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  1. 27 12月, 2019 11 次提交
    • Q
      btrfs: qgroup: Always free PREALLOC META reserve in btrfs_delalloc_release_extents() · fd55189a
      由 Qu Wenruo 提交于 
      [ Upstream commit 8702ba9396bf7bbae2ab93c94acd4bd37cfa4f09 ]

[Background]
Btrfs qgroup uses two types of reserved space for METADATA space,
PERTRANS and PREALLOC.

PERTRANS is metadata space reserved for each transaction started by
btrfs_start_transaction().
While PREALLOC is for delalloc, where we reserve space before joining a
transaction, and finally it will be converted to PERTRANS after the
writeback is done.

[Inconsistency]
However there is inconsistency in how we handle PREALLOC metadata space.

The most obvious one is:
In btrfs_buffered_write():
	btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes, true);

We always free qgroup PREALLOC meta space.

While in btrfs_truncate_block():
	btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0));

We only free qgroup PREALLOC meta space when something went wrong.

[The Correct Behavior]
The correct behavior should be the one in btrfs_buffered_write(), we
should always free PREALLOC metadata space.

The reason is, the btrfs_delalloc_* mechanism works by:
- Reserve metadata first, even it's not necessary
  In btrfs_delalloc_reserve_metadata()

- Free the unused metadata space
  Normally in:
  btrfs_delalloc_release_extents()
  |- btrfs_inode_rsv_release()
     Here we do calculation on whether we should release or not.

E.g. for 64K buffered write, the metadata rsv works like:

/* The first page */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=0
total:		num_bytes=calc_inode_reservations()
/* The first page caused one outstanding extent, thus needs metadata
   rsv */

/* The 2nd page */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=calc_inode_reservations()
total:		not changed
/* The 2nd page doesn't cause new outstanding extent, needs no new meta
   rsv, so we free what we have reserved */

/* The 3rd~16th pages */
reserve_meta:	num_bytes=calc_inode_reservations()
free_meta:	num_bytes=calc_inode_reservations()
total:		not changed (still space for one outstanding extent)

This means, if btrfs_delalloc_release_extents() determines to free some
space, then those space should be freed NOW.
So for qgroup, we should call btrfs_qgroup_free_meta_prealloc() other
than btrfs_qgroup_convert_reserved_meta().

The good news is:
- The callers are not that hot
  The hottest caller is in btrfs_buffered_write(), which is already
  fixed by commit 336a8bb8 ("btrfs: Fix wrong
  btrfs_delalloc_release_extents parameter"). Thus it's not that
  easy to cause false EDQUOT.

- The trans commit in advance for qgroup would hide the bug
  Since commit f5fef4593653 ("btrfs: qgroup: Make qgroup async transaction
  commit more aggressive"), when btrfs qgroup metadata free space is slow,
  it will try to commit transaction and free the wrongly converted
  PERTRANS space, so it's not that easy to hit such bug.

[FIX]
So to fix the problem, remove the @qgroup_free parameter for
btrfs_delalloc_release_extents(), and always pass true to
btrfs_inode_rsv_release().
Reported-by: NFilipe Manana <fdmanana@suse.com>
Fixes: 43b18595 ("btrfs: qgroup: Use separate meta reservation type for delalloc")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      fd55189a
    • C
      btrfs: fix allocation of free space cache v1 bitmap pages · d9179ba8
      由 Christophe Leroy 提交于 
      commit 3acd48507dc43eeeb0a1fe965b8bad91cab904a7 upstream.

Various notifications of type "BUG kmalloc-4096 () : Redzone
overwritten" have been observed recently in various parts of the kernel.
After some time, it has been made a relation with the use of BTRFS
filesystem and with SLUB_DEBUG turned on.

