Commit Graph

33433 Commits

Author SHA1 Message Date
Miklos Szeredi 5ca1db41ec GFS2: fix dentry leaks
We need to dput() the result of d_splice_alias(), unless it is passed to
finish_no_open().

Edited by Steven Whitehouse in order to make it apply to the current
GFS2 git tree, and taking account of a prerequisite patch which hasn't
been applied.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: stable@vger.kernel.org
2013-09-23 13:30:57 +01:00
Bob Peterson 149ed7f51e GFS2: new function gfs2_rbm_incr
Since the previous patch eliminated bi in favor of bii, this follow-on
patch needed to be adjusted accordingly. Here is the revised version.

This patch adds a new function, gfs2_rbm_incr, which increments
an rbm structure. This is more efficient than calling gfs2_rbm_to_block,
incrementing, then calling gfs2_rbm_from_block.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-09-18 10:40:38 +01:00
Bob Peterson e579ed4f44 GFS2: Introduce rbm field bii
This is a respin of the original patch. As Steve pointed out, the
introduction of field bii makes it easy to eliminate bi itself.
This revised patch does just that, replacing bi with bii.

This patch adds a new field to the rbm structure, called bii,
which is an index into the array of bitmaps for an rgrp.
This replaces *bi which was a pointer to the bitmap.
This is being done for further optimizations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-09-18 10:39:53 +01:00
Bob Peterson b870890519 GFS2: Do not reset flags on active reservations
When we used try locks for rgrps on block allocations, it was important
to clear the flags field so that we used a blocking hold on the glock.
Now that we're not doing try locks, clearing flags is unnecessary, and
a waste of time. In fact, it's probably doing the wrong thing because
it clears the GL_SKIP bit that was set for the lvb tracking purposes.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-09-17 10:19:29 +01:00
Bob Peterson 7e230f5774 GFS2: introduce bi_blocks for optimization
This patch introduces a new field in the bitmap structure called
bi_blocks. Its purpose is to save us from constantly multiplying
bi_len by the constant GFS2_NBBY. It also paves the way for more
optimization in a future patch.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-09-17 10:15:13 +01:00
Bob Peterson 6aa7640f30 GFS2: optimize rbm_from_block wrt bi_start
In function gfs2_rbm_from_block, it starts by checking if the block
falls within the first bitmap. It does so by checking if the rbm's
offset is less than (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY.
However, the first bitmap will always have bi_start==0. Therefore
this is an unnecessary calculation in a function that gets called
billions of times. This patch removes the reference to bi_start.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2013-09-17 10:14:39 +01:00
Miklos Szeredi 0d0d110720 GFS2: d_splice_alias() can't return error
unless it was given an IS_ERR(inode), which isn't the case here.  So clean
up the unnecessary error handling in gfs2_create_inode().

This paves the way for real fixes (hence the stable Cc).

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: stable@vger.kernel.org
2013-09-17 10:04:07 +01:00
Linus Torvalds 3369d11693 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS fixes from Steve French:
 "Two minor cifs fixes and a minor documentation cleanup for cifs.txt"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: update cifs.txt and remove some outdated infos
  cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscache
  cifs: Do not take a reference to the page in cifs_readpage_worker()
2013-09-16 15:39:21 -04:00
Linus Torvalds 098e7f1665 Just one patch which fixes the power-cut recovery testing mode.
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Merge tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs

Pull ubifs fix from Artem Bityutskiy:
 "Just one patch which fixes the power-cut recovery testing mode.

  I'll start using a single UBI/UBIFS tree instead of 2 trees from now
  on.  So in the future you'll get 1 small pull request instead of 2
  tiny ones"

* tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs:
  UBIFS: remove invalid warn msg with tst_recovery enabled
2013-09-16 15:36:55 -04:00
Linus Torvalds 05a8252bde vfs: fix typo in comment in recent dentry work
Sedat points out that I transposed some letters in "LRU" and wrote "RLU"
instead in one of the new comments explaining the flow.  Let's just fix
it.

Reported-by: Sedat Dilek <sedat.dilek@jpberlin.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-15 07:11:01 -04:00
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
Linus Torvalds 89dc77bcda vfs: fix dentry LRU list handling and nr_dentry_unused accounting
The LRU list changes interacted badly with our nr_dentry_unused
accounting, and even worse with the new DCACHE_LRU_LIST bit logic.

This introduces helper functions to make sure everything follows the
proper dcache d_lru list rules: the dentry cache is complicated by the
fact that some of the hotpaths don't even want to look at the LRU list
at all, and the fact that we use the same list entry in the dentry for
both the LRU list and for our temporary shrinking lists when removing
things from the LRU.

The helper functions temporarily have some extra sanity checking for the
flag bits that have to match the current LRU state of the dentry.  We'll
remove that before the final 3.12 release, but considering how easy it
is to get wrong, this first cleanup version has some very particular
sanity checking.

Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-13 22:55:10 -04:00
Sachin Prabhu 466bd31bbd cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscache
When reading a single page with cifs_readpage(), we make a call to
fscache_read_or_alloc_page() which once done, asynchronously calls
the completion function cifs_readpage_from_fscache_complete(). This
completion function unlocks the page once it has been populated from
cache. The module then attempts to unlock the page a second time in
cifs_readpage() which leads to warning messages.

In case of a successful call to fscache_read_or_alloc_page() we should skip
the second unlock_page() since this will be called by the
cifs_readpage_from_fscache_complete() once the page has been populated by
fscache.

With the modifications to cifs_readpage_worker(), we will need to re-grab the
page lock in cifs_write_begin().

The problem was first noticed when testing new fscache patches for cifs.
https://bugzilla.redhat.com/show_bug.cgi?id=1005737

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-13 16:24:49 -05:00
Sachin Prabhu a9e9b7bc15 cifs: Do not take a reference to the page in cifs_readpage_worker()
We do not need to take a reference to the pagecache in
cifs_readpage_worker() since the calling function will have already
taken one before passing the pointer to the page as an argument to the
function.

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2013-09-13 16:24:43 -05:00
Linus Torvalds 9bf12df31f Merge git://git.kvack.org/~bcrl/aio-next
Pull aio changes from Ben LaHaise:
 "First off, sorry for this pull request being late in the merge window.
  Al had raised a couple of concerns about 2 items in the series below.
  I addressed the first issue (the race introduced by Gu's use of
  mm_populate()), but he has not provided any further details on how he
  wants to rework the anon_inode.c changes (which were sent out months
  ago but have yet to be commented on).

  The bulk of the changes have been sitting in the -next tree for a few
  months, with all the issues raised being addressed"

* git://git.kvack.org/~bcrl/aio-next: (22 commits)
  aio: rcu_read_lock protection for new rcu_dereference calls
  aio: fix race in ring buffer page lookup introduced by page migration support
  aio: fix rcu sparse warnings introduced by ioctx table lookup patch
  aio: remove unnecessary debugging from aio_free_ring()
  aio: table lookup: verify ctx pointer
  staging/lustre: kiocb->ki_left is removed
  aio: fix error handling and rcu usage in "convert the ioctx list to table lookup v3"
  aio: be defensive to ensure request batching is non-zero instead of BUG_ON()
  aio: convert the ioctx list to table lookup v3
  aio: double aio_max_nr in calculations
  aio: Kill ki_dtor
  aio: Kill ki_users
  aio: Kill unneeded kiocb members
  aio: Kill aio_rw_vect_retry()
  aio: Don't use ctx->tail unnecessarily
  aio: io_cancel() no longer returns the io_event
  aio: percpu ioctx refcount
  aio: percpu reqs_available
  aio: reqs_active -> reqs_available
  aio: fix build when migration is disabled
  ...
2013-09-13 10:55:58 -07:00
Linus Torvalds e0ea4045bc xfs: update #2 for v3.12-rc1
Here we have defrag support for v5 superblock, a number of bugfixes and
 a cleanup or two.
 
 - defrag support for CRC filesystems
 - fix endian worning in xlog_recover_get_buf_lsn
 - fixes for sparse warnings
 - fix for assert in xfs_dir3_leaf_hdr_from_disk
 - fix for log recovery of remote symlinks
 - fix for log recovery of btree root splits
 - fixes formemory allocation failures with ACLs
 - fix for assert in xfs_buf_item_relse
 - fix for assert in xfs_inode_buf_verify
 - fix an assignment in an assert that should be a test in
   xfs_bmbt_change_owner
 - remove dead code in xlog_recover_inode_pass2
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Merge tag 'xfs-for-linus-v3.12-rc1-2' of git://oss.sgi.com/xfs/xfs

Pull xfs update #2 from Ben Myers:
 "Here we have defrag support for v5 superblock, a number of bugfixes
  and a cleanup or two.

   - defrag support for CRC filesystems
   - fix endian worning in xlog_recover_get_buf_lsn
   - fixes for sparse warnings
   - fix for assert in xfs_dir3_leaf_hdr_from_disk
   - fix for log recovery of remote symlinks
   - fix for log recovery of btree root splits
   - fixes formemory allocation failures with ACLs
   - fix for assert in xfs_buf_item_relse
   - fix for assert in xfs_inode_buf_verify
   - fix an assignment in an assert that should be a test in
     xfs_bmbt_change_owner
   - remove dead code in xlog_recover_inode_pass2"

