Factor out some common vfs bits from do_tmpfile()
to be used by overlayfs for concurrent copy up.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Currenly blk_get_backing_dev_info() is not safe to be called when the
block device is not open as bdev->bd_disk is NULL in that case. However
inode_to_bdi() uses this function and may be call called from flusher
worker or other writeback related functions without bdev being open
which leads to crashes such as:
[113031.075540] Unable to handle kernel paging request for data at address 0x00000000
[113031.075614] Faulting instruction address: 0xc0000000003692e0
0:mon> t
[c0000000fb65f900] c00000000036cb6c writeback_sb_inodes+0x30c/0x590
[c0000000fb65fa10] c00000000036ced4 __writeback_inodes_wb+0xe4/0x150
[c0000000fb65fa70] c00000000036d33c wb_writeback+0x30c/0x450
[c0000000fb65fb40] c00000000036e198 wb_workfn+0x268/0x580
[c0000000fb65fc50] c0000000000f3470 process_one_work+0x1e0/0x590
[c0000000fb65fce0] c0000000000f38c8 worker_thread+0xa8/0x660
[c0000000fb65fd80] c0000000000fc4b0 kthread+0x110/0x130
[c0000000fb65fe30] c0000000000098f0 ret_from_kernel_thread+0x5c/0x6c
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, block device inodes stay around after corresponding gendisk
hash died until memory reclaim finds them and frees them. Since we will
make block device inode pin the bdi, we want to free the block device
inode as soon as the device goes away so that bdi does not stay around
unnecessarily. Furthermore we need to avoid issues when new device with
the same major,minor pair gets created since reusing the bdi structure
would be rather difficult in this case.
Unhashing block device inode on gendisk destruction nicely deals with
these problems. Once last block device inode reference is dropped (which
may be directly in del_gendisk()), the inode gets evicted. Furthermore if
the major,minor pair gets reallocated, we are guaranteed to get new
block device inode even if old block device inode is not yet evicted and
thus we avoid issues with possible reuse of bdi.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull quota, fsnotify and ext2 updates from Jan Kara:
"Changes to locking of some quota operations from dedicated quota mutex
to s_umount semaphore, a fsnotify fix and a simple ext2 fix"
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
quota: Fix bogus warning in dquot_disable()
fsnotify: Fix possible use-after-free in inode iteration on umount
ext2: reject inodes with negative size
quota: Remove dqonoff_mutex
ocfs2: Use s_umount for quota recovery protection
quota: Remove dqonoff_mutex from dquot_scan_active()
ocfs2: Protect periodic quota syncing with s_umount semaphore
quota: Use s_umount protection for quota operations
quota: Hold s_umount in exclusive mode when enabling / disabling quotas
fs: Provide function to get superblock with exclusive s_umount
Pull partial readlink cleanups from Miklos Szeredi.
This is the uncontroversial part of the readlink cleanup patch-set that
simplifies the default readlink handling.
Miklos and Al are still discussing the rest of the series.
* git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
vfs: make generic_readlink() static
vfs: remove ".readlink = generic_readlink" assignments
vfs: default to generic_readlink()
vfs: replace calling i_op->readlink with vfs_readlink()
proc/self: use generic_readlink
ecryptfs: use vfs_get_link()
bad_inode: add missing i_op initializers
Pull more vfs updates from Al Viro:
"In this pile:
- autofs-namespace series
- dedupe stuff
- more struct path constification"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
ocfs2: charge quota for reflinked blocks
ocfs2: fix bad pointer cast
ocfs2: always unlock when completing dio writes
ocfs2: don't eat io errors during _dio_end_io_write
ocfs2: budget for extent tree splits when adding refcount flag
ocfs2: prohibit refcounted swapfiles
ocfs2: add newlines to some error messages
ocfs2: convert inode refcount test to a helper
simple_write_end(): don't zero in short copy into uptodate
exofs: don't mess with simple_write_{begin,end}
9p: saner ->write_end() on failing copy into non-uptodate page
fix gfs2_stuffed_write_end() on short copies
fix ceph_write_end()
nfs_write_end(): fix handling of short copies
vfs: refactor clone/dedupe_file_range common functions
fs: try to clone files first in vfs_copy_file_range
vfs: misc struct path constification
namespace.c: constify struct path passed to a bunch of primitives
quota: constify struct path in quota_on
...
