if the quota feature is enabled
  ext4 crypto: fix some error handling
  ext4: avoid calling dquot_get_next_id() if quota is not enabled
  ext4: retry block allocation for failed DIO and DAX writes
  ext4: add lockdep annotations for i_data_sem
  ext4: allow readdir()'s of large empty directories to be interrupted
  btrfs: fix crash/invalid memory access on fsync when using overlayfs
  ext4 crypto: use dget_parent() in ext4_d_revalidate()
  ext4: use file_dentry()
  ext4: use dget_parent() in ext4_file_open()
  nfs: use file_dentry()
  fs: add file_dentry()
  ext4 crypto: don't let data integrity writebacks fail with ENOMEM
  ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()
2016-04-07 17:22:20 -07:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Andreas Gruenbacher b8a7a3a667 posix_acl: Inode acl caching fixes
When get_acl() is called for an inode whose ACL is not cached yet, the
get_acl inode operation is called to fetch the ACL from the filesystem.
The inode operation is responsible for updating the cached acl with
set_cached_acl().  This is done without locking at the VFS level, so
another task can call set_cached_acl() or forget_cached_acl() before the
get_acl inode operation gets to calling set_cached_acl(), and then
get_acl's call to set_cached_acl() results in caching an outdate ACL.

Prevent this from happening by setting the cached ACL pointer to a
task-specific sentinel value before calling the get_acl inode operation.
Move the responsibility for updating the cached ACL from the get_acl
inode operations to get_acl().  There, only set the cached ACL if the
sentinel value hasn't changed.

The sentinel values are chosen to have odd values.  Likewise, the value
of ACL_NOT_CACHED is odd.  In contrast, ACL object pointers always have
an even value (ACLs are aligned in memory).  This allows to distinguish
uncached ACLs values from ACL objects.

In addition, switch from guarding inode->i_acl and inode->i_default_acl
upates by the inode->i_lock spinlock to using xchg() and cmpxchg().

Filesystems that do not want ACLs returned from their get_acl inode
operations to be cached must call forget_cached_acl() to prevent the VFS
from doing so.

(Patch written by Al Viro and Andreas Gruenbacher.)

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-31 00:30:15 -04:00
Linus Walleij 49db08c358 chrdev: emit a warning when we go below dynamic major range
Currently a dynamically allocated character device major is taken
from 254 and downward. This mechanism is used for RTC, IIO and a
few other subsystems.

The kernel currently has no check prevening these dynamic
allocations from eating into the assigned numbers at 233 and
downward.

In a recent test it was reported that so many dynamic device
majors were used on a test server, that the major number for
infiniband (231) was stolen. This occurred when allocating a new
major number for GPIO chips. The error messages from the kernel
were not helpful. (See: https://lkml.org/lkml/2016/2/14/124)

This patch adds a defined lower limit of the dynamic major
allocation region will henceforth emit a warning if we start to
eat into the assigned numbers. It does not do any semantic
changes and will not change the kernels behaviour: numbers will
still continue to be stolen, but we will know from dmesg what
is going on.

This also updates the Documentation/devices.txt to clearly
reflect that we are using this range of major numbers for dynamic
allocation.

Reported-by: Ying Huang <ying.huang@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-29 10:11:44 -07:00
Al Viro 7df818b237 constify vfs_truncate()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-28 00:47:22 -04:00
Miklos Szeredi d101a12595 fs: add file_dentry()
This series fixes bugs in nfs and ext4 due to 4bacc9c923 ("overlayfs:
Make f_path always point to the overlay and f_inode to the underlay").

Regular files opened on overlayfs will result in the file being opened on
the underlying filesystem, while f_path points to the overlayfs
mount/dentry.

This confuses filesystems which get the dentry from struct file and assume
it's theirs.

Add a new helper, file_dentry() [*], to get the filesystem's own dentry
from the file.  This checks file->f_path.dentry->d_flags against
DCACHE_OP_REAL, and returns file->f_path.dentry if DCACHE_OP_REAL is not
set (this is the common, non-overlayfs case).

In the uncommon case it will call into overlayfs's ->d_real() to get the
underlying dentry, matching file_inode(file).

The reason we need to check against the inode is that if the file is copied
up while being open, d_real() would return the upper dentry, while the open
file comes from the lower dentry.

[*] If possible, it's better simply to use file_inode() instead.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Cc: <stable@vger.kernel.org> # v4.2
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Daniel Axtens <dja@axtens.net>
2016-03-26 16:14:37 -04:00
Jann Horn 378c6520e7 fs/coredump: prevent fsuid=0 dumps into user-controlled directories
This commit fixes the following security hole affecting systems where
all of the following conditions are fulfilled:

 - The fs.suid_dumpable sysctl is set to 2.
 - The kernel.core_pattern sysctl's value starts with "/". (Systems
   where kernel.core_pattern starts with "|/" are not affected.)
 - Unprivileged user namespace creation is permitted. (This is
   true on Linux >=3.8, but some distributions disallow it by
   default using a distro patch.)

Under these conditions, if a program executes under secure exec rules,
causing it to run with the SUID_DUMP_ROOT flag, then unshares its user
namespace, changes its root directory and crashes, the coredump will be
written using fsuid=0 and a path derived from kernel.core_pattern - but
this path is interpreted relative to the root directory of the process,
allowing the attacker to control where a coredump will be written with
root privileges.

To fix the security issue, always interpret core_pattern for dumps that
are written under SUID_DUMP_ROOT relative to the root directory of init.

Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-22 15:36:02 -07:00
Linus Torvalds 53d2e6976b xfs: Changes for 4.6-rc1
Change summary:
 o error propagation for direct IO failures fixes for both XFS and ext4
 o new quota interfaces and XFS implementation for iterating all the quota IDs
   in the filesystem
 o locking fixes for real-time device extent allocation
 o reduction of duplicate information in the xfs and vfs inode, saving roughly
   100 bytes of memory per cached inode.
 o buffer flag cleanup
 o rework of the writepage code to use the generic write clustering mechanisms
 o several fixes for inode flag based DAX enablement
 o rework of remount option parsing
 o compile time verification of on-disk format structure sizes
 o delayed allocation reservation overrun fixes
 o lots of little error handling fixes
 o small memory leak fixes
 o enable xfsaild freezing again
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Merge tag 'xfs-for-linus-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "There's quite a lot in this request, and there's some cross-over with
  ext4, dax and quota code due to the nature of the changes being made.

  As for the rest of the XFS changes, there are lots of little things
  all over the place, which add up to a lot of changes in the end.

  The major changes are that we've reduced the size of the struct
  xfs_inode by ~100 bytes (gives an inode cache footprint reduction of
  >10%), the writepage code now only does a single set of mapping tree
  lockups so uses less CPU, delayed allocation reservations won't
  overrun under random write loads anymore, and we added compile time
  verification for on-disk structure sizes so we find out when a commit
  or platform/compiler change breaks the on disk structure as early as
  possible.

  Change summary:

   - error propagation for direct IO failures fixes for both XFS and
     ext4
   - new quota interfaces and XFS implementation for iterating all the
     quota IDs in the filesystem
   - locking fixes for real-time device extent allocation
   - reduction of duplicate information in the xfs and vfs inode, saving
     roughly 100 bytes of memory per cached inode.
   - buffer flag cleanup
   - rework of the writepage code to use the generic write clustering
     mechanisms
   - several fixes for inode flag based DAX enablement
   - rework of remount option parsing
   - compile time verification of on-disk format structure sizes
   - delayed allocation reservation overrun fixes
   - lots of little error handling fixes
   - small memory leak fixes
   - enable xfsaild freezing again"

* tag 'xfs-for-linus-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (66 commits)
  xfs: always set rvalp in xfs_dir2_node_trim_free
  xfs: ensure committed is initialized in xfs_trans_roll
  xfs: borrow indirect blocks from freed extent when available
  xfs: refactor delalloc indlen reservation split into helper
  xfs: update freeblocks counter after extent deletion
  xfs: debug mode forced buffered write failure
  xfs: remove impossible condition
  xfs: check sizes of XFS on-disk structures at compile time
  xfs: ioends require logically contiguous file offsets
  xfs: use named array initializers for log item dumping
  xfs: fix computation of inode btree maxlevels
  xfs: reinitialise per-AG structures if geometry changes during recovery
  xfs: remove xfs_trans_get_block_res
  xfs: fix up inode32/64 (re)mount handling
  xfs: fix format specifier , should be %llx and not %llu
  xfs: sanitize remount options
  xfs: convert mount option parsing to tokens
  xfs: fix two memory leaks in xfs_attr_list.c error paths
  xfs: XFS_DIFLAG2_DAX limited by PAGE_SIZE
  xfs: dynamically switch modes when XFS_DIFLAG2_DAX is set/cleared
  ...
2016-03-21 11:53:05 -07:00
Linus Torvalds d407574e79 Merge tag 'for-f2fs-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
 "New Features:
   - uplift filesystem encryption into fs/crypto/
   - give sysfs entries to control memroy consumption

  Enhancements:
   - aio performance by preallocating blocks in ->write_iter
   - use writepages lock for only WB_SYNC_ALL
   - avoid redundant inline_data conversion
   - enhance forground GC
   - use wait_for_stable_page as possible
   - speed up SEEK_DATA and fiiemap

  Bug Fixes:
   - corner case in terms of -ENOSPC for inline_data
   - hung task caused by long latency in shrinker
   - corruption between atomic write and f2fs_trace_pid
   - avoid garbage lengths in dentries
   - revoke atomicly written pages if an error occurs

  In addition, there are various minor bug fixes and clean-ups"

* tag 'for-f2fs-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (81 commits)
  f2fs: submit node page write bios when really required
  f2fs: add missing argument to f2fs_setxattr stub
  f2fs: fix to avoid unneeded unlock_new_inode
  f2fs: clean up opened code with f2fs_update_dentry
  f2fs: declare static functions
  f2fs: use cryptoapi crc32 functions
  f2fs: modify the readahead method in ra_node_page()
  f2fs crypto: sync ext4_lookup and ext4_file_open
  fs crypto: move per-file encryption from f2fs tree to fs/crypto
  f2fs: mutex can't be used by down_write_nest_lock()
  f2fs: recovery missing dot dentries in root directory
  f2fs: fix to avoid deadlock when merging inline data
  f2fs: introduce f2fs_flush_merged_bios for cleanup
  f2fs: introduce f2fs_update_data_blkaddr for cleanup
  f2fs crypto: fix incorrect positioning for GCing encrypted data page
  f2fs: fix incorrect upper bound when iterating inode mapping tree
  f2fs: avoid hungtask problem caused by losing wake_up
  f2fs: trace old block address for CoWed page
  f2fs: try to flush inode after merging inline data
  f2fs: show more info about superblock recovery
  ...
2016-03-21 11:03:02 -07:00
Linus Torvalds 3c2de27d79 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:

 - Preparations of parallel lookups (the remaining main obstacle is the
   need to move security_d_instantiate(); once that becomes safe, the
   rest will be a matter of rather short series local to fs/*.c

 - preadv2/pwritev2 series from Christoph

 - assorted fixes

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits)
  splice: handle zero nr_pages in splice_to_pipe()
  vfs: show_vfsstat: do not ignore errors from show_devname method
  dcache.c: new helper: __d_add()
  don't bother with __d_instantiate(dentry, NULL)
  untangle fsnotify_d_instantiate() a bit
  uninline d_add()
  replace d_add_unique() with saner primitive
  quota: use lookup_one_len_unlocked()
  cifs_get_root(): use lookup_one_len_unlocked()
  nfs_lookup: don't bother with d_instantiate(dentry, NULL)
  kill dentry_unhash()
  ceph_fill_trace(): don't bother with d_instantiate(dn, NULL)
  autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup()
  configfs: move d_rehash() into configfs_create() for regular files
  ceph: don't bother with d_rehash() in splice_dentry()
  namei: teach lookup_slow() to skip revalidate
  namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()
  lookup_one_len_unlocked(): use lookup_dcache()
  namei: simplify invalidation logics in lookup_dcache()
  namei: change calling conventions for lookup_{fast,slow} and follow_managed()
  ...
2016-03-19 18:52:29 -07:00
Al Viro 8b23a8ce10 Merge branches 'work.lookups', 'work.misc' and 'work.preadv2' into for-next 2016-03-18 16:07:38 -04:00
Jaegeuk Kim 0b81d07790 fs crypto: move per-file encryption from f2fs tree to fs/crypto
This patch adds the renamed functions moved from the f2fs crypto files.

1. definitions for per-file encryption used by ext4 and f2fs.

2. crypto.c for encrypt/decrypt functions
 a. IO preparation:
  - fscrypt_get_ctx / fscrypt_release_ctx
 b. before IOs:
  - fscrypt_encrypt_page
  - fscrypt_decrypt_page
  - fscrypt_zeroout_range
 c. after IOs:
  - fscrypt_decrypt_bio_pages
  - fscrypt_pullback_bio_page
  - fscrypt_restore_control_page

3. policy.c supporting context management.
 a. For ioctls:
  - fscrypt_process_policy
  - fscrypt_get_policy
 b. For context permission
  - fscrypt_has_permitted_context
  - fscrypt_inherit_context

4. keyinfo.c to handle permissions
  - fscrypt_get_encryption_info
  - fscrypt_free_encryption_info

5. fname.c to support filename encryption
 a. general wrapper functions
  - fscrypt_fname_disk_to_usr
  - fscrypt_fname_usr_to_disk
  - fscrypt_setup_filename
  - fscrypt_free_filename

 b. specific filename handling functions
  - fscrypt_fname_alloc_buffer
  - fscrypt_fname_free_buffer

6. Makefile and Kconfig

Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-03-17 21:19:33 -07:00
Al Viro 9d95afd597 kill dentry_unhash()
the last user is gone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-14 00:16:33 -04:00
Christoph Hellwig 97be7ebe53 vfs: add the RWF_HIPRI flag for preadv2/pwritev2
This adds a flag that tells the file system that this is a high priority
request for which it's worth to poll the hardware.  The flag is purely
advisory and can be ignored if not supported.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stephen Bates <stephen.bates@pmcs.com>
Tested-by: Stephen Bates <stephen.bates@pmcs.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-04 12:20:10 -05:00
Christoph Hellwig 793b80ef14 vfs: pass a flags argument to vfs_readv/vfs_writev
This way we can set kiocb flags also from the sync read/write path for
the read_iter/write_iter operations.  For now there is no way to pass
flags to plain read/write operations as there is no real need for that,
and all flags passed are explicitly rejected for these files.

Signed-off-by: Milosz Tanski <milosz@adfin.com>
[hch: rebased on top of my kiocb changes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stephen Bates <stephen.bates@pmcs.com>
Tested-by: Stephen Bates <stephen.bates@pmcs.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-03-04 12:20:10 -05:00
Dmitry Kasatkin 7429b09281 ima: load policy using path
We currently cannot do appraisal or signature vetting of IMA policies
since we currently can only load IMA policies by writing the contents
of the policy directly in, as follows:

cat policy-file > <securityfs>/ima/policy

If we provide the kernel the path to the IMA policy so it can load
the policy itself it'd be able to later appraise or vet the file
signature if it has one.  This patch adds support to load the IMA
policy with a given path as follows:

echo /etc/ima/ima_policy > /sys/kernel/security/ima/policy

Changelog v4+:
- moved kernel_read_file_from_path() error messages to callers
v3:
- moved kernel_read_file_from_path() to a separate patch
v2:
- after re-ordering the patches, replace calling integrity_kernel_read()
  to read the file with kernel_read_file_from_path() (Mimi)
- Patch description re-written by Luis R. Rodriguez

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-21 09:34:05 -05:00
Mimi Zohar b804defe42 kexec: replace call to copy_file_from_fd() with kernel version
Replace copy_file_from_fd() with kernel_read_file_from_fd().

Two new identifiers named READING_KEXEC_IMAGE and READING_KEXEC_INITRAMFS
are defined for measuring, appraising or auditing the kexec image and
initramfs.

Changelog v3:
- return -EBADF, not -ENOEXEC
- identifier change
- split patch, moving copy_file_from_fd() to a separate patch
- split patch, moving IMA changes to a separate patch
v0:
- use kstat file size type loff_t, not size_t
- Calculate the file hash from the in memory buffer - Dave Young

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Acked-by: Dave Young <dyoung@redhat.com>
2016-02-21 09:06:14 -05:00
Mimi Zohar a1db742094 module: replace copy_module_from_fd with kernel version
Replace copy_module_from_fd() with kernel_read_file_from_fd().

Although none of the upstreamed LSMs define a kernel_module_from_file
hook, IMA is called, based on policy, to prevent unsigned kernel modules
from being loaded by the original kernel module syscall and to
measure/appraise signed kernel modules.

The security function security_kernel_module_from_file() was called prior
to reading a kernel module.  Preventing unsigned kernel modules from being
loaded by the original kernel module syscall remains on the pre-read
kernel_read_file() security hook.  Instead of reading the kernel module
twice, once for measuring/appraising and again for loading the kernel
module, the signature validation is moved to the kernel_post_read_file()
security hook.

This patch removes the security_kernel_module_from_file() hook and security
call.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2016-02-21 09:06:12 -05:00
Mimi Zohar b844f0ecbc vfs: define kernel_copy_file_from_fd()
This patch defines kernel_read_file_from_fd(), a wrapper for the VFS
common kernel_read_file().

Changelog:
- Separated from the kernel modules patch
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2016-02-21 09:06:10 -05:00
Mimi Zohar e40ba6d56b firmware: replace call to fw_read_file_contents() with kernel version
Replace the fw_read_file_contents with kernel_file_read_from_path().

Although none of the upstreamed LSMs define a kernel_fw_from_file hook,
IMA is called by the security function to prevent unsigned firmware from
being loaded and to measure/appraise signed firmware, based on policy.

Instead of reading the firmware twice, once for measuring/appraising the
firmware and again for reading the firmware contents into memory, the
kernel_post_read_file() security hook calculates the file hash based on
the in memory file buffer.  The firmware is read once.

This patch removes the LSM kernel_fw_from_file() hook and security call.

Changelog v4+:
- revert dropped buf->size assignment - reported by Sergey Senozhatsky
v3:
- remove kernel_fw_from_file hook
- use kernel_file_read_from_path() - requested by Luis
v2:
- reordered and squashed firmware patches
- fix MAX firmware size (Kees Cook)

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
2016-02-21 09:03:44 -05:00
Mimi Zohar 09596b94f7 vfs: define kernel_read_file_from_path
This patch defines kernel_read_file_from_path(), a wrapper for the VFS
common kernel_read_file().

Changelog:
- revert error msg regression - reported by Sergey Senozhatsky
- Separated from the IMA patch

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
2016-02-21 08:55:00 -05:00
Mimi Zohar bc8ca5b92d vfs: define kernel_read_file_id enumeration
To differentiate between the kernel_read_file() callers, this patch
defines a new enumeration named kernel_read_file_id and includes the
caller identifier as an argument.

Subsequent patches define READING_KEXEC_IMAGE, READING_KEXEC_INITRAMFS,
READING_FIRMWARE, READING_MODULE, and READING_POLICY.

Changelog v3:
- Replace the IMA specific enumeration with a generic one.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
2016-02-18 17:14:04 -05:00
Mimi Zohar b44a7dfc6f vfs: define a generic function to read a file from the kernel
For a while it was looked down upon to directly read files from Linux.
These days there exists a few mechanisms in the kernel that do just
this though to load a file into a local buffer.  There are minor but
important checks differences on each.  This patch set is the first
attempt at resolving some of these differences.

This patch introduces a common function for reading files from the kernel
with the corresponding security post-read hook and function.

Changelog v4+:
- export security_kernel_post_read_file() - Fengguang Wu
v3:
- additional bounds checking - Luis
v2:
- To simplify patch review, re-ordered patches

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
2016-02-18 17:14:03 -05:00
Christoph Hellwig 187372a3b9 direct-io: always call ->end_io if non-NULL
This way we can pass back errors to the file system, and allow for
cleanup required for all direct I/O invocations.

Also allow the ->end_io handlers to return errors on their own, so that
I/O completion errors can be passed on to the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-08 14:40:51 +11:00
Dan Williams 9f4736fe7c block: revert runtime dax control of the raw block device
Dynamically enabling DAX requires that the page cache first be flushed
and invalidated.  This must occur atomically with the change of DAX mode
otherwise we confuse the fsync/msync tracking and violate data
durability guarantees.  Eliminate the possibilty of DAX-disabled to
DAX-enabled transitions for now and revisit this for the next cycle.

Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-30 13:35:31 -08:00
Dan Williams 65f87ee718 fs, block: force direct-I/O for dax-enabled block devices
Similar to the file I/O path, re-direct all I/O to the DAX path for I/O
to a block-device special file.  Both regular files and device special
files can use the common filp->f_mapping->host lookup to determing is
DAX is enabled.

Otherwise, we confuse the DAX code that does not expect to find live
data in the page cache:

    ------------[ cut here ]------------
    WARNING: CPU: 0 PID: 7676 at mm/filemap.c:217
    __delete_from_page_cache+0x9f6/0xb60()
    Modules linked in:
    CPU: 0 PID: 7676 Comm: a.out Not tainted 4.4.0+ #276
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
     00000000ffffffff ffff88006d3f7738 ffffffff82999e2d 0000000000000000
     ffff8800620a0000 ffffffff86473d20 ffff88006d3f7778 ffffffff81352089
     ffffffff81658d36 ffffffff86473d20 00000000000000d9 ffffea0000009d60
    Call Trace:
     [<     inline     >] __dump_stack lib/dump_stack.c:15
     [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
     [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
     [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
     [<ffffffff81658d36>] __delete_from_page_cache+0x9f6/0xb60 mm/filemap.c:217
     [<ffffffff81658fb2>] delete_from_page_cache+0x112/0x200 mm/filemap.c:244
     [<ffffffff818af369>] __dax_fault+0x859/0x1800 fs/dax.c:487
     [<ffffffff8186f4f6>] blkdev_dax_fault+0x26/0x30 fs/block_dev.c:1730
     [<     inline     >] wp_pfn_shared mm/memory.c:2208
     [<ffffffff816e9145>] do_wp_page+0xc85/0x14f0 mm/memory.c:2307
     [<     inline     >] handle_pte_fault mm/memory.c:3323
     [<     inline     >] __handle_mm_fault mm/memory.c:3417
     [<ffffffff816ecec3>] handle_mm_fault+0x2483/0x4640 mm/memory.c:3446
     [<ffffffff8127eff6>] __do_page_fault+0x376/0x960 arch/x86/mm/fault.c:1238
     [<ffffffff8127f738>] trace_do_page_fault+0xe8/0x420 arch/x86/mm/fault.c:1331
     [<ffffffff812705c4>] do_async_page_fault+0x14/0xd0 arch/x86/kernel/kvm.c:264
     [<ffffffff86338f78>] async_page_fault+0x28/0x30 arch/x86/entry/entry_64.S:986
     [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
    arch/x86/entry/entry_64.S:185
    ---[ end trace dae21e0f85f1f98c ]---

Fixes: 5a023cdba5 ("block: enable dax for raw block devices")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Suggested-by: Matthew Wilcox <willy@linux.intel.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-30 13:33:59 -08:00
Linus Torvalds cc673757e2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull final vfs updates from Al Viro:

 - The ->i_mutex wrappers (with small prereq in lustre)

 - a fix for too early freeing of symlink bodies on shmem (they need to
   be RCU-delayed) (-stable fodder)

 - followup to dedupe stuff merged this cycle

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: abort dedupe loop if fatal signals are pending
  make sure that freeing shmem fast symlinks is RCU-delayed
  wrappers for ->i_mutex access
  lustre: remove unused declaration
2016-01-23 12:24:56 -08:00
Ross Zwisler f9fe48bece dax: support dirty DAX entries in radix tree
Add support for tracking dirty DAX entries in the struct address_space
radix tree.  This tree is already used for dirty page writeback, and it
already supports the use of exceptional (non struct page*) entries.

In order to properly track dirty DAX pages we will insert new
exceptional entries into the radix tree that represent dirty DAX PTE or
PMD pages.  These exceptional entries will also contain the writeback
addresses for the PTE or PMD faults that we can use at fsync/msync time.

There are currently two types of exceptional entries (shmem and shadow)
that can be placed into the radix tree, and this adds a third.  We rely
on the fact that only one type of exceptional entry can be found in a
given radix tree based on its usage.  This happens for free with DAX vs
shmem but we explicitly prevent shadow entries from being added to radix
trees for DAX mappings.

The only shadow entries that would be generated for DAX radix trees
would be to track zero page mappings that were created for holes.  These
pages would receive minimal benefit from having shadow entries, and the
choice to have only one type of exceptional entry in a given radix tree
makes the logic simpler both in clear_exceptional_entry() and in the
rest of DAX.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-22 17:02:18 -08:00
Al Viro 5955102c99 wrappers for ->i_mutex access
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22 18:04:28 -05:00
Linus Torvalds d080827f85 libnvdimm for 4.5
1/ Media error handling: The 'badblocks' implementation that originated
    in md-raid is up-levelled to a generic capability of a block device.
    This initial implementation is limited to being consulted in the pmem
    block-i/o path.  Later, 'badblocks' will be consulted when creating
    dax mappings.
 
 2/ Raw block device dax: For virtualization and other cases that want
    large contiguous mappings of persistent memory, add the capability to
    dax-mmap a block device directly.
 
 3/ Increased /dev/mem restrictions: Add an option to treat all io-memory
    as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is
    actively using an address range.  This behavior is controlled via the
    new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the
    existing "iomem=relaxed" kernel command line option.
 
 4/ Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
    block device shutdown crash fix, and other small libnvdimm fixes.
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Merge tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has appeared in -next and independently received a
  build success notification from the kbuild robot.  The 'for-4.5/block-
  dax' topic branch was rebased over the weekend to drop the "block
  device end-of-life" rework that Al would like to see re-implemented
  with a notifier, and to address bug reports against the badblocks
  integration.

  There is pending feedback against "libnvdimm: Add a poison list and
  export badblocks" received last week.  Linda identified some localized
  fixups that we will handle incrementally.

  Summary:

   - Media error handling: The 'badblocks' implementation that
     originated in md-raid is up-levelled to a generic capability of a
     block device.  This initial implementation is limited to being
     consulted in the pmem block-i/o path.  Later, 'badblocks' will be
     consulted when creating dax mappings.

   - Raw block device dax: For virtualization and other cases that want
     large contiguous mappings of persistent memory, add the capability
     to dax-mmap a block device directly.

   - Increased /dev/mem restrictions: Add an option to treat all
     io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access
     while a driver is actively using an address range.  This behavior
     is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be
     overridden by the existing "iomem=relaxed" kernel command line
     option.

   - Miscellaneous fixes include a 'pfn'-device huge page alignment fix,
     block device shutdown crash fix, and other small libnvdimm fixes"

* tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits)
  block: kill disk_{check|set|clear|alloc}_badblocks
  libnvdimm, pmem: nvdimm_read_bytes() badblocks support
  pmem, dax: disable dax in the presence of bad blocks
  pmem: fail io-requests to known bad blocks
  libnvdimm: convert to statically allocated badblocks
  libnvdimm: don't fail init for full badblocks list
  block, badblocks: introduce devm_init_badblocks
  block: clarify badblocks lifetime
  badblocks: rename badblocks_free to badblocks_exit
  libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h
  libnvdimm: Add a poison list and export badblocks
  nfit_test: Enable DSMs for all test NFITs
  md: convert to use the generic badblocks code
  block: Add badblock management for gendisks
  badblocks: Add core badblock management code
  block: fix del_gendisk() vs blkdev_ioctl crash
  block: enable dax for raw block devices
  block: introduce bdev_file_inode()
  restrict /dev/mem to idle io memory ranges
  arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug
  ...
2016-01-13 19:15:14 -08:00
Linus Torvalds 33caf82acf Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "All kinds of stuff.  That probably should've been 5 or 6 separate
  branches, but by the time I'd realized how large and mixed that bag
  had become it had been too close to -final to play with rebasing.

  Some fs/namei.c cleanups there, memdup_user_nul() introduction and
  switching open-coded instances, burying long-dead code, whack-a-mole
  of various kinds, several new helpers for ->llseek(), assorted
  cleanups and fixes from various people, etc.