* tag 'xfs-for-linus-v3.12-rc1-2' of git://oss.sgi.com/xfs/xfs:
  xfs: remove dead code from xlog_recover_inode_pass2
  xfs: = vs == typo in ASSERT()
  xfs: don't assert fail on bad inode numbers
  xfs: aborted buf items can be in the AIL.
  xfs: factor all the kmalloc-or-vmalloc fallback allocations
  xfs: fix memory allocation failures with ACLs
  xfs: ensure we copy buffer type in da btree root splits
  xfs: set remote symlink buffer type for recovery
  xfs: recovery of swap extents operations for CRC filesystems
  xfs: swap extents operations for CRC filesystems
  xfs: check magic numbers in dir3 leaf verifier first
  xfs: fix some minor sparse warnings
  xfs: fix endian warning in xlog_recover_get_buf_lsn()
2013-09-12 16:13:41 -07:00
Linus Torvalds ac4de9543a Merge branch 'akpm' (patches from Andrew Morton)
Merge more patches from Andrew Morton:
 "The rest of MM.  Plus one misc cleanup"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  mm/Kconfig: add MMU dependency for MIGRATION.
  kernel: replace strict_strto*() with kstrto*()
  mm, thp: count thp_fault_fallback anytime thp fault fails
  thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()
  thp: do_huge_pmd_anonymous_page() cleanup
  thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
  mm: cleanup add_to_page_cache_locked()
  thp: account anon transparent huge pages into NR_ANON_PAGES
  truncate: drop 'oldsize' truncate_pagecache() parameter
  mm: make lru_add_drain_all() selective
  memcg: document cgroup dirty/writeback memory statistics
  memcg: add per cgroup writeback pages accounting
  memcg: check for proper lock held in mem_cgroup_update_page_stat
  memcg: remove MEMCG_NR_FILE_MAPPED
  memcg: reduce function dereference
  memcg: avoid overflow caused by PAGE_ALIGN
  memcg: rename RESOURCE_MAX to RES_COUNTER_MAX
  memcg: correct RESOURCE_MAX to ULLONG_MAX
  mm: memcg: do not trap chargers with full callstack on OOM
  mm: memcg: rework and document OOM waiting and wakeup
  ...
2013-09-12 15:44:27 -07:00
Kirill A. Shutemov 3cd14fcd3f thp: account anon transparent huge pages into NR_ANON_PAGES
We use NR_ANON_PAGES as base for reporting AnonPages to user.  There's
not much sense in not accounting transparent huge pages there, but add
them on printing to user.

Let's account transparent huge pages in NR_ANON_PAGES in the first place.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Ning Qu <quning@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:03 -07:00
Kirill A. Shutemov 7caef26767 truncate: drop 'oldsize' truncate_pagecache() parameter
truncate_pagecache() doesn't care about old size since commit
cedabed49b ("vfs: Fix vmtruncate() regression").  Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:02 -07:00
Linus Torvalds 26935fb06e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pile 4 from Al Viro:
 "list_lru pile, mostly"

This came out of Andrew's pile, Al ended up doing the merge work so that
Andrew didn't have to.

Additionally, a few fixes.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (42 commits)
  super: fix for destroy lrus
  list_lru: dynamically adjust node arrays
  shrinker: Kill old ->shrink API.
  shrinker: convert remaining shrinkers to count/scan API
  staging/lustre/libcfs: cleanup linux-mem.h
  staging/lustre/ptlrpc: convert to new shrinker API
  staging/lustre/obdclass: convert lu_object shrinker to count/scan API
  staging/lustre/ldlm: convert to shrinkers to count/scan API
  hugepage: convert huge zero page shrinker to new shrinker API
  i915: bail out earlier when shrinker cannot acquire mutex
  drivers: convert shrinkers to new count/scan API
  fs: convert fs shrinkers to new scan/count API
  xfs: fix dquot isolation hang
  xfs-convert-dquot-cache-lru-to-list_lru-fix
  xfs: convert dquot cache lru to list_lru
  xfs: rework buffer dispose list tracking
  xfs-convert-buftarg-lru-to-generic-code-fix
  xfs: convert buftarg LRU to generic code
  fs: convert inode and dentry shrinking to be node aware
  vmscan: per-node deferred work
  ...
2013-09-12 15:01:38 -07:00
Linus Torvalds 1d7b24ff33 NFS client bugfixes:
- Fix a few credential reference leaks resulting from the SP4_MACH_CRED
   NFSv4.1 state protection code.
 - Fix the SUNRPC bloatometer footprint: convert a 256K hashtable into the
   intended 64 byte structure.
 - Fix a long standing XDR issue with FREE_STATEID
 - Fix a potential WARN_ON spamming issue
 - Fix a missing dprintk() kuid conversion
 
