litmus-rt.git/fs/xfs, branch master

xfs: fix broken i_nlink accounting for whiteout tmpfile inode

2015-05-28T22:14:55+00:00

XFS uses the internal tmpfile() infrastructure for the whiteout inode
used for RENAME_WHITEOUT operations. For tmpfile inodes, XFS allocates
the inode, drops di_nlink, adds the inode to the agi unlinked list,
calls d_tmpfile() which correspondingly drops i_nlink of the vfs inode,
and then finishes the common inode setup (e.g., clear I_NEW and unlock).

The d_tmpfile() call was originally made inxfs_create_tmpfile(), but was
pulled up out of that function as part of the following commit to
resolve a deadlock issue:

	330033d6 xfs: fix tmpfile/selinux deadlock and initialize security

As a result, callers of xfs_create_tmpfile() are responsible for either
calling d_tmpfile() or fixing up i_nlink appropriately. The whiteout
tmpfile allocation helper does neither. As a result, the vfs ->i_nlink
becomes inconsistent with the on-disk ->di_nlink once xfs_rename() links
it back into the source dentry and calls xfs_bumplink().

Update the assert in xfs_rename() to help detect this problem in the
future and update xfs_rename_alloc_whiteout() to decrement the link
count as part of the manual tmpfile inode setup.

Signed-off-by: Brian Foster 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner

xfs: xfs_iozero can return positive errno

2015-05-28T21:40:32+00:00

It was missed when we converted everything in XFs to use negative error
numbers, so fix it now. Bug introduced in 3.17 by commit 2451337 ("xfs: global
error sign conversion"), and should go back to stable kernels.

Thanks to Brian Foster for noticing it.

cc:  # 3.17, 3.18, 3.19, 4.0
Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner

xfs: xfs_attr_inactive leaves inconsistent attr fork state behind

2015-05-28T21:40:08+00:00

xfs_attr_inactive() is supposed to clean up the attribute fork when
the inode is being freed. While it removes attribute fork extents,
it completely ignores attributes in local format, which means that
there can still be active attributes on the inode after
xfs_attr_inactive() has run.

This leads to problems with concurrent inode writeback - the in-core
inode attribute fork is removed without locking on the assumption
that nothing will be attempting to access the attribute fork after a
call to xfs_attr_inactive() because it isn't supposed to exist on
disk any more.

To fix this, make xfs_attr_inactive() completely remove all traces
of the attribute fork from the inode, regardless of it's state.
Further, also remove the in-core attribute fork structure safely so
that there is nothing further that needs to be done by callers to
clean up the attribute fork. This means we can remove the in-core
and on-disk attribute forks atomically.

Also, on error simply remove the in-memory attribute fork. There's
nothing that can be done with it once we have failed to remove the
on-disk attribute fork, so we may as well just blow it away here
anyway.

cc:  # 3.12 to 4.0
Reported-by: Waiman Long 
Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner

xfs: extent size hints can round up extents past MAXEXTLEN

2015-05-28T21:40:06+00:00

This results in BMBT corruption, as seen by this test:

# mkfs.xfs -f -d size=40051712b,agcount=4 /dev/vdc
....
# mount /dev/vdc /mnt/scratch
# xfs_io -ft -c "extsize 16m" -c "falloc 0 30g" -c "bmap -vp" /mnt/scratch/foo

which results in this failure on a debug kernel:

XFS: Assertion failed: (blockcount & xfs_mask64hi(64-BMBT_BLOCKCOUNT_BITLEN)) == 0, file: fs/xfs/libxfs/xfs_bmap_btree.c, line: 211
....
Call Trace:
 [] xfs_bmbt_set_allf+0x8f/0x100
 [] xfs_bmbt_set_all+0x1d/0x20
 [] xfs_iext_insert+0x9e/0x120
 [] ? xfs_bmap_add_extent_hole_real+0x1c6/0xc70
 [] xfs_bmap_add_extent_hole_real+0x1c6/0xc70
 [] xfs_bmapi_write+0x72b/0xed0
 [] ? kmem_cache_alloc+0x15c/0x170
 [] xfs_alloc_file_space+0x160/0x400
 [] ? down_write+0x29/0x60
 [] xfs_file_fallocate+0x29b/0x310
 [] ? __sb_start_write+0x58/0x120
 [] ? do_vfs_ioctl+0x318/0x570
 [] vfs_fallocate+0x140/0x260
 [] SyS_fallocate+0x48/0x80
 [] system_call_fastpath+0x12/0x17

The tracepoint that indicates the extent that triggered the assert
failure is:

xfs_iext_insert:   idx 0 offset 0 block 16777224 count 2097152 flag 1

Clearly indicating that the extent length is greater than MAXEXTLEN,
which is 2097151. A prior trace point shows the allocation was an
exact size match and that a length greater than MAXEXTLEN was asked
for:

xfs_alloc_size_done:  agno 1 agbno 8 minlen 2097152 maxlen 2097152
					    ^^^^^^^        ^^^^^^^

We don't see this problem with extent size hints through the IO path
because we can't do single IOs large enough to trigger MAXEXTLEN
allocation. fallocate(), OTOH, is not limited in it's allocation
sizes and so needs help here.