  One piece probably deserves special mention - Neil's
  lookup_one_len_unlocked().  Similar to lookup_one_len(), but gets
  called without ->i_mutex and tries to avoid ever taking it.  That, of
  course, means that it's not useful for any directory modifications,
  but things like getting inode attributes in nfds readdirplus are fine
  with that.  I really should've asked for moratorium on lookup-related
  changes this cycle, but since I hadn't done that early enough...  I
  *am* asking for that for the coming cycle, though - I'm going to try
  and get conversion of i_mutex to rwsem with ->lookup() done under lock
  taken shared.

  There will be a patch closer to the end of the window, along the lines
  of the one Linus had posted last May - mechanical conversion of
  ->i_mutex accesses to inode_lock()/inode_unlock()/inode_trylock()/
  inode_is_locked()/inode_lock_nested().  To quote Linus back then:

    -----
    |    This is an automated patch using
    |
    |        sed 's/mutex_lock(&\(.*\)->i_mutex)/inode_lock(\1)/'
    |        sed 's/mutex_unlock(&\(.*\)->i_mutex)/inode_unlock(\1)/'
    |        sed 's/mutex_lock_nested(&\(.*\)->i_mutex,[     ]*I_MUTEX_\([A-Z0-9_]*\))/inode_lock_nested(\1, I_MUTEX_\2)/'
    |        sed 's/mutex_is_locked(&\(.*\)->i_mutex)/inode_is_locked(\1)/'
    |        sed 's/mutex_trylock(&\(.*\)->i_mutex)/inode_trylock(\1)/'
    |
    |    with a very few manual fixups
    -----

  I'm going to send that once the ->i_mutex-affecting stuff in -next
  gets mostly merged (or when Linus says he's about to stop taking
  merges)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  nfsd: don't hold i_mutex over userspace upcalls
  fs:affs:Replace time_t with time64_t
  fs/9p: use fscache mutex rather than spinlock
  proc: add a reschedule point in proc_readfd_common()
  logfs: constify logfs_block_ops structures
  fcntl: allow to set O_DIRECT flag on pipe
  fs: __generic_file_splice_read retry lookup on AOP_TRUNCATED_PAGE
  fs: xattr: Use kvfree()
  [s390] page_to_phys() always returns a multiple of PAGE_SIZE
  nbd: use ->compat_ioctl()
  fs: use block_device name vsprintf helper
  lib/vsprintf: add %*pg format specifier
  fs: use gendisk->disk_name where possible
  poll: plug an unused argument to do_poll
  amdkfd: don't open-code memdup_user()
  cdrom: don't open-code memdup_user()
  rsxx: don't open-code memdup_user()
  mtip32xx: don't open-code memdup_user()
  [um] mconsole: don't open-code memdup_user_nul()
  [um] hostaudio: don't open-code memdup_user()
  ...
2016-01-12 17:11:47 -08:00
Linus Torvalds fce205e9da Merge branch 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs copy_file_range updates from Al Viro:
 "Several series around copy_file_range/CLONE"

* 'work.copy_file_range' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  btrfs: use new dedupe data function pointer
  vfs: hoist the btrfs deduplication ioctl to the vfs
  vfs: wire up compat ioctl for CLONE/CLONE_RANGE
  cifs: avoid unused variable and label
  nfsd: implement the NFSv4.2 CLONE operation
  nfsd: Pass filehandle to nfs4_preprocess_stateid_op()
  vfs: pull btrfs clone API to vfs layer
  locks: new locks_mandatory_area calling convention
  vfs: Add vfs_copy_file_range() support for pagecache copies
  btrfs: add .copy_file_range file operation
  x86: add sys_copy_file_range to syscall tables
  vfs: add copy_file_range syscall and vfs helper
2016-01-12 16:30:34 -08:00
Linus Torvalds 065019a38f File locking related changes for v4.5 (pile #1)
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Merge tag 'locks-v4.5-1' of git://git.samba.org/jlayton/linux

Pull file locking updates from Jeff Layton:
 "File locking related changes for v4.5 (pile #1)

  Highlights:
   - new Kconfig option to allow disabling mandatory locking (which is
     racy anyway)
   - new tracepoints for setlk and close codepaths
   - fix for a long-standing bug in code that handles races between
     setting a POSIX lock and close()"

* tag 'locks-v4.5-1' of git://git.samba.org/jlayton/linux:
  locks: rename __posix_lock_file to posix_lock_inode
  locks: prink more detail when there are leaked locks
  locks: pass inode pointer to locks_free_lock_context
  locks: sprinkle some tracepoints around the file locking code
  locks: don't check for race with close when setting OFD lock
  locks: fix unlock when fcntl_setlk races with a close
  fs: make locks.c explicitly non-modular
  locks: use list_first_entry_or_null()
  locks: Don't allow mounts in user namespaces to enable mandatory locking
  locks: Allow disabling mandatory locking at compile time
2016-01-12 15:46:17 -08:00
Linus Torvalds 32fb378437 Merge branch 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs RCU symlink updates from Al Viro:
 "Replacement of ->follow_link/->put_link, allowing to stay in RCU mode
  even if the symlink is not an embedded one.

  No changes since the mailbomb on Jan 1"

* 'work.symlinks' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  switch ->get_link() to delayed_call, kill ->put_link()
  kill free_page_put_link()
  teach nfs_get_link() to work in RCU mode
  teach proc_self_get_link()/proc_thread_self_get_link() to work in RCU mode
  teach shmem_get_link() to work in RCU mode
  teach page_get_link() to work in RCU mode
  replace ->follow_link() with new method that could stay in RCU mode
  don't put symlink bodies in pagecache into highmem
  namei: page_getlink() and page_follow_link_light() are the same thing
  ufs: get rid of ->setattr() for symlinks
  udf: don't duplicate page_symlink_inode_operations
  logfs: don't duplicate page_symlink_inode_operations
  switch befs long symlinks to page_symlink_operations
2016-01-11 13:13:23 -08:00
Dan Williams 5a023cdba5 block: enable dax for raw block devices
If an application wants exclusive access to all of the persistent memory
provided by an NVDIMM namespace it can use this raw-block-dax facility
to forgo establishing a filesystem.  This capability is targeted
primarily to hypervisors wanting to provision persistent memory for
guests.  It can be disabled / enabled dynamically via the new BLKDAXSET
ioctl.

Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-01-09 06:30:49 -08:00
Al Viro 6108209c4a Merge branch 'for-linus' into work.misc 2016-01-08 21:20:11 -05:00
Al Viro 66cf191f3e compat_ioctl: don't pass fd around when not needed
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-08 21:16:50 -05:00
Jeff Layton f27a0fe083 locks: pass inode pointer to locks_free_lock_context
...so we can print information about it if there are leaked locks.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
2016-01-08 11:38:19 -05:00
Darrick J. Wong 54dbc15172 vfs: hoist the btrfs deduplication ioctl to the vfs
Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name
more systematic (FIDEDUPERANGE).

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-01 02:36:19 -05:00
Al Viro fceef393a5 switch ->get_link() to delayed_call, kill ->put_link()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30 13:01:03 -05:00
Al Viro cd3417c8fc kill free_page_put_link()
all callers are better off with kfree_put_link()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-29 16:03:53 -05:00
Al Viro b25472f9b9 new helpers: no_seek_end_llseek{,_size}()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-23 10:41:31 -05:00
Al Viro 6b2553918d replace ->follow_link() with new method that could stay in RCU mode
new method: ->get_link(); replacement of ->follow_link().  The differences
are:
	* inode and dentry are passed separately
	* might be called both in RCU and non-RCU mode;
the former is indicated by passing it a NULL dentry.
	* when called that way it isn't allowed to block
and should return ERR_PTR(-ECHILD) if it needs to be called
in non-RCU mode.

It's a flagday change - the old method is gone, all in-tree instances
converted.  Conversion isn't hard; said that, so far very few instances
do not immediately bail out when called in RCU mode.  That'll change
in the next commits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:54 -05:00
Al Viro 21fc61c73c don't put symlink bodies in pagecache into highmem
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08 22:41:36 -05:00
Christoph Hellwig 04b38d6012 vfs: pull btrfs clone API to vfs layer
The btrfs clone ioctls are now adopted by other file systems, with NFS
and CIFS already having support for them, and XFS being under active
development.  To avoid growth of various slightly incompatible
implementations, add one to the VFS.  Note that clones are different from
file copies in several ways:

 - they are atomic vs other writers
 - they support whole file clones
 - they support 64-bit legth clones
 - they do not allow partial success (aka short writes)
 - clones are expected to be a fast metadata operation

Because of that it would be rather cumbersome to try to piggyback them on
top of the recent clone_file_range infrastructure.  The converse isn't
true and the clone_file_range system call could try clone file range as
a first attempt to copy, something that further patches will enable.

Based on earlier work from Peng Tao.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:11:33 -05:00
Christoph Hellwig acc15575e7 locks: new locks_mandatory_area calling convention
Pass a loff_t end for the last byte instead of the 32-bit count
parameter to allow full file clones even on 32-bit architectures.
While we're at it also simplify the read/write selection.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:09:16 -05:00
Yaowei Bai d37177bacd fs/attr.c: is_sxid can be boolean
This patch makes is_sxid return bool to improve readability
due to this particular function only using either one or zero
as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:17:14 -05:00
Yaowei Bai 0e3ef1fe45 fs/bad_inode.c: is_bad_inode can be boolean
This patch makes is_bad_inode return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:17:14 -05:00
Yaowei Bai a6e5787fc8 fs/dcache.c: is_subdir can be boolean
This patch makes is_subdir return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:17:13 -05:00
Yaowei Bai 25ab4c9b1c fs/namespace.c: path_is_under can be boolean
This patch makes path_is_under return bool to improve
readability due to this particular function only using either
one or zero as its return value.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:17:13 -05:00
Yaowei Bai 3e004eea56 fs/block_dev.c: make sb_is_blkdev_sb return bool when CONFIG_BLOCK undefined
Currently when CONFIG_BLOCK is defined sb_is_blkdev_sb returns bool,
while when CONFIG_BLOCK is not defined it returns int. Let's keep
consistent to make sb_is_blkdev_sb return bool as well when CONFIG_BLOCK
isn't defined.

No functional change.

Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-06 21:17:12 -05:00
Zach Brown 29732938a6 vfs: add copy_file_range syscall and vfs helper
Add a copy_file_range() system call for offloading copies between
regular files.

This gives an interface to underlying layers of the storage stack which
can copy without reading and writing all the data.  There are a few
candidates that should support copy offloading in the nearer term:

- btrfs shares extent references with its clone ioctl
- NFS has patches to add a COPY command which copies on the server
- SCSI has a family of XCOPY commands which copy in the device

This system call avoids the complexity of also accelerating the creation
of the destination file by operating on an existing destination file
descriptor, not a path.

Currently the high level vfs entry point limits copy offloading to files
on the same mount and super (and not in the same file).  This can be
relaxed if we get implementations which can copy between file systems
safely.

Signed-off-by: Zach Brown <zab@redhat.com>
[Anna Schumaker: Change -EINVAL to -EBADF during file verification,
                 Change flags parameter from int to unsigned int,
                 Add function to include/linux/syscalls.h,
                 Check copy len after file open mode,
                 Don't forbid ranges inside the same file,
                 Use rw_verify_area() to veriy ranges,
                 Use file_out rather than file_in,
                 Add COPY_FR_REFLINK flag]
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-01 14:00:53 -05:00
Jeff Layton 9e8925b67a locks: Allow disabling mandatory locking at compile time
Mandatory locking appears to be almost unused and buggy and there
appears no real interest in doing anything with it.  Since effectively
no one uses the code and since the code is buggy let's allow it to be
disabled at compile time.  I would just suggest removing the code but
undoubtedly that will break some piece of userspace code somewhere.

For the distributions that don't care about this piece of code
this gives a nice starting point to make mandatory locking go away.

Cc: Benjamin Coddington <bcodding@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jeff Layton <jeff.layton@primarydata.com>
Cc: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-11-16 09:49:34 -05:00
Linus Torvalds 842cf0b952 Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:

 - misc stable fixes

 - trivial kernel-doc and comment fixups

 - remove never-used block_page_mkwrite() wrapper function, and rename
   the function that is _actually_ used to not have double underscores.

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: 9p: cache.h: Add #define of include guard
  vfs: remove stale comment in inode_operations
  vfs: remove unused wrapper block_page_mkwrite()
  binfmt_elf: Correct `arch_check_elf's description
  fs: fix writeback.c kernel-doc warnings
  fs: fix inode.c kernel-doc warning
  fs/pipe.c: return error code rather than 0 in pipe_write()
  fs/pipe.c: preserve alloc_file() error code
  binfmt_elf: Don't clobber passed executable's file header
  FS-Cache: Handle a write to the page immediately beyond the EOF marker
  cachefiles: perform test on s_blocksize when opening cache file.
  FS-Cache: Don't override netfs's primary_index if registering failed
  FS-Cache: Increase reference of parent after registering, netfs success
  debugfs: fix refcount imbalance in start_creating
2015-11-11 09:45:24 -08:00
Ross Zwisler c8fffa6435 vfs: remove stale comment in inode_operations
The big warning comment that is currently at the end of struct
inode_operations was added as part of this commit:

4aa7c6346b ("vfs: add i_op->dentry_open()")

It was added to warn people not to use the newly added 'dentry_open'
function pointer.

This function pointer was removed as part of this commit:

4bacc9c923 ("overlayfs: Make f_path always point to the overlay and
		f_inode to the underlay")

The comment was left behind and now refers to nothing, so remove it.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-11 02:19:38 -05:00
Linus Torvalds 3419b45039 Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-block
Pull block IO poll support from Jens Axboe:
 "Various groups have been doing experimentation around IO polling for
  (really) fast devices.  The code has been reviewed and has been
  sitting on the side for a few releases, but this is now good enough
  for coordinated benchmarking and further experimentation.

  Currently O_DIRECT sync read/write are supported.  A framework is in
  the works that allows scalable stats tracking so we can auto-tune
  this.  And we'll add libaio support as well soon.  Fow now, it's an
  opt-in feature for test purposes"

* 'for-4.4/io-poll' of git://git.kernel.dk/linux-block:
  direct-io: be sure to assign dio->bio_bdev for both paths
  directio: add block polling support
  NVMe: add blk polling support
  block: add block polling support
  blk-mq: return tag/queue combo in the make_request_fn handlers
  block: change ->make_request_fn() and users to return a queue cookie
2015-11-10 17:23:49 -08:00
Jens Axboe dece16353e block: change ->make_request_fn() and users to return a queue cookie
No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-07 10:40:46 -07:00
Linus Torvalds 2e3078af2c Merge branch 'akpm' (patches from Andrew)
Merge patch-bomb from Andrew Morton:

 - inotify tweaks

 - some ocfs2 updates (many more are awaiting review)

 - various misc bits

 - kernel/watchdog.c updates

 - Some of mm.  I have a huge number of MM patches this time and quite a
   lot of it is quite difficult and much will be held over to next time.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (162 commits)
  selftests: vm: add tests for lock on fault
  mm: mlock: add mlock flags to enable VM_LOCKONFAULT usage
  mm: introduce VM_LOCKONFAULT
  mm: mlock: add new mlock system call
  mm: mlock: refactor mlock, munlock, and munlockall code
  kasan: always taint kernel on report
  mm, slub, kasan: enable user tracking by default with KASAN=y
  kasan: use IS_ALIGNED in memory_is_poisoned_8()
  kasan: Fix a type conversion error
  lib: test_kasan: add some testcases
  kasan: update reference to kasan prototype repo
  kasan: move KASAN_SANITIZE in arch/x86/boot/Makefile
  kasan: various fixes in documentation
  kasan: update log messages
  kasan: accurately determine the type of the bad access
  kasan: update reported bug types for kernel memory accesses
  kasan: update reported bug types for not user nor kernel memory accesses
  mm/kasan: prevent deadlock in kasan reporting
  mm/kasan: don't use kasan shadow pointer in generic functions
  mm/kasan: MODULE_VADDR is not available on all archs
  ...
2015-11-05 23:10:54 -08:00
Junichi Nomura aa750fd71c mm/filemap.c: make global sync not clear error status of individual inodes
filemap_fdatawait() is a function to wait for on-going writeback to
complete but also consume and clear error status of the mapping set during
writeback.

The latter functionality is critical for applications to detect writeback
error with system calls like fsync(2)/fdatasync(2).

However filemap_fdatawait() is also used by sync(2) or FIFREEZE ioctl,
which don't check error status of individual mappings.

As a result, fsync() may not be able to detect writeback error if events
happen in the following order:

   Application                    System admin
   ----------------------------------------------------------
   write data on page cache
                                  Run sync command
                                  writeback completes with error
                                  filemap_fdatawait() clears error
   fsync returns success
   (but the data is not on disk)

This patch adds filemap_fdatawait_keep_errors() for call sites where
writeback error is not handled so that they don't clear error status.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Tejun Heo <tj@kernel.org>
Cc: Fengguang Wu <fengguang.wu@gmail.com>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
Benjamin Coddington 616fb38fa7 locks: cleanup posix_lock_inode_wait and flock_lock_inode_wait
All callers use locks_lock_inode_wait() instead.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-10-22 14:57:42 -04:00
Benjamin Coddington e55c34a66f locks: introduce locks_lock_inode_wait()
Users of the locks API commonly call either posix_lock_file_wait() or
flock_lock_file_wait() depending upon the lock type.  Add a new function
locks_lock_inode_wait() which will check and call the correct function for
the type of lock passed in.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-10-22 14:57:20 -04:00
Matthew Wilcox c94c2acf84 dax: move DAX-related functions to a new header
In order to handle the !CONFIG_TRANSPARENT_HUGEPAGES case, we need to
return VM_FAULT_FALLBACK from the inlined dax_pmd_fault(), which is
defined in linux/mm.h.  Given that we don't want to include <linux/mm.h>
in <linux/fs.h>, the easiest solution is to move the DAX-related
functions to a new header, <linux/dax.h>.  We could also have moved
VM_FAULT_* definitions to a new header, or a different header that isn't
quite such a boil-the-ocean header as <linux/mm.h>, but this felt like
the best option.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Linus Torvalds 7d9071a095 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "In this one:

   - d_move fixes (Eric Biederman)

   - UFS fixes (me; locking is mostly sane now, a bunch of bugs in error
     handling ought to be fixed)

   - switch of sb_writers to percpu rwsem (Oleg Nesterov)

   - superblock scalability (Josef Bacik and Dave Chinner)

   - swapon(2) race fix (Hugh Dickins)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits)
  vfs: Test for and handle paths that are unreachable from their mnt_root
  dcache: Reduce the scope of i_lock in d_splice_alias
  dcache: Handle escaped paths in prepend_path
  mm: fix potential data race in SyS_swapon
  inode: don't softlockup when evicting inodes
  inode: rename i_wb_list to i_io_list
  sync: serialise per-superblock sync operations
  inode: convert inode_sb_list_lock to per-sb
  inode: add hlist_fake to avoid the inode hash lock in evict
  writeback: plug writeback at a high level
  change sb_writers to use percpu_rw_semaphore
  shift percpu_counter_destroy() into destroy_super_work()
  percpu-rwsem: kill CONFIG_PERCPU_RWSEM
  percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
  percpu-rwsem: introduce percpu_down_read_trylock()
  document rwsem_release() in sb_wait_write()
  fix the broken lockdep logic in __sb_start_write()
  introduce __sb_writers_{acquired,release}() helpers
  ufs_inode_get{frag,block}(): get rid of 'phys' argument
  ufs_getfrag_block(): tidy up a bit
  ...
2015-09-05 20:34:28 -07:00
Linus Torvalds 17447717a3 Nothing major, but:
- Add Jeff Layton as an nfsd co-maintainer: no change to
           existing practice, just an acknowledgement of the status quo.
         - Two patches ("nfsd: ensure that...") for a race overlooked by
           the state locking rewrite, causing a crash noticed by multiple
           users.
         - Lots of smaller bugfixes all over from Kinglong Mee.
         - From Jeff, some cleanup of server rpc code in preparation for
           possible shift of nfsd threads to workqueues.
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Merge tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "Nothing major, but:

   - Add Jeff Layton as an nfsd co-maintainer: no change to existing
     practice, just an acknowledgement of the status quo.

   - Two patches ("nfsd: ensure that...") for a race overlooked by the
     state locking rewrite, causing a crash noticed by multiple users.

   - Lots of smaller bugfixes all over from Kinglong Mee.

   - From Jeff, some cleanup of server rpc code in preparation for
     possible shift of nfsd threads to workqueues"

* tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linux: (52 commits)
  nfsd: deal with DELEGRETURN racing with CB_RECALL
  nfsd: return CLID_INUSE for unexpected SETCLIENTID_CONFIRM case
  nfsd: ensure that delegation stateid hash references are only put once
  nfsd: ensure that the ol stateid hash reference is only put once
  net: sunrpc: fix tracepoint Warning: unknown op '->'
  nfsd: allow more than one laundry job to run at a time
  nfsd: don't WARN/backtrace for invalid container deployment.
  fs: fix fs/locks.c kernel-doc warning
  nfsd: Add Jeff Layton as co-maintainer
  NFSD: Return word2 bitmask if setting security label in OPEN/CREATE
  NFSD: Set the attributes used to store the verifier for EXCLUSIVE4_1
  nfsd: SUPPATTR_EXCLCREAT must be encoded before SECURITY_LABEL.
  nfsd: Fix an FS_LAYOUT_TYPES/LAYOUT_TYPES encode bug
  NFSD: Store parent's stat in a separate value
  nfsd: Fix two typos in comments
  lockd: NLM grace period shouldn't block NFSv4 opens
  nfsd: include linux/nfs4.h in export.h
  sunrpc: Switch to using hash list instead single list
  sunrpc/nfsd: Remove redundant code by exports seq_operations functions
  sunrpc: Store cache_detail in seq_file's private directly
  ...
2015-09-05 17:26:24 -07:00
Oleg Nesterov 5477e70a64 mm: move ->mremap() from file_operations to vm_operations_struct
vma->vm_ops->mremap() looks more natural and clean in move_vma(), and this
way ->mremap() can have more users.  Say, vdso.

While at it, s/aio_ring_remap/aio_ring_mremap/.

Note: this is the minimal change before ->mremap() finds another user in
file_operations; this method should have more arguments, and it can be
used to kill arch_remap().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04 16:54:41 -07:00
Linus Torvalds 73b6fa8e49 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "This finishes up the changes to ensure proc and sysfs do not start
  implementing executable files, as the there are application today that
  are only secure because such files do not exist.

  It akso fixes a long standing misfeature of /proc/<pid>/mountinfo that
  did not show the proper source for files bind mounted from
  /proc/<pid>/ns/*.

  It also straightens out the handling of clone flags related to user
  namespaces, fixing an unnecessary failure of unshare(CLONE_NEWUSER)
  when files such as /proc/<pid>/environ are read while <pid> is calling
  unshare.  This winds up fixing a minor bug in unshare flag handling
  that dates back to the first version of unshare in the kernel.

  Finally, this fixes a minor regression caused by the introduction of
  sysfs_create_mount_point, which broke someone's in house application,
  by restoring the size of /sys/fs/cgroup to 0 bytes.  Apparently that
  application uses the directory size to determine if a tmpfs is mounted
  on /sys/fs/cgroup.

  The bind mount escape fixes are present in Al Viros for-next branch.
  and I expect them to come from there.  The bind mount escape is the
  last of the user namespace related security bugs that I am aware of"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  fs: Set the size of empty dirs to 0.
  userns,pidns: Force thread group sharing, not signal handler sharing.
  unshare: Unsharing a thread does not require unsharing a vm
  nsfs: Add a show_path method to fix mountinfo
  mnt: fs_fully_visible enforce noexec and nosuid  if !SB_I_NOEXEC
  vfs: Commit to never having exectuables on proc and sysfs.
2015-09-01 16:13:25 -07:00
Al Viro 061f98e959 Merge branch 'superblock-scaling' of git://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-next into for-next
Conflicts:
	include/linux/fs.h
2015-08-21 02:31:20 -04:00
Dave Chinner c7f5408493 inode: rename i_wb_list to i_io_list
There's a small consistency problem between the inode and writeback
naming. Writeback calls the "for IO" inode queues b_io and
b_more_io, but the inode calls these the "writeback list" or
i_wb_list. This makes it hard to an new "under writeback" list to
the inode, or call it an "under IO" list on the bdi because either
way we'll have writeback on IO and IO on writeback and it'll just be
confusing. I'm getting confused just writing this!

So, rename the inode "for IO" list variable to i_io_list so we can
add a new "writeback list" in a subsequent patch.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 23:38:10 -04:00
Dave Chinner e97fedb9ef sync: serialise per-superblock sync operations
When competing sync(2) calls walk the same filesystem, they need to
walk the list of inodes on the superblock to find all the inodes
that we need to wait for IO completion on. However, when multiple
wait_sb_inodes() calls do this at the same time, they contend on the
the inode_sb_list_lock and the contention causes system wide
slowdowns. In effect, concurrent sync(2) calls can take longer and
burn more CPU than if they were serialised.

Stop the worst of the contention by adding a per-sb mutex to wrap
around wait_sb_inodes() so that we only execute one sync(2) IO
completion walk per superblock superblock at a time and hence avoid
contention being triggered by concurrent sync(2) calls.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 18:39:47 -04:00
Dave Chinner 74278da9f7 inode: convert inode_sb_list_lock to per-sb
The process of reducing contention on per-superblock inode lists
starts with moving the locking to match the per-superblock inode
list. This takes the global lock out of the picture and reduces the
contention problems to within a single filesystem. This doesn't get
rid of contention as the locks still have global CPU scope, but it
does isolate operations on different superblocks form each other.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 18:39:46 -04:00
Josef Bacik cbedaac634 inode: add hlist_fake to avoid the inode hash lock in evict
Some filesystems don't use the VFS inode hash and fake the fact they
are hashed so that all the writeback code works correctly. However,
this means the evict() path still tries to remove the inode from the
hash, meaning that the inode_hash_lock() needs to be taken
unnecessarily. Hence under certain workloads the inode_hash_lock can
be contended even if the inode is never actually hashed.

To avoid this add hlist_fake to test if the inode isn't actually
hashed to avoid taking the hash lock on inodes that have never been
hashed.  Based on Dave Chinner's

inode: add IOP_NOTHASHED to avoid inode hash lock in evict

basd on Al's suggestions.  Thanks,

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Dave Chinner <dchinner@redhat.com>
2015-08-17 18:39:45 -04:00
Oleg Nesterov 8129ed2964 change sb_writers to use percpu_rw_semaphore
We can remove everything from struct sb_writers except frozen
and add the array of percpu_rw_semaphore's instead.

This patch doesn't remove sb_writers->wait_unfrozen yet, we keep
it for get_super_thawed(). We will probably remove it later.

This change tries to address the following problems:

	- Firstly, __sb_start_write() looks simply buggy. It does
	  __sb_end_write() if it sees ->frozen, but if it migrates
	  to another CPU before percpu_counter_dec(), sb_wait_write()
	  can wrongly succeed if there is another task which holds
	  the same "semaphore": sb_wait_write() can miss the result
	  of the previous percpu_counter_inc() but see the result
	  of this percpu_counter_dec().

	- As Dave Hansen reports, it is suboptimal. The trivial
	  microbenchmark that writes to a tmpfs file in a loop runs
	  12% faster if we change this code to rely on RCU and kill
	  the memory barriers.

	- This code doesn't look simple. It would be better to rely
	  on the generic locking code.

	  According to Dave, this change adds the same performance
	  improvement.

Note: with this change both freeze_super() and thaw_super() will do
synchronize_sched_expedited() 3 times. This is just ugly. But:

	- This will be "fixed" by the rcu_sync changes we are going
	  to merge. After that freeze_super()->percpu_down_write()
	  will use synchronize_sched(), and thaw_super() won't use
	  synchronize() at all.

	  This doesn't need any changes in fs/super.c.

	- Once we merge rcu_sync changes, we can also change super.c
	  so that all wb_write->rw_sem's will share the single ->rss
	  in struct sb_writes, then freeze_super() will need only one
	  synchronize_sched().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>
2015-08-15 13:52:13 +02:00
Oleg Nesterov 853b39a7c8 shift percpu_counter_destroy() into destroy_super_work()
Of course, this patch is ugly as hell. It will be (partially)
reverted later. We add it to ensure that other WIP changes in
percpu_rw_semaphore won't break fs/super.c.

We do not even need this change right now, percpu_free_rwsem()
is fine in atomic context. But we are going to change this, it
will be might_sleep() after we merge the rcu_sync() patches.