 New features:
 - Enable the NFSv4.1 state protection support for the WRITE and COMMIT
   operations.
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Merge tag 'nfs-for-3.12-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes (part 2) from Trond Myklebust:
 "Bugfixes:
   - Fix a few credential reference leaks resulting from the
     SP4_MACH_CRED NFSv4.1 state protection code.
   - Fix the SUNRPC bloatometer footprint: convert a 256K hashtable into
     the intended 64 byte structure.
   - Fix a long standing XDR issue with FREE_STATEID
   - Fix a potential WARN_ON spamming issue
   - Fix a missing dprintk() kuid conversion

  New features:
   - Enable the NFSv4.1 state protection support for the WRITE and
     COMMIT operations"

* tag 'nfs-for-3.12-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: No, I did not intend to create a 256KiB hashtable
  sunrpc: Add missing kuids conversion for printing
  NFSv4.1: sp4_mach_cred: WARN_ON -> WARN_ON_ONCE
  NFSv4.1: sp4_mach_cred: no need to ref count creds
  NFSv4.1: fix SECINFO* use of put_rpccred
  NFSv4.1: sp4_mach_cred: ask for WRITE and COMMIT
  NFSv4.1 fix decode_free_stateid
2013-09-12 13:39:34 -07:00
Linus Torvalds 68f0d9d92e vfs: make d_path() get the root path under RCU
This avoids the spinlocks and refcounts in the d_path() sequence too
(used by /proc and various other entities).  See commit 8b19e34188 for
the equivalent getcwd() system call path.

And unlike getcwd(), d_path() doesn't copy the result to user space, so
I don't need to fear _that_ particular bug happening again.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 13:24:55 -07:00
Linus Torvalds 3272c544da vfs: use __getname/__putname for getcwd() system call
It's a pathname.  It should use the pathname allocators and
deallocators, and PATH_MAX instead of PAGE_SIZE.  Never mind that the
two are commonly the same.

With this, the allocations scale up nicely too, and I can do getcwd()
system calls at a rate of about 300M/s, with no lock contention
anywhere.

Of course, nobody sane does that, especially since getcwd() is
traditionally a very slow operation in Unix.  But this was also the
simplest way to benchmark the prepend_path() improvements by Waiman, and
once I saw the profiles I couldn't leave it well enough alone.

But apart from being an performance improvement (from using per-cpu slab
allocators instead of the raw page allocator), it's actually a valid and
real cleanup.

Signed-off-by: Linus "OCD" Torvalds <torvalds@linux-foundation.org>
2013-09-12 12:40:15 -07:00
Linus Torvalds ff812d7242 vfs: don't copy things to user space holding the rcu readlock
Oops.  That wasn't very smart.  We don't actually need the RCU lock any
more by the time we copy the cwd string to user space, but I had
stupidly surrounded the whole thing with it.

Introduced by commit 8b19e34188 ("vfs: make getcwd() get the root and
pwd path under rcu")

Is-a-big-hairy-idiot: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 11:57:01 -07:00
Linus Torvalds 8b19e34188 vfs: make getcwd() get the root and pwd path under rcu
This allows us to skip all the crazy spinlocks and reference count
updates, and instead use the fs sequence read-lock to get an atomic
snapshot of the root and cwd information.

We might want to make the rule that "prepend_path()" is always called
with the RCU lock held, but the RCU lock nests fine and this is the
minimal fix.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 10:35:47 -07:00
Linus Torvalds 5762482f54 vfs: move get_fs_root_and_pwd() to single caller
Let's not pollute the include files with inline functions that are only
used in a single place.  Especially not if we decide we might want to
change the semantics of said function to make it more efficient..

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 10:12:47 -07:00
Linus Torvalds b7c09ad401 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "This is against 3.11-rc7, but was pulled and tested against your tree
  as of yesterday.  We do have two small incrementals queued up, but I
  wanted to get this bunch out the door before I hop on an airplane.

  This is a fairly large batch of fixes, performance improvements, and
  cleanups from the usual Btrfs suspects.

  We've included Stefan Behren's work to index subvolume UUIDs, which is
  targeted at speeding up send/receive with many subvolumes or snapshots
  in place.  It closes a long standing performance issue that was built
  in to the disk format.