The issue is that the extent size hint alignment is rounding up the
extent size past MAXEXTLEN, because xfs_bmapi_write() is not taking
into account extent size hints when calculating the maximum extent
length to allocate. xfs_bmapi_reserve_delalloc() is already doing
this, but direct extent allocation is not.

Unfortunately, the calculation in xfs_bmapi_reserve_delalloc() is
wrong, and it works only because delayed allocation extents are not
limited in size to MAXEXTLEN in the in-core extent tree. hence this
calculation does not work for direct allocation, and the delalloc
code needs fixing. This may, in fact be the underlying bug that
occassionally causes transaction overruns in delayed allocation
extent conversion, so now we know it's wrong we should fix it, too.
Many thanks to Brian Foster for finding this problem during review
of this patch.

Hence the fix, after much code reading, is to allow
xfs_bmap_extsize_align() to align partial extents when full
alignment would extend the alignment past MAXEXTLEN. We can safely
do this because all callers have higher layer allocation loops that
already handle short allocations, and so will simply run another
allocation to cover the remainder of the requested allocation range
that we ignored during alignment. The advantage of this approach is
that it also removes the need for callers to do anything other than
limit their requests to MAXEXTLEN - they don't really need to be
aware of extent size hints at all.

Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner

xfs: inode and free block counters need to use __percpu_counter_compare

2015-05-28T21:39:34+00:00

Because the counters use a custom batch size, the comparison
functions need to be aware of that batch size otherwise the
comparison does not work correctly. This leads to ASSERT failures
on generic/027 like this:

 XFS: Assertion failed: 0, file: fs/xfs/xfs_mount.c, line: 1099
 ------------[ cut here ]------------
....
 Call Trace:
  [] xfs_mod_icount+0x99/0xc0
  [] xfs_trans_unreserve_and_mod_sb+0x28b/0x5b0
  [] xfs_log_commit_cil+0x321/0x580
  [] xfs_trans_commit+0xb7/0x260
  [] xfs_bmap_finish+0xcd/0x1b0
  [] xfs_inactive_ifree+0x1e1/0x250
  [] xfs_inactive+0x130/0x200
  [] xfs_fs_evict_inode+0x91/0xf0
  [] evict+0xb8/0x190
  [] iput+0x18b/0x1f0
  [] do_unlinkat+0x1f3/0x320
  [] ? filp_close+0x5a/0x80
  [] SyS_unlinkat+0x1b/0x40
  [] system_call_fastpath+0x12/0x71

This is a regression introduced by commit 501ab32 ("xfs: use generic
percpu counters for inode counter").

This patch fixes the same problem for both the inode counter and the
free block counter in the superblocks.

Signed-off-by: Dave Chinner 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner

xfs: use percpu_counter_read_positive for mp->m_icount

2015-05-28T21:39:34+00:00

Function percpu_counter_read just return the current counter, which can be
negative. This will cause the checking of "allocated inode
counts <= m_maxicount" false positive. Use percpu_counter_read_positive can
solve this problem, and be consistent with the purpose to introduce percpu
mechanism to xfs.

Signed-off-by: George Wang 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-04-27T00:22:07+00:00

Pull fourth vfs update from Al Viro:
 "d_inode() annotations from David Howells (sat in for-next since before
  the beginning of merge window) + four assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  RCU pathwalk breakage when running into a symlink overmounting something
  fix I_DIO_WAKEUP definition
  direct-io: only inc/dec inode->i_dio_count for file systems
  fs/9p: fix readdir()
  VFS: assorted d_backing_inode() annotations
  VFS: fs/inode.c helpers: d_inode() annotations
  VFS: fs/cachefiles: d_backing_inode() annotations
  VFS: fs library helpers: d_inode() annotations
  VFS: assorted weird filesystems: d_inode() annotations
  VFS: normal filesystems (and lustre): d_inode() annotations
  VFS: security/: d_inode() annotations
  VFS: security/: d_backing_inode() annotations
  VFS: net/: d_inode() annotations
  VFS: net/unix: d_backing_inode() annotations
  VFS: kernel/: d_inode() annotations
  VFS: audit: d_backing_inode() annotations
  VFS: Fix up some ->d_inode accesses in the chelsio driver
  VFS: Cachefiles should perform fs modifications on the top layer only
  VFS: AF_UNIX sockets should call mknod on the top layer only