And even after that we do not really need destroy_super_work(),
we will kill it in any case. Instead, destroy_super_rcu() should
just check that rss->cb_state == CB_IDLE and do call_rcu() again
in the (very unlikely) case this is not true.

So this is just the temporary kludge which helps us to avoid the
conflicts with the changes which will be (hopefully) routed via
rcu tree.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>
2015-08-15 13:52:11 +02:00
Oleg Nesterov bee9182d95 introduce __sb_writers_{acquired,release}() helpers
Preparation to hide the sb->s_writers internals from xfs and btrfs.
Add 2 trivial define's they can use rather than play with ->s_writers
directly. No changes in btrfs/transaction.o and xfs/xfs_aops.o.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Jan Kara <jack@suse.com>
2015-08-15 13:52:08 +02:00
J. Bruce Fields c87fb4a378 lockd: NLM grace period shouldn't block NFSv4 opens
NLM locks don't conflict with NFSv4 share reservations, so we're not
going to learn anything new by watiting for them.

They do conflict with NFSv4 locks and with delegations.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-13 10:22:06 -04:00
Mel Gorman 4248b0da46 fs, file table: reinit files_stat.max_files after deferred memory initialisation
Dave Hansen reported the following;

	My laptop has been behaving strangely with 4.2-rc2.  Once I log
	in to my X session, I start getting all kinds of strange errors
	from applications and see this in my dmesg:

        	VFS: file-max limit 8192 reached

The problem is that the file-max is calculated before memory is fully
initialised and miscalculates how much memory the kernel is using.  This
patch recalculates file-max after deferred memory initialisation.  Note
that using memory hotplug infrastructure would not have avoided this
problem as the value is not recalculated after memory hot-add.

4.1:             files_stat.max_files = 6582781
4.2-rc2:         files_stat.max_files = 8192
4.2-rc2 patched: files_stat.max_files = 6562467

Small differences with the patch applied and 4.1 but not enough to matter.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reported-by: Dave Hansen <dave.hansen@intel.com>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Alex Ng <alexng@microsoft.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-07 04:39:40 +03:00
Jeff Layton ee296d7c57 locks: inline posix_lock_file_wait and flock_lock_file_wait
They just call file_inode and then the corresponding *_inode_file_wait
function. Just make them static inlines instead.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-07-13 06:29:11 -04:00
Jeff Layton 29d01b22ea locks: new helpers - flock_lock_inode_wait and posix_lock_inode_wait
Allow callers to pass in an inode instead of a filp.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Reviewed-by: "J. Bruce Fields" <bfields@fieldses.org>
Tested-by: "J. Bruce Fields" <bfields@fieldses.org>
2015-07-13 06:29:11 -04:00
Eric W. Biederman 90f8572b0f vfs: Commit to never having exectuables on proc and sysfs.
Today proc and sysfs do not contain any executable files.  Several
applications today mount proc or sysfs without noexec and nosuid and
then depend on there being no exectuables files on proc or sysfs.
Having any executable files show on proc or sysfs would cause
a user space visible regression, and most likely security problems.

Therefore commit to never allowing executables on proc and sysfs by
adding a new flag to mark them as filesystems without executables and
enforce that flag.

Test the flag where MNT_NOEXEC is tested today, so that the only user
visible effect will be that exectuables will be treated as if the
execute bit is cleared.

The filesystems proc and sysfs do not currently incoporate any
executable files so this does not result in any user visible effects.

This makes it unnecessary to vet changes to proc and sysfs tightly for
adding exectuable files or changes to chattr that would modify
existing files, as no matter what the individual file say they will
not be treated as exectuable files by the vfs.

Not having to vet changes to closely is important as without this we
are only one proc_create call (or another goof up in the
implementation of notify_change) from having problematic executables
on proc.  Those mistakes are all too easy to make and would create
a situation where there are security issues or the assumptions of
some program having to be broken (and cause userspace regressions).

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-10 10:39:25 -05:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds 0cbee99269 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull user namespace updates from Eric Biederman:
 "Long ago and far away when user namespaces where young it was realized
  that allowing fresh mounts of proc and sysfs with only user namespace
  permissions could violate the basic rule that only root gets to decide
  if proc or sysfs should be mounted at all.

  Some hacks were put in place to reduce the worst of the damage could
  be done, and the common sense rule was adopted that fresh mounts of
  proc and sysfs should allow no more than bind mounts of proc and
  sysfs.  Unfortunately that rule has not been fully enforced.

  There are two kinds of gaps in that enforcement.  Only filesystems
  mounted on empty directories of proc and sysfs should be ignored but
  the test for empty directories was insufficient.  So in my tree
  directories on proc, sysctl and sysfs that will always be empty are
  created specially.  Every other technique is imperfect as an ordinary
  directory can have entries added even after a readdir returns and
  shows that the directory is empty.  Special creation of directories
  for mount points makes the code in the kernel a smidge clearer about
  it's purpose.  I asked container developers from the various container
  projects to help test this and no holes were found in the set of mount
  points on proc and sysfs that are created specially.

  This set of changes also starts enforcing the mount flags of fresh
  mounts of proc and sysfs are consistent with the existing mount of
  proc and sysfs.  I expected this to be the boring part of the work but
  unfortunately unprivileged userspace winds up mounting fresh copies of
  proc and sysfs with noexec and nosuid clear when root set those flags
  on the previous mount of proc and sysfs.  So for now only the atime,
  read-only and nodev attributes which userspace happens to keep
  consistent are enforced.  Dealing with the noexec and nosuid
  attributes remains for another time.

  This set of changes also addresses an issue with how open file
  descriptors from /proc/<pid>/ns/* are displayed.  Recently readlink of
  /proc/<pid>/fd has been triggering a WARN_ON that has not been
  meaningful since it was added (as all of the code in the kernel was
  converted) and is not now actively wrong.

  There is also a short list of issues that have not been fixed yet that
  I will mention briefly.

  It is possible to rename a directory from below to above a bind mount.
  At which point any directory pointers below the renamed directory can
  be walked up to the root directory of the filesystem.  With user
  namespaces enabled a bind mount of the bind mount can be created
  allowing the user to pick a directory whose children they can rename
  to outside of the bind mount.  This is challenging to fix and doubly
  so because all obvious solutions must touch code that is in the
  performance part of pathname resolution.

  As mentioned above there is also a question of how to ensure that
  developers by accident or with purpose do not introduce exectuable
  files on sysfs and proc and in doing so introduce security regressions
  in the current userspace that will not be immediately obvious and as
  such are likely to require breaking userspace in painful ways once
  they are recognized"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  vfs: Remove incorrect debugging WARN in prepend_path
  mnt: Update fs_fully_visible to test for permanently empty directories
  sysfs: Create mountpoints with sysfs_create_mount_point
  sysfs: Add support for permanently empty directories to serve as mount points.
  kernfs: Add support for always empty directories.
  proc: Allow creating permanently empty directories that serve as mount points
  sysctl: Allow creating permanently empty directories that serve as mountpoints.
  fs: Add helper functions for permanently empty directories.
  vfs: Ignore unlocked mounts in fs_fully_visible
  mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
  mnt: Refactor the logic for mounting sysfs and proc in a user namespace
2015-07-03 15:20:57 -07:00
Eric W. Biederman fbabfd0f4e fs: Add helper functions for permanently empty directories.
To ensure it is safe to mount proc and sysfs I need to check if
filesystems that are mounted on top of them are mounted on truly empty
directories.  Given that some directories can gain entries over time,
knowing that a directory is empty right now is insufficient.

Therefore add supporting infrastructure for permantently empty
directories that proc and sysfs can use when they create mount points
for filesystems and fs_fully_visible can use to test for permanently
empty directories to ensure that nothing will be gained by mounting a
fresh copy of proc or sysfs.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-07-01 10:36:37 -05:00
Linus Torvalds 68b4449d79 xfs: update for 4.2-rc1
This update contains:
 
 o A new sparse on-disk inode record format to allow small extents to
   be used for inode allocation when free space is fragmented.
 o DAX support. This includes minor changes to the DAX core code to
   fix problems with lock ordering and bufferhead mapping abuse.
 o transaction commit interface cleanup
 o removal of various unnecessary XFS specific type definitions
 o cleanup and optimisation of freelist preparation before allocation
 o various minor cleanups
 o bug fixes for
 	- transaction reservation leaks
 	- incorrect inode logging in unwritten extent conversion
 	- mmap lock vs freeze ordering
 	- remote symlink mishandling
 	- attribute fork removal issues.
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Merge tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pul xfs updates from Dave Chinner:
 "There's a couple of small API changes to the core DAX code which
  required small changes to the ext2 and ext4 code bases, but otherwise
  everything is within the XFS codebase.

  This update contains:

   - A new sparse on-disk inode record format to allow small extents to
     be used for inode allocation when free space is fragmented.

   - DAX support.  This includes minor changes to the DAX core code to
     fix problems with lock ordering and bufferhead mapping abuse.

   - transaction commit interface cleanup

   - removal of various unnecessary XFS specific type definitions

   - cleanup and optimisation of freelist preparation before allocation

   - various minor cleanups

   - bug fixes for
	- transaction reservation leaks
	- incorrect inode logging in unwritten extent conversion
	- mmap lock vs freeze ordering
	- remote symlink mishandling
	- attribute fork removal issues"

* tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits)
  xfs: don't truncate attribute extents if no extents exist
  xfs: clean up XFS_MIN_FREELIST macros
  xfs: sanitise error handling in xfs_alloc_fix_freelist
  xfs: factor out free space extent length check
  xfs: xfs_alloc_fix_freelist() can use incore perag structures
  xfs: remove xfs_caddr_t
  xfs: use void pointers in log validation helpers
  xfs: return a void pointer from xfs_buf_offset
  xfs: remove inst_t
  xfs: remove __psint_t and __psunsigned_t
  xfs: fix remote symlinks on V5/CRC filesystems
  xfs: fix xfs_log_done interface
  xfs: saner xfs_trans_commit interface
  xfs: remove the flags argument to xfs_trans_cancel
  xfs: pass a boolean flag to xfs_trans_free_items
  xfs: switch remaining xfs_trans_dup users to xfs_trans_roll
  xfs: check min blks for random debug mode sparse allocations
  xfs: fix sparse inodes 32-bit compile failure
  xfs: add initial DAX support
  xfs: add DAX IO path support
  ...
2015-06-30 20:16:08 -07:00
Linus Torvalds e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00
Linus Torvalds bfffa1cc9d Merge branch 'for-4.2/core' of git://git.kernel.dk/linux-block
Pull core block IO update from Jens Axboe:
 "Nothing really major in here, mostly a collection of smaller
  optimizations and cleanups, mixed with various fixes.  In more detail,
  this contains:

   - Addition of policy specific data to blkcg for block cgroups.  From
     Arianna Avanzini.

   - Various cleanups around command types from Christoph.

   - Cleanup of the suspend block I/O path from Christoph.

   - Plugging updates from Shaohua and Jeff Moyer, for blk-mq.

   - Eliminating atomic inc/dec of both remaining IO count and reference
     count in a bio.  From me.

   - Fixes for SG gap and chunk size support for data-less (discards)
     IO, so we can merge these better.  From me.

   - Small restructuring of blk-mq shared tag support, freeing drivers
     from iterating hardware queues.  From Keith Busch.

   - A few cfq-iosched tweaks, from Tahsin Erdogan and me.  Makes the
     IOPS mode the default for non-rotational storage"

* 'for-4.2/core' of git://git.kernel.dk/linux-block: (35 commits)
  cfq-iosched: fix other locations where blkcg_to_cfqgd() can return NULL
  cfq-iosched: fix sysfs oops when attempting to read unconfigured weights
  cfq-iosched: move group scheduling functions under ifdef
  cfq-iosched: fix the setting of IOPS mode on SSDs
  blktrace: Add blktrace.c to BLOCK LAYER in MAINTAINERS file
  block, cgroup: implement policy-specific per-blkcg data
  block: Make CFQ default to IOPS mode on SSDs
  block: add blk_set_queue_dying() to blkdev.h
  blk-mq: Shared tag enhancements
  block: don't honor chunk sizes for data-less IO
  block: only honor SG gap prevention for merges that contain data
  block: fix returnvar.cocci warnings
  block, dm: don't copy bios for request clones
  block: remove management of bi_remaining when restoring original bi_end_io
  block: replace trylock with mutex_lock in blkdev_reread_part()
  block: export blkdev_reread_part() and __blkdev_reread_part()
  suspend: simplify block I/O handling
  block: collapse bio bit space
  block: remove unused BIO_RW_BLOCK and BIO_EOF flags
  block: remove BIO_EOPNOTSUPP
  ...
2015-06-25 14:29:53 -07:00
Jan Kara 45f147a1bc fs: Call security_ops->inode_killpriv on truncate
Comment in include/linux/security.h says that ->inode_killpriv() should
be called when setuid bit is being removed and that similar security
labels (in fact this applies only to file capabilities) should be
removed at this time as well. However we don't call ->inode_killpriv()
when we remove suid bit on truncate.

We fix the problem by calling ->inode_need_killpriv() and subsequently
->inode_killpriv() on truncate the same way as we do it on file write.

After this patch there's only one user of should_remove_suid() - ocfs2 -
and indeed it's buggy because it doesn't call ->inode_killpriv() on
write. However fixing it is difficult because of special locking
constraints.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:01:09 -04:00
Jan Kara dbfae0cdcd fs: Provide function telling whether file_remove_privs() will do anything
Provide function telling whether file_remove_privs() will do anything.
Currently we only have should_remove_suid() and that does something
slightly different.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:01:09 -04:00
Jan Kara 5fa8e0a1c6 fs: Rename file_remove_suid() to file_remove_privs()
file_remove_suid() is a misnomer since it removes also file capabilities
stored in xattrs and sets S_NOSEC flag. Also should_remove_suid() tells
something else than whether file_remove_suid() call is necessary which
leads to bugs.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:01:08 -04:00
Miklos Szeredi 9bf39ab2ad vfs: add file_path() helper
Turn
	d_path(&file->f_path, ...);
into
	file_path(file, ...);

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:00:05 -04:00
David Howells 4bacc9c923 overlayfs: Make f_path always point to the overlay and f_inode to the underlay
Make file->f_path always point to the overlay dentry so that the path in
/proc/pid/fd is correct and to ensure that label-based LSMs have access to the
overlay as well as the underlay (path-based LSMs probably don't need it).

Using my union testsuite to set things up, before the patch I see:

	[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
	[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
	...
	lr-x------. 1 root root 64 Jun  5 14:38 5 -> /a/foo107
	[root@andromeda union-testsuite]# stat /mnt/a/foo107
	...
	Device: 23h/35d Inode: 13381       Links: 1
	...
	[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
	...
	Device: 23h/35d Inode: 13381       Links: 1
	...

After the patch:

	[root@andromeda union-testsuite]# bash 5</mnt/a/foo107
	[root@andromeda union-testsuite]# ls -l /proc/$$/fd/
	...
	lr-x------. 1 root root 64 Jun  5 14:22 5 -> /mnt/a/foo107
	[root@andromeda union-testsuite]# stat /mnt/a/foo107
	...
	Device: 23h/35d Inode: 40346       Links: 1
	...
	[root@andromeda union-testsuite]# stat -L /proc/$$/fd/5
	...
	Device: 23h/35d Inode: 40346       Links: 1
	...

Note the change in where /proc/$$/fd/5 points to in the ls command.  It was
pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107
(which is correct).

The inode accessed, however, is the lower layer.  The union layer is on device
25h/37d and the upper layer on 24h/36d.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-19 03:19:32 -04:00
Tejun Heo 46b15caa7c vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
FS_CGROUP_WRITEBACK indicates whether a file_system_type supports
cgroup writeback; however, different super_blocks of the same
file_system_type may or may not support cgroup writeback depending on
filesystem options.  This patch replaces FS_CGROUP_WRITEBACK with a
per-super_block flag.

super_block->s_flags carries some internal flags in the high bits but
it's exposd to userland through uapi header and running out of space
anyway.  This patch adds a new field super_block->s_iflags to carry
kernel-internal flags.  It is currently only used by the new
SB_I_CGROUPWB flag whose concatenated and abbreviated name is for
consistency with other super_block flags.

ext2_fill_super() is updated to set SB_I_CGROUPWB.

v2: Added super_block->s_iflags instead of stealing another high bit
    from sb->s_flags as suggested by Christoph and Jan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-17 12:47:39 -06:00
Dave Chinner ce5c5d554d dax: expose __dax_fault for filesystems with locking constraints
Some filesystems cannot call dax_fault() directly because they have
different locking and/or allocation constraints in the page fault IO
path. To handle this, we need to follow the same model as the
generic block_page_mkwrite code, where the internals are exposed via
__block_page_mkwrite() so that filesystems can wrap the correct
locking and operations around the outside. 

This is loosely based on a patch originally from Matthew Willcox.
Unlike the original patch, it does not change ext4 code, error
returns or unwritten extent conversion handling.  It also adds a
__dax_mkwrite() wrapper for .page_mkwrite implementations to do the
right thing, too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:18:18 +10:00
Dave Chinner e842f29039 dax: don't abuse get_block mapping for endio callbacks
dax_fault() currently relies on the get_block callback to attach an
io completion callback to the mapping buffer head so that it can
run unwritten extent conversion after zeroing allocated blocks.

Instead of this hack, pass the conversion callback directly into
dax_fault() similar to the get_block callback. When the filesystem
allocates unwritten extents, it will set the buffer_unwritten()
flag, and hence the dax_fault code can call the completion function
in the contexts where it is necessary without overloading the
mapping buffer head.

Note: The changes to ext4 to use this interface are suspect at best.
In fact, the way ext4 did this end_io assignment in the first place
looks suspect because it only set a completion callback when there
wasn't already some other write() call taking place on the same
inode. The ext4 end_io code looks rather intricate and fragile with
all it's reference counting and passing to different contexts for
modification via inode private pointers that aren't protected by
locks...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:18:18 +10:00
Tejun Heo 682aa8e1a6 writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
The mechanism for detecting whether an inode should switch its wb
(bdi_writeback) association is now in place.  This patch build the
framework for the actual switching.

This patch adds a new inode flag I_WB_SWITCHING, which has two
functions.  First, the easy one, it ensures that there's only one
switching in progress for a give inode.  Second, it's used as a
mechanism to synchronize wb stat updates.

The two stats, WB_RECLAIMABLE and WB_WRITEBACK, aren't event counters
but track the current number of dirty pages and pages under writeback
respectively.  As such, when an inode is moved from one wb to another,
the inode's portion of those stats have to be transferred together;
unfortunately, this is a bit tricky as those stat updates are percpu
operations which are performed without holding any lock in some
places.

This patch solves the problem in a similar way as memcg.  Each such
lockless stat updates are wrapped in transaction surrounded by
unlocked_inode_to_wb_begin/end().  During normal operation, they map
to rcu_read_lock/unlock(); however, if I_WB_SWITCHING is asserted,
mapping->tree_lock is grabbed across the transaction.

In turn, the switching path sets I_WB_SWITCHING and waits for a RCU
grace period to pass before actually starting to switch, which
guarantees that all stat update paths are synchronizing against
mapping->tree_lock.

This patch still doesn't implement the actual switching.

v3: Updated on top of the recent cancel_dirty_page() updates.
    unlocked_inode_to_wb_begin() now nests inside
    mem_cgroup_begin_page_stat() to match the locking order.

v2: The i_wb access transaction will be used for !stat accesses too.
    Function names and comments updated accordingly.

    s/inode_wb_stat_unlocked_{begin|end}/unlocked_inode_to_wb_{begin|end}/
    s/switch_wb/switch_wbs/

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:40:20 -06:00
Tejun Heo 2a81490811 writeback: implement foreign cgroup inode detection
As concurrent write sharing of an inode is expected to be very rare
and memcg only tracks page ownership on first-use basis severely
confining the usefulness of such sharing, cgroup writeback tracks
ownership per-inode.  While the support for concurrent write sharing
of an inode is deemed unnecessary, an inode being written to by
different cgroups at different points in time is a lot more common,
and, more importantly, charging only by first-use can too readily lead
to grossly incorrect behaviors (single foreign page can lead to
gigabytes of writeback to be incorrectly attributed).

To resolve this issue, cgroup writeback detects the majority dirtier
of an inode and will transfer the ownership to it.  To avoid
unnnecessary oscillation, the detection mechanism keeps track of
history and gives out the switch verdict only if the foreign usage
pattern is stable over a certain amount of time and/or writeback
attempts.

The detection mechanism has fairly low space and computation overhead.
It adds 8 bytes to struct inode (one int and two u16's) and minimal
amount of calculation per IO.  The detection mechanism converges to
the correct answer usually in several seconds of IO time when there's
a clear majority dirtier.  Even when there isn't, it can reach an
acceptable answer fairly quickly under most circumstances.

Please see wb_detach_inode() for more details.

This patch only implements detection.  Following patches will
implement actual switching.

v2: wbc_account_io() now checks whether the wbc is associated with a
    wb before dereferencing it.  This can happen when pageout() is
    writing pages directly without going through the usual writeback
    path.  As pageout() path is single-threaded, we don't want it to
    be blocked behind a slow cgroup and ultimately want it to delegate
    actual writing to the usual writeback path.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:40:20 -06:00
Tejun Heo 52ebea749a writeback: make backing_dev_info host cgroup-specific bdi_writebacks
For the planned cgroup writeback support, on each bdi
(backing_dev_info), each memcg will be served by a separate wb
(bdi_writeback).  This patch updates bdi so that a bdi can host
multiple wbs (bdi_writebacks).

On the default hierarchy, blkcg implicitly enables memcg.  This allows
using memcg's page ownership for attributing writeback IOs, and every
memcg - blkcg combination can be served by its own wb by assigning a
dedicated wb to each memcg.  This means that there may be multiple
wb's of a bdi mapped to the same blkcg.  As congested state is per
blkcg - bdi combination, those wb's should share the same congested
state.  This is achieved by tracking congested state via
bdi_writeback_congested structs which are keyed by blkcg.

bdi->wb remains unchanged and will keep serving the root cgroup.
cgwb's (cgroup wb's) for non-root cgroups are created on-demand or
looked up while dirtying an inode according to the memcg of the page
being dirtied or current task.  Each cgwb is indexed on bdi->cgwb_tree
by its memcg id.  Once an inode is associated with its wb, it can be
retrieved using inode_to_wb().

Currently, none of the filesystems has FS_CGROUP_WRITEBACK and all
pages will keep being associated with bdi->wb.

v3: inode_attach_wb() in account_page_dirtied() moved inside
    mapping_cap_account_dirty() block where it's known to be !NULL.
    Also, an unnecessary NULL check before kfree() removed.  Both
    detected by the kbuild bot.

v2: Updated so that wb association is per inode and wb is per memcg
    rather than blkcg.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo 89e9b9e07a writeback: add {CONFIG|BDI_CAP|FS}_CGROUP_WRITEBACK
cgroup writeback requires support from both bdi and filesystem sides.
Add BDI_CAP_CGROUP_WRITEBACK and FS_CGROUP_WRITEBACK to indicate
support and enable BDI_CAP_CGROUP_WRITEBACK on block based bdi's by
default.  Also, define CONFIG_CGROUP_WRITEBACK which is enabled if
both MEMCG and BLK_CGROUP are enabled.

inode_cgwb_enabled() which determines whether a given inode's both bdi
and fs support cgroup writeback is added.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:35 -06:00
Tejun Heo a212b105b0 bdi: make inode_to_bdi() inline
Now that bdi definitions are moved to backing-dev-defs.h,
backing-dev.h can include blkdev.h and inline inode_to_bdi() without
worrying about introducing circular include dependency.  The function
gets called from hot paths and fairly trivial.

This patch makes inode_to_bdi() and sb_is_blkdev_sb() that the
function calls inline.  blockdev_superblock and noop_backing_dev_info
are EXPORT_GPL'd to allow the inline functions to be used from
modules.

While at it, make sb_is_blkdev_sb() return bool instead of int.

v2: Fixed typo in description as suggested by Jan.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Jarod Wilson be32417796 block: export blkdev_reread_part() and __blkdev_reread_part()
This patch exports blkdev_reread_part() for block drivers, also
introduce __blkdev_reread_part().

For some drivers, such as loop, reread of partitions can be run
from the release path, and bd_mutex may already be held prior to
calling ioctl_by_bdev(bdev, BLKRRPART, 0), so introduce
__blkdev_reread_part for use in such cases.

CC: Christoph Hellwig <hch@lst.de>
CC: Jens Axboe <axboe@kernel.dk>
CC: Tejun Heo <tj@kernel.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Markus Pargmann <mpa@pengutronix.de>
CC: Stefan Weinhuber <wein@de.ibm.com>
CC: Stefan Haberland <stefan.haberland@de.ibm.com>
CC: Sebastian Ott <sebott@linux.vnet.ibm.com>
CC: Fabian Frederick <fabf@skynet.be>
CC: Ming Lei <ming.lei@canonical.com>
CC: David Herrmann <dh.herrmann@gmail.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: nbd-general@lists.sourceforge.net
CC: linux-s390@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-20 09:05:42 -06:00
Al Viro 89076bc319 get rid of assorted nameidata-related debris
pointless forward declarations, stale comments

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-15 01:10:37 -04:00
NeilBrown 8fa9dd2466 VFS/namei: make the use of touch_atime() in get_link() RCU-safe.
touch_atime is not RCU-safe, and so cannot be called on an RCU walk.
However, in situations where RCU-walk makes a difference, the symlink
will likely to accessed much more often than it is useful to update
the atime.

So split out the test of "Does the atime actually need to be updated"
into  atime_needs_update(), and have get_link() unlazy if it finds that
it will need to do that update.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-15 01:06:27 -04:00
Eric W. Biederman 1b852bceb0 mnt: Refactor the logic for mounting sysfs and proc in a user namespace
Fresh mounts of proc and sysfs are a very special case that works very
much like a bind mount.  Unfortunately the current structure can not
preserve the MNT_LOCK... mount flags.  Therefore refactor the logic
into a form that can be modified to preserve those lock bits.

Add a new filesystem flag FS_USERNS_VISIBLE that requires some mount
of the filesystem be fully visible in the current mount namespace,
before the filesystem may be mounted.

Move the logic for calling fs_fully_visible from proc and sysfs into
fs/namespace.c where it has greater access to mount namespace state.

Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-05-13 21:44:11 -05:00
Al Viro ecc087ff14 new helper: free_page_put_link()
similar to kfree_put_link()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11 08:13:13 -04:00
Al Viro 5f2c4179e1 switch ->put_link() from dentry to inode
only one instance looks at that argument at all; that sole
exception wants inode rather than dentry.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11 08:13:12 -04:00
Al Viro 6e77137b36 don't pass nameidata to ->follow_link()
its only use is getting passed to nd_jump_link(), which can obtain
it from current->nameidata

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:20:15 -04:00
Al Viro 680baacbca new ->follow_link() and ->put_link() calling conventions
a) instead of storing the symlink body (via nd_set_link()) and returning
an opaque pointer later passed to ->put_link(), ->follow_link() _stores_
that opaque pointer (into void * passed by address by caller) and returns
the symlink body.  Returning ERR_PTR() on error, NULL on jump (procfs magic
symlinks) and pointer to symlink body for normal symlinks.  Stored pointer
is ignored in all cases except the last one.

Storing NULL for opaque pointer (or not storing it at all) means no call
of ->put_link().

b) the body used to be passed to ->put_link() implicitly (via nameidata).
Now only the opaque pointer is.  In the cases when we used the symlink body
to free stuff, ->follow_link() now should store it as opaque pointer in addition
to returning it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:19:45 -04:00
Al Viro 61ba64fc07 libfs: simple_follow_link()
let "fast" symlinks store the pointer to the body into ->i_link and
use simple_follow_link for ->follow_link()

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10 22:18:20 -04:00
Linus Torvalds 9ec3a646fe Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-26 17:22:07 -07:00
Eric Sandeen ac74d8d65c fix I_DIO_WAKEUP definition
I_DIO_WAKEUP is never directly used, but fix it up anyway.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-24 15:45:34 -04:00
Jens Axboe fe0f07d08e direct-io: only inc/dec inode->i_dio_count for file systems
do_blockdev_direct_IO() increments and decrements the inode
->i_dio_count for each IO operation. It does this to protect against
truncate of a file. Block devices don't need this sort of protection.