Pull overlayfs updates from Miklos Szeredi:
"This update contains:
- try to clone on copy-up
- allow renaming a directory
- split source into managable chunks
- misc cleanups and fixes
It does not contain the read-only fd data inconsistency fix, which Al
didn't like. I'll leave that to the next year..."
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (36 commits)
ovl: fix reStructuredText syntax errors in documentation
ovl: fix return value of ovl_fill_super
ovl: clean up kstat usage
ovl: fold ovl_copy_up_truncate() into ovl_copy_up()
ovl: create directories inside merged parent opaque
ovl: opaque cleanup
ovl: show redirect_dir mount option
ovl: allow setting max size of redirect
ovl: allow redirect_dir to default to "on"
ovl: check for emptiness of redirect dir
ovl: redirect on rename-dir
ovl: lookup redirects
ovl: consolidate lookup for underlying layers
ovl: fix nested overlayfs mount
ovl: check namelen
ovl: split super.c
ovl: use d_is_dir()
ovl: simplify lookup
ovl: check lower existence of rename target
ovl: rename: simplify handling of lower/merged directory
...
Move sb_start_write()/sb_end_write() out of the vfs helper and up into the
ioctl handler.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Pull block layer updates from Jens Axboe:
"This is the main block pull request this series. Contrary to previous
release, I've kept the core and driver changes in the same branch. We
always ended up having dependencies between the two for obvious
reasons, so makes more sense to keep them together. That said, I'll
probably try and keep more topical branches going forward, especially
for cycles that end up being as busy as this one.
The major parts of this pull request is:
- Improved support for O_DIRECT on block devices, with a small
private implementation instead of using the pig that is
fs/direct-io.c. From Christoph.
- Request completion tracking in a scalable fashion. This is utilized
by two components in this pull, the new hybrid polling and the
writeback queue throttling code.
- Improved support for polling with O_DIRECT, adding a hybrid mode
that combines pure polling with an initial sleep. From me.
- Support for automatic throttling of writeback queues on the block
side. This uses feedback from the device completion latencies to
scale the queue on the block side up or down. From me.
- Support from SMR drives in the block layer and for SD. From Hannes
and Shaun.
- Multi-connection support for nbd. From Josef.
- Cleanup of request and bio flags, so we have a clear split between
which are bio (or rq) private, and which ones are shared. From
Christoph.
- A set of patches from Bart, that improve how we handle queue
stopping and starting in blk-mq.
- Support for WRITE_ZEROES from Chaitanya.
- Lightnvm updates from Javier/Matias.
- Supoort for FC for the nvme-over-fabrics code. From James Smart.
- A bunch of fixes from a whole slew of people, too many to name
here"
* 'for-4.10/block' of git://git.kernel.dk/linux-block: (182 commits)
blk-stat: fix a few cases of missing batch flushing
blk-flush: run the queue when inserting blk-mq flush
elevator: make the rqhash helpers exported
blk-mq: abstract out blk_mq_dispatch_rq_list() helper
blk-mq: add blk_mq_start_stopped_hw_queue()
block: improve handling of the magic discard payload
blk-wbt: don't throttle discard or write zeroes
nbd: use dev_err_ratelimited in io path
nbd: reset the setup task for NBD_CLEAR_SOCK
nvme-fabrics: Add FC LLDD loopback driver to test FC-NVME
nvme-fabrics: Add target support for FC transport
nvme-fabrics: Add host support for FC transport
nvme-fabrics: Add FC transport LLDD api definitions
nvme-fabrics: Add FC transport FC-NVME definitions
nvme-fabrics: Add FC transport error codes to nvme.h
Add type 0x28 NVME type code to scsi fc headers
nvme-fabrics: patch target code in prep for FC transport support
nvme-fabrics: set sqe.command_id in core not transports
parser: add u64 number parser
nvme-rdma: align to generic ib_event logging helper
...
Hoist both the XFS reflink inode state and preparation code and the XFS
file blocks compare functions into the VFS so that ocfs2 can take
advantage of it for reflink and dedupe.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
If i_op->readlink is NULL, but i_op->get_link is set then vfs_readlink()
defaults to calling generic_readlink().