[   22.809700] BUG kmalloc-4096 (Tainted: G        W        ): Redzone overwritten

[   22.810286] INFO: 0xbe1a5921-0xfbfc06cd. First byte 0x0 instead of 0xcc
[   22.810866] INFO: Allocated in __load_free_space_cache+0x588/0x780 [btrfs] age=22 cpu=0 pid=224
[   22.811193] 	__slab_alloc.constprop.26+0x44/0x70
[   22.811345] 	kmem_cache_alloc_trace+0xf0/0x2ec
[   22.811588] 	__load_free_space_cache+0x588/0x780 [btrfs]
[   22.811848] 	load_free_space_cache+0xf4/0x1b0 [btrfs]
[   22.812090] 	cache_block_group+0x1d0/0x3d0 [btrfs]
[   22.812321] 	find_free_extent+0x680/0x12a4 [btrfs]
[   22.812549] 	btrfs_reserve_extent+0xec/0x220 [btrfs]
[   22.812785] 	btrfs_alloc_tree_block+0x178/0x5f4 [btrfs]
[   22.813032] 	__btrfs_cow_block+0x150/0x5d4 [btrfs]
[   22.813262] 	btrfs_cow_block+0x194/0x298 [btrfs]
[   22.813484] 	commit_cowonly_roots+0x44/0x294 [btrfs]
[   22.813718] 	btrfs_commit_transaction+0x63c/0xc0c [btrfs]
[   22.813973] 	close_ctree+0xf8/0x2a4 [btrfs]
[   22.814107] 	generic_shutdown_super+0x80/0x110
[   22.814250] 	kill_anon_super+0x18/0x30
[   22.814437] 	btrfs_kill_super+0x18/0x90 [btrfs]
[   22.814590] INFO: Freed in proc_cgroup_show+0xc0/0x248 age=41 cpu=0 pid=83
[   22.814841] 	proc_cgroup_show+0xc0/0x248
[   22.814967] 	proc_single_show+0x54/0x98
[   22.815086] 	seq_read+0x278/0x45c
[   22.815190] 	__vfs_read+0x28/0x17c
[   22.815289] 	vfs_read+0xa8/0x14c
[   22.815381] 	ksys_read+0x50/0x94
[   22.815475] 	ret_from_syscall+0x0/0x38

Commit 69d24804 ("btrfs: use copy_page for copying pages instead of
memcpy") changed the way bitmap blocks are copied. But allthough bitmaps
have the size of a page, they were allocated with kzalloc().

Most of the time, kzalloc() allocates aligned blocks of memory, so
copy_page() can be used. But when some debug options like SLAB_DEBUG are
activated, kzalloc() may return unaligned pointer.

On powerpc, memcpy(), copy_page() and other copying functions use
'dcbz' instruction which provides an entire zeroed cacheline to avoid
memory read when the intention is to overwrite a full line. Functions
like memcpy() are writen to care about partial cachelines at the start
and end of the destination, but copy_page() assumes it gets pages. As
pages are naturally cache aligned, copy_page() doesn't care about
partial lines. This means that when copy_page() is called with a
misaligned pointer, a few leading bytes are zeroed.

To fix it, allocate bitmaps through kmem_cache instead of using kzalloc()
The cache pool is created with PAGE_SIZE alignment constraint.
Reported-by: NErhard F. <erhard_f@mailbox.org>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204371
Fixes: 69d24804 ("btrfs: use copy_page for copying pages instead of memcpy")
Cc: stable@vger.kernel.org # 4.19+
Signed-off-by: NChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ rename to btrfs_free_space_bitmap ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      d9179ba8
    • N
      btrfs: Fix error handling in btrfs_cleanup_ordered_extents · a1984f15
      由 Nikolay Borisov 提交于 
      [ Upstream commit d1051d6ebf8ef3517a5a3cf82bba8436d190f1c2 ]

Running btrfs/124 in a loop hung up on me sporadically with the
following call trace:

	btrfs           D    0  5760   5324 0x00000000
	Call Trace:
	 ? __schedule+0x243/0x800
	 schedule+0x33/0x90
	 btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs]
	 ? wait_woken+0xa0/0xa0
	 btrfs_wait_ordered_range+0xbb/0x100 [btrfs]
	 btrfs_relocate_block_group+0x1ff/0x230 [btrfs]
	 btrfs_relocate_chunk+0x49/0x100 [btrfs]
	 btrfs_balance+0xbeb/0x1740 [btrfs]
	 btrfs_ioctl_balance+0x2ee/0x380 [btrfs]
	 btrfs_ioctl+0x1691/0x3110 [btrfs]
	 ? lockdep_hardirqs_on+0xed/0x180
	 ? __handle_mm_fault+0x8e7/0xfb0
	 ? _raw_spin_unlock+0x24/0x30
	 ? __handle_mm_fault+0x8e7/0xfb0
	 ? do_vfs_ioctl+0xa5/0x6e0
	 ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
	 do_vfs_ioctl+0xa5/0x6e0
	 ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
	 ksys_ioctl+0x3a/0x70
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x60/0x1b0
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

This happens because during page writeback it's valid for
writepage_delalloc to instantiate a delalloc range which doesn't belong
to the page currently being written back.