For a capable multiqueue setup, this atomic int is the only shared
state between applications accessing the device for O_DIRECT, and it
presents a scaling wall for that. In my testing, as much as 30% of
system time is spent incrementing and decrementing this value. A mixed
read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with
better latencies too. Before:

clat percentiles (usec):
 |  1.00th=[   33],  5.00th=[   34], 10.00th=[   34], 20.00th=[   34],
 | 30.00th=[   34], 40.00th=[   34], 50.00th=[   35], 60.00th=[   35],
 | 70.00th=[   35], 80.00th=[   35], 90.00th=[   37], 95.00th=[   80],
 | 99.00th=[   98], 99.50th=[  151], 99.90th=[  155], 99.95th=[  155],
 | 99.99th=[  165]

After:

clat percentiles (usec):
 |  1.00th=[   95],  5.00th=[  108], 10.00th=[  129], 20.00th=[  149],
 | 30.00th=[  155], 40.00th=[  161], 50.00th=[  167], 60.00th=[  171],
 | 70.00th=[  177], 80.00th=[  185], 90.00th=[  201], 95.00th=[  270],
 | 99.00th=[  390], 99.50th=[  398], 99.90th=[  418], 99.95th=[  422],
 | 99.99th=[  438]

In other setups, Robert Elliott reported seeing good performance
improvements:

https://lkml.org/lkml/2015/4/3/557

The more applications accessing the device, the worse it gets.

Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells
do_blockdev_direct_IO() that it need not worry about incrementing
or decrementing the inode i_dio_count for this caller.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Elliott, Robert (Server Storage) <elliott@hp.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-24 15:45:28 -04:00
Linus Torvalds 54e514b91b Merge branch 'akpm' (patches from Andrew)
Merge third patchbomb from Andrew Morton:

 - various misc things

 - a couple of lib/ optimisations

 - provide DIV_ROUND_CLOSEST_ULL()

 - checkpatch updates

 - rtc tree

 - befs, nilfs2, hfs, hfsplus, fatfs, adfs, affs, bfs

 - ptrace fixes

 - fork() fixes

 - seccomp cleanups

 - more mmap_sem hold time reductions from Davidlohr

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (138 commits)
  proc: show locks in /proc/pid/fdinfo/X
  docs: add missing and new /proc/PID/status file entries, fix typos
  drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic
  Documentation/spi/spidev_test.c: fix warning
  drivers/rtc/rtc-s5m.c: allow usage on device type different than main MFD type
  .gitignore: ignore *.tar
  MAINTAINERS: add Mediatek SoC mailing list
  tomoyo: reduce mmap_sem hold for mm->exe_file
  powerpc/oprofile: reduce mmap_sem hold for exe_file
  oprofile: reduce mmap_sem hold for mm->exe_file
  mips: ip32: add platform data hooks to use DS1685 driver
  lib/Kconfig: fix up HAVE_ARCH_BITREVERSE help text
  x86: switch to using asm-generic for seccomp.h
  sparc: switch to using asm-generic for seccomp.h
  powerpc: switch to using asm-generic for seccomp.h
  parisc: switch to using asm-generic for seccomp.h
  mips: switch to using asm-generic for seccomp.h
  microblaze: use asm-generic for seccomp.h
  arm: use asm-generic for seccomp.h
  seccomp: allow COMPAT sigreturn overrides
  ...
2015-04-17 09:04:38 -04:00
Andrey Vagin 6c8c90319c proc: show locks in /proc/pid/fdinfo/X
Let's show locks which are associated with a file descriptor in
its fdinfo file.

Currently we don't have a reliable way to determine who holds a lock.  We
can find some information in /proc/locks, but PID which is reported there
can be wrong.  For example, a process takes a lock, then forks a child and
dies.  In this case /proc/locks contains the parent pid, which can be
reused by another process.

$ cat /proc/locks
...
6: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF
...

$ ps -C rpcbind
  PID TTY          TIME CMD
  332 ?        00:00:00 rpcbind

$ cat /proc/332/fdinfo/4
pos:	0
flags:	0100000
mnt_id:	22
lock:	1: FLOCK  ADVISORY  WRITE 324 00:13:13431 0 EOF

$ ls -l /proc/332/fd/4
lr-x------ 1 root root 64 Mar  5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock

$ ls -l /proc/324/fd/
total 0
lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0
lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0

You can see that the process with the 324 pid doesn't hold the lock.

This information is required for proper dumping and restoring file
locks.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:12 -04:00
Konstantin Khlebnikov 90f31d0ea8 mm: rcu-protected get_mm_exe_file()
This patch removes mm->mmap_sem from mm->exe_file read side.
Also it kills dup_mm_exe_file() and moves exe_file duplication into
dup_mmap() where both mmap_sems are locked.

[akpm@linux-foundation.org: fix comment typo]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17 09:04:07 -04:00
Linus Torvalds 4fc8adcfec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull third hunk of vfs changes from Al Viro:
 "This contains the ->direct_IO() changes from Omar + saner
  generic_write_checks() + dealing with fcntl()/{read,write}() races
  (mirroring O_APPEND/O_DIRECT into iocb->ki_flags and instead of
  repeatedly looking at ->f_flags, which can be changed by fcntl(2),
  check ->ki_flags - which cannot) + infrastructure bits for dhowells'
  d_inode annotations + Christophs switch of /dev/loop to
  vfs_iter_write()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (30 commits)
  block: loop: switch to VFS ITER_BVEC
  configfs: Fix inconsistent use of file_inode() vs file->f_path.dentry->d_inode
  VFS: Make pathwalk use d_is_reg() rather than S_ISREG()
  VFS: Fix up debugfs to use d_is_dir() in place of S_ISDIR()
  VFS: Combine inode checks with d_is_negative() and d_is_positive() in pathwalk
  NFS: Don't use d_inode as a variable name
  VFS: Impose ordering on accesses of d_inode and d_flags
  VFS: Add owner-filesystem positive/negative dentry checks
  nfs: generic_write_checks() shouldn't be done on swapout...
  ocfs2: use __generic_file_write_iter()
  mirror O_APPEND and O_DIRECT into iocb->ki_flags
  switch generic_write_checks() to iocb and iter
  ocfs2: move generic_write_checks() before the alignment checks
  ocfs2_file_write_iter: stop messing with ppos
  udf_file_write_iter: reorder and simplify
  fuse: ->direct_IO() doesn't need generic_write_checks()
  ext4_file_write_iter: move generic_write_checks() up
  xfs_file_aio_write_checks: switch to iocb/iov_iter
  generic_write_checks(): drop isblk argument
  blkdev_write_iter: expand generic_file_checks() call in there
  ...
2015-04-16 23:27:56 -04:00
Linus Torvalds eea3a00264 Merge branch 'akpm' (patches from Andrew)
Merge second patchbomb from Andrew Morton:

 - the rest of MM

 - various misc bits

 - add ability to run /sbin/reboot at reboot time

 - printk/vsprintf changes

 - fiddle with seq_printf() return value

* akpm: (114 commits)
  parisc: remove use of seq_printf return value
  lru_cache: remove use of seq_printf return value
  tracing: remove use of seq_printf return value
  cgroup: remove use of seq_printf return value
  proc: remove use of seq_printf return value
  s390: remove use of seq_printf return value
  cris fasttimer: remove use of seq_printf return value
  cris: remove use of seq_printf return value
  openrisc: remove use of seq_printf return value
  ARM: plat-pxa: remove use of seq_printf return value
  nios2: cpuinfo: remove use of seq_printf return value
  microblaze: mb: remove use of seq_printf return value
  ipc: remove use of seq_printf return value
  rtc: remove use of seq_printf return value
  power: wakeup: remove use of seq_printf return value
  x86: mtrr: if: remove use of seq_printf return value
  linux/bitmap.h: improve BITMAP_{LAST,FIRST}_WORD_MASK
  MAINTAINERS: CREDITS: remove Stefano Brivio from B43
  .mailmap: add Ricardo Ribalda
  CREDITS: add Ricardo Ribalda Delgado
  ...
2015-04-15 16:39:15 -07:00
Boaz Harrosh 0e3b210ce1 dax: use pfn_mkwrite to update c/mtime + freeze protection
From: Yigal Korman <yigal@plexistor.com>

[v1]
Without this patch, c/mtime is not updated correctly when mmap'ed page is
first read from and then written to.

A new xfstest is submitted for testing this (generic/080)

[v2]
Jan Kara has pointed out that if we add the
sb_start/end_pagefault pair in the new pfn_mkwrite we
are then fixing another bug where: A user could start
writing to the page while filesystem is frozen.

Signed-off-by: Yigal Korman <yigal@plexistor.com>
Signed-off-by: Boaz Harrosh <boaz@plexistor.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:20 -07:00
Zhang Zhen f2b91d8d38 vfs: delete vfs_readdir function declaration
vfs_readdir() was replaced by iterate_dir() in commit 5c0ba4e076
("[readdir] introduce iterate_dir() and dir_context").

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-15 16:35:16 -07:00
Linus Torvalds 6d50ff91d9 File locking related changes for v4.1 (pile #1)
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Merge tag 'locks-v4.1-1' of git://git.samba.org/jlayton/linux

Pull file locking related changes from Jeff Layton:
 "This set is mostly minor cleanups to the overhaul that went in last
  cycle.  The other noticeable items are the changes to the lm_get_owner
  and lm_put_owner prototypes, and the fact that we no longer need to
  use the i_lock to protect the i_flctx pointer"

* tag 'locks-v4.1-1' of git://git.samba.org/jlayton/linux:
  locks: use cmpxchg to assign i_flctx pointer
  locks: get rid of WE_CAN_BREAK_LSLK_NOW dead code
  locks: change lm_get_owner and lm_put_owner prototypes
  locks: don't allocate a lock context for an F_UNLCK request
  locks: Add lockdep assertion for blocked_lock_lock
  locks: remove extraneous IS_POSIX and IS_FLOCK tests
  locks: Remove unnecessary IS_POSIX test
2015-04-15 14:22:45 -07:00
Linus Torvalds fa927894bb Merge branch 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second vfs update from Al Viro:
 "Now that net-next went in...  Here's the next big chunk - killing
  ->aio_read() and ->aio_write().

  There'll be one more pile today (direct_IO changes and
  generic_write_checks() cleanups/fixes), but I'd prefer to keep that
  one separate"

* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits)
  ->aio_read and ->aio_write removed
  pcm: another weird API abuse
  infinibad: weird APIs switched to ->write_iter()
  kill do_sync_read/do_sync_write
  fuse: use iov_iter_get_pages() for non-splice path
  fuse: switch to ->read_iter/->write_iter
  switch drivers/char/mem.c to ->read_iter/->write_iter
  make new_sync_{read,write}() static
  coredump: accept any write method
  switch /dev/loop to vfs_iter_write()
  serial2002: switch to __vfs_read/__vfs_write
  ashmem: use __vfs_read()
  export __vfs_read()
  autofs: switch to __vfs_write()
  new helper: __vfs_write()
  switch hugetlbfs to ->read_iter()
  coda: switch to ->read_iter/->write_iter
  ncpfs: switch to ->read_iter/->write_iter
  net/9p: remove (now-)unused helpers
  p9_client_attach(): set fid->uid correctly
  ...
2015-04-15 13:22:56 -07:00
Linus Torvalds ca2ec32658 Merge branch 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs update from Al Viro:
 "Part one:

   - struct filename-related cleanups

   - saner iov_iter_init() replacements (and switching the syscalls to
     use of those)

   - ntfs switch to ->write_iter() (Anton)

   - aio cleanups and splitting iocb into common and async parts
     (Christoph)

   - assorted fixes (me, bfields, Andrew Elble)

  There's a lot more, including the completion of switchover to
  ->{read,write}_iter(), d_inode/d_backing_inode annotations, f_flags
  race fixes, etc, but that goes after #for-davem merge.  David has
  pulled it, and once it's in I'll send the next vfs pull request"

* 'for-linus-1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (35 commits)
  sg_start_req(): use import_iovec()
  sg_start_req(): make sure that there's not too many elements in iovec
  blk_rq_map_user(): use import_single_range()
  sg_io(): use import_iovec()
  process_vm_access: switch to {compat_,}import_iovec()
  switch keyctl_instantiate_key_common() to iov_iter
  switch {compat_,}do_readv_writev() to {compat_,}import_iovec()
  aio_setup_vectored_rw(): switch to {compat_,}import_iovec()
  vmsplice_to_user(): switch to import_iovec()
  kill aio_setup_single_vector()
  aio: simplify arguments of aio_setup_..._rw()
  aio: lift iov_iter_init() into aio_setup_..._rw()
  lift iov_iter into {compat_,}do_readv_writev()
  NFS: fix BUG() crash in notify_change() with patch to chown_common()
  dcache: return -ESTALE not -EBUSY on distributed fs race
  NTFS: Version 2.1.32 - Update file write from aio_write to write_iter.
  VFS: Add iov_iter_fault_in_multipages_readable()
  drop bogus check in file_open_root()
  switch security_inode_getattr() to struct path *
  constify tomoyo_realpath_from_path()
  ...
2015-04-14 15:31:03 -07:00
Al Viro 2ba48ce513 mirror O_APPEND and O_DIRECT into iocb->ki_flags
... avoiding write_iter/fcntl races.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:30:22 -04:00
Al Viro 3309dd04cb switch generic_write_checks() to iocb and iter
... returning -E... upon error and amount of data left in iter after
(possible) truncation upon success.  Note, that normal case gives
a non-zero (positive) return value, so any tests for != 0 _must_ be
updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/ext4/file.c
2015-04-11 22:30:21 -04:00
Al Viro dfea934575 Merge branch 'for-linus' into for-next 2015-04-11 22:29:51 -04:00
Al Viro 0fa6b005af generic_write_checks(): drop isblk argument
all remaining callers are passing 0; some just obscure that fact.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:48 -04:00
Omar Sandoval 22c6186ece direct_IO: remove rw from a_ops->direct_IO()
Now that no one is using rw, remove it completely.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:45 -04:00
Omar Sandoval a95cd63115 Remove rw from dax_{do_,}io()
And use iov_iter_rw() instead.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:44 -04:00
Omar Sandoval 17f8c842d2 Remove rw from {,__,do_}blockdev_direct_IO()
Most filesystems call through to these at some point, so we'll start
here.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:44 -04:00
Al Viro 8436318205 ->aio_read and ->aio_write removed
no remaining users

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:43 -04:00
Al Viro 9a219bc70b kill do_sync_read/do_sync_write
all remaining instances of aio_{read,write} (all 4 of them) have explicit
->read and ->write resp.; do_sync_read/do_sync_write is never called by
__vfs_read/__vfs_write anymore and no other users had been left.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:42 -04:00
Al Viro 5d5d568975 make new_sync_{read,write}() static
All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:40 -04:00
Al Viro 493c84c072 new helper: __vfs_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:37 -04:00
Al Viro 39c853ebfe Merge branch 'for-davem' into for-next 2015-04-11 22:27:19 -04:00
Al Viro c0fec3a98b Merge branch 'iocb' into for-next 2015-04-11 22:24:41 -04:00
Al Viro fd2f7cb5bc kill struct filename.separate
just make const char iname[] the last member and compare name->name with
name->iname instead of checking name->separate

We need to make sure that out-of-line name doesn't end up allocated adjacent
to struct filename refering to it; fortunately, it's easy to achieve - just
allocate that struct filename with one byte in ->iname[], so that ->iname[0]
will be inside the same object and thus have an address different from that
of out-of-line name [spotted by Boqun Feng <boqun.feng@gmail.com>]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:21:24 -04:00
Al Viro 237dae8890 Merge branch 'iocb' into for-davem
trivial conflict in net/socket.c and non-trivial one in crypto -
that one had evaded aio_complete() removal.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-09 00:01:38 -04:00
Al Viro b2edffdd91 fix mremap() vs. ioctx_kill() race
teach ->mremap() method to return an error and have it fail for
aio mappings in process of being killed

Note that in case of ->mremap() failure we need to undo move_page_tables()
we'd already done; we could call ->mremap() first, but then the failure of
move_page_tables() would require undoing whatever _successful_ ->mremap()
has done, which would be a lot more headache in general.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-06 17:50:59 -04:00
Jeff Layton cae80b305e locks: change lm_get_owner and lm_put_owner prototypes
The current prototypes for these operations are somewhat awkward as they
deal with fl_owners but take struct file_lock arguments. In the future,
we'll want to be able to take references without necessarily dealing
with a struct file_lock.

Change them to take fl_owner_t arguments instead and have the callers
deal with assigning the values to the file_lock structs.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2015-04-03 09:04:04 -04:00
Christoph Hellwig e2e40f2c1e fs: move struct kiocb to fs.h
struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25 20:28:11 -04:00
Theodore Ts'o a2f4870697 fs: make sure the timestamps for lazytime inodes eventually get written
Jan Kara pointed out that if there is an inode which is constantly
getting dirtied with I_DIRTY_PAGES, an inode with an updated timestamp
will never be written since inode->dirtied_when is constantly getting
updated.  We fix this by adding an extra field to the inode,
dirtied_time_when, so inodes with a stale dirtytime can get detected
and handled.

In addition, if we have a dirtytime inode caused by an atime update,
and there is no write activity on the file system, we need to have a
secondary system to make sure these inodes get written out.  We do
this by setting up a second delayed work structure which wakes up the
CPU much more rarely compared to writeback_expire_centisecs.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
2015-03-17 12:23:19 -04:00
Linus Torvalds b2b89ebfc0 File locking related fixes for v3.20 (pile #2)
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Merge tag 'locks-v3.20-2' of git://git.samba.org/jlayton/linux

Pull file locking fixes from Jeff Layton:
 "A small set of patches to fix problems with the recent file locking
  changes that we discussed earlier this week"
"

* tag 'locks-v3.20-2' of git://git.samba.org/jlayton/linux:
  locks: fix list insertion when lock is split in two
  locks: remove conditional lock release in middle of flock_lock_file
  locks: only remove leases associated with the file being closed
  Revert "locks: keep a count of locks on the flctx lists"
2015-02-18 10:21:47 -08:00
Linus Torvalds 038911597e Merge branch 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull lazytime mount option support from Al Viro:
 "Lazytime stuff from tytso"

* 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  ext4: add optimization for the lazytime mount option
  vfs: add find_inode_nowait() function
  vfs: add support for a lazytime mount option
2015-02-17 16:12:34 -08:00
Linus Torvalds 66dc830d14 Merge branch 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
 "More iov_iter work - missing counterpart of iov_iter_init() for
  bvec-backed ones and vfs_read_iter()/vfs_write_iter() - wrappers for
  sync calls of ->read_iter()/->write_iter()"

* 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: add vfs_iter_{read,write} helpers
  new helper: iov_iter_bvec()
2015-02-17 15:48:33 -08:00
Linus Torvalds 05016b0f0a Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull getname/putname updates from Al Viro:
 "Rework of getname/getname_kernel/etc., mostly from Paul Moore.  Gets
  rid of quite a pile of kludges between namei and audit..."

* 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  audit: replace getname()/putname() hacks with reference counters
  audit: fix filename matching in __audit_inode() and __audit_inode_child()
  audit: enable filename recording via getname_kernel()
  simpler calling conventions for filename_mountpoint()
  fs: create proper filename objects using getname_kernel()
  fs: rework getname_kernel to handle up to PATH_MAX sized filenames
  cut down the number of do_path_lookup() callers
2015-02-17 15:27:47 -08:00
Matthew Wilcox 25726bc157 dax: add dax_zero_page_range
This new function allows us to support hole-punch for DAX files by zeroing
a partial page, as opposed to the dax_truncate_page() function which can
only truncate to the end of the page.  Reimplement dax_truncate_page() to
call dax_zero_page_range().

[ross.zwisler@linux.intel.com: ported to 3.13-rc2]
[akpm@linux-foundation.org: fix typos in comments]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:04 -08:00
Matthew Wilcox 6cd176a51e vfs,ext2: remove CONFIG_EXT2_FS_XIP and rename CONFIG_FS_XIP to CONFIG_FS_DAX
The fewer Kconfig options we have the better.  Use the generic
CONFIG_FS_DAX to enable XIP support in ext2 as well as in the core.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:04 -08:00
Matthew Wilcox e748dcd095 vfs: remove get_xip_mem
All callers of get_xip_mem() are now gone.  Remove checks for it,
initialisers of it, documentation of it and the only implementation of it.
 Also remove mm/filemap_xip.c as it is now empty.  Also remove
documentation of the long-gone get_xip_page().

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Matthew Wilcox 4c0ccfef2e dax,ext2: replace xip_truncate_page with dax_truncate_page
It takes a get_block parameter just like nobh_truncate_page() and
block_truncate_page()

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Matthew Wilcox f7ca90b160 dax,ext2: replace the XIP page fault handler with the DAX page fault handler
Instead of calling aops->get_xip_mem from the fault handler, the
filesystem passes a get_block_t that is used to find the appropriate
blocks.

This requires that all architectures implement copy_user_page().  At the
time of writing, mips and arm do not.  Patches exist and are in progress.

[akpm@linux-foundation.org: remap_file_pages went away]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Matthew Wilcox 289c6aedac dax,ext2: replace ext2_clear_xip_target with dax_clear_blocks
This is practically generic code; other filesystems will want to call it
from other places, but there's nothing ext2-specific about it.

Make it a little more generic by allowing it to take a count of the number
of bytes to zero rather than fixing it to a single page.  Thanks to Dave
Hansen for suggesting that I need to call cond_resched() if zeroing more
than one page.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Matthew Wilcox d475c6346a dax,ext2: replace XIP read and write with DAX I/O
Use the generic AIO infrastructure instead of custom read and write
methods.  In addition to giving us support for AIO, this adds the missing
locking between read() and truncate().

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Matthew Wilcox fbbbad4bc2 vfs,ext2: introduce IS_DAX(inode)
Use an inode flag to tag inodes which should avoid using the page cache.
Convert ext2 to use it instead of mapping_is_xip().  Prevent I/Os to files
tagged with the DAX flag from falling back to buffered I/O.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-16 17:56:03 -08:00
Jeff Layton e084c1bd40 Revert "locks: keep a count of locks on the flctx lists"
This reverts commit 9bd0f45b70.

Linus rightly pointed out that I failed to initialize the counters
when adding them, so they don't work as expected. Just revert this
patch for now.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
2015-02-16 14:32:03 -05:00
Linus Torvalds 818099574b Merge branch 'akpm' (patches from Andrew)
Merge third set of updates from Andrew Morton:

 - the rest of MM

   [ This includes getting rid of the numa hinting bits, in favor of
     just generic protnone logic.  Yay.     - Linus ]

 - core kernel

 - procfs

 - some of lib/ (lots of lib/ material this time)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (104 commits)
  lib/lcm.c: replace include
  lib/percpu_ida.c: remove redundant includes
  lib/strncpy_from_user.c: replace module.h include
  lib/stmp_device.c: replace module.h include
  lib/sort.c: move include inside #if 0
  lib/show_mem.c: remove redundant include
  lib/radix-tree.c: change to simpler include
  lib/plist.c: remove redundant include
  lib/nlattr.c: remove redundant include
  lib/kobject_uevent.c: remove redundant include
  lib/llist.c: remove redundant include
  lib/md5.c: simplify include
  lib/list_sort.c: rearrange includes
  lib/genalloc.c: remove redundant include
  lib/idr.c: remove redundant include
  lib/halfmd4.c: simplify includes
  lib/dynamic_queue_limits.c: simplify includes
  lib/sort.c: use simpler includes
  lib/interval_tree.c: simplify includes
  hexdump: make it return number of bytes placed in buffer
  ...
2015-02-12 18:54:28 -08:00
Vladimir Davydov 4101b62435 fs: consolidate {nr,free}_cached_objects args in shrink_control
We are going to make FS shrinkers memcg-aware.  To achieve that, we will
have to pass the memcg to scan to the nr_cached_objects and
free_cached_objects VFS methods, which currently take only the NUMA node
to scan.  Since the shrink_control structure already holds the node, and
the memcg to scan will be added to it when we introduce memcg-aware
vmscan, let us consolidate the methods' arguments in this structure to
keep things clean.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-12 18:54:08 -08:00
Linus Torvalds 6bec003528 Merge branch 'for-3.20/bdi' of git://git.kernel.dk/linux-block
Pull backing device changes from Jens Axboe:
 "This contains a cleanup of how the backing device is handled, in
  preparation for a rework of the life time rules.  In this part, the
  most important change is to split the unrelated nommu mmap flags from
  it, but also removing a backing_dev_info pointer from the
  address_space (and inode), and a cleanup of other various minor bits.

  Christoph did all the work here, I just fixed an oops with pages that
  have a swap backing.  Arnd fixed a missing export, and Oleg killed the
  lustre backing_dev_info from staging.  Last patch was from Al,
  unexporting parts that are now no longer needed outside"

* 'for-3.20/bdi' of git://git.kernel.dk/linux-block:
  Make super_blocks and sb_lock static
  mtd: export new mtd_mmap_capabilities
  fs: make inode_to_bdi() handle NULL inode
  staging/lustre/llite: get rid of backing_dev_info
  fs: remove default_backing_dev_info
  fs: don't reassign dirty inodes to default_backing_dev_info
  nfs: don't call bdi_unregister
  ceph: remove call to bdi_unregister
  fs: remove mapping->backing_dev_info
  fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info
  nilfs2: set up s_bdi like the generic mount_bdev code
  block_dev: get bdev inode bdi directly from the block device
  block_dev: only write bdev inode on close
  fs: introduce f_op->mmap_capabilities for nommu mmap support
  fs: kill BDI_CAP_SWAP_BACKED
  fs: deduplicate noop_backing_dev_info
2015-02-12 13:50:21 -08:00
Linus Torvalds 61845143fe Merge branch 'for-3.20' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "The main change is the pNFS block server support from Christoph, which
  allows an NFS client connected to shared disk to do block IO to the
  shared disk in place of NFS reads and writes.  This also requires xfs
  patches, which should arrive soon through the xfs tree, barring
  unexpected problems.  Support for other filesystems is also possible
  if there's interest.

  Thanks also to Chuck Lever for continuing work to get NFS/RDMA into
  shape"

* 'for-3.20' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd: default NFSv4.2 to on
  nfsd: pNFS block layout driver
  exportfs: add methods for block layout exports
  nfsd: add trace events
  nfsd: update documentation for pNFS support
  nfsd: implement pNFS layout recalls
  nfsd: implement pNFS operations
  nfsd: make find_any_file available outside nfs4state.c
  nfsd: make find/get/put file available outside nfs4state.c
  nfsd: make lookup/alloc/unhash_stid available outside nfs4state.c
  nfsd: add fh_fsid_match helper
  nfsd: move nfsd_fh_match to nfsfh.h
  fs: add FL_LAYOUT lease type
  fs: track fl_owner for leases
  nfs: add LAYOUT_TYPE_MAX enum value
  nfsd: factor out a helper to decode nfstime4 values
  sunrpc/lockd: fix references to the BKL
  nfsd: fix year-2038 nfs4 state problem
  svcrdma: Handle additional inline content
  svcrdma: Move read list XDR round-up logic
  ...
2015-02-12 10:39:41 -08:00
Linus Torvalds 992de5a8ec Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:
 "Bite-sized chunks this time, to avoid the MTA ratelimiting woes.

   - fs/notify updates

   - ocfs2

   - some of MM"

That laconic "some MM" is mainly the removal of remap_file_pages(),
which is a big simplification of the VM, and which gets rid of a *lot*
of random cruft and special cases because we no longer support the
non-linear mappings that it used.

From a user interface perspective, nothing has changed, because the
remap_file_pages() syscall still exists, it's just done by emulating the
old behavior by creating a lot of individual small mappings instead of
one non-linear one.