  Mark Fasheh's offline dedup work is also here.  In this case offline
  means the FS is mounted and active, but the dedup work is not done
  inline during file IO.  This is a building block where utilities are
  able to ask the FS to dedup a series of extents.  The kernel takes
  care of verifying the data involved really is the same.  Today this
  involves reading both extents, but we'll continue to evolve the
  patches"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (118 commits)
  Btrfs: optimize key searches in btrfs_search_slot
  Btrfs: don't use an async starter for most of our workers
  Btrfs: only update disk_i_size as we remove extents
  Btrfs: fix deadlock in uuid scan kthread
  Btrfs: stop refusing the relocation of chunk 0
  Btrfs: fix memory leak of uuid_root in free_fs_info
  btrfs: reuse kbasename helper
  btrfs: return btrfs error code for dev excl ops err
  Btrfs: allow partial ordered extent completion
  Btrfs: convert all bug_ons in free-space-cache.c
  Btrfs: add support for asserts
  Btrfs: adjust the fs_devices->missing count on unmount
  Btrf: cleanup: don't check for root_refs == 0 twice
  Btrfs: fix for patch "cleanup: don't check the same thing twice"
  Btrfs: get rid of one BUG() in write_all_supers()
  Btrfs: allocate prelim_ref with a slab allocater
  Btrfs: pass gfp_t to __add_prelim_ref() to avoid always using GFP_ATOMIC
  Btrfs: fix race conditions in BTRFS_IOC_FS_INFO ioctl
  Btrfs: fix race between removing a dev and writing sbs
  Btrfs: remove ourselves from the cluster list under lock
  ...
2013-09-12 09:58:51 -07:00
Waiman Long 1812997720 dcache: get/release read lock in read_seqbegin_or_lock() & friend
This patch modifies read_seqbegin_or_lock() and need_seqretry() to use
newly introduced read_seqlock_excl() and read_sequnlock_excl()
primitives so that they won't change the sequence number even if they
fall back to take the lock.  This is OK as no change to the protected
data structure is being made.

It will prevent one fallback to lock taking from cascading into a series
of lock taking reducing performance because of the sequence number
change.  It will also allow other sequence readers to go forward while
an exclusive reader lock is taken.

This patch also updates some of the inaccurate comments in the code.

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
To: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 09:25:23 -07:00
Mark Tinguely 08474ed639 xfs: remove dead code from xlog_recover_inode_pass2
Additional code in the error handler of xlog_recover_inode_pass2()
results in the following error:

static checker warning: "fs/xfs/xfs_log_recover.c:2999
xlog_recover_inode_pass2()
	 info: ignoring unreachable code."

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Ben Myers <bpm@sgi.com
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-09-12 09:51:49 -05:00
Dan Carpenter aa9e10409e xfs: = vs == typo in ASSERT()
There is a '=' vs '==' typo so the ASSERT()s are always true.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
2013-09-12 09:42:08 -05:00
Linus Torvalds 7b7a2f0a31 Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS fixes from Steve French:
 "CIFS update including case insensitive file name matching improvements
  for UTF-8 to Unicode, various small cifs fixes, SMB2/SMB3 leasing
  improvements, support for following SMB2 symlinks, SMB3 packet signing
  improvements"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6: (25 commits)
  CIFS: Respect epoch value from create lease context v2
  CIFS: Add create lease v2 context for SMB3
  CIFS: Move parsing lease buffer to ops struct
  CIFS: Move creating lease buffer to ops struct
  CIFS: Store lease state itself rather than a mapped oplock value
  CIFS: Replace clientCanCache* bools with an integer
  [CIFS] quiet sparse compile warning
  cifs: Start using per session key for smb2/3 for signature generation
  cifs: Add a variable specific to NTLMSSP for key exchange.
  cifs: Process post session setup code in respective dialect functions.
  CIFS: convert to use le32_add_cpu()
  CIFS: Fix missing lease break
  CIFS: Fix a memory leak when a lease break comes
  cifs: add winucase_convert.pl to Documentation/ directory
  cifs: convert case-insensitive dentry ops to use new case conversion routines
  cifs: add new case-insensitive conversion routines that are based on wchar_t's
  [CIFS] Add Scott to list of cifs contributors
  cifs: Move and expand MAX_SERVER_SIZE definition
  cifs: Expand max share name length to 256
  cifs: Move string length definitions to uapi
  ...
2013-09-12 07:41:12 -07:00
Linus Torvalds 1ae276a911 Two small fixes to the code that initializes the per-file crypto
contexts.
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Merge tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull eCryptfs fixes from Tyler Hicks:
 "Two small fixes to the code that initializes the per-file crypto
  contexts"