The reason this case is valid is due to find_lock_delalloc_range
returning any available range after the passed delalloc_start and
ignoring whether the page under writeback is within that range.

In turn ordered extents (OE) are always created for the returned range
from find_lock_delalloc_range. If, however, a failure occurs while OE
are being created then the clean up code in btrfs_cleanup_ordered_extents
will be called.

Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider
the case of such 'foreign' range being processed and instead it always
assumes that the range OE are created for belongs to the page. This
leads to the first page of such foregin range to not be cleaned up since
it's deliberately missed and skipped by the current cleaning up code.

Fix this by correctly checking whether the current page belongs to the
range being instantiated and if so adjsut the range parameters passed
for cleaning up. If it doesn't, then just clean the whole OE range
directly.

Fixes: 52427260 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      a1984f15
    • N
      btrfs: Remove extent_io_ops::fill_delalloc · c5bcfc0d
      由 Nikolay Borisov 提交于 
      [ Upstream commit 5eaad97af8aeff38debe7d3c69ec3a0d71f8350f ]

This callback is called only from writepage_delalloc which in turn is
guaranteed to be called from the data page writeout path. In the end
there is no reason to have the call to this function to be indrected via
the extent_io_ops structure. This patch removes the callback definition,
exports the function and calls it directly. No functional changes.
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ rename to btrfs_run_delalloc_range ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      c5bcfc0d
    • Q
      btrfs: inode: Don't compress if NODATASUM or NODATACOW set · 0582ae0c
      由 Qu Wenruo 提交于 
      commit 42c16da6d684391db83788eb680accd84f6c2083 upstream.

As btrfs(5) specified:

	Note
	If nodatacow or nodatasum are enabled, compression is disabled.

If NODATASUM or NODATACOW set, we should not compress the extent.

Normally NODATACOW is detected properly in run_delalloc_range() so
compression won't happen for NODATACOW.

However for NODATASUM we don't have any check, and it can cause
compressed extent without csum pretty easily, just by:
  mkfs.btrfs -f $dev
  mount $dev $mnt -o nodatasum
  touch $mnt/foobar
  mount -o remount,datasum,compress $mnt
  xfs_io -f -c "pwrite 0 128K" $mnt/foobar

And in fact, we have a bug report about corrupted compressed extent
without proper data checksum so even RAID1 can't recover the corruption.
(https://bugzilla.kernel.org/show_bug.cgi?id=199707)

Running compression without proper checksum could cause more damage when
corruption happens, as compressed data could make the whole extent
unreadable, so there is no need to allow compression for
NODATACSUM.

The fix will refactor the inode compression check into two parts:

- inode_can_compress()
  As the hard requirement, checked at btrfs_run_delalloc_range(), so no
  compression will happen for NODATASUM inode at all.

- inode_need_compress()
  As the soft requirement, checked at btrfs_run_delalloc_range() and
  compress_file_range().
Reported-by: NJames Harvey <jamespharvey20@gmail.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      0582ae0c
    • F
      Btrfs: fix wrong ctime and mtime of a directory after log replay · 6e347d71
      由 Filipe Manana 提交于 
      commit 5338e43abbab13791144d37fd8846847062351c6 upstream.

When replaying a log that contains a new file or directory name that needs
to be added to its parent directory, we end up updating the mtime and the
ctime of the parent directory to the current time after we have set their
values to the correct ones (set at fsync time), efectivelly losing them.