Merge tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

2015-04-24T14:08:41+00:00

Pull xfs update from Dave Chinner:
 "This update contains:

   - RENAME_WHITEOUT support

   - conversion of per-cpu superblock accounting to use generic counters

   - new inode mmap lock so that we can lock page faults out of
     truncate, hole punch and other direct extent manipulation functions
     to avoid racing mmap writes from causing data corruption

   - rework of direct IO submission and completion to solve data
     corruption issue when running concurrent extending DIO writes.
     Also solves problem of running IO completion transactions in
     interrupt context during size extending AIO writes.

   - FALLOC_FL_INSERT_RANGE support for inserting holes into a file via
     direct extent manipulation to avoid needing to copy data within the
     file

   - attribute block header field overflow fix for 64k block size
     filesystems

   - Lots of changes to log messaging to be more informative and concise
     when errors occur.  Also prevent a lot of unnecessary log spamming
     due to cascading failures in error conditions.

   - lots of cleanups and bug fixes

  One thing of note is the direct IO fixes that we merged last week
  after the window opened.  Even though a little late, they fix a user
  reported data corruption and have been pretty well tested.  I figured
  there was not much point waiting another 2 weeks for -rc1 to be
  released just so I could send them to you..."

* tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits)
  xfs: using generic_file_direct_write() is unnecessary
  xfs: direct IO EOF zeroing needs to drain AIO
  xfs: DIO write completion size updates race
  xfs: DIO writes within EOF don't need an ioend
  xfs: handle DIO overwrite EOF update completion correctly
  xfs: DIO needs an ioend for writes
  xfs: move DIO mapping size calculation
  xfs: factor DIO write mapping from get_blocks
  xfs: unlock i_mutex in xfs_break_layouts
  xfs: kill unnecessary firstused overflow check on attr3 leaf removal
  xfs: use larger in-core attr firstused field and detect overflow
  xfs: pass attr geometry to attr leaf header conversion functions
  xfs: disallow ro->rw remount on norecovery mount
  xfs: xfs_shift_file_space can be static
  xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate
  fs: Add support FALLOC_FL_INSERT_RANGE for fallocate
  xfs: Fix incorrect positive ENOMEM return
  xfs: xfs_mru_cache_insert() should use GFP_NOFS
  xfs: %pF is only for function pointers
  xfs: fix shadow warning in xfs_da3_root_split()
  ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-04-17T03:27:56+00:00

Pull third hunk of vfs changes from Al Viro:
 "This contains the ->direct_IO() changes from Omar + saner
  generic_write_checks() + dealing with fcntl()/{read,write}() races
  (mirroring O_APPEND/O_DIRECT into iocb->ki_flags and instead of
  repeatedly looking at ->f_flags, which can be changed by fcntl(2),
  check ->ki_flags - which cannot) + infrastructure bits for dhowells'
  d_inode annotations + Christophs switch of /dev/loop to
  vfs_iter_write()"

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

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

2015-04-17T02:19:33+00:00

Pull quota and udf updates from Jan Kara:
 "The pull contains quota changes which complete unification of XFS and
  VFS quota interfaces (so tools can use either interface to manipulate
  any filesystem).  There's also a patch to support project quotas in
  VFS quota subsystem from Li Xi.

  Finally there's a bunch of UDF fixes and cleanups and tiny cleanup in
  reiserfs & ext3"

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: (21 commits)
  udf: Update ctime and mtime when directory is modified
  udf: return correct errno for udf_update_inode()
  ext3: Remove useless condition in if statement.
  vfs: Add general support to enforce project quota limits
  reiserfs: fix __RASSERT format string
  udf: use int for allocated blocks instead of sector_t
  udf: remove redundant buffer_head.h includes
  udf: remove else after return in __load_block_bitmap()
  udf: remove unused variable in udf_table_free_blocks()
  quota: Fix maximum quota limit settings
  quota: reorder flags in quota state
  quota: paranoia: check quota tree root
  quota: optimize i_dquot access
  quota: Hook up Q_XSETQLIM for id 0 to ->set_info
  xfs: Add support for Q_SETINFO
  quota: Make ->set_info use structure with neccesary info to VFS and XFS
  quota: Remove ->get_xstate and ->get_xstatev callbacks
  gfs2: Convert to using ->get_state callback
  xfs: Convert to using ->get_state callback
  quota: Wire up Q_GETXSTATE and Q_GETXSTATV calls to work with ->get_state
  ...