The emulation is slower than the old "native" non-linear mappings, but
nobody really uses or cares about remap_file_pages(), and simplifying
the VM is a big advantage.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (78 commits)
  memcg: zap memcg_slab_caches and memcg_slab_mutex
  memcg: zap memcg_name argument of memcg_create_kmem_cache
  memcg: zap __memcg_{charge,uncharge}_slab
  mm/page_alloc.c: place zone_id check before VM_BUG_ON_PAGE check
  mm: hugetlb: fix type of hugetlb_treat_as_movable variable
  mm, hugetlb: remove unnecessary lower bound on sysctl handlers"?
  mm: memory: merge shared-writable dirtying branches in do_wp_page()
  mm: memory: remove ->vm_file check on shared writable vmas
  xtensa: drop _PAGE_FILE and pte_file()-related helpers
  x86: drop _PAGE_FILE and pte_file()-related helpers
  unicore32: drop pte_file()-related helpers
  um: drop _PAGE_FILE and pte_file()-related helpers
  tile: drop pte_file()-related helpers
  sparc: drop pte_file()-related helpers
  sh: drop _PAGE_FILE and pte_file()-related helpers
  score: drop _PAGE_FILE and pte_file()-related helpers
  s390: drop pte_file()-related helpers
  parisc: drop _PAGE_FILE and pte_file()-related helpers
  openrisc: drop _PAGE_FILE and pte_file()-related helpers
  nios2: drop _PAGE_FILE and pte_file()-related helpers
  ...
2015-02-10 16:45:56 -08:00
Kirill A. Shutemov 27ba0644ea rmap: drop support of non-linear mappings
We don't create non-linear mappings anymore.  Let's drop code which
handles them in rmap.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:31 -08:00
Kirill A. Shutemov d83a08db5b mm: drop vm_ops->remap_pages and generic_file_remap_pages() stub
Nobody uses it anymore.

[akpm@linux-foundation.org: fix filemap_xip.c]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:30 -08:00
Kirill A. Shutemov c8d78c1823 mm: replace remap_file_pages() syscall with emulation
remap_file_pages(2) was invented to be able efficiently map parts of
huge file into limited 32-bit virtual address space such as in database
workloads.

Nonlinear mappings are pain to support and it seems there's no
legitimate use-cases nowadays since 64-bit systems are widely available.

Let's drop it and get rid of all these special-cased code.

The patch replaces the syscall with emulation which creates new VMA on
each remap_file_pages(), unless they it can be merged with an adjacent
one.

I didn't find *any* real code that uses remap_file_pages(2) to test
emulation impact on.  I've checked Debian code search and source of all
packages in ALT Linux.  No real users: libc wrappers, mentions in
strace, gdb, valgrind and this kind of stuff.

There are few basic tests in LTP for the syscall.  They work just fine
with emulation.

To test performance impact, I've written small test case which
demonstrate pretty much worst case scenario: map 4G shmfs file, write to
begin of every page pgoff of the page, remap pages in reverse order,
read every page.

The test creates 1 million of VMAs if emulation is in use, so I had to
set vm.max_map_count to 1100000 to avoid -ENOMEM.

Before:		23.3 ( +-  4.31% ) seconds
After:		43.9 ( +-  0.85% ) seconds
Slowdown:	1.88x

I believe we can live with that.

Test case:

        #define _GNU_SOURCE
        #include <assert.h>
        #include <stdlib.h>
        #include <stdio.h>
        #include <sys/mman.h>

        #define MB	(1024UL * 1024)
        #define SIZE	(4096 * MB)

        int main(int argc, char **argv)
        {
                unsigned long *p;
                long i, pass;

                for (pass = 0; pass < 10; pass++) {
                        p = mmap(NULL, SIZE, PROT_READ|PROT_WRITE,
                                        MAP_SHARED | MAP_ANONYMOUS, -1, 0);
                        if (p == MAP_FAILED) {
                                perror("mmap");
                                return -1;
                        }

                        for (i = 0; i < SIZE / 4096; i++)
                                p[i * 4096 / sizeof(*p)] = i;

                        for (i = 0; i < SIZE / 4096; i++) {
                                if (remap_file_pages(p + i * 4096 / sizeof(*p), 4096,
                                                0, (SIZE - 4096 * (i + 1)) >> 12, 0)) {
                                        perror("remap_file_pages");
                                        return -1;
                                }
                        }

                        for (i = SIZE / 4096 - 1; i >= 0; i--)
                                assert(p[i * 4096 / sizeof(*p)] == SIZE / 4096 - i - 1);

                        munmap(p, SIZE);
                }

                return 0;
        }

[akpm@linux-foundation.org: fix spello]
[sasha.levin@oracle.com: initialize populate before usage]
[sasha.levin@oracle.com: grab file ref to prevent race while mmaping]
Signed-off-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Dave Jones <davej@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Armin Rigo <arigo@tunes.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-10 14:30:30 -08:00
Theodore Ts'o fe032c422c vfs: add find_inode_nowait() function
Add a new function find_inode_nowait() which is an even more general
version of ilookup5_nowait().  It is designed for callers which need
very fine grained control over when the function is allowed to block
or increment the inode's reference count.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-05 02:45:00 -05:00
Theodore Ts'o 0ae45f63d4 vfs: add support for a lazytime mount option
Add a new mount option which enables a new "lazytime" mode.  This mode
causes atime, mtime, and ctime updates to only be made to the
in-memory version of the inode.  The on-disk times will only get
updated when (a) if the inode needs to be updated for some non-time
related change, (b) if userspace calls fsync(), syncfs() or sync(), or
(c) just before an undeleted inode is evicted from memory.

This is OK according to POSIX because there are no guarantees after a
crash unless userspace explicitly requests via a fsync(2) call.

For workloads which feature a large number of random write to a
preallocated file, the lazytime mount option significantly reduces
writes to the inode table.  The repeated 4k writes to a single block
will result in undesirable stress on flash devices and SMR disk
drives.  Even on conventional HDD's, the repeated writes to the inode
table block will trigger Adjacent Track Interference (ATI) remediation
latencies, which very negatively impact long tail latencies --- which
is a very big deal for web serving tiers (for example).

Google-Bug-Id: 18297052

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-05 02:45:00 -05:00
Christoph Hellwig 11afe9f76e fs: add FL_LAYOUT lease type
This (ab-)uses the file locking code to allow filesystems to recall
outstanding pNFS layouts on a file.  This new lease type is similar but
not quite the same as FL_DELEG.  A FL_LAYOUT lease can always be granted,
an a per-filesystem lock (XFS iolock for the initial implementation)
ensures not FL_LAYOUT leases granted when we would need to recall them.

Also included are changes that allow multiple outstanding read
leases of different types on the same file as long as they have a
differnt owner.  This wasn't a problem until now as nfsd never set
FL_LEASE leases, and no one else used FL_DELEG leases, but given that
nfsd will also issues FL_LAYOUT leases we will have to handle it now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2015-02-02 18:09:38 +01:00
Al Viro 15d0f5ea34 Make super_blocks and sb_lock static
The only user outside of fs/super.c is gone now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-02-02 10:07:59 -07:00
Christoph Hellwig dbe4e192a2 fs: add vfs_iter_{read,write} helpers
Simple helpers that pass an arbitrary iov_iter to filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-29 00:13:13 -05:00
Paul Moore 55422d0bd2 audit: replace getname()/putname() hacks with reference counters
In order to ensure that filenames are not released before the audit
subsystem is done with the strings there are a number of hacks built
into the fs and audit subsystems around getname() and putname().  To
say these hacks are "ugly" would be kind.

This patch removes the filename hackery in favor of a more
conventional reference count based approach.  The diffstat below tells
most of the story; lots of audit/fs specific code is replaced with a
traditional reference count based approach that is easily understood,
even by those not familiar with the audit and/or fs subsystems.

CC: viro@zeniv.linux.org.uk
CC: linux-fsdevel@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-01-23 00:23:58 -05:00
Jeff Layton 8116bf4cb6 locks: update comments that refer to inode->i_flock
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2015-01-21 20:44:01 -05:00
Christoph Hellwig b83ae6d421 fs: remove mapping->backing_dev_info
Now that we never use the backing_dev_info pointer in struct address_space
we can simply remove it and save 4 to 8 bytes in every inode.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Reviewed-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:03:05 -07:00
Christoph Hellwig b4caecd480 fs: introduce f_op->mmap_capabilities for nommu mmap support
Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-01-20 14:02:58 -07:00
Jeff Layton 9bd0f45b70 locks: keep a count of locks on the flctx lists
This makes things a bit more efficient in the cifs and ceph lock
pushing code.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:50 -05:00
Jeff Layton 7448cc37b1 locks: clean up the lm_change prototype
Now that we use standard list_heads for tracking leases, we can have
lm_change take a pointer to the lease to be modified instead of a
double pointer.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:50 -05:00
Jeff Layton 6109c85037 locks: add a dedicated spinlock to protect i_flctx lists
We can now add a dedicated spinlock without expanding struct inode.
Change to using that to protect the various i_flctx lists.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:49 -05:00
Jeff Layton a7231a9746 locks: remove i_flock field from struct inode
Nothing uses it anymore. Also add a forward declaration for struct
file_lock to silence some compiler warnings that the removal triggers.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:49 -05:00
Jeff Layton 8634b51f6c locks: convert lease handling to file_lock_context
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:17 -05:00
Jeff Layton bd61e0a9c8 locks: convert posix locks to file_lock_context
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 16:08:16 -05:00
Jeff Layton 4a075e39c8 locks: add a new struct file_locking_context pointer to struct inode
The current scheme of using the i_flock list is really difficult to
manage. There is also a legitimate desire for a per-inode spinlock to
manage these lists that isn't the i_lock.

Start conversion to a new scheme to eventually replace the old i_flock
list with a new "file_lock_context" object.

We start by adding a new i_flctx to struct inode. For now, it lives in
parallel with i_flock list, but will eventually replace it. The idea is
to allocate a structure to sit in that pointer and act as a locus for
all things file locking.

We allocate a file_lock_context for an inode when the first lock is
added to it, and it's only freed when the inode is freed. We use the
i_lock to protect the assignment, but afterward it should mostly be
accessed locklessly.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 15:05:54 -05:00
Jeff Layton 6dee60f69d locks: add new struct list_head to struct file_lock
...that we can use to queue file_locks to per-ctx list_heads. Go ahead
and convert locks_delete_lock and locks_dispose_list to use it instead
of the fl_block list.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Christoph Hellwig <hch@lst.de>
2015-01-16 15:05:54 -05:00
David Drysdale 75069f2b5b vfs: renumber FMODE_NONOTIFY and add to uniqueness check
Fix clashing values for O_PATH and FMODE_NONOTIFY on sparc.  The
clashing O_PATH value was added in commit 5229645bdc ("vfs: add
nonconflicting values for O_PATH") but this can't be changed as it is
user-visible.

FMODE_NONOTIFY is only used internally in the kernel, but it is in the
same numbering space as the other O_* flags, as indicated by the comment
at the top of include/uapi/asm-generic/fcntl.h (and its use in
fs/notify/fanotify/fanotify_user.c).  So renumber it to avoid the clash.

All of this has happened before (commit 12ed2e36c98a: "fanotify:
FMODE_NONOTIFY and __O_SYNC in sparc conflict"), and all of this will
happen again -- so update the uniqueness check in fcntl_init() to
include __FMODE_NONOTIFY.

Signed-off-by: David Drysdale <drysdale@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Jan Kara <jack@suse.cz>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-08 15:10:52 -08:00
Linus Torvalds 603ba7e41b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns
2014-12-16 15:53:03 -08:00
Linus Torvalds 0b233b7c79 Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "A comparatively quieter cycle for nfsd this time, but still with two
  larger changes:

   - RPC server scalability improvements from Jeff Layton (using RCU
     instead of a spinlock to find idle threads).

   - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna
     Schumaker, enabling fallocate on new clients"

* 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd4: fix xdr4 count of server in fs_location4
  nfsd4: fix xdr4 inclusion of escaped char
  sunrpc/cache: convert to use string_escape_str()
  sunrpc: only call test_bit once in svc_xprt_received
  fs: nfsd: Fix signedness bug in compare_blob
  sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt
  sunrpc: convert to lockless lookup of queued server threads
  sunrpc: fix potential races in pool_stats collection
  sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it
  sunrpc: require svc_create callers to pass in meaningful shutdown routine
  sunrpc: have svc_wake_up only deal with pool 0
  sunrpc: convert sp_task_pending flag to use atomic bitops
  sunrpc: move rq_cachetype field to better optimize space
  sunrpc: move rq_splice_ok flag into rq_flags
  sunrpc: move rq_dropme flag into rq_flags
  sunrpc: move rq_usedeferral flag to rq_flags
  sunrpc: move rq_local field to rq_flags
  sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it
  nfsd: minor off by one checks in __write_versions()
  sunrpc: release svc_pool_map reference when serv allocation fails
  ...
2014-12-16 15:25:31 -08:00
Linus Torvalds 67e2c38838 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security layer updates from James Morris:
 "In terms of changes, there's general maintenance to the Smack,
  SELinux, and integrity code.

  The IMA code adds a new kconfig option, IMA_APPRAISE_SIGNED_INIT,
  which allows IMA appraisal to require signatures.  Support for reading
  keys from rootfs before init is call is also added"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: Remove security_ops extern
  security: smack: fix out-of-bounds access in smk_parse_smack()
  VFS: refactor vfs_read()
  ima: require signature based appraisal
  integrity: provide a hook to load keys when rootfs is ready
  ima: load x509 certificate from the kernel
  integrity: provide a function to load x509 certificate from the kernel
  integrity: define a new function integrity_read_file()
  Security: smack: replace kzalloc with kmem_cache for inode_smack
  Smack: Lock mode for the floor and hat labels
  ima: added support for new kernel cmdline parameter ima_template_fmt
  ima: allocate field pointers array on demand in template_desc_init_fields()
  ima: don't allocate a copy of template_fmt in template_desc_init_fields()
  ima: display template format in meas. list if template name length is zero
  ima: added error messages to template-related functions
  ima: use atomic bit operations to protect policy update interface
  ima: ignore empty and with whitespaces policy lines
  ima: no need to allocate entry for comment
  ima: report policy load status
  ima: use path names cache
  ...
2014-12-14 20:36:37 -08:00
Linus Torvalds 7d22286ff7 Merge git://git.kvack.org/~bcrl/aio-next
Pull aio updates from Benjamin LaHaise.

* git://git.kvack.org/~bcrl/aio-next:
  aio: Skip timer for io_getevents if timeout=0
  aio: Make it possible to remap aio ring
2014-12-14 13:36:57 -08:00
Pavel Emelyanov e4a0d3e720 aio: Make it possible to remap aio ring
There are actually two issues this patch addresses. Let me start with
the one I tried to solve in the beginning.

So, in the checkpoint-restore project (criu) we try to dump tasks'
state and restore one back exactly as it was. One of the tasks' state
bits is rings set up with io_setup() call. There's (almost) no problems
in dumping them, there's a problem restoring them -- if I dump a task
with aio ring originally mapped at address A, I want to restore one
back at exactly the same address A. Unfortunately, the io_setup() does
not allow for that -- it mmaps the ring at whatever place mm finds
appropriate (it calls do_mmap_pgoff() with zero address and without
the MAP_FIXED flag).

To make restore possible I'm going to mremap() the freshly created ring
into the address A (under which it was seen before dump). The problem is
that the ring's virtual address is passed back to the user-space as the
context ID and this ID is then used as search key by all the other io_foo()
calls. Reworking this ID to be just some integer doesn't seem to work, as
this value is already used by libaio as a pointer using which this library
accesses memory for aio meta-data.

So, to make restore work we need to make sure that

a) ring is mapped at desired virtual address
b) kioctx->user_id matches this value

Having said that, the patch makes mremap() on aio region update the
kioctx's user_id and mmap_base values.

Here appears the 2nd issue I mentioned in the beginning of this mail.
If (regardless of the C/R dances I do) someone creates an io context
with io_setup(), then mremap()-s the ring and then destroys the context,
the kill_ioctx() routine will call munmap() on wrong (old) address.
This will result in a) aio ring remaining in memory and b) some other
vma get unexpectedly unmapped.

What do you think?

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
2014-12-13 17:49:50 -05:00
David Drysdale 51f39a1f0c syscalls: implement execveat() system call
This patchset adds execveat(2) for x86, and is derived from Meredydd
Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).

The primary aim of adding an execveat syscall is to allow an
implementation of fexecve(3) that does not rely on the /proc filesystem,
at least for executables (rather than scripts).  The current glibc version
of fexecve(3) is implemented via /proc, which causes problems in sandboxed
or otherwise restricted environments.

Given the desire for a /proc-free fexecve() implementation, HPA suggested
(https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be
an appropriate generalization.

Also, having a new syscall means that it can take a flags argument without
back-compatibility concerns.  The current implementation just defines the
AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be
added in future -- for example, flags for new namespaces (as suggested at
https://lkml.org/lkml/2006/7/11/474).

Related history:
 - https://lkml.org/lkml/2006/12/27/123 is an example of someone
   realizing that fexecve() is likely to fail in a chroot environment.
 - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
   documenting the /proc requirement of fexecve(3) in its manpage, to
   "prevent other people from wasting their time".
 - https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
   problem where a process that did setuid() could not fexecve()
   because it no longer had access to /proc/self/fd; this has since
   been fixed.

This patch (of 4):

Add a new execveat(2) system call.  execveat() is to execve() as openat()
is to open(): it takes a file descriptor that refers to a directory, and
resolves the filename relative to that.

In addition, if the filename is empty and AT_EMPTY_PATH is specified,
execveat() executes the file to which the file descriptor refers.  This
replicates the functionality of fexecve(), which is a system call in other
UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/<fd>" (and
so relies on /proc being mounted).

The filename fed to the executed program as argv[0] (or the name of the
script fed to a script interpreter) will be of the form "/dev/fd/<fd>"
(for an empty filename) or "/dev/fd/<fd>/<filename>", effectively
reflecting how the executable was found.  This does however mean that
execution of a script in a /proc-less environment won't work; also, script
execution via an O_CLOEXEC file descriptor fails (as the file will not be
accessible after exec).

Based on patches by Meredydd Luff.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Davidlohr Bueso 3dec0ba0be mm/rmap: share the i_mmap_rwsem
Similarly to the anon memory counterpart, we can share the mapping's lock
ownership as the interval tree is not modified when doing doing the walk,
only the file page.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Davidlohr Bueso c8c06efa8b mm: convert i_mmap_mutex to rwsem
The i_mmap_mutex is a close cousin of the anon vma lock, both protecting
similar data, one for file backed pages and the other for anon memory.  To
this end, this lock can also be a rwsem.  In addition, there are some
important opportunities to share the lock when there are no tree
modifications.

This conversion is straightforward.  For now, all users take the write
lock.

[sfr@canb.auug.org.au: update fremap.c]
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Davidlohr Bueso 8b28f621be mm,fs: introduce helpers around the i_mmap_mutex
This series is a continuation of the conversion of the i_mmap_mutex to
rwsem, following what we have for the anon memory counterpart.  With
Hugh's feedback from the first iteration.

Ultimately, the most obvious paths that require exclusive ownership of the
lock is when we modify the VMA interval tree, via
vma_interval_tree_insert() and vma_interval_tree_remove() families.  Cases
such as unmapping, where the ptes content is changed but the tree remains
untouched should make it safe to share the i_mmap_rwsem.

As such, the code of course is straightforward, however the devil is very
much in the details.  While its been tested on a number of workloads
without anything exploding, I would not be surprised if there are some
less documented/known assumptions about the lock that could suffer from
these changes.  Or maybe I'm just missing something, but either way I
believe its at the point where it could use more eyes and hopefully some
time in linux-next.

Because the lock type conversion is the heart of this patchset,
its worth noting a few comparisons between mutex vs rwsem (xadd):

  (i) Same size, no extra footprint.

  (ii) Both have CONFIG_XXX_SPIN_ON_OWNER capabilities for
       exclusive lock ownership.

  (iii) Both can be slightly unfair wrt exclusive ownership, with
        writer lock stealing properties, not necessarily respecting
        FIFO order for granting the lock when contended.

  (iv) Mutexes can be slightly faster than rwsems when
       the lock is non-contended.

  (v) Both suck at performance for debug (slowpaths), which
      shouldn't matter anyway.

Sharing the lock is obviously beneficial, and sem writer ownership is
close enough to mutexes.  The biggest winner of these changes is
migration.

As for concrete numbers, the following performance results are for a
4-socket 60-core IvyBridge-EX with 130Gb of RAM.

Both alltests and disk (xfs+ramdisk) workloads of aim7 suite do quite well
with this set, with a steady ~60% throughput (jpm) increase for alltests
and up to ~30% for disk for high amounts of concurrency.  Lower counts of
workload users (< 100) does not show much difference at all, so at least
no regressions.

                    3.18-rc1            3.18-rc1-i_mmap_rwsem
alltests-100     17918.72 (  0.00%)    28417.97 ( 58.59%)
alltests-200     16529.39 (  0.00%)    26807.92 ( 62.18%)
alltests-300     16591.17 (  0.00%)    26878.08 ( 62.00%)
alltests-400     16490.37 (  0.00%)    26664.63 ( 61.70%)
alltests-500     16593.17 (  0.00%)    26433.72 ( 59.30%)
alltests-600     16508.56 (  0.00%)    26409.20 ( 59.97%)
alltests-700     16508.19 (  0.00%)    26298.58 ( 59.31%)
alltests-800     16437.58 (  0.00%)    26433.02 ( 60.81%)
alltests-900     16418.35 (  0.00%)    26241.61 ( 59.83%)
alltests-1000    16369.00 (  0.00%)    26195.76 ( 60.03%)
alltests-1100    16330.11 (  0.00%)    26133.46 ( 60.03%)
alltests-1200    16341.30 (  0.00%)    26084.03 ( 59.62%)
alltests-1300    16304.75 (  0.00%)    26024.74 ( 59.61%)
alltests-1400    16231.08 (  0.00%)    25952.35 ( 59.89%)
alltests-1500    16168.06 (  0.00%)    25850.58 ( 59.89%)
alltests-1600    16142.56 (  0.00%)    25767.42 ( 59.62%)
alltests-1700    16118.91 (  0.00%)    25689.58 ( 59.38%)
alltests-1800    16068.06 (  0.00%)    25599.71 ( 59.32%)
alltests-1900    16046.94 (  0.00%)    25525.92 ( 59.07%)
alltests-2000    16007.26 (  0.00%)    25513.07 ( 59.38%)

disk-100          7582.14 (  0.00%)     7257.48 ( -4.28%)
disk-200          6962.44 (  0.00%)     7109.15 (  2.11%)
disk-300          6435.93 (  0.00%)     6904.75 (  7.28%)
disk-400          6370.84 (  0.00%)     6861.26 (  7.70%)
disk-500          6353.42 (  0.00%)     6846.71 (  7.76%)
disk-600          6368.82 (  0.00%)     6806.75 (  6.88%)
disk-700          6331.37 (  0.00%)     6796.01 (  7.34%)
disk-800          6324.22 (  0.00%)     6788.00 (  7.33%)
disk-900          6253.52 (  0.00%)     6750.43 (  7.95%)
disk-1000         6242.53 (  0.00%)     6855.11 (  9.81%)
disk-1100         6234.75 (  0.00%)     6858.47 ( 10.00%)
disk-1200         6312.76 (  0.00%)     6845.13 (  8.43%)
disk-1300         6309.95 (  0.00%)     6834.51 (  8.31%)
disk-1400         6171.76 (  0.00%)     6787.09 (  9.97%)
disk-1500         6139.81 (  0.00%)     6761.09 ( 10.12%)
disk-1600         4807.12 (  0.00%)     6725.33 ( 39.90%)
disk-1700         4669.50 (  0.00%)     5985.38 ( 28.18%)
disk-1800         4663.51 (  0.00%)     5972.99 ( 28.08%)
disk-1900         4674.31 (  0.00%)     5949.94 ( 27.29%)
disk-2000         4668.36 (  0.00%)     5834.93 ( 24.99%)

In addition, a 67.5% increase in successfully migrated NUMA pages, thus
improving node locality.

The patch layout is simple but designed for bisection (in case reversion
is needed if the changes break upstream) and easier review:

o Patches 1-4 convert the i_mmap lock from mutex to rwsem.
o Patches 5-10 share the lock in specific paths, each patch
  details the rationale behind why it should be safe.

This patchset has been tested with: postgres 9.4 (with brand new hugetlb
support), hugetlbfs test suite (all tests pass, in fact more tests pass
with these changes than with an upstream kernel), ltp, aim7 benchmarks,
memcached and iozone with the -B option for mmap'ing.  *Untested* paths
are nommu, memory-failure, uprobes and xip.

This patch (of 8):

Various parts of the kernel acquire and release this mutex, so add
i_mmap_lock_write() and immap_unlock_write() helper functions that will
encapsulate this logic.  The next patch will make use of these.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:45 -08:00
Al Viro bd9b51e79c make default ->i_fop have ->open() fail with ENXIO
As it is, default ->i_fop has NULL ->open() (along with all other methods).
The only case where it matters is reopening (via procfs symlink) a file that
didn't get its ->f_op from ->i_fop - anything else will have ->i_fop assigned
to something sane (default would fail on read/write/ioctl/etc.).

	Unfortunately, such case exists - alloc_file() users, especially
anon_get_file() ones.  There we have tons of opened files of very different
kinds sharing the same inode.  As the result, attempt to reopen those via
procfs succeeds and you get a descriptor you can't do anything with.

	Moreover, in case of sockets we set ->i_fop that will only be used
on such reopen attempts - and put a failing ->open() into it to make sure
those do not succeed.

	It would be simpler to put such ->open() into default ->i_fop and leave
it unchanged both for anon inode (as we do anyway) and for socket ones.  Result:
	* everything going through do_dentry_open() works as it used to
	* sock_no_open() kludge is gone
	* attempts to reopen anon-inode files fail as they really ought to
	* ditto for aio_private_file()
	* ditto for perfmon - this one actually tried to imitate sock_no_open()
trick, but failed to set ->i_fop, so in the current tree reopens succeed and
yield completely useless descriptor.  Intent clearly had been to fail with
-ENXIO on such reopens; now it actually does.
	* everything else that used alloc_file() keeps working - it has ->i_fop
set for its inodes anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-10 21:32:15 -05:00
Linus Torvalds cbfe0de303 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS changes from Al Viro:
 "First pile out of several (there _definitely_ will be more).  Stuff in
  this one:

   - unification of d_splice_alias()/d_materialize_unique()

   - iov_iter rewrite

   - killing a bunch of ->f_path.dentry users (and f_dentry macro).

     Getting that completed will make life much simpler for
     unionmount/overlayfs, since then we'll be able to limit the places
     sensitive to file _dentry_ to reasonably few.  Which allows to have
     file_inode(file) pointing to inode in a covered layer, with dentry
     pointing to (negative) dentry in union one.

     Still not complete, but much closer now.

   - crapectomy in lustre (dead code removal, mostly)

   - "let's make seq_printf return nothing" preparations

   - assorted cleanups and fixes

  There _definitely_ will be more piles"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  copy_from_iter_nocache()
  new helper: iov_iter_kvec()
  csum_and_copy_..._iter()
  iov_iter.c: handle ITER_KVEC directly
  iov_iter.c: convert copy_to_iter() to iterate_and_advance
  iov_iter.c: convert copy_from_iter() to iterate_and_advance
  iov_iter.c: get rid of bvec_copy_page_{to,from}_iter()
  iov_iter.c: convert iov_iter_zero() to iterate_and_advance
  iov_iter.c: convert iov_iter_get_pages_alloc() to iterate_all_kinds
  iov_iter.c: convert iov_iter_get_pages() to iterate_all_kinds
  iov_iter.c: convert iov_iter_npages() to iterate_all_kinds
  iov_iter.c: iterate_and_advance
  iov_iter.c: macros for iterating over iov_iter
  kill f_dentry macro
  dcache: fix kmemcheck warning in switch_names
  new helper: audit_file()
  nfsd_vfs_write(): use file_inode()
  ncpfs: use file_inode()
  kill f_dentry uses
  lockd: get rid of ->f_path.dentry->d_sb
  ...
2014-12-10 16:10:49 -08:00
Linus Torvalds 1366f5d312 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull quota updates from Jan Kara:
 "Quota improvements and some minor cleanups.

  The main portion in the pull request are changes which move i_dquot
  array from struct inode into fs-private part of an inode which saves
  memory for filesystems which don't use VFS quotas"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  udf: One function call less in udf_fill_super() after error detection
  udf: Deletion of unnecessary checks before the function call "iput"
  jbd: Deletion of an unnecessary check before the function call "iput"
  vfs: Remove i_dquot field from inode
  jfs: Convert to private i_dquot field
  reiserfs: Convert to private i_dquot field
  ocfs2: Convert to private i_dquot field
  ext4: Convert to private i_dquot field
  ext3: Convert to private i_dquot field
  ext2: Convert to private i_dquot field
  quota: Use function to provide i_dquot pointers
  xfs: Set allowed quota types
  gfs2: Set allowed quota types
  quota: Allow each filesystem to specify which quota types it supports
  quota: Remove const from function declarations
  quota: Add log level to printk
2014-12-10 15:43:30 -08:00
Al Viro 8ce74dd605 Merge tag 'trace-seq-file-cleanup' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into for-next
Pull the beginning of seq_file cleanup from Steven:
  "I'm looking to clean up the seq_file code and to eventually merge the
  trace_seq code with seq_file as well, since they basically do the same thing.