Sample reproducer:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/dir
  $ touch /mnt/dir/file

  # fsync of the directory is optional, not needed
  $ xfs_io -c fsync /mnt/dir
  $ xfs_io -c fsync /mnt/dir/file

  $ stat -c %Y /mnt/dir
  1557856079

  <power failure>

  $ sleep 3
  $ mount /dev/sdb /mnt
  $ stat -c %Y /mnt/dir
  1557856082

    --> should have been 1557856079, the mtime is updated to the current
        time when replaying the log

Fix this by not updating the mtime and ctime to the current time at
btrfs_add_link() when we are replaying a log tree.

This could be triggered by my recent fsync fuzz tester for fstests, for
which an fstests patch exists titled "fstests: generic, fsync fuzz tester
with fsstress".

Fixes: e02119d5 ("Btrfs: Add a write ahead tree log to optimize synchronous operations")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      6e347d71
    • E
      btrfs: use tagged writepage to mitigate livelock of snapshot · b3518f7c
      由 Ethan Lien 提交于 
      [ Upstream commit 3cd24c698004d2f7668e0eb9fc1f096f533c791b ]

Snapshot is expected to be fast. But if there are writers steadily
creating dirty pages in our subvolume, the snapshot may take a very long
time to complete. To fix the problem, we use tagged writepage for
snapshot flusher as we do in the generic write_cache_pages(), so we can
omit pages dirtied after the snapshot command.

This does not change the semantics regarding which data get to the
snapshot, if there are pages being dirtied during the snapshotting
operation.  There's a sync called before snapshot is taken in old/new
case, any IO in flight just after that may be in the snapshot but this
depends on other system effects that might still sync the IO.

We do a simple snapshot speed test on a Intel D-1531 box:

fio --ioengine=libaio --iodepth=32 --bs=4k --rw=write --size=64G
--direct=0 --thread=1 --numjobs=1 --time_based --runtime=120
--filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio

original: 1m58sec
patched:  6.54sec

This is the best case for this patch since for a sequential write case,
we omit nearly all pages dirtied after the snapshot command.

For a multi writers, random write test:

fio --ioengine=libaio --iodepth=32 --bs=4k --rw=randwrite --size=64G
--direct=0 --thread=1 --numjobs=4 --time_based --runtime=120
--filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5;
time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio

original: 15.83sec
patched:  10.35sec

The improvement is smaller compared to the sequential write case,
since we omit only half of the pages dirtied after snapshot command.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NEthan Lien <ethanlien@synology.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      b3518f7c
    • J
      btrfs: improve error handling of btrfs_add_link · d59679a9
      由 Johannes Thumshirn 提交于 
      [ Upstream commit 1690dd41e0cb1dade80850ed8a3eb0121b96d22f ]

In the error handling block, err holds the return value of either
btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked
since it's introduction with commit fe66a05a (Btrfs: improve error
handling for btrfs_insert_dir_item callers) in 2012.

If the error handling in the error handling fails, there's not much left
to do and the abort either happened earlier in the callees or is
necessary here.

So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort
the transaction, but still return the original code of the failure
stored in 'ret' as this will be reported to the user.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      d59679a9
    • D
      Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io" · 58afa74e
      由 David Sterba 提交于 
      commit 77b7aad195099e7c6da11e94b7fa6ef5e6fb0025 upstream.

This reverts commit e73e81b6.

This patch causes a few problems:

- adds latency to btrfs_finish_ordered_io
- as btrfs_finish_ordered_io is used for free space cache, generating
  more work from btrfs_btree_balance_dirty_nodelay could end up in the
  same workque, effectively deadlocking

12260 kworker/u96:16+btrfs-freespace-write D
[<0>] balance_dirty_pages+0x6e6/0x7ad
[<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90
[<0>] btrfs_finish_ordered_io+0x3da/0x770
[<0>] normal_work_helper+0x1c5/0x5a0
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x46/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Transaction commit will wait on the freespace cache:

838 btrfs-transacti D
[<0>] btrfs_start_ordered_extent+0x154/0x1e0
[<0>] btrfs_wait_ordered_range+0xbd/0x110
[<0>] __btrfs_wait_cache_io+0x49/0x1a0
[<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0
[<0>] commit_cowonly_roots+0x215/0x2b0
[<0>] btrfs_commit_transaction+0x37e/0x910
[<0>] transaction_kthread+0x14d/0x180
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