* tag 'ecryptfs-3.12-rc1-crypt-ctx' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  ecryptfs: avoid ctx initialization race
  ecryptfs: remove check for if an array is NULL
2013-09-11 19:17:04 -07:00
Linus Torvalds c2d95729e3 Merge branch 'akpm' (patches from Andrew Morton)
Merge first patch-bomb from Andrew Morton:
 - Some pidns/fork/exec tweaks
 - OCFS2 updates
 - Most of MM - there remain quite a few memcg parts which depend on
   pending core cgroups changes.  Which might have been already merged -
   I'll check tomorrow...
 - Various misc stuff all over the place
 - A few block bits which I never got around to sending to Jens -
   relatively minor things.
 - MAINTAINERS maintenance
 - A small number of lib/ updates
 - checkpatch updates
 - epoll
 - firmware/dmi-scan
 - Some kprobes work for S390
 - drivers/rtc updates
 - hfsplus feature work
 - vmcore feature work
 - rbtree upgrades
 - AOE updates
 - pktcdvd cleanups
 - PPS
 - memstick
 - w1
 - New "inittmpfs" feature, which does the obvious
 - More IPC work from Davidlohr.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (303 commits)
  lz4: fix compression/decompression signedness mismatch
  ipc: drop ipc_lock_check
  ipc, shm: drop shm_lock_check
  ipc: drop ipc_lock_by_ptr
  ipc, shm: guard against non-existant vma in shmdt(2)
  ipc: document general ipc locking scheme
  ipc,msg: drop msg_unlock
  ipc: rename ids->rw_mutex
  ipc,shm: shorten critical region for shmat
  ipc,shm: cleanup do_shmat pasta
  ipc,shm: shorten critical region for shmctl
  ipc,shm: make shmctl_nolock lockless
  ipc,shm: introduce shmctl_nolock
  ipc: drop ipcctl_pre_down
  ipc,shm: shorten critical region in shmctl_down
  ipc,shm: introduce lockless functions to obtain the ipc object
  initmpfs: use initramfs if rootfstype= or root= specified
  initmpfs: make rootfs use tmpfs when CONFIG_TMPFS enabled
  initmpfs: move rootfs code from fs/ramfs/ to init/
  initmpfs: move bdi setup from init_rootfs to init_ramfs
  ...
2013-09-11 16:08:54 -07:00
Rob Landley 57f150a58c initmpfs: move rootfs code from fs/ramfs/ to init/
When the rootfs code was a wrapper around ramfs, having them in the same
file made sense.  Now that it can wrap another filesystem type, move it in
with the init code instead.

This also allows a subsequent patch to access rootfstype= command line
arg.

Signed-off-by: Rob Landley <rob@landley.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:37 -07:00
Rob Landley 4bbee76bc9 initmpfs: move bdi setup from init_rootfs to init_ramfs
Even though ramfs hasn't got a backing device, commit e0bf68ddec ("mm:
bdi init hooks") added one anyway, and put the initialization in
init_rootfs() since that's the first user, leaving it out of init_ramfs()
to avoid duplication.

But initmpfs uses init_tmpfs() instead, so move the init into the
filesystem's init function, add a "once" guard to prevent duplicate
initialization, and call the filesystem init from rootfs init.

This goes part of the way to allowing ramfs to be built as a module.

[akpm@linux-foundation.org; using bit 1 was odd]
Signed-off-by: Rob Landley <rob@landley.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:37 -07:00
Rob Landley 137fdcc18a initmpfs: replace MS_NOUSER in initramfs
Mounting MS_NOUSER prevents --bind mounts from rootfs.  Prevent new rootfs
mounts with a different mechanism that doesn't affect bind mounts.

Signed-off-by: Rob Landley <rob@landley.net>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jim Cromie <jim.cromie@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:36 -07:00
Jan Kara 5e4c0d9741 lib/radix-tree.c: make radix_tree_node_alloc() work correctly within interrupt
With users of radix_tree_preload() run from interrupt (block/blk-ioc.c is
one such possible user), the following race can happen:

radix_tree_preload()
...
radix_tree_insert()
  radix_tree_node_alloc()
    if (rtp->nr) {
      ret = rtp->nodes[rtp->nr - 1];
<interrupt>
...
radix_tree_preload()
...
radix_tree_insert()
  radix_tree_node_alloc()
    if (rtp->nr) {
      ret = rtp->nodes[rtp->nr - 1];

And we give out one radix tree node twice.  That clearly results in radix
tree corruption with different results (usually OOPS) depending on which
two users of radix tree race.

We fix the problem by making radix_tree_node_alloc() always allocate fresh
radix tree nodes when in interrupt.  Using preloading when in interrupt
doesn't make sense since all the allocations have to be atomic anyway and
we cannot steal nodes from process-context users because some users rely
on radix_tree_insert() succeeding after radix_tree_preload().
in_interrupt() check is somewhat ugly but we cannot simply key off passed
gfp_mask as that is acquired from root_gfp_mask() and thus the same for
all preload users.

Another part of the fix is to avoid node preallocation in
radix_tree_preload() when passed gfp_mask doesn't allow waiting.  Again,
preallocation in such case doesn't make sense and when preallocation would
happen in interrupt we could possibly leak some allocated nodes.  However,
some users of radix_tree_preload() require following radix_tree_insert()
to succeed.  To avoid unexpected effects for these users,
radix_tree_preload() only warns if passed gfp mask doesn't allow waiting
and we provide a new function radix_tree_maybe_preload() for those users
which get different gfp mask from different call sites and which are
prepared to handle radix_tree_insert() failure.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <jaxboe@fusionio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:36 -07:00
Dan Carpenter 6325932666 affs: use loff_t in affs_truncate()
It seems pretty unlikely that AFFS supports files over 4GB but we may as
well leave use loff_t just for cleanness sake instead of truncating it to
32 bits.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Marco Stornelli <marco.stornelli@gmail.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>
2013-09-11 15:59:29 -07:00
Michael Holzheu 11e376a3f9 vmcore: enable /proc/vmcore mmap for s390
The patch "s390/vmcore: Implement remap_oldmem_pfn_range for s390" allows
now to use mmap also on s390.