  Part of this process is to remove the return code of seq_printf() and friends
  as they are rather inconsistent. It is better to use the new function
  seq_has_overflowed() if you want to stop processing when the buffer
  is full. Note, if the buffer is full, the seq_file code will throw away
  the contents, allocate a bigger buffer, and then call your code again
  to fill in the data. The only thing that breaking out of the function
  early does is to save a little time which is probably never noticed.

  I started with patches from Joe Perches and modified them as well.
  There's many more places that need to be updated before we can convert
  seq_printf() and friends to return void. But this patch set introduces
  the seq_has_overflowed() and does some initial updates."
2014-11-19 13:02:53 -05:00
Al Viro 78d28e651f kill f_dentry macro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-19 13:02:11 -05:00
J. Bruce Fields 56429e9b3b merge nfs bugfixes into nfsd for-3.19 branch
In addition to nfsd bugfixes, there are some fixes in -rc5 for client
bugs that can interfere with my testing.
2014-11-19 12:06:30 -05:00
James Morris a6aacbde40 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity into next 2014-11-19 21:36:07 +11:00
Dmitry Kasatkin 6fb5032ebb VFS: refactor vfs_read()
integrity_kernel_read() duplicates the file read operations code
in vfs_read(). This patch refactors vfs_read() code creating a
helper function __vfs_read(). It is used by both vfs_read() and
integrity_kernel_read().

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
2014-11-17 23:14:22 -05:00
Benjamin Marzinski 48b6bca6b7 fs: add freeze_super/thaw_super fs hooks
Currently, freezing a filesystem involves calling freeze_super, which locks
sb->s_umount and then calls the fs-specific freeze_fs hook. This makes it
hard for gfs2 (and potentially other cluster filesystems) to use the vfs
freezing code to do freezes on all the cluster nodes.

In order to communicate that a freeze has been requested, and to make sure
that only one node is trying to freeze at a time, gfs2 uses a glock
(sd_freeze_gl). The problem is that there is no hook for gfs2 to acquire
this lock before calling freeze_super. This means that two nodes can
attempt to freeze the filesystem by both calling freeze_super, acquiring
the sb->s_umount lock, and then attempting to grab the cluster glock
sd_freeze_gl. Only one will succeed, and the other will be stuck in
freeze_super, making it impossible to finish freezing the node.

To solve this problem, this patch adds the freeze_super and thaw_super
hooks.  If a filesystem implements these hooks, they are called instead of
the vfs freeze_super and thaw_super functions. This means that every
filesystem that implements these hooks must call the vfs freeze_super and
thaw_super functions itself within the hook function to make use of the vfs
freezing code.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2014-11-17 10:35:17 +00:00
Jan Kara 75cbe701a4 vfs: Remove i_dquot field from inode
All filesystems using VFS quotas are now converted to use their private
i_dquot fields. Remove the i_dquot field from generic inode structure.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2014-11-10 10:06:18 +01:00
Jan Kara 2d0fa46791 quota: Use function to provide i_dquot pointers
i_dquot array is used by relatively few filesystems (ext?, ocfs2, jfs,
reiserfs) so it is beneficial to move this array to fs-private part of
the inode. We cannot just pass quota pointers from filesystems to quota
functions because during quotaon and quotaoff we have to traverse list
of all inodes and manipulate i_dquot pointers for each inode. So we
provide a function which generic quota code can use to get pointer to
the i_dquot array from the filesystem.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2014-11-10 10:06:09 +01:00
Jan Kara 2c5f648aa2 quota: Allow each filesystem to specify which quota types it supports
Currently all filesystems supporting VFS quota support user and group
quotas. With introduction of project quotas this is going to change so
make sure filesystem isn't called for quota type it doesn't support by
introduction of a bitmask determining which quota types each filesystem
supports.

Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2014-11-10 10:06:08 +01:00
Anna Schumaker 72c72bdf7b VFS: Rename do_fallocate() to vfs_fallocate()
This function needs to be exported so it can be used by the NFSD module
when responding to the new ALLOCATE and DEALLOCATE operations in NFS
v4.2.  Christoph Hellwig suggested renaming the function to stay
consistent with how other vfs functions are named.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-07 16:17:44 -05:00
Joe Perches a3816ab0e8 fs: Convert show_fdinfo functions to void
seq_printf functions shouldn't really check the return value.
Checking seq_has_overflowed() occasionally is used instead.

Update vfs documentation.

Link: http://lkml.kernel.org/p/e37e6e7b76acbdcc3bb4ab2a57c8f8ca1ae11b9a.1412031505.git.joe@perches.com

Cc: David S. Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Joe Perches <joe@perches.com>
[ did a few clean ups ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-05 14:13:23 -05:00
Al Viro a7400222e3 new helper: is_root_inode()
replace open-coded instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 17:48:54 -04:00
Miklos Szeredi ac7576f4b1 vfs: make first argument of dir_context.actor typed
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 17:48:54 -04:00
David Jeffery b2de525f09 Return short read or 0 at end of a raw device, not EIO
Author: David Jeffery <djeffery@redhat.com>
Changes to the basic direct I/O code have broken the raw driver when reading
to the end of a raw device.  Instead of returning a short read for a read that
extends partially beyond the device's end or 0 when at the end of the device,
these reads now return EIO.

The raw driver needs the same end of device handling as was added for normal
block devices.  Using blkdev_read_iter, which has the needed size checks,
prevents the EIO conditions at the end of the device.

Signed-off-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 06:33:26 -04:00
Miklos Szeredi d1b72cc6d8 overlayfs: fix lockdep misannotation
In an overlay directory that shadows an empty lower directory, say
/mnt/a/empty102, do:

 	touch /mnt/a/empty102/x
 	unlink /mnt/a/empty102/x
 	rmdir /mnt/a/empty102

It's actually harmless, but needs another level of nesting between
I_MUTEX_CHILD and I_MUTEX_NORMAL.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28 18:32:47 -04:00
Miklos Szeredi 69c433ed2e fs: limit filesystem stacking depth
Add a simple read-only counter to super_block that indicates how deep this
is in the stack of filesystems.  Previously ecryptfs was the only stackable
filesystem and it explicitly disallowed multiple layers of itself.

Overlayfs, however, can be stacked recursively and also may be stacked
on top of ecryptfs or vice versa.

To limit the kernel stack usage we must limit the depth of the
filesystem stack.  Initially the limit is set to 2.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:39 +02:00
Miklos Szeredi 787fb6bc96 vfs: add whiteout support
Whiteout isn't actually a new file type, but is represented as a char
device (Linus's idea) with 0/0 device number.

This has several advantages compared to introducing a new whiteout file
type:

 - no userspace API changes (e.g. trivial to make backups of upper layer
   filesystem, without losing whiteouts)

 - no fs image format changes (you can boot an old kernel/fsck without
   whiteout support and things won't break)

 - implementation is trivial

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:36 +02:00
Miklos Szeredi cbdf35bcb8 vfs: export check_sticky()
It's already duplicated in btrfs and about to be used in overlayfs too.

Move the sticky bit check to an inline helper and call the out-of-line
helper only in the unlikly case of the sticky bit being set.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:36 +02:00
Miklos Szeredi bd5d08569c vfs: export __inode_permission() to modules
We need to be able to check inode permissions (but not filesystem implied
permissions) for stackable filesystems.  Expose this interface for overlayfs.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Miklos Szeredi 1c118596a7 vfs: export do_splice_direct() to modules
Export do_splice_direct() to modules.  Needed by overlay filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Miklos Szeredi 4aa7c6346b vfs: add i_op->dentry_open()
Add a new inode operation i_op->dentry_open().  This is for stacked filesystems
that want to return a struct file from a different filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:35 +02:00
Linus Torvalds d3dc366bba Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block
Pull core block layer changes from Jens Axboe:
 "This is the core block IO pull request for 3.18.  Apart from the new
  and improved flush machinery for blk-mq, this is all mostly bug fixes
  and cleanups.

   - blk-mq timeout updates and fixes from Christoph.

   - Removal of REQ_END, also from Christoph.  We pass it through the
     ->queue_rq() hook for blk-mq instead, freeing up one of the request
     bits.  The space was overly tight on 32-bit, so Martin also killed
     REQ_KERNEL since it's no longer used.

   - blk integrity updates and fixes from Martin and Gu Zheng.

   - Update to the flush machinery for blk-mq from Ming Lei.  Now we
     have a per hardware context flush request, which both cleans up the
     code should scale better for flush intensive workloads on blk-mq.

   - Improve the error printing, from Rob Elliott.

   - Backing device improvements and cleanups from Tejun.

   - Fixup of a misplaced rq_complete() tracepoint from Hannes.

   - Make blk_get_request() return error pointers, fixing up issues
     where we NULL deref when a device goes bad or missing.  From Joe
     Lawrence.

   - Prep work for drastically reducing the memory consumption of dm
     devices from Junichi Nomura.  This allows creating clone bio sets
     without preallocating a lot of memory.

   - Fix a blk-mq hang on certain combinations of queue depths and
     hardware queues from me.

   - Limit memory consumption for blk-mq devices for crash dump
     scenarios and drivers that use crazy high depths (certain SCSI
     shared tag setups).  We now just use a single queue and limited
     depth for that"

* 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits)
  block: Remove REQ_KERNEL
  blk-mq: allocate cpumask on the home node
  bio-integrity: remove the needless fail handle of bip_slab creating
  block: include func name in __get_request prints
  block: make blk_update_request print prefix match ratelimited prefix
  blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
  block: fix alignment_offset math that assumes io_min is a power-of-2
  blk-mq: Make bt_clear_tag() easier to read
  blk-mq: fix potential hang if rolling wakeup depth is too high
  block: add bioset_create_nobvec()
  block: use bio_clone_fast() in blk_rq_prep_clone()
  block: misplaced rq_complete tracepoint
  sd: Honor block layer integrity handling flags
  block: Replace strnicmp with strncasecmp
  block: Add T10 Protection Information functions
  block: Don't merge requests if integrity flags differ
  block: Integrity checksum flag
  block: Relocate bio integrity flags
  block: Add a disk flag to block integrity profile
  block: Add prefix to block integrity profile flags
  ...
2014-10-18 11:53:51 -07:00
Martin K. Petersen e19a8a0ad2 block: Remove REQ_KERNEL
REQ_KERNEL is no longer used. Remove it and drop the redundant uio
argument to nfs_file_direct_{read,write}.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-14 09:00:44 -06:00
Linus Torvalds 77c688ac87 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The big thing in this pile is Eric's unmount-on-rmdir series; we
  finally have everything we need for that.  The final piece of prereqs
  is delayed mntput() - now filesystem shutdown always happens on
  shallow stack.

  Other than that, we have several new primitives for iov_iter (Matt
  Wilcox, culled from his XIP-related series) pushing the conversion to
  ->read_iter()/ ->write_iter() a bit more, a bunch of fs/dcache.c
  cleanups and fixes (including the external name refcounting, which
  gives consistent behaviour of d_move() wrt procfs symlinks for long
  and short names alike) and assorted cleanups and fixes all over the
  place.

  This is just the first pile; there's a lot of stuff from various
  people that ought to go in this window.  Starting with
  unionmount/overlayfs mess...  ;-/"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (60 commits)
  fs/file_table.c: Update alloc_file() comment
  vfs: Deduplicate code shared by xattr system calls operating on paths
  reiserfs: remove pointless forward declaration of struct nameidata
  don't need that forward declaration of struct nameidata in dcache.h anymore
  take dname_external() into fs/dcache.c
  let path_init() failures treated the same way as subsequent link_path_walk()
  fix misuses of f_count() in ppp and netlink
  ncpfs: use list_for_each_entry() for d_subdirs walk
  vfs: move getname() from callers to do_mount()
  gfs2_atomic_open(): skip lookups on hashed dentry
  [infiniband] remove pointless assignments
  gadgetfs: saner API for gadgetfs_create_file()
  f_fs: saner API for ffs_sb_create_file()
  jfs: don't hash direct inode
  [s390] remove pointless assignment of ->f_op in vmlogrdr ->open()
  ecryptfs: ->f_op is never NULL
  android: ->f_op is never NULL
  nouveau: __iomem misannotations
  missing annotation in fs/file.c
  fs: namespace: suppress 'may be used uninitialized' warnings
  ...
2014-10-13 11:28:42 +02:00
Seunghun Lee 5e6123f347 vfs: move getname() from callers to do_mount()
It would make more sense to pass char __user * instead of
char * in callers of do_mount() and do getname() inside do_mount().

Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Seunghun Lee <waydi1@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:16 -04:00
Al Viro 1fa97e8b1f constify file_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-09 02:39:00 -04:00
Jeff Layton 1b2b32dcdb locks: fix fcntl_setlease/getlease return when !CONFIG_FILE_LOCKING
Currently they both just return 0. Fix them to return more appropriate
values instead.

For better or worse, most places in the kernel return -EINVAL when
leases aren't available. -ENOLCK would probably have been better, but
let's follow suit here in the case of F_SETLEASE.

In the F_GETLEASE case, just return F_UNLCK since we know that no
lease will have been set.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:13 -04:00
Jeff Layton 7ca76311fe locks: set fl_owner for leases to filp instead of current->files
Like flock locks, leases are owned by the file description. Now that the
i_have_this_lease check in __break_lease is gone, we don't actually use
the fl_owner for leases for anything. So, it's now safe to set this more
appropriately to the same value as the fl_file.

While we're at it, fix up the comments over the fl_owner_t definition
since they're rather out of date.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-10-07 14:06:13 -04:00
Jeff Layton 4d01b7f5e7 locks: give lm_break a return value
Christoph suggests:

   "Add a return value to lm_break so that the lock manager can tell the
    core code "you can delete this lease right now".  That gets rid of
    the games with the timeout which require all kinds of race avoidance
    code in the users."

Do that here and have the nfsd lease break routine use it when it detects
that there was a race between setting up the lease and it being broken.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:13 -04:00
Jeff Layton c45198eda2 locks: move freeing of leases outside of i_lock
There was only one place where we still could free a file_lock while
holding the i_lock -- lease_modify. Add a new list_head argument to the
lm_change operation, pass in a private list when calling it, and fix
those callers to dispose of the list once the lock has been dropped.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:13 -04:00
Jeff Layton 1c7dd2ff43 locks: define a lm_setup handler for leases
...and move the fasync setup into it for fcntl lease calls. At the same
time, change the semantics of how the file_lock double-pointer is
handled. Up until now, on a successful lease return you got a pointer to
the lock on the list. This is bad, since that pointer can no longer be
relied on as valid once the inode->i_lock has been released.

Change the code to instead just zero out the pointer if the lease we
passed in ended up being used. Then the callers can just check to see
if it's NULL after the call and free it if it isn't.

The priv argument has the same semantics. The lm_setup function can
zero the pointer out to signal to the caller that it should not be
freed after the function returns.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:12 -04:00
Jeff Layton e6f5c78930 locks: plumb a "priv" pointer into the setlease routines
In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-10-07 14:06:12 -04:00
Jeff Layton e0b93eddfe security: make security_file_set_fowner, f_setown and __f_setown void return
security_file_set_fowner always returns 0, so make it f_setown and
__f_setown void return functions and fix up the error handling in the
callers.

Cc: linux-security-module@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-09-09 16:01:36 -04:00
Jeff Layton 1c994a0909 locks: consolidate "nolease" routines
GFS2 and NFS have setlease routines that always just return -EINVAL.
Turn that into a generic routine that can live in fs/libfs.c.

Cc: <linux-nfs@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: <cluster-devel@redhat.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2014-09-09 16:01:36 -04:00
Jeff Layton 699688a416 locks: remove lock_may_read and lock_may_write
There are no callers of these functions.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-09 16:01:09 -04:00
Kinglong Mee 5c97d7b147 locks: New ops in lock_manager_operations for get/put owner
NFSD or other lockmanager may increase the owner's reference,
so adds two new options for copying and releasing owner.

v5: change order from 2/6 to 3/6
v4: rename lm_copy_owner/lm_release_owner to lm_get_owner/lm_put_owner

Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-09 16:01:09 -04:00
Kinglong Mee 3fe0fff18f locks: Rename __locks_copy_lock() to locks_copy_conflock()
Jeff advice, " Right now __locks_copy_lock is only used to copy
conflocks. It would be good to rename that to something more
distinct (i.e.locks_copy_conflock), to make it clear that we're
generating a conflock there."

v5: change order from 3/6 to 2/6
v4: new patch only renaming function name

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-09 16:01:09 -04:00
Joe Perches d0449b90f8 locks: Remove unused conf argument from lm_grant
This argument is always NULL so don't pass it around.

[jlayton: remove dependencies on previous patches in series]

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-09-09 16:01:06 -04:00
Linus Torvalds f6f993328b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "Stuff in here:

   - acct.c fixes and general rework of mnt_pin mechanism.  That allows
     to go for delayed-mntput stuff, which will permit mntput() on deep
     stack without worrying about stack overflows - fs shutdown will
     happen on shallow stack.  IOW, we can do Eric's umount-on-rmdir
     series without introducing tons of stack overflows on new mntput()
     call chains it introduces.
   - Bruce's d_splice_alias() patches
   - more Miklos' rename() stuff.
   - a couple of regression fixes (stable fodder, in the end of branch)
     and a fix for API idiocy in iov_iter.c.

  There definitely will be another pile, maybe even two.  I'd like to
  get Eric's series in this time, but even if we miss it, it'll go right
  in the beginning of for-next in the next cycle - the tricky part of
  prereqs is in this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  fix copy_tree() regression
  __generic_file_write_iter(): fix handling of sync error after DIO
  switch iov_iter_get_pages() to passing maximal number of pages
  fs: mark __d_obtain_alias static
  dcache: d_splice_alias should detect loops
  exportfs: update Exporting documentation
  dcache: d_find_alias needn't recheck IS_ROOT && DCACHE_DISCONNECTED
  dcache: remove unused d_find_alias parameter
  dcache: d_obtain_alias callers don't all want DISCONNECTED
  dcache: d_splice_alias should ignore DCACHE_DISCONNECTED
  dcache: d_splice_alias mustn't create directory aliases
  dcache: close d_move race in d_splice_alias
  dcache: move d_splice_alias
  namei: trivial fix to vfs_rename_dir comment
  VFS: allow ->d_manage() to declare -EISDIR in rcu_walk mode.
  cifs: support RENAME_NOREPLACE
  hostfs: support rename flags
  shmem: support RENAME_EXCHANGE
  shmem: support RENAME_NOREPLACE
  btrfs: add RENAME_NOREPLACE
  ...
2014-08-11 11:44:11 -07:00
David Herrmann 4bb5f5d939 mm: allow drivers to prevent new writable mappings
This patch (of 6):

The i_mmap_writable field counts existing writable mappings of an
address_space.  To allow drivers to prevent new writable mappings, make
this counter signed and prevent new writable mappings if it is negative.
This is modelled after i_writecount and DENYWRITE.

This will be required by the shmem-sealing infrastructure to prevent any
new writable mappings after the WRITE seal has been set.  In case there
exists a writable mapping, this operation will fail with EBUSY.

Note that we rely on the fact that iff you already own a writable mapping,
you can increase the counter without using the helpers.  This is the same
that we do for i_writecount.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Ryan Lortie <desrt@desrt.ca>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Daniel Mack <zonque@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08 15:57:31 -07:00
Al Viro 215752fce3 acct: get rid of acct_list
Put these suckers on per-vfsmount and per-superblock lists instead.
Note: right now it's still acct_lock for everything, but that's
going to change.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:08 -04:00
Al Viro ed44724b79 acct: switch to __kernel_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07 14:40:07 -04:00
Joe Perches 68be302963 fs.h, drivers/hwmon/asus_atk0110.c: fix DEFINE_SIMPLE_ATTRIBUTE semicolon definition and use
The DEFINE_SIMPLE_ATTRIBUTE macro should not end in a ; Fix the one use
in the kernel tree that did not have a semicolon.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06 18:01:23 -07:00
Christoph Hellwig 17fa388ddc locks: typedef fl_owner_t to void *
fl_owner_t is a cookie that can store all kinds of different pointers,
so don't pretends it points to a file structure.

For now just change the typedef, but as a follow on this will allow
to get rids of lots of casts and eventually the typedef itself.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-07-13 21:38:49 -04:00
Linus Torvalds 2dfded8210 File locking related bugfixes for v3.16 (pile #2)
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Merge tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux

Pull file locking fixes from Jeff Layton:
 "File locking related bugfixes

  Nothing too earth-shattering here.  A fix for a potential regression
  due to a patch in pile #1, and the addition of a memory barrier to
  prevent a race condition between break_deleg and generic_add_lease"

* tag 'locks-v3.16-2' of git://git.samba.org/jlayton/linux:
  locks: set fl_owner for leases back to current->files
  locks: add missing memory barrier in break_deleg
2014-06-21 16:40:30 -10:00
Linus Torvalds 16b9057804 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "This the bunch that sat in -next + lock_parent() fix.  This is the
  minimal set; there's more pending stuff.

  In particular, I really hope to get acct.c fixes merged this cycle -
  we need that to deal sanely with delayed-mntput stuff.  In the next
  pile, hopefully - that series is fairly short and localized
  (kernel/acct.c, fs/super.c and fs/namespace.c).  In this pile: more
  iov_iter work.  Most of prereqs for ->splice_write with sane locking
  order are there and Kent's dio rewrite would also fit nicely on top of
  this pile"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (70 commits)
  lock_parent: don't step on stale ->d_parent of all-but-freed one
  kill generic_file_splice_write()
  ceph: switch to iter_file_splice_write()
  shmem: switch to iter_file_splice_write()
  nfs: switch to iter_splice_write_file()
  fs/splice.c: remove unneeded exports
  ocfs2: switch to iter_file_splice_write()
  ->splice_write() via ->write_iter()
  bio_vec-backed iov_iter
  optimize copy_page_{to,from}_iter()
  bury generic_file_aio_{read,write}
  lustre: get rid of messing with iovecs
  ceph: switch to ->write_iter()
  ceph_sync_direct_write: stop poking into iov_iter guts
  ceph_sync_read: stop poking into iov_iter guts
  new helper: copy_page_from_iter()
  fuse: switch to ->write_iter()
  btrfs: switch to ->write_iter()
  ocfs2: switch to ->write_iter()
  xfs: switch to ->write_iter()
  ...
2014-06-12 10:30:18 -07:00
Al Viro 5f07385060 kill generic_file_splice_write()
no callers left

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-12 00:21:13 -04:00
Al Viro 8d0207652c ->splice_write() via ->write_iter()
iter_file_splice_write() - a ->splice_write() instance that gathers the
pipe buffers, builds a bio_vec-based iov_iter covering those and feeds
it to ->write_iter().  A bunch of simple cases coverted to that...

[AV: fixed the braino spotted by Cyrill]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-06-12 00:18:51 -04:00
Jeff Layton 962bd40bc3 locks: add missing memory barrier in break_deleg
break_deleg is subject to the same potential race as break_lease. Add
a memory barrier to prevent it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
2014-06-10 12:24:40 -04:00
Fabian Frederick ac13a829f6 fs/libfs.c: add generic data flush to fsync
Description by Jan Kara:
 "A lot of older filesystems don't properly flush volatile disk caches
  on fsync(2) which can lead to loss of fsynced data after power failure.

This patch makes generic_file_fsync() issue proper cache flush to fix the
problem.  Sysadmin can use /sys/devices/.../cache_type to tell the system
it should not send the cache flush."

[akpm@linux-foundation.org: nuke ifdef]
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Suggested-by: Jan Kara <jack@suse.cz>
Suggested-by: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:55 -07:00
Al Viro 6abd232274 bury generic_file_aio_{read,write}
no callers left

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:39:44 -04:00
Al Viro a8f3550cd2 bury __generic_file_aio_write()
all users converted to __generic_file_write_iter() now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:39:37 -04:00
Al Viro 1456c0a87c blkdev_aio_write() - turn into blkdev_write_iter()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:38:01 -04:00
Al Viro 8174202b34 write_iter variants of {__,}generic_file_aio_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:38:00 -04:00
Al Viro 293bc9822f new methods: ->read_iter() and ->write_iter()
Beginning to introduce those.  Just the callers for now, and it's
clumsier than it'll eventually become; once we finish converting
aio_read and aio_write instances, the things will get nicer.

For now, these guys are in parallel to ->aio_read() and ->aio_write();
they take iocb and iov_iter, with everything in iov_iter already
validated.  File offset is passed in iocb->ki_pos, iov/nr_segs -
in iov_iter.

Main concerns in that series are stack footprint and ability to
split the damn thing cleanly.

[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:36:00 -04:00
Al Viro 7f7f25e82d replace checking for ->read/->aio_read presence with check in ->f_mode
Since we are about to introduce new methods (read_iter/write_iter), the
tests in a bunch of places would have to grow inconveniently.  Check
once (at open() time) and store results in ->f_mode as FMODE_CAN_READ
and FMODE_CAN_WRITE resp.  It might end up being a temporary measure -
once everything switches from ->aio_{read,write} to ->{read,write}_iter
it might make sense to return to open-coded checks.  We'll see...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:55 -04:00
Al Viro 0c949334a9 iov_iter_truncate()
Now It Can Be Done(tm) - we don't need to do iov_shorten() in
generic_file_direct_write() anymore, now that all ->direct_IO()
instances are converted to proper iov_iter methods and honour
iter->count and iter->iov_offset properly.

Get rid of count/ocount arguments of generic_file_direct_write(),
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:54 -04:00
Al Viro ed978a811e new helper: generic_file_read_iter()
iov_iter-using variant of generic_file_aio_read().  Some callers
converted.  Note that it's still not quite there for use as ->read_iter() -
we depend on having zero iter->iov_offset in O_DIRECT case.  Fortunately,
that's true for all converted callers (and for generic_file_aio_read() itself).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:49 -04:00
Al Viro 31b140398c switch {__,}blockdev_direct_IO() to iov_iter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:46 -04:00
Al Viro d8d3d94b80 pass iov_iter to ->direct_IO()
unmodified, for now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:44 -04:00
Al Viro cb66a7a1f1 kill generic_segment_checks()
all callers of ->aio_read() and ->aio_write() have iov/nr_segs already
checked - generic_segment_checks() done after that is just an odd way
to spell iov_length().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:43 -04:00
Al Viro f8579f8673 generic_file_direct_write(): switch to iov_iter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-05-06 17:32:42 -04:00
Jeff Layton cff2fce58b locks: rename FL_FILE_PVT and IS_FILE_PVT to use "*_OFDLCK" instead
File-private locks have been re-christened as "open file description"
locks.  Finish the symbol name cleanup in the internal implementation.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-04-23 16:17:03 -04:00
Linus Torvalds 5166701b36 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "The first vfs pile, with deep apologies for being very late in this
  window.

  Assorted cleanups and fixes, plus a large preparatory part of iov_iter
  work.  There's a lot more of that, but it'll probably go into the next
  merge window - it *does* shape up nicely, removes a lot of
  boilerplate, gets rid of locking inconsistencie between aio_write and
  splice_write and I hope to get Kent's direct-io rewrite merged into
  the same queue, but some of the stuff after this point is having
  (mostly trivial) conflicts with the things already merged into
  mainline and with some I want more testing.