The IOP_DEFAULT_READLINK flag indicates that the above conditions are met
and the default action can be taken.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Also check d_is_symlink() in callers instead of inode->i_op->readlink
because following patches will allow NULL ->readlink for symlinks.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The function path_is_under() doesn't modify the paths pointed by its
arguments but only browse them. Constifying this pointers make a cleaner
interface to be used by (future) code which may only have access to
const struct path pointers (e.g. LSM hooks).
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Quota code will need a variant of get_super_thawed() that returns
superblock with s_umount held in exclusive mode to serialize quota on
and quota off operations. Provide this functionality.
Signed-off-by: Jan Kara <jack@suse.cz>
This is where all the other bio operations live, so users must include
bio.h anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Move READ and WRITE to kernel.h and don't define them in terms of block
layer ops; they are our generic data direction indicators these days
and have no more resemblance with the block layer ops.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags
directly. Where applicable this also drops usage of the
bio_set_op_attrs wrapper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Noidle should be the default for writes as seen by all the compounds
definitions in fs.h using it. In fact only direct I/O really should
be using NODILE, so turn the whole flag around to get the defaults
right, which will make our life much easier especially onces the
WRITE_* defines go away.
This assumes all the existing "raw" users of REQ_SYNC for writes
want noidle behavior, which seems to be spot on from a quick audit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Instead of requiring everyone to specify the REQ_SYNC flag aѕ well.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Reads are synchronous per definition, don't add another flag for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently we dropped freeze protection of aio writes just after IO was
submitted. Thus aio write could be in flight while the filesystem was
frozen and that could result in unexpected situation like aio completion
wanting to convert extent type on frozen filesystem. Testcase from
Dmitry triggering this is like:
for ((i=0;i<60;i++));do fsfreeze -f /mnt ;sleep 1;fsfreeze -u /mnt;done &
fio --bs=4k --ioengine=libaio --iodepth=128 --size=1g --direct=1 \
--runtime=60 --filename=/mnt/file --name=rand-write --rw=randwrite
Fix the problem by dropping freeze protection only once IO is completed
in aio_complete().
Reported-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
[hch: forward ported on top of various VFS and aio changes]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Currently the block layer op_is_write, bio_data_dir and rq_data_dir
helper treat every operation that is not a READ as a data out operation.
This worked surprisingly long, but the new REQ_OP_ZONE_REPORT operation
actually adds a second operation that reads data from the device.
Surprisingly nothing critical relied on this direction, but this might
be a good opportunity to properly fix this issue up.
We take a little inspiration and use the least significant bit of the
operation number to encode the data direction, which just requires us
to renumber the operations to fix this scheme.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull overlayfs updates from Miklos Szeredi:
"This update contains fixes to the "use mounter's permission to access
underlying layers" area, and miscellaneous other fixes and cleanups.
No new features this time"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: use vfs_get_link()
vfs: add vfs_get_link() helper
ovl: use generic_readlink
ovl: explain error values when removing acl from workdir
ovl: Fix info leak in ovl_lookup_temp()
ovl: during copy up, switch to mounter's creds early
ovl: lookup: do getxattr with mounter's permission
ovl: copy_up_xattr(): use strnlen
This helper is for filesystems that want to read the symlink and are better
off with the get_link() interface (returning a char *) rather than the
readlink() interface (copy into a userspace buffer).
Also call the LSM hook for readlink (not get_link) since this is for
symlink reading not following.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
mapping->flags currently encodes two different things into a single flag.
It contains sticky gfp_mask for page cache allocations and AS_ codes used
to report errors/enospace and other states which are mapping specific.
Condensing the two semantically unrelated things saves few bytes but it
also complicates other things. For one thing the gfp flags space is
reduced and in fact we are already running out of available bits. It can
be assumed that more gfp flags will be necessary later on.