So enable mmap for s390 again.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:14 -07:00
Michael Holzheu 9cb218131d vmcore: introduce remap_oldmem_pfn_range()
For zfcpdump we can't map the HSA storage because it is only available via
a read interface.  Therefore, for the new vmcore mmap feature we have
introduce a new mechanism to create mappings on demand.

This patch introduces a new architecture function remap_oldmem_pfn_range()
that should be used to create mappings with remap_pfn_range() for oldmem
areas that can be directly mapped.  For zfcpdump this is everything
besides of the HSA memory.  For the areas that are not mapped by
remap_oldmem_pfn_range() a generic vmcore a new generic vmcore fault
handler mmap_vmcore_fault() is called.

This handler works as follows:

* Get already available or new page from page cache (find_or_create_page)
* Check if /proc/vmcore page is filled with data (PageUptodate)
* If yes:
  Return that page
* If no:
  Fill page using __vmcore_read(), set PageUptodate, and return page

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:10 -07:00
Michael Holzheu be8a8d069e vmcore: introduce ELF header in new memory feature
For s390 we want to use /proc/vmcore for our SCSI stand-alone dump
(zfcpdump).  We have support where the first HSA_SIZE bytes are saved into
a hypervisor owned memory area (HSA) before the kdump kernel is booted.
When the kdump kernel starts, it is restricted to use only HSA_SIZE bytes.

The advantages of this mechanism are:

 * No crashkernel memory has to be defined in the old kernel.
 * Early boot problems (before kexec_load has been done) can be dumped
 * Non-Linux systems can be dumped.

We modify the s390 copy_oldmem_page() function to read from the HSA memory
if memory below HSA_SIZE bytes is requested.

Since we cannot use the kexec tool to load the kernel in this scenario,
we have to build the ELF header in the 2nd (kdump/new) kernel.

So with the following patch set we would like to introduce the new
function that the ELF header for /proc/vmcore can be created in the 2nd
kernel memory.

The following steps are done during zfcpdump execution:

1.  Production system crashes
2.  User boots a SCSI disk that has been prepared with the zfcpdump tool
3.  Hypervisor saves CPU state of boot CPU and HSA_SIZE bytes of memory into HSA
4.  Boot loader loads kernel into low memory area
5.  Kernel boots and uses only HSA_SIZE bytes of memory
6.  Kernel saves registers of non-boot CPUs
7.  Kernel does memory detection for dump memory map
8.  Kernel creates ELF header for /proc/vmcore
9.  /proc/vmcore uses this header for initialization
10. The zfcpdump user space reads /proc/vmcore to write dump to SCSI disk
    - copy_oldmem_page() copies from HSA for memory below HSA_SIZE
    - copy_oldmem_page() copies from real memory for memory above HSA_SIZE

Currently for s390 we create the ELF core header in the 2nd kernel with a
small trick.  We relocate the addresses in the ELF header in a way that
for the /proc/vmcore code it seems to be in the 1st kernel (old) memory
and the read_from_oldmem() returns the correct data.  This allows the
/proc/vmcore code to use the ELF header in the 2nd kernel.

This patch:

Exchange the old mechanism with the new and much cleaner function call
override feature that now offcially allows to create the ELF core header
in the 2nd kernel.

To use the new feature the following function have to be defined
by the architecture backend code to read from new memory:

 * elfcorehdr_alloc: Allocate ELF header
 * elfcorehdr_free: Free the memory of the ELF header
 * elfcorehdr_read: Read from ELF header
 * elfcorehdr_read_notes: Read from ELF notes

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Jan Willeke <willeke@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:10 -07:00
Oleg Nesterov 6b3c538f5b exec: cleanup the error handling in search_binary_handler()
The error hanling and ret-from-loop look confusing and inconsistent.

- "retval >= 0" simply returns

- "!bprm->file" returns too but with read_unlock() because
   binfmt_lock was already re-acquired

- "retval != -ENOEXEC || bprm->mm == NULL" does "break" and
  relies on the same check after the main loop

Consolidate these checks into a single if/return statement.

need_retry still checks "retval == -ENOEXEC", but this and -ENOENT before
the main loop are not needed.  This is only for pathological and
impossible list_empty(&formats) case.