  This one passes LTP and xfstests without regressions, in addition to
  usual beating.  BTW, readahead02 in ltp syscalls testsuite has started
  giving failures since "mm/readahead.c: fix readahead failure for
  memoryless NUMA nodes and limit readahead pages" - might be a false
  positive, might be a real regression..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  kill generic_file_buffered_write()
  ocfs2_file_aio_write(): switch to generic_perform_write()
  ceph_aio_write(): switch to generic_perform_write()
  xfs_file_buffered_aio_write(): switch to generic_perform_write()
  export generic_perform_write(), start getting rid of generic_file_buffer_write()
  generic_file_direct_write(): get rid of ppos argument
  btrfs_file_aio_write(): get rid of ppos
  kill the 5th argument of generic_file_buffered_write()
  kill the 4th argument of __generic_file_aio_write()
  lustre: don't open-code kernel_recvmsg()
  ocfs2: don't open-code kernel_recvmsg()
  drbd: don't open-code kernel_recvmsg()
  constify blk_rq_map_user_iov() and friends
  lustre: switch to kernel_sendmsg()
  ocfs2: don't open-code kernel_sendmsg()
  take iov_iter stuff to mm/iov_iter.c
  process_vm_access: tidy up a bit
  ...
2014-04-12 14:49:50 -07:00
Linus Torvalds d15e03104e xfs: update for 3.15-rc1
The main changes in the XFS tree for 3.15-rc1 are:
 
         - O_TMPFILE support
         - allowing AIO+DIO writes beyond EOF
         - FALLOC_FL_COLLAPSE_RANGE support for fallocate syscall and XFS
           implementation
         - FALLOC_FL_ZERO_RANGE support for fallocate syscall and XFS
           implementation
         - IO verifier cleanup and rework
         - stack usage reduction changes
         - vm_map_ram NOIO context fixes to remove lockdep warings
         - various bug fixes and cleanups
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Merge tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs

Pull xfs update from Dave Chinner:
 "There are a couple of new fallocate features in this request - it was
  decided that it was easiest to push them through the XFS tree using
  topic branches and have the ext4 support be based on those branches.
  Hence you may see some overlap with the ext4 tree merge depending on
  how they including those topic branches into their tree.  Other than
  that, there is O_TMPFILE support, some cleanups and bug fixes.

  The main changes in the XFS tree for 3.15-rc1 are:

   - O_TMPFILE support
   - allowing AIO+DIO writes beyond EOF
   - FALLOC_FL_COLLAPSE_RANGE support for fallocate syscall and XFS
     implementation
   - FALLOC_FL_ZERO_RANGE support for fallocate syscall and XFS
     implementation
   - IO verifier cleanup and rework
   - stack usage reduction changes
   - vm_map_ram NOIO context fixes to remove lockdep warings
   - various bug fixes and cleanups"

* tag 'xfs-for-linus-3.15-rc1' of git://oss.sgi.com/xfs/xfs: (34 commits)
  xfs: fix directory hash ordering bug
  xfs: extra semi-colon breaks a condition
  xfs: Add support for FALLOC_FL_ZERO_RANGE
  fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  xfs: inode log reservations are still too small
  xfs: xfs_check_page_type buffer checks need help
  xfs: avoid AGI/AGF deadlock scenario for inode chunk allocation
  xfs: use NOIO contexts for vm_map_ram
  xfs: don't leak EFSBADCRC to userspace
  xfs: fix directory inode iolock lockdep false positive
  xfs: allocate xfs_da_args to reduce stack footprint
  xfs: always do log forces via the workqueue
  xfs: modify verifiers to differentiate CRC from other errors
  xfs: print useful caller information in xfs_error_report
  xfs: add xfs_verifier_error()
  xfs: add helper for updating checksums on xfs_bufs
  xfs: add helper for verifying checksums on xfs_bufs
  xfs: Use defines for CRC offsets in all cases
  xfs: skip pointless CRC updates after verifier failures
  xfs: Add support FALLOC_FL_COLLAPSE_RANGE for fallocate
  ...
2014-04-04 15:50:08 -07:00
Linus Torvalds 24e7ea3bea Major changes for 3.14 include support for the newly added ZERO_RANGE
and COLLAPSE_RANGE fallocate operations, and scalability improvements
 in the jbd2 layer and in xattr handling when the extended attributes
 spill over into an external block.
 
 Other than that, the usual clean ups and minor bug fixes.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Major changes for 3.14 include support for the newly added ZERO_RANGE
  and COLLAPSE_RANGE fallocate operations, and scalability improvements
  in the jbd2 layer and in xattr handling when the extended attributes
  spill over into an external block.

  Other than that, the usual clean ups and minor bug fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (42 commits)
  ext4: fix premature freeing of partial clusters split across leaf blocks
  ext4: remove unneeded test of ret variable
  ext4: fix comment typo
  ext4: make ext4_block_zero_page_range static
  ext4: atomically set inode->i_flags in ext4_set_inode_flags()
  ext4: optimize Hurd tests when reading/writing inodes
  ext4: kill i_version support for Hurd-castrated file systems
  ext4: each filesystem creates and uses its own mb_cache
  fs/mbcache.c: doucple the locking of local from global data
  fs/mbcache.c: change block and index hash chain to hlist_bl_node
  ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate
  ext4: refactor ext4_fallocate code
  ext4: Update inode i_size after the preallocation
  ext4: fix partial cluster handling for bigalloc file systems
  ext4: delete path dealloc code in ext4_ext_handle_uninitialized_extents
  ext4: only call sync_filesystm() when remounting read-only
  fs: push sync_filesystem() down to the file system's remount_fs()
  jbd2: improve error messages for inconsistent journal heads
  jbd2: minimize region locked by j_list_lock in jbd2_journal_forget()
  jbd2: minimize region locked by j_list_lock in journal_get_create_access()
  ...
2014-04-04 15:39:39 -07:00
Linus Torvalds f7789dc0d4 Merge branch 'locks-3.15' of git://git.samba.org/jlayton/linux
Pull file locking updates from Jeff Layton:
 "Highlights:

   - maintainership change for fs/locks.c.  Willy's not interested in
     maintaining it these days, and is OK with Bruce and I taking it.
   - fix for open vs setlease race that Al ID'ed
   - cleanup and consolidation of file locking code
   - eliminate unneeded BUG() call
   - merge of file-private lock implementation"

* 'locks-3.15' of git://git.samba.org/jlayton/linux:
  locks: make locks_mandatory_area check for file-private locks
  locks: fix locks_mandatory_locked to respect file-private locks
  locks: require that flock->l_pid be set to 0 for file-private locks
  locks: add new fcntl cmd values for handling file private locks
  locks: skip deadlock detection on FL_FILE_PVT locks
  locks: pass the cmd value to fcntl_getlk/getlk64
  locks: report l_pid as -1 for FL_FILE_PVT locks
  locks: make /proc/locks show IS_FILE_PVT locks as type "FLPVT"
  locks: rename locks_remove_flock to locks_remove_file
  locks: consolidate checks for compatible filp->f_mode values in setlk handlers
  locks: fix posix lock range overflow handling
  locks: eliminate BUG() call when there's an unexpected lock on file close
  locks: add __acquires and __releases annotations to locks_start and locks_stop
  locks: remove "inline" qualifier from fl_link manipulation functions
  locks: clean up comment typo
  locks: close potential race between setlease and open
  MAINTAINERS: update entry for fs/locks.c
2014-04-04 14:21:20 -07:00
Linus Torvalds 7df934526c Merge branch 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull renameat2 system call from Miklos Szeredi:
 "This adds a new syscall, renameat2(), which is the same as renameat()
  but with a flags argument.

  The purpose of extending rename is to add cross-rename, a symmetric
  variant of rename, which exchanges the two files.  This allows
  interesting things, which were not possible before, for example
  atomically replacing a directory tree with a symlink, etc...  This
  also allows overlayfs and friends to operate on whiteouts atomically.

  Andy Lutomirski also suggested a "noreplace" flag, which disables the
  overwriting behavior of rename.

  These two flags, RENAME_EXCHANGE and RENAME_NOREPLACE are only
  implemented for ext4 as an example and for testing"

* 'cross-rename' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ext4: add cross rename support
  ext4: rename: split out helper functions
  ext4: rename: move EMLINK check up
  ext4: rename: create ext4_renament structure for local vars
  vfs: add cross-rename
  vfs: lock_two_nondirectories: allow directory args
  security: add flags to rename hooks
  vfs: add RENAME_NOREPLACE flag
  vfs: add renameat2 syscall
  vfs: rename: use common code for dir and non-dir
  vfs: rename: move d_move() up
  vfs: add d_is_dir()
2014-04-04 14:03:05 -07:00
Johannes Weiner 91b0abe36a mm + fs: store shadow entries in page cache
Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:21:01 -07:00
Linus Torvalds bea803183e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Apart from reordering the SELinux mmap code to ensure DAC is called
  before MAC, these are minor maintenance updates"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (23 commits)
  selinux: correctly label /proc inodes in use before the policy is loaded
  selinux: put the mmap() DAC controls before the MAC controls
  selinux: fix the output of ./scripts/get_maintainer.pl for SELinux
  evm: enable key retention service automatically
  ima: skip memory allocation for empty files
  evm: EVM does not use MD5
  ima: return d_name.name if d_path fails
  integrity: fix checkpatch errors
  ima: fix erroneous removal of security.ima xattr
  security: integrity: Use a more current logging style
  MAINTAINERS: email updates and other misc. changes
  ima: reduce memory usage when a template containing the n field is used
  ima: restore the original behavior for sending data with ima template
  Integrity: Pass commname via get_task_comm()
  fs: move i_readcount
  ima: use static const char array definitions
  security: have cap_dentry_init_security return error
  ima: new helper: file_inode(file)
  kernel: Mark function as static in kernel/seccomp.c
  capability: Use current logging styles
  ...
2014-04-03 09:26:18 -07:00
Al Viro ccad236566 kill generic_file_buffered_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:38 -04:00
Al Viro 3b93f911d5 export generic_perform_write(), start getting rid of generic_file_buffer_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:36 -04:00
Al Viro 5cb6c6c7eb generic_file_direct_write(): get rid of ppos argument
always equal to &iocb->ki_pos.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:35 -04:00
Al Viro fcacafd269 kill the 5th argument of generic_file_buffered_write()
same story - it's &iocb->ki_pos in all cases

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:34 -04:00
Al Viro 41fc56d573 kill the 4th argument of __generic_file_aio_write()
It's always equal to &iocb->ki_pos, where iocb is the value of the 1st
argument.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:34 -04:00
Al Viro 6e58e79db8 introduce copy_page_to_iter, kill loop over iovec in generic_file_aio_read()
generic_file_aio_read() was looping over the target iovec, with loop over
(source) pages nested inside that.  Just set an iov_iter up and pass *that*
to do_generic_file_aio_read().  With copy_page_to_iter() doing all work
of mapping and copying a page to iovec and advancing iov_iter.

Switch shmem_file_aio_read() to the same and kill file_read_actor(), while
we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:21 -04:00
Kent Overstreet 9223687863 iov_iter: Move iov_iter to uio.h
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
2014-04-01 23:19:21 -04:00
Al Viro c186afb4db switch ->is_partially_uptodate() to saner arguments
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:19 -04:00
Al Viro 5d826c847b new helper: readlink_copy()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:15 -04:00
Al Viro 83f936c75e mark struct file that had write access grabbed by open()
new flag in ->f_mode - FMODE_WRITER.  Set by do_dentry_open() in case
when it has grabbed write access, checked by __fput() to decide whether
it wants to drop the sucker.  Allows to stop bothering with mnt_clone_write()
in alloc_file(), along with fewer special_file() checks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:12 -04:00
Al Viro 4597e695b8 get rid of DEBUG_WRITECOUNT
it only makes control flow in __fput() and friends more convoluted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-04-01 23:19:12 -04:00
Miklos Szeredi 520c8b1650 vfs: add renameat2 syscall
Add new renameat2 syscall, which is the same as renameat with an added
flags argument.

Pass flags to vfs_rename() and to i_op->rename() as well.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
2014-04-01 17:08:42 +02:00
Jeff Layton d7a06983a0 locks: fix locks_mandatory_locked to respect file-private locks
As Trond pointed out, you can currently deadlock yourself by setting a
file-private lock on a file that requires mandatory locking and then
trying to do I/O on it.

Avoid this problem by plumbing some knowledge of file-private locks into
the mandatory locking code. In order to do this, we must pass down
information about the struct file that's being used to
locks_verify_locked.

Reported-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
2014-03-31 08:24:43 -04:00
Jeff Layton c1e62b8fc3 locks: pass the cmd value to fcntl_getlk/getlk64
Once we introduce file private locks, we'll need to know what cmd value
was used, as that affects the ownership and whether a conflict would
arise.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-03-31 08:24:43 -04:00
Jeff Layton c918d42a27 locks: make /proc/locks show IS_FILE_PVT locks as type "FLPVT"
In a later patch, we'll be adding a new type of lock that's owned by
the struct file instead of the files_struct. Those sorts of locks
will be flagged with a new FL_FILE_PVT flag.

Report these types of locks as "FLPVT" in /proc/locks to distinguish
them from "classic" POSIX locks.

Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-03-31 08:24:42 -04:00
Jeff Layton 78ed8a1338 locks: rename locks_remove_flock to locks_remove_file
This function currently removes leases in addition to flock locks and in
a later patch we'll have it deal with file-private locks too. Rename it
to locks_remove_file to indicate that it removes locks that are
associated with a particular struct file, and not just flock locks.

Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2014-03-31 08:24:42 -04:00
Jeff Layton 24cbe7845e locks: close potential race between setlease and open
As Al Viro points out, there is an unlikely, but possible race between
opening a file and setting a lease on it. generic_add_lease is done with
the i_lock held, but the inode->i_flock check in break_lease is
lockless. It's possible for another task doing an open to do the entire
pathwalk and call break_lease between the point where generic_add_lease
checks for a conflicting open and adds the lease to the list. If this
occurs, we can end up with a lease set on the file with a conflicting
open.

To guard against that, check again for a conflicting open after adding
the lease to the i_flock list. If the above race occurs, then we can
simply unwind the lease setting and return -EAGAIN.

Because we take dentry references and acquire write access on the file
before calling break_lease, we know that if the i_flock list is empty
when the open caller goes to check it then the necessary refcounts have
already been incremented. Thus the additional check for a conflicting
open will see that there is one and the setlease call will fail.

Cc: Bruce Fields <bfields@fieldses.org>
Cc: David Howells <dhowells@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@fieldses.org>
2014-03-31 08:24:42 -04:00
Theodore Ts'o 5f16f3225b ext4: atomically set inode->i_flags in ext4_set_inode_flags()
Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Reported-by: John Sullivan <jsrhbz@kanargh.force9.co.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2014-03-24 14:43:12 -04:00
Al Viro bd2a31d522 get rid of fget_light()
instead of returning the flags by reference, we can just have the
low-level primitive return those in lower bits of unsigned long,
with struct file * derived from the rest.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-10 11:44:42 -04:00
Linus Torvalds 9c225f2655 vfs: atomic f_pos accesses as per POSIX
Our write() system call has always been atomic in the sense that you get
the expected thread-safe contiguous write, but we haven't actually
guaranteed that concurrent writes are serialized wrt f_pos accesses, so
threads (or processes) that share a file descriptor and use "write()"
concurrently would quite likely overwrite each others data.

This violates POSIX.1-2008/SUSv4 Section XSI 2.9.7 that says:

 "2.9.7 Thread Interactions with Regular File Operations

  All of the following functions shall be atomic with respect to each
  other in the effects specified in POSIX.1-2008 when they operate on
  regular files or symbolic links: [...]"

and one of the effects is the file position update.

This unprotected file position behavior is not new behavior, and nobody
has ever cared.  Until now.  Yongzhi Pan reported unexpected behavior to
Michael Kerrisk that was due to this.

This resolves the issue with a f_pos-specific lock that is taken by
read/write/lseek on file descriptors that may be shared across threads
or processes.

Reported-by: Yongzhi Pan <panyongzhi@gmail.com>
Reported-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-10 11:44:41 -04:00
Mimi Zohar d984ea6049 fs: move i_readcount
On a 64-bit system, a hole exists in the 'inode' structure after
i_writecount.  This patch moves i_readcount to fill this hole.

Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: David Howells <dhowells@redhat.com>
2014-03-07 11:31:55 -05:00
Linus Torvalds f94aa7c7f1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs fixes from Al Viro:
 "A couple of fixes, both -stable fodder.  The O_SYNC bug is fairly
  old..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fix a kmap leak in virtio_console
  fix O_SYNC|O_APPEND syncing the wrong range on write()
2014-02-09 18:12:07 -08:00
Christoph Hellwig 6039257378 direct-io: add flag to allow aio writes beyond i_size
Some filesystems can handle direct I/O writes beyond i_size safely,
so allow them to opt into receiving them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-02-10 10:27:11 +11:00
Al Viro d311d79de3 fix O_SYNC|O_APPEND syncing the wrong range on write()
It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
	pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
	pos_before_write .. pos_before_write + written - 1
instead.  Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().

All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().

The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-02-09 15:18:09 -05:00
Linus Torvalds c4ad8f98be execve: use 'struct filename *' for executable name passing
This changes 'do_execve()' to get the executable name as a 'struct
filename', and to free it when it is done.  This is what the normal
users want, and it simplifies and streamlines their error handling.

The controlled lifetime of the executable name also fixes a
use-after-free problem with the trace_sched_process_exec tracepoint: the
lifetime of the passed-in string for kernel users was not at all
obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize
the pathname allocation lifetime with the execve() having finished,
which in turn meant that the trace point that happened after
mm_release() of the old process VM ended up using already free'd memory.

To solve the kernel string lifetime issue, this simply introduces
"getname_kernel()" that works like the normal user-space getname()
function, except with the source coming from kernel memory.

As Oleg points out, this also means that we could drop the tcomm[] array
from 'struct linux_binprm', since the pathname lifetime now covers
setup_new_exec().  That would be a separate cleanup.

Reported-by: Igor Zhbanov <i.zhbanov@samsung.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-02-05 12:54:53 -08:00
Christoph Hellwig 893d46e443 fs: add a set_acl inode operation
This will allow moving all the Posix ACL handling into the VFS and clean
up tons of cruft in the filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-25 23:58:17 -05:00
Al Viro b26d4cd385 consolidate simple ->d_delete() instances
Rename simple_delete_dentry() to always_delete_dentry() and export it.
Export simple_dentry_operations, while we are at it, and get rid of
their duplicates

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-15 22:04:17 -05:00
Linus Torvalds 9bc9ccd7db Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
 "All kinds of stuff this time around; some more notable parts:

   - RCU'd vfsmounts handling
   - new primitives for coredump handling
   - files_lock is gone
   - Bruce's delegations handling series
   - exportfs fixes

  plus misc stuff all over the place"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits)
  ecryptfs: ->f_op is never NULL
  locks: break delegations on any attribute modification
  locks: break delegations on link
  locks: break delegations on rename
  locks: helper functions for delegation breaking
  locks: break delegations on unlink
  namei: minor vfs_unlink cleanup
  locks: implement delegations
  locks: introduce new FL_DELEG lock flag
  vfs: take i_mutex on renamed file
  vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
  vfs: don't use PARENT/CHILD lock classes for non-directories
  vfs: pull ext4's double-i_mutex-locking into common code
  exportfs: fix quadratic behavior in filehandle lookup
  exportfs: better variable name
  exportfs: move most of reconnect_path to helper function
  exportfs: eliminate unused "noprogress" counter
  exportfs: stop retrying once we race with rename/remove
  exportfs: clear DISCONNECTED on all parents sooner
  exportfs: more detailed comment for path_reconnect
  ...
2013-11-13 15:34:18 +09:00
J. Bruce Fields 27ac0ffeac locks: break delegations on any attribute modification
NFSv4 uses leases to guarantee that clients can cache metadata as well
as data.

Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:44 -05:00
J. Bruce Fields 146a8595c6 locks: break delegations on link
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:43 -05:00
J. Bruce Fields 8e6d782cab locks: break delegations on rename
Cc: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:43 -05:00
J. Bruce Fields 5a14696c17 locks: helper functions for delegation breaking
We'll need the same logic for rename and link.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:42 -05:00
J. Bruce Fields b21996e36c locks: break delegations on unlink
We need to break delegations on any operation that changes the set of
links pointing to an inode.  Start with unlink.

Such operations also hold the i_mutex on a parent directory.  Breaking a
delegation may require waiting for a timeout (by default 90 seconds) in
the case of a unresponsive NFS client.  To avoid blocking all directory
operations, we therefore drop locks before waiting for the delegation.
The logic then looks like:

	acquire locks
	...
	test for delegation; if found:
		take reference on inode
		release locks
		wait for delegation break
		drop reference on inode
		retry

It is possible this could never terminate.  (Even if we take precautions
to prevent another delegation being acquired on the same inode, we could
get a different inode on each retry.)  But this seems very unlikely.

The initial test for a delegation happens after the lock on the target
inode is acquired, but the directory inode may have been acquired
further up the call stack.  We therefore add a "struct inode **"
argument to any intervening functions, which we use to pass the inode
back up to the caller in the case it needs a delegation synchronously
broken.

Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:42 -05:00
J. Bruce Fields df4e8d2c1d locks: implement delegations
Implement NFSv4 delegations at the vfs level using the new FL_DELEG lock
type.

Note nfsd is the only delegation user and is only using read
delegations.  Warn on any attempt to set a write delegation for now.
We'll come back to that case later.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:41 -05:00
J. Bruce Fields 617588d518 locks: introduce new FL_DELEG lock flag
For now FL_DELEG is just a synonym for FL_LEASE.  So this patch doesn't
change behavior.

Next we'll modify break_lease to treat FL_DELEG leases differently, to
account for the fact that NFSv4 delegations should be broken in more
situations than Windows oplocks.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:41 -05:00
J. Bruce Fields 40bd22c9f8 vfs: rename I_MUTEX_QUOTA now that it's not used for quotas
I_MUTEX_QUOTA is now just being used whenever we want to lock two
non-directories.  So the name isn't right.  I_MUTEX_NONDIR2 isn't
especially elegant but it's the best I could think of.

Also fix some outdated documentation.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:40 -05:00
J. Bruce Fields 375e289ea8 vfs: pull ext4's double-i_mutex-locking into common code
We want to do this elsewhere as well.

Also catch any attempts to use it for directories (where this ordering
would conflict with ancestor-first directory ordering in lock_rename).

Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:39 -05:00
J. Bruce Fields b7a6ec52dd vfs: split out vfs_getattr_nosec
The filehandle lookup code wants this version of getattr.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:31 -05:00
Al Viro 6987843ff7 take anon inode allocation to libfs.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:27 -05:00
Al Viro eee5cc2702 get rid of s_files and files_lock
The only thing we need it for is alt-sysrq-r (emergency remount r/o)
and these days we can do just as well without going through the
list of files.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-11-09 00:16:20 -05:00
Al Viro e2fec7c355 make freeing super_block rcu-delayed
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:43:26 -04:00
Al Viro e84f9e57b9 consolidate the reassignments of ->f_op in ->open() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:53 -04:00
Al Viro 87dc800be2 new helper: kfree_put_link()
duplicated to hell and back...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-10-24 23:34:49 -04:00
David Howells f1fe29b4a0 NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()
Use i_writecount to control whether to get an fscache cookie in nfs_open() as
NFS does not do write caching yet.  I *think* this is the cause of a problem
encountered by Mark Moseley whereby __fscache_uncache_page() gets a NULL
pointer dereference because cookie->def is NULL:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160
PGD 0
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP
Modules linked in: ...
CPU: 7 PID: 18993 Comm: php Not tainted 3.11.1 #1
Hardware name: Dell Inc. PowerEdge R420/072XWF, BIOS 1.3.5 08/21/2012
task: ffff8804203460c0 ti: ffff880420346640
RIP: 0010:[<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160
RSP: 0018:ffff8801053af878 EFLAGS: 00210286
RAX: 0000000000000000 RBX: ffff8800be2f8780 RCX: ffff88022ffae5e8
RDX: 0000000000004c66 RSI: ffffea00055ff440 RDI: ffff8800be2f8780
RBP: ffff8801053af898 R08: 0000000000000001 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00055ff440
R13: 0000000000001000 R14: ffff8800c50be538 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88042fc60000(0063) knlGS:00000000e439c700
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000001d8f000 CR4: 00000000000607f0
Stack:
...
Call Trace:
[<ffffffff81365a72>] __nfs_fscache_invalidate_page+0x42/0x70
[<ffffffff813553d5>] nfs_invalidate_page+0x75/0x90
[<ffffffff811b8f5e>] truncate_inode_page+0x8e/0x90
[<ffffffff811b90ad>] truncate_inode_pages_range.part.12+0x14d/0x620
[<ffffffff81d6387d>] ? __mutex_lock_slowpath+0x1fd/0x2e0
[<ffffffff811b95d3>] truncate_inode_pages_range+0x53/0x70
[<ffffffff811b969d>] truncate_inode_pages+0x2d/0x40
[<ffffffff811b96ff>] truncate_pagecache+0x4f/0x70
[<ffffffff81356840>] nfs_setattr_update_inode+0xa0/0x120
[<ffffffff81368de4>] nfs3_proc_setattr+0xc4/0xe0
[<ffffffff81357f78>] nfs_setattr+0xc8/0x150
[<ffffffff8122d95b>] notify_change+0x1cb/0x390
[<ffffffff8120a55b>] do_truncate+0x7b/0xc0
[<ffffffff8121f96c>] do_last+0xa4c/0xfd0
[<ffffffff8121ffbc>] path_openat+0xcc/0x670
[<ffffffff81220a0e>] do_filp_open+0x4e/0xb0
[<ffffffff8120ba1f>] do_sys_open+0x13f/0x2b0
[<ffffffff8126aaf6>] compat_SyS_open+0x36/0x50
[<ffffffff81d7204c>] sysenter_dispatch+0x7/0x24

The code at the instruction pointer was disassembled:

> (gdb) disas __fscache_uncache_page
> Dump of assembler code for function __fscache_uncache_page:
> ...
> 0xffffffff812a18ff <+31>: mov 0x48(%rbx),%rax
> 0xffffffff812a1903 <+35>: cmpb $0x0,0x10(%rax)
> 0xffffffff812a1907 <+39>: je 0xffffffff812a19cd <__fscache_uncache_page+237>

These instructions make up:

	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);

That cmpb is the faulting instruction (%rax is 0).  So cookie->def is NULL -
which presumably means that the cookie has already been at least partway
through __fscache_relinquish_cookie().

What I think may be happening is something like a three-way race on the same
file:

	PROCESS 1	PROCESS 2	PROCESS 3
	===============	===============	===============
	open(O_TRUNC|O_WRONLY)
			open(O_RDONLY)
					open(O_WRONLY)
	-->nfs_open()
	-->nfs_fscache_set_inode_cookie()
	nfs_fscache_inode_lock()
	nfs_fscache_disable_inode_cookie()
	__fscache_relinquish_cookie()
	nfs_inode->fscache = NULL
	<--nfs_fscache_set_inode_cookie()

			-->nfs_open()
			-->nfs_fscache_set_inode_cookie()
			nfs_fscache_inode_lock()
			nfs_fscache_enable_inode_cookie()
			__fscache_acquire_cookie()
			nfs_inode->fscache = cookie
			<--nfs_fscache_set_inode_cookie()
	<--nfs_open()
	-->nfs_setattr()
	...
	...
	-->nfs_invalidate_page()
	-->__nfs_fscache_invalidate_page()
	cookie = nfsi->fscache
					-->nfs_open()
					-->nfs_fscache_set_inode_cookie()
					nfs_fscache_inode_lock()
					nfs_fscache_disable_inode_cookie()
					-->__fscache_relinquish_cookie()
	-->__fscache_uncache_page(cookie)
	<crash>
					<--__fscache_relinquish_cookie()
					nfs_inode->fscache = NULL
					<--nfs_fscache_set_inode_cookie()

What is needed is something to prevent process #2 from reacquiring the cookie
- and I think checking i_writecount should do the trick.

It's also possible to have a two-way race on this if the file is opened
O_TRUNC|O_RDONLY instead.

Reported-by: Mark Moseley <moseleymark@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-27 18:40:25 +01:00
Linus Torvalds 3711d86a2d a trivial writeback fix
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Merge tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux

Pull writeback fix from Wu Fengguang:
 "A trivial writeback fix"

* tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: Do not sort b_io list only because of block device inode
2013-09-13 23:06:40 -04:00
Dave Chinner 9b17c62382 fs: convert inode and dentry shrinking to be node aware
Now that the shrinker is passing a node in the scan control structure, we
can pass this to the the generic LRU list code to isolate reclaim to the
lists on matching nodes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:31 -04:00
Dave Chinner f604156751 dcache: convert to use new lru list infrastructure
[glommer@openvz.org: don't reintroduce double decrement of nr_unused_dentries, adapted for new LRU return codes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner bc3b14cb2d inode: convert inode lru list to generic lru list code.
[glommer@openvz.org: adapted for new LRU return codes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner 0a234c6dcb shrinker: convert superblock shrinkers to new API
Convert superblock shrinker to use the new count/scan API, and propagate
the API changes through to the filesystem callouts.  The filesystem
callouts already use a count/scan API, so it's just changing counters to
longs to match the VM API.