To not introduce the address_space grow (at least on x86_64) we can stick
it right after private_lock because we have a hole there.
struct address_space {
struct inode * host; /* 0 8 */
struct radix_tree_root page_tree; /* 8 16 */
spinlock_t tree_lock; /* 24 4 */
atomic_t i_mmap_writable; /* 28 4 */
struct rb_root i_mmap; /* 32 8 */
struct rw_semaphore i_mmap_rwsem; /* 40 40 */
/* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */
long unsigned int nrpages; /* 80 8 */
long unsigned int nrexceptional; /* 88 8 */
long unsigned int writeback_index; /* 96 8 */
const struct address_space_operations * a_ops; /* 104 8 */
long unsigned int flags; /* 112 8 */
spinlock_t private_lock; /* 120 4 */
/* XXX 4 bytes hole, try to pack */
/* --- cacheline 2 boundary (128 bytes) --- */
struct list_head private_list; /* 128 16 */
void * private_data; /* 144 8 */
/* size: 152, cachelines: 3, members: 14 */
/* sum members: 148, holes: 1, sum holes: 4 */
/* last cacheline: 24 bytes */
};
Link: http://lkml.kernel.org/r/20160912114852.GI14524@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
Pull vfs xattr updates from Al Viro:
"xattr stuff from Andreas
This completes the switch to xattr_handler ->get()/->set() from
->getxattr/->setxattr/->removexattr"
* 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
vfs: Remove {get,set,remove}xattr inode operations
xattr: Stop calling {get,set,remove}xattr inode operations
vfs: Check for the IOP_XATTR flag in listxattr
xattr: Add __vfs_{get,set,remove}xattr helpers
libfs: Use IOP_XATTR flag for empty directory handling
vfs: Use IOP_XATTR flag for bad-inode handling
vfs: Add IOP_XATTR inode operations flag
vfs: Move xattr_resolve_name to the front of fs/xattr.c
ecryptfs: Switch to generic xattr handlers
sockfs: Get rid of getxattr iop
sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names
kernfs: Switch to generic xattr handlers
hfs: Switch to generic xattr handlers
jffs2: Remove jffs2_{get,set,remove}xattr macros
xattr: Remove unnecessary NULL attribute name check
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.
There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
These inode operations are no longer used; remove them.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The IOP_XATTR inode operations flag in inode->i_opflags indicates that
the inode has xattr support. The flag is automatically set by
new_inode() on filesystems with xattr support (where sb->s_xattr is
defined), and cleared otherwise. Filesystems can explicitly clear it
for inodes that should not have xattr support.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If we allow pseudo-filesystems created with mount_pseudo to have xattr
handlers, we can replace sockfs_getxattr with a sockfs_xattr_get handler
to use the xattr handler name parsing.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
current_fs_time() is used for inode timestamps.
Change the signature of the function to take inode pointer
instead of superblock as per Linus's suggestion.
Also, move the api under vfs as per the discussion on the
thread: https://lkml.org/lkml/2016/6/9/36 . As per Arnd's
suggestion on the thread, changing the function name.
current_fs_time() will be deleted after all the references
to it are replaced by current_time().
There was a bug reported by kbuild test bot with the change
as some of the calls to current_time() were made before the
super_block was initialized. Catch these accidental assignments
as timespec_trunc() does for wrong granularities. This allows
for the function to work right even in these circumstances.
But, adds a warning to make the user aware of the bug.
A coccinelle script was used to identify all the current
.alloc_inode super_block callbacks that updated inode timestamps.
proc filesystem was the only one that was modifying inode times
as part of this callback. The series includes a patch to fix that.
Note that timespec_trunc() will also be moved to fs/inode.c
in a separate patch when this will need to be revamped for
bounds checking purposes.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is trivial to do:
- add flags argument to simple_rename()
- check if flags doesn't have any other than RENAME_NOREPLACE
- assign simple_rename() to .rename2 instead of .rename
Filesystems converted:
hugetlbfs, ramfs, bpf.
Debugfs uses simple_rename() to implement debugfs_rename(), which is for
debugfs instances to rename files internally, not for userspace filesystem
access. For this case pass zero flags to simple_rename().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
inode_change_ok() will be resposible for clearing capabilities and IMA
extended attributes and as such will need dentry. Give it as an argument
to inode_change_ok() instead of an inode. Also rename inode_change_ok()
to setattr_prepare() to better relect that it does also some
modifications in addition to checks.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
This patch allows flock, posix locks, ofd locks and leases to work
correctly on overlayfs.