It is not clear why do we check "bprm->mm == NULL", probably this
should be removed.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:09 -07:00
Oleg Nesterov 4e0621a07e exec: don't retry if request_module() fails
A separate one-liner for better documentation.

It doesn't make sense to retry if request_module() fails to exec
/sbin/modprobe, add the additional "request_module() < 0" check.

However, this logic still doesn't look exactly right:

1. It would be better to check "request_module() != 0", the user
   space modprobe process should report the correct exit code.
   But I didn't dare to add the user-visible change.

2. The whole ENOEXEC logic looks suboptimal. Suppose that we try
   to exec a "#!path-to-unsupported-binary" script. In this case
   request_module() + "retry" will be done twice: first by the
   "depth == 1" code, and then again by the "depth == 0" caller
   which doesn't make sense.

3. And note that in the case above bprm->buf was already changed
   by load_script()->prepare_binprm(), so this looks even more
   ugly.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:07 -07:00
Oleg Nesterov cb7b6b1cbc exec: cleanup the CONFIG_MODULES logic
search_binary_handler() uses "for (try=0; try<2; try++)" to avoid "goto"
but the code looks too complicated and horrible imho.  We still need to
check "try == 0" before request_module() and add the additional "break"
for !CONFIG_MODULES case.

Kill this loop and use a simple "bool need_retry" + "goto retry".  The
code looks much simpler and we do not even need ifdef's, gcc can optimize
out the "if (need_retry)" block if !IS_ENABLED().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:05 -07:00
Oleg Nesterov 92eaa565ad exec: kill ->load_binary != NULL check in search_binary_handler()
search_binary_handler() checks ->load_binary != NULL for no reason, this
method should be always defined.  Turn this check into WARN_ON() and move
it into __register_binfmt().

Also, kill the function pointer.  The current code looks confusing, as if
->load_binary can go away after read_unlock(&binfmt_lock).  But we rely on
module_get(fmt->module), this fmt can't be changed or unregistered,
otherwise this code is buggy anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:05 -07:00
Oleg Nesterov 52f14282bb exec: move allow_write_access/fput to exec_binprm()
When search_binary_handler() succeeds it does allow_write_access() and
fput(), then it clears bprm->file to ensure the caller will not do the
same.

We can simply move this code to exec_binprm() which is called only once.
In fact we could move this to free_bprm() and remove the same code in
do_execve_common's error path.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:05 -07:00
Oleg Nesterov 9beb266f2d exec: proc_exec_connector() should be called only once
A separate one-liner with the minor fix.

PROC_EVENT_EXEC reports the "exec" event, but this message is sent at
least twice if search_binary_handler() is called by ->load_binary()
recursively, say, load_script().

Move it to exec_binprm(), this is "depth == 0" code too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:05 -07:00
Oleg Nesterov 131b2f9f12 exec: kill "int depth" in search_binary_handler()
Nobody except search_binary_handler() should touch ->recursion_depth, "int
depth" buys nothing but complicates the code, kill it.

Probably we should also kill "fn" and the !NULL check, ->load_binary
should be always defined.  And it can not go away after read_unlock() or
this code is buggy anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:04 -07:00
Oleg Nesterov 5d1baf3b63 exec: introduce exec_binprm() for "depth == 0" code
task_pid_nr_ns() and trace/ptrace code in the middle of the recursive
search_binary_handler() looks confusing and imho annoying.  We only need
this code if "depth == 0", lets add a simple helper which calls
search_binary_handler() and does trace_sched_process_exec() +
ptrace_event().

The patch also moves the setting of task->did_exec, we need to do this
only once.

Note: we can kill either task->did_exec or PF_FORKNOEXEC.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Zach Levis <zml@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:03 -07:00
Oleg Nesterov 96d0df79f2 proc: make proc_fd_permission() thread-friendly
proc_fd_permission() says "process can still access /proc/self/fd after it
has executed a setuid()", but the "task_pid() = proc_pid() check only
helps if the task is group leader, /proc/self points to
/proc/<leader-pid>.

Change this check to use task_tgid() so that the whole thread group can
access its /proc/self/fd or /proc/<tid-of-sub-thread>/fd.

Notes:
	- CLONE_THREAD does not require CLONE_FILES so task->files
	  can differ, but I don't think this can lead to any security
	  problem. And this matches same_thread_group() in
	  __ptrace_may_access().

	- /proc/self should probably point to /proc/<thread-tid>, but
	  it is too late to change the rules. Perhaps it makes sense
	  to add /proc/thread though.

Test-case:

	void *tfunc(void *arg)
	{
		assert(opendir("/proc/self/fd"));
		return NULL;
	}

	int main(void)
	{
		pthread_t t;
		pthread_create(&t, NULL, tfunc, NULL);
		pthread_join(t, NULL);
		return 0;
	}

fails if, say, this executable is not readable and suid_dumpable = 0.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:59:03 -07:00