This requires the dentry and inode shrinker callouts to be converted to
the count/scan API.  This is mainly a mechanical change.

[glommer@openvz.org: use mult_frac for fractional proportions, build fixes]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Dave Chinner 19156840e3 dentry: move to per-sb LRU locks
With the dentry LRUs being per-sb structures, there is no real need for
a global dentry_lru_lock. The locking can be made more fine-grained by
moving to a per-sb LRU lock, isolating the LRU operations of different
filesytsems completely from each other. The need for this is independent
of any performance consideration that may arise: in the interest of
abstracting the lru operations away, it is mandatory that each lru works
around its own lock instead of a global lock for all of them.

[glommer@openvz.org: updated changelog ]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:30 -04:00
Glauber Costa 3942c07ccf fs: bump inode and dentry counters to long
This series reworks our current object cache shrinking infrastructure in
two main ways:

 * Noticing that a lot of users copy and paste their own version of LRU
   lists for objects, we put some effort in providing a generic version.
   It is modeled after the filesystem users: dentries, inodes, and xfs
   (for various tasks), but we expect that other users could benefit in
   the near future with little or no modification.  Let us know if you
   have any issues.

 * The underlying list_lru being proposed automatically and
   transparently keeps the elements in per-node lists, and is able to
   manipulate the node lists individually.  Given this infrastructure, we
   are able to modify the up-to-now hammer called shrink_slab to proceed
   with node-reclaim instead of always searching memory from all over like
   it has been doing.

Per-node lru lists are also expected to lead to less contention in the lru
locks on multi-node scans, since we are now no longer fighting for a
global lock.  The locks usually disappear from the profilers with this
change.

Although we have no official benchmarks for this version - be our guest to
independently evaluate this - earlier versions of this series were
performance tested (details at
http://permalink.gmane.org/gmane.linux.kernel.mm/100537) yielding no
visible performance regressions while yielding a better qualitative
behavior in NUMA machines.

With this infrastructure in place, we can use the list_lru entry point to
provide memcg isolation and per-memcg targeted reclaim.  Historically,
those two pieces of work have been posted together.  This version presents
only the infrastructure work, deferring the memcg work for a later time,
so we can focus on getting this part tested.  You can see more about the
history of such work at http://lwn.net/Articles/552769/

Dave Chinner (18):
  dcache: convert dentry_stat.nr_unused to per-cpu counters
  dentry: move to per-sb LRU locks
  dcache: remove dentries from LRU before putting on dispose list
  mm: new shrinker API
  shrinker: convert superblock shrinkers to new API
  list: add a new LRU list type
  inode: convert inode lru list to generic lru list code.
  dcache: convert to use new lru list infrastructure
  list_lru: per-node list infrastructure
  shrinker: add node awareness
  fs: convert inode and dentry shrinking to be node aware
  xfs: convert buftarg LRU to generic code
  xfs: rework buffer dispose list tracking
  xfs: convert dquot cache lru to list_lru
  fs: convert fs shrinkers to new scan/count API
  drivers: convert shrinkers to new count/scan API
  shrinker: convert remaining shrinkers to count/scan API
  shrinker: Kill old ->shrink API.

Glauber Costa (7):
  fs: bump inode and dentry counters to long
  super: fix calculation of shrinkable objects for small numbers
  list_lru: per-node API
  vmscan: per-node deferred work
  i915: bail out earlier when shrinker cannot acquire mutex
  hugepage: convert huge zero page shrinker to new shrinker API
  list_lru: dynamically adjust node arrays

This patch:

There are situations in very large machines in which we can have a large
quantity of dirty inodes, unused dentries, etc.  This is particularly true
when umounting a filesystem, where eventually since every live object will
eventually be discarded.

Dave Chinner reported a problem with this while experimenting with the
shrinker revamp patchset.  So we believe it is time for a change.  This
patch just moves int to longs.  Machines where it matters should have a
big long anyway.

Signed-off-by: Glauber Costa <glommer@openvz.org>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:29 -04:00
Christoph Hellwig aac34df117 fs: remove vfs_follow_link
For a long time no filesystem has been using vfs_follow_link, and as seen
by recent filesystem submissions any new use is accidental as well.

Remove vfs_follow_link, document the replacement in
Documentation/filesystems/porting and also rename __vfs_follow_link
to match its only caller better.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-10 18:56:29 -04:00
Linus Torvalds c7c4591db6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace changes from Eric Biederman:
 "This is an assorted mishmash of small cleanups, enhancements and bug
  fixes.

  The major theme is user namespace mount restrictions.  nsown_capable
  is killed as it encourages not thinking about details that need to be
  considered.  A very hard to hit pid namespace exiting bug was finally
  tracked and fixed.  A couple of cleanups to the basic namespace
  infrastructure.

  Finally there is an enhancement that makes per user namespace
  capabilities usable as capabilities, and an enhancement that allows
  the per userns root to nice other processes in the user namespace"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  userns:  Kill nsown_capable it makes the wrong thing easy
  capabilities: allow nice if we are privileged
  pidns: Don't have unshare(CLONE_NEWPID) imply CLONE_THREAD
  userns: Allow PR_CAPBSET_DROP in a user namespace.
  namespaces: Simplify copy_namespaces so it is clear what is going on.
  pidns: Fix hang in zap_pid_ns_processes by sending a potentially extra wakeup
  sysfs: Restrict mounting sysfs
  userns: Better restrictions on when proc and sysfs can be mounted
  vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces
  kernel/nsproxy.c: Improving a snippet of code.
  proc: Restrict mounting the proc filesystem
  vfs: Lock in place mounts from more privileged users
2013-09-07 14:35:32 -07:00
Linus Torvalds 45d9a2220f Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 1 from Al Viro:
 "Unfortunately, this merge window it'll have a be a lot of small piles -
  my fault, actually, for not keeping #for-next in anything that would
  resemble a sane shape ;-/

  This pile: assorted fixes (the first 3 are -stable fodder, IMO) and
  cleanups + %pd/%pD formats (dentry/file pathname, up to 4 last
  components) + several long-standing patches from various folks.

  There definitely will be a lot more (starting with Miklos'
  check_submount_and_drop() series)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
  direct-io: Handle O_(D)SYNC AIO
  direct-io: Implement generic deferred AIO completions
  add formats for dentry/file pathnames
  kvm eventfd: switch to fdget
  powerpc kvm: use fdget
  switch fchmod() to fdget
  switch epoll_ctl() to fdget
  switch copy_module_from_fd() to fdget
  git simplify nilfs check for busy subtree
  ibmasmfs: don't bother passing superblock when not needed
  don't pass superblock to hypfs_{mkdir,create*}
  don't pass superblock to hypfs_diag_create_files
  don't pass superblock to hypfs_vm_create_files()
  oprofile: get rid of pointless forward declarations of struct super_block
  oprofilefs_create_...() do not need superblock argument
  oprofilefs_mkdir() doesn't need superblock argument
  don't bother with passing superblock to oprofile_create_stats_files()
  oprofile: don't bother with passing superblock to ->create_files()
  don't bother passing sb to oprofile_create_files()
  coh901318: don't open-code simple_read_from_buffer()
  ...
2013-09-05 08:50:26 -07:00
Christoph Hellwig 7b7a8665ed direct-io: Implement generic deferred AIO completions
Add support to the core direct-io code to defer AIO completions to user
context using a workqueue.  This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.

The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.

Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara.  I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.

JK: Fixed ext4 part, dynamic allocation of the workqueue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-04 09:23:46 -04:00
Al Viro badcf2b7b8 constify touch_atime()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-09-03 22:52:45 -04:00
Eric W. Biederman e51db73532 userns: Better restrictions on when proc and sysfs can be mounted
Rely on the fact that another flavor of the filesystem is already
mounted and do not rely on state in the user namespace.

Verify that the mounted filesystem is not covered in any significant
way.  I would love to verify that the previously mounted filesystem
has no mounts on top but there are at least the directories
/proc/sys/fs/binfmt_misc and /sys/fs/cgroup/ that exist explicitly
for other filesystems to mount on top of.

Refactor the test into a function named fs_fully_visible and call that
function from the mount routines of proc and sysfs.  This makes this
test local to the filesystems involved and the results current of when
the mounts take place, removing a weird threading of the user
namespace, the mount namespace and the filesystems themselves.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2013-08-26 19:17:03 -07:00
Jan Kara 1c8924eb10 quota: provide interface for readding allocated space into reserved space
ext4 needs to convert allocated (metadata) blocks back into blocks
reserved for delayed allocation. Add functions into quota code for
supporting such operation.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2013-08-17 09:32:32 -04:00
Linus Torvalds 41d9884c44 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs stuff from Al Viro:
 "O_TMPFILE ABI changes, Oleg's fput() series, misc cleanups, including
  making simple_lookup() usable for filesystems with non-NULL s_d_op,
  which allows us to get rid of quite a bit of ugliness"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  sunrpc: now we can just set ->s_d_op
  cgroup: we can use simple_lookup() now
  efivarfs: we can use simple_lookup() now
  make simple_lookup() usable for filesystems that set ->s_d_op
  configfs: don't open-code d_alloc_name()
  __rpc_lookup_create_exclusive: pass string instead of qstr
  rpc_create_*_dir: don't bother with qstr
  llist: llist_add() can use llist_add_batch()
  llist: fix/simplify llist_add() and llist_add_batch()
  fput: turn "list_head delayed_fput_list" into llist_head
  fs/file_table.c:fput(): add comment
  Safer ABI for O_TMPFILE
2013-07-14 11:42:26 -07:00
Oleg Nesterov 4f5e65a1cc fput: turn "list_head delayed_fput_list" into llist_head
fput() and delayed_fput() can use llist and avoid the locking.

This is unlikely path, it is not that this change can improve
the performance, but this way the code looks simpler.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-13 13:29:10 +04:00
Linus Torvalds a82a729f04 Merge branch 'akpm' (updates from Andrew Morton)
Merge second patch-bomb from Andrew Morton:
 - misc fixes
 - audit stuff
 - fanotify/inotify/dnotify things
 - most of the rest of MM.  The new cache shrinker code from Glauber and
   Dave Chinner probably isn't quite stabilized yet.
 - ptrace
 - ipc
 - partitions
 - reboot cleanups
 - add LZ4 decompressor, use it for kernel compression

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (118 commits)
  lib/scatterlist: error handling in __sg_alloc_table()
  scsi_debug: fix do_device_access() with wrap around range
  crypto: talitos: use sg_pcopy_to_buffer()
  lib/scatterlist: introduce sg_pcopy_from_buffer() and sg_pcopy_to_buffer()
  lib/scatterlist: factor out sg_miter_get_next_page() from sg_miter_next()
  crypto: add lz4 Cryptographic API
  lib: add lz4 compressor module
  arm: add support for LZ4-compressed kernel
  lib: add support for LZ4-compressed kernel
  decompressor: add LZ4 decompressor module
  lib: add weak clz/ctz functions
  reboot: move arch/x86 reboot= handling to generic kernel
  reboot: arm: change reboot_mode to use enum reboot_mode
  reboot: arm: prepare reboot_mode for moving to generic kernel code
  reboot: arm: remove unused restart_mode fields from some arm subarchs
  reboot: unicore32: prepare reboot_mode for moving to generic kernel code
  reboot: x86: prepare reboot_mode for moving to generic kernel code
  reboot: checkpatch.pl the new kernel/reboot.c file
  reboot: move shutdown/reboot related functions to kernel/reboot.c
  reboot: remove -stable friendly PF_THREAD_BOUND define
  ...
2013-07-09 13:33:36 -07:00
Tang Chen ef277c73ca page migration: fix wrong comment in address_space_operations.migratepage()
There is no parameter "sync" in address_space_operations->migratepage().
It should be migrate_mode.  And the comment is for MIGRATE_ASYNC.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-09 10:33:23 -07:00
Jan Kara a8855990e3 writeback: Do not sort b_io list only because of block device inode
It is very likely that block device inode will be part of BDI dirty list
as well. However it doesn't make sence to sort inodes on the b_io list
just because of this inode (as it contains buffers all over the device
anyway). So save some CPU cycles which is valuable since we hold relatively
contented wb->list_lock.

Signed-off-by: Jan Kara <jack@suse.cz>
2013-07-09 22:36:45 +08:00
Jeff Layton 7012b02a2b locks: move file_lock_list to a set of percpu hlist_heads and convert file_lock_lock to an lglock
The file_lock_list is only used for /proc/locks. The vastly common case
is for locks to be put onto the list and come off again, without ever
being traversed.

Help optimize for this use-case by moving to percpu hlist_head-s. At the
same time, we can make the locking less contentious by moving to an
lglock. When iterating over the lists for /proc/locks, we must take the
global lock and then iterate over each CPU's list in turn.

This change necessitates a new fl_link_cpu field to keep track of which
CPU the entry is on. On x86_64 at least, this field is placed within an
existing hole in the struct to avoid growing the size.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-08 13:36:42 +04:00
Mel Gorman b45972265f mm: vmscan: take page buffers dirty and locked state into account
Page reclaim keeps track of dirty and under writeback pages and uses it
to determine if wait_iff_congested() should stall or if kswapd should
begin writing back pages.  This fails to account for buffer pages that
can be under writeback but not PageWriteback which is the case for
filesystems like ext3 ordered mode.  Furthermore, PageDirty buffer pages
can have all the buffers clean and writepage does no IO so it should not
be accounted as congested.

This patch adds an address_space operation that filesystems may
optionally use to check if a page is really dirty or really under
writeback.  An implementation is provided for for buffer_heads is added
and used for block operations and ext3 in ordered mode.  By default the
page flags are obeyed.

Credit goes to Jan Kara for identifying that the page flags alone are
not sufficient for ext3 and sanity checking a number of ideas on how the
problem could be addressed.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Rik van Riel <riel@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Zlatko Calusic <zcalusic@bitsync.net>
Cc: dormando <dormando@rydia.net>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-07-03 16:07:29 -07:00
Linus Torvalds 790eac5640 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull second set of VFS changes from Al Viro:
 "Assorted f_pos race fixes, making do_splice_direct() safe to call with
  i_mutex on parent, O_TMPFILE support, Jeff's locks.c series,
  ->d_hash/->d_compare calling conventions changes from Linus, misc
  stuff all over the place."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
  Document ->tmpfile()
  ext4: ->tmpfile() support
  vfs: export lseek_execute() to modules
  lseek_execute() doesn't need an inode passed to it
  block_dev: switch to fixed_size_llseek()
  cpqphp_sysfs: switch to fixed_size_llseek()
  tile-srom: switch to fixed_size_llseek()
  proc_powerpc: switch to fixed_size_llseek()
  ubi/cdev: switch to fixed_size_llseek()
  pci/proc: switch to fixed_size_llseek()
  isapnp: switch to fixed_size_llseek()
  lpfc: switch to fixed_size_llseek()
  locks: give the blocked_hash its own spinlock
  locks: add a new "lm_owner_key" lock operation
  locks: turn the blocked_list into a hashtable
  locks: convert fl_link to a hlist_node
  locks: avoid taking global lock if possible when waking up blocked waiters
  locks: protect most of the file_lock handling with i_lock
  locks: encapsulate the fl_link list handling
  locks: make "added" in __posix_lock_file a bool
  ...
2013-07-03 09:10:19 -07:00
Jie Liu 46a1c2c7ae vfs: export lseek_execute() to modules
For those file systems(btrfs/ext4/ocfs2/tmpfs) that support
SEEK_DATA/SEEK_HOLE functions, we end up handling the similar
matter in lseek_execute() to update the current file offset
to the desired offset if it is valid, ceph also does the
simliar things at ceph_llseek().

To reduce the duplications, this patch make lseek_execute()
public accessible so that we can call it directly from the
underlying file systems.

Thanks Dave Chinner for this suggestion.

[AV: call it vfs_setpos(), don't bring the removed 'inode' argument back]

v2->v1:
- Add kernel-doc comments for lseek_execute()
- Call lseek_execute() in ceph->llseek()

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Ted Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-07-03 16:23:27 +04:00
Linus Torvalds 9e239bb939 Lots of bug fixes, cleanups and optimizations. In the bug fixes
category, of note is a fix for on-line resizing file systems where the
 block size is smaller than the page size (i.e., file systems 1k blocks
 on x86, or more interestingly file systems with 4k blocks on Power or
 ia64 systems.)
 
 In the cleanup category, the ext4's punch hole implementation was
 significantly improved by Lukas Czerner, and now supports bigalloc
 file systems.  In addition, Jan Kara significantly cleaned up the
 write submission code path.  We also improved error checking and added
 a few sanity checks.
 
 In the optimizations category, two major optimizations deserve
 mention.  The first is that ext4_writepages() is now used for
 nodelalloc and ext3 compatibility mode.  This allows writes to be
 submitted much more efficiently as a single bio request, instead of
 being sent as individual 4k writes into the block layer (which then
 relied on the elevator code to coalesce the requests in the block
 queue).  Secondly, the extent cache shrink mechanism, which was
 introduce in 3.9, no longer has a scalability bottleneck caused by the
 i_es_lru spinlock.  Other optimizations include some changes to reduce
 CPU usage and to avoid issuing empty commits unnecessarily.
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Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 update from Ted Ts'o:
 "Lots of bug fixes, cleanups and optimizations.  In the bug fixes
  category, of note is a fix for on-line resizing file systems where the
  block size is smaller than the page size (i.e., file systems 1k blocks
  on x86, or more interestingly file systems with 4k blocks on Power or
  ia64 systems.)

  In the cleanup category, the ext4's punch hole implementation was
  significantly improved by Lukas Czerner, and now supports bigalloc
  file systems.  In addition, Jan Kara significantly cleaned up the
  write submission code path.  We also improved error checking and added
  a few sanity checks.

  In the optimizations category, two major optimizations deserve
  mention.  The first is that ext4_writepages() is now used for
  nodelalloc and ext3 compatibility mode.  This allows writes to be
  submitted much more efficiently as a single bio request, instead of
  being sent as individual 4k writes into the block layer (which then
  relied on the elevator code to coalesce the requests in the block
  queue).  Secondly, the extent cache shrink mechanism, which was
  introduce in 3.9, no longer has a scalability bottleneck caused by the
  i_es_lru spinlock.  Other optimizations include some changes to reduce
  CPU usage and to avoid issuing empty commits unnecessarily."

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (86 commits)
  ext4: optimize starting extent in ext4_ext_rm_leaf()
  jbd2: invalidate handle if jbd2_journal_restart() fails
  ext4: translate flag bits to strings in tracepoints
  ext4: fix up error handling for mpage_map_and_submit_extent()
  jbd2: fix theoretical race in jbd2__journal_restart
  ext4: only zero partial blocks in ext4_zero_partial_blocks()
  ext4: check error return from ext4_write_inline_data_end()
  ext4: delete unnecessary C statements
  ext3,ext4: don't mess with dir_file->f_pos in htree_dirblock_to_tree()
  jbd2: move superblock checksum calculation to jbd2_write_superblock()
  ext4: pass inode pointer instead of file pointer to punch hole
  ext4: improve free space calculation for inline_data
  ext4: reduce object size when !CONFIG_PRINTK
  ext4: improve extent cache shrink mechanism to avoid to burn CPU time
  ext4: implement error handling of ext4_mb_new_preallocation()
  ext4: fix corruption when online resizing a fs with 1K block size
  ext4: delete unused variables
  ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extents
  jbd2: remove debug dependency on debug_fs and update Kconfig help text
  jbd2: use a single printk for jbd_debug()
  ...
2013-07-02 09:39:34 -07:00
Jeff Layton 3999e49364 locks: add a new "lm_owner_key" lock operation
Currently, the hashing that the locking code uses to add these values
to the blocked_hash is simply calculated using fl_owner field. That's
valid in most cases except for server-side lockd, which validates the
owner of a lock based on fl_owner and fl_pid.

In the case where you have a small number of NFS clients doing a lot
of locking between different processes, you could end up with all
the blocked requests sitting in a very small number of hash buckets.

Add a new lm_owner_key operation to the lock_manager_operations that
will generate an unsigned long to use as the key in the hashtable.
That function is only implemented for server-side lockd, and simply
XORs the fl_owner and fl_pid.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:45 +04:00
Jeff Layton 139ca04ee5 locks: convert fl_link to a hlist_node
Testing has shown that iterating over the blocked_list for deadlock
detection turns out to be a bottleneck. In order to alleviate that,
begin the process of turning it into a hashtable. We start by turning
the fl_link into a hlist_node and the global lists into hlists. A later
patch will do the conversion of the blocked_list to a hashtable.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:44 +04:00
Jeff Layton 1c8c601a8c locks: protect most of the file_lock handling with i_lock
Having a global lock that protects all of this code is a clear
scalability problem. Instead of doing that, move most of the code to be
protected by the i_lock instead. The exceptions are the global lists
that the ->fl_link sits on, and the ->fl_block list.

->fl_link is what connects these structures to the
global lists, so we must ensure that we hold those locks when iterating
over or updating these lists.

Furthermore, sound deadlock detection requires that we hold the
blocked_list state steady while checking for loops. We also must ensure
that the search and update to the list are atomic.

For the checking and insertion side of the blocked_list, push the
acquisition of the global lock into __posix_lock_file and ensure that
checking and update of the  blocked_list is done without dropping the
lock in between.

On the removal side, when waking up blocked lock waiters, take the
global lock before walking the blocked list and dequeue the waiters from
the global list prior to removal from the fl_block list.

With this, deadlock detection should be race free while we minimize
excessive file_lock_lock thrashing.

Finally, in order to avoid a lock inversion problem when handling
/proc/locks output we must ensure that manipulations of the fl_block
list are also protected by the file_lock_lock.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:42 +04:00
Jeff Layton 1cb3601259 locks: comment cleanups and clarifications
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:39 +04:00
Jeff Layton 1a9e64a711 cifs: use posix_unblock_lock instead of locks_delete_block
commit 66189be74 (CIFS: Fix VFS lock usage for oplocked files) exported
the locks_delete_block symbol. There's already an exported helper
function that provides this capability however, so make cifs use that
instead and turn locks_delete_block back into a static function.

Note that if fl->fl_next == NULL then this lock has already been through
locks_delete_block(), so we should be OK to ignore an ENOENT error here
and simply not retry the lock.

Cc: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:38 +04:00
Jeff Layton f891a29f46 locks: drop the unused filp argument to posix_unblock_lock
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:37 +04:00
Al Viro 68d70d03f8 constify rw_verify_area()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:34 +04:00
Al Viro 1bf9d14dff new helper: fixed_size_llseek()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:26 +04:00
Al Viro 0b3fca1fd1 kill find_inode_number()
the only remaining caller (in ncpfs) is guaranteed to return 0 -
we only hit it if we'd just checked that there's no dentry with
such name.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:20 +04:00
Al Viro f4e0c30c19 allow the temp files created by open() to be linked to
O_TMPFILE | O_CREAT => linkat() with AT_SYMLINK_FOLLOW and /proc/self/fd/<n>
as oldpath (i.e. flink()) will create a link
O_TMPFILE | O_CREAT | O_EXCL => ENOENT on attempt to link those guys

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:11 +04:00
Al Viro 60545d0d46 [O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:10 +04:00
Al Viro ac6614b764 [readdir] constify ->actor
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:05 +04:00
Al Viro 2233f31aad [readdir] ->readdir() is gone
everything's converted to ->iterate()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:57:04 +04:00
Al Viro 5ded75ec4c [readdir] convert ext3
new helper: dir_relax(inode).  Call when you are in location that will
_not_ be invalidated by directory modifications (block boundary, in case
of ext*).  Returns whether the directory has survived (dropping i_mutex
allows rmdir to kill the sucker; if it returns false to us, ->iterate()
is obviously done)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:49 +04:00
Al Viro 5f99f4e79a [readdir] switch dcache_readdir() users to ->iterate()
new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx),
dir_emit_dots(file, ctx).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:48 +04:00
Al Viro bb6f619b3a [readdir] introduce ->iterate(), ctx->pos, dir_emit()
New method - ->iterate(file, ctx).  That's the replacement for ->readdir();
it takes callback from ctx->actor, uses ctx->pos instead of file->f_pos and
calls dir_emit(ctx, ...) instead of filldir(data, ...).  It does *not*
update file->f_pos (or look at it, for that matter); iterate_dir() does the
update.

Note that dir_emit() takes the offset from ctx->pos (and eventually
filldir_t will lose that argument).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:47 +04:00
Al Viro 5c0ba4e076 [readdir] introduce iterate_dir() and dir_context
iterate_dir(): new helper, replacing vfs_readdir().

struct dir_context: contains the readdir callback (and will get more stuff
in it), embedded into whatever data that callback wants to deal with;
eventually, we'll be passing it to ->readdir() replacement instead of
(data,filldir) pair.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-29 12:46:46 +04:00
Al Viro 7995bd2871 splice: don't pass the address of ->f_pos to methods
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-06-20 19:02:45 +04:00
Lukas Czerner d47992f86b mm: change invalidatepage prototype to accept length
Currently there is no way to truncate partial page where the end
truncate point is not at the end of the page. This is because it was not
needed and the functionality was enough for file system truncate
operation to work properly. However more file systems now support punch
hole feature and it can benefit from mm supporting truncating page just
up to the certain point.

Specifically, with this functionality truncate_inode_pages_range() can
be changed so it supports truncating partial page at the end of the
range (currently it will BUG_ON() if 'end' is not at the end of the
page).

This commit changes the invalidatepage() address space operation
prototype to accept range to be invalidated and update all the instances
for it.

We also change the block_invalidatepage() in the same way and actually
make a use of the new length argument implementing range invalidation.

Actual file system implementations will follow except the file systems
where the changes are really simple and should not change the behaviour
in any way .Implementation for truncate_page_range() which will be able
to accept page unaligned ranges will follow as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
2013-05-21 23:17:23 -04:00
Al Viro 4385bab128 make blkdev_put() return void
same story as with the previous patches - note that return
value of blkdev_close() is lost, since there's nowhere the
caller (__fput()) could return it to.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-07 02:16:31 -04:00
Jan Kara 5ae98f1589 fs: Fix hang with BSD accounting on frozen filesystem
When BSD process accounting is enabled and logs information to a
filesystem which gets frozen, system easily becomes unusable because
each attempt to account process information blocks. Thus e.g. every task
gets blocked in exit.

It seems better to drop accounting information (which can already happen
when filesystem is running out of space) instead of locking system up.
So we just skip the write if the filesystem is frozen.

Reported-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-05-04 14:57:58 -04:00
Linus Torvalds 20b4fb4852 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS updates from Al Viro,

Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).

7kloc removed.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
  don't bother with deferred freeing of fdtables
  proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
  proc: Make the PROC_I() and PDE() macros internal to procfs
  proc: Supply a function to remove a proc entry by PDE
  take cgroup_open() and cpuset_open() to fs/proc/base.c
  ppc: Clean up scanlog
  ppc: Clean up rtas_flash driver somewhat
  hostap: proc: Use remove_proc_subtree()
  drm: proc: Use remove_proc_subtree()
  drm: proc: Use minor->index to label things, not PDE->name
  drm: Constify drm_proc_list[]
  zoran: Don't print proc_dir_entry data in debug
  reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
  proc: Supply an accessor for getting the data from a PDE's parent
  airo: Use remove_proc_subtree()
  rtl8192u: Don't need to save device proc dir PDE
  rtl8187se: Use a dir under /proc/net/r8180/
  proc: Add proc_mkdir_data()
  proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
  proc: Move PDE_NET() to fs/proc/proc_net.c
  ...
2013-05-01 17:51:54 -07:00
Fan Du 74e3d1e17b include/linux/fs.h: disable preempt when acquire i_size_seqcount write lock
Two rt tasks bind to one CPU core.

The higher priority rt task A preempts a lower priority rt task B which
has already taken the write seq lock, and then the higher priority rt
task A try to acquire read seq lock, it's doomed to lockup.

rt task A with lower priority: call write
i_size_write                                        rt task B with higher priority: call sync, and preempt task A
  write_seqcount_begin(&inode->i_size_seqcount);    i_size_read
  inode->i_size = i_size;                             read_seqcount_begin <-- lockup here...

So disable preempt when acquiring every i_size_seqcount *write* lock will
cure the problem.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:03 -07:00
Al Viro 599a0ac14e pipe: fold file_operations instances in one
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:12:58 -04:00
Al Viro 8d71db4f08 lift sb_start_write/sb_end_write out of ->aio_write()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-04-09 14:12:55 -04:00