Instead of using the underlying inode for storing lock context use the
overlay inode. This allows locks to be persistent across copy-up.
This is done by introducing locks_inode() helper and using it instead of
file_inode() to get the inode in locking code. For non-overlayfs the two
are equivalent, except for an extra pointer dereference in locks_inode().
Since lock operations are in "struct file_operations" we must also make
sure not to call underlying filesystem's lock operations. Introcude a
super block flag MS_NOREMOTELOCK to this effect.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Jeff Layton <jlayton@poochiereds.net>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
On overlayfs relatime_need_update() needs inode times to be correct on
overlay inode. But i_mtime and i_ctime are updated by filesystem code on
underlying inode only, so they will be out-of-date on the overlay inode.
This patch copies the times from the underlying inode if needed. This
can't be done if called from RCU lookup (link following) but link m/ctime
are not updated by fs, so this is all right.
This patch doesn't change functionality for anything but overlayfs.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This fixes a bug where the permission was not properly checked in
overlayfs. The testcase is ltp/utimensat01.
It is also cleaner and safer to do the permission checking in the vfs
helper instead of the caller.
This patch introduces an additional ia_valid flag ATTR_TOUCH (since
touch(1) is the most obvious user of utimes(NULL)) that is passed into
notify_change whenever the conditions for this special permission checking
mode are met.
Reported-by: Aihua Zhang <zhangaihua1@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Aihua Zhang <zhangaihua1@huawei.com>
Cc: <stable@vger.kernel.org> # v3.18+
Some operations (setxattr/chmod) can make the cached acl stale. We either
need to clear overlay's acl cache for the affected inode or prevent acl
caching on the overlay altogether. Preventing caching has the following
advantages:
- no double caching, less memory used
- overlay cache doesn't go stale when fs clears it's own cache
Possible disadvantage is performance loss. If that becomes a problem
get_acl() can be optimized for overlayfs.
This patch disables caching by pre setting i_*acl to a value that
- has bit 0 set, so is_uncached_acl() will return true
- is not equal to ACL_NOT_CACHED, so get_acl() will not overwrite it
The constant -3 was chosen for this purpose.
Fixes: 39a25b2b37 ("ovl: define ->get_acl() for overlay inodes")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Commit abf545484d changed it from an 'rw' flags type to the
newer ops based interface, but now we're effectively leaking
some bdev internals to the rest of the kernel. Since we only
care about whether it's a read or a write at that level, just
pass in a bool 'is_write' parameter instead.
Then we can also move op_is_write() and friends back under
CONFIG_BLOCK protection.
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Pull more vfs updates from Al Viro:
"Assorted cleanups and fixes.
In the "trivial API change" department - ->d_compare() losing 'parent'
argument"
* 'for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
cachefiles: Fix race between inactivating and culling a cache object
9p: use clone_fid()
9p: fix braino introduced in "9p: new helper - v9fs_parent_fid()"
vfs: make dentry_needs_remove_privs() internal
vfs: remove file_needs_remove_privs()
vfs: fix deadlock in file_remove_privs() on overlayfs
get rid of 'parent' argument of ->d_compare()
cifs, msdos, vfat, hfs+: don't bother with parent in ->d_compare()
affs ->d_compare(): don't bother with ->d_inode
fold _d_rehash() and __d_rehash() together
fold dentry_rcuwalk_invalidate() into its only remaining caller
The rw_page users were not converted to use bio/req ops. As a result
bdev_write_page is not passing down REQ_OP_WRITE and the IOs will
be sent down as reads.
Signed-off-by: Mike Christie <mchristi@redhat.com>
Fixes: 4e1b2d52a8 ("block, fs, drivers: remove REQ_OP compat defs and related code")
Modified by me to:
1) Drop op_flags passing into ->rw_page(), as we don't use it.
2) Make op_is_write() and friends safe to use for !CONFIG_BLOCK
Signed-off-by: Jens Axboe <axboe@fb.com>
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>
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.
...
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
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
...
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
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>
- 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
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
...
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>
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()
...
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
...
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
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
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>
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>
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>
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>
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>
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>
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>
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>
Amir Goldstein