And then writepages ends up waiting on transaction commit:

9520 kworker/u96:13+flush-btrfs-1 D
[<0>] wait_current_trans+0xac/0xe0
[<0>] start_transaction+0x21b/0x4b0
[<0>] cow_file_range_inline+0x10b/0x6b0
[<0>] cow_file_range.isra.69+0x329/0x4a0
[<0>] run_delalloc_range+0x105/0x3c0
[<0>] writepage_delalloc+0x119/0x180
[<0>] __extent_writepage+0x10c/0x390
[<0>] extent_write_cache_pages+0x26f/0x3d0
[<0>] extent_writepages+0x4f/0x80
[<0>] do_writepages+0x17/0x60
[<0>] __writeback_single_inode+0x59/0x690
[<0>] writeback_sb_inodes+0x291/0x4e0
[<0>] __writeback_inodes_wb+0x87/0xb0
[<0>] wb_writeback+0x3bb/0x500
[<0>] wb_workfn+0x40d/0x610
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x1e0/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Eventually, we have every process in the system waiting on
balance_dirty_pages(), and nobody is able to make progress on page
writeback.

The original patch tried to fix an OOM condition, that happened on 4.4 but no
success reproducing that on later kernels (4.19 and 4.20). This is more likely
a problem in OOM itself.

Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/Reported-by: NChris Mason <clm@fb.com>
CC: stable@vger.kernel.org # 4.18+
CC: ethanlien <ethanlien@synology.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      58afa74e
    • F
      Btrfs: fix fsync of files with multiple hard links in new directories · 4bb3a2cc
      由 Filipe Manana 提交于 
      commit 41bd60676923822de1df2c50b3f9a10171f4338a upstream.

The log tree has a long standing problem that when a file is fsync'ed we
only check for new ancestors, created in the current transaction, by
following only the hard link for which the fsync was issued. We follow the
ancestors using the VFS' dget_parent() API. This means that if we create a
new link for a file in a directory that is new (or in an any other new
ancestor directory) and then fsync the file using an old hard link, we end
up not logging the new ancestor, and on log replay that new hard link and
ancestor do not exist. In some cases, involving renames, the file will not
exist at all.

Example:

  mkfs.btrfs -f /dev/sdb
  mount /dev/sdb /mnt

  mkdir /mnt/A
  touch /mnt/foo
  ln /mnt/foo /mnt/A/bar
  xfs_io -c fsync /mnt/foo

  <power failure>

In this example after log replay only the hard link named 'foo' exists
and directory A does not exist, which is unexpected. In other major linux
filesystems, such as ext4, xfs and f2fs for example, both hard links exist
and so does directory A after mounting again the filesystem.

Checking if any new ancestors are new and need to be logged was added in
2009 by commit 12fcfd22 ("Btrfs: tree logging unlink/rename fixes"),
however only for the ancestors of the hard link (dentry) for which the
fsync was issued, instead of checking for all ancestors for all of the
inode's hard links.

So fix this by tracking the id of the last transaction where a hard link
was created for an inode and then on fsync fallback to a full transaction
commit when an inode has more than one hard link and at least one new hard
link was created in the current transaction. This is the simplest solution
since this is not a common use case (adding frequently hard links for
which there's an ancestor created in the current transaction and then
fsync the file). In case it ever becomes a common use case, a solution
that consists of iterating the fs/subvol btree for each hard link and
check if any ancestor is new, could be implemented.

This solves many unexpected scenarios reported by Jayashree Mohan and
Vijay Chidambaram, and for which there is a new test case for fstests
under review.

Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Reported-by: NVijay Chidambaram <vvijay03@gmail.com>
Reported-by: NJayashree Mohan <jayashree2912@gmail.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      4bb3a2cc
    • L
      btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow · e967a98f
      由 Lu Fengqi 提交于 
      commit 27a7ff554e8d349627a90bda275c527b7348adae upstream.

The test case btrfs/001 with inode_cache mount option will encounter the
following warning:

  WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs]
  CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G        W  O      4.20.0-rc4-custom+ #30
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs]
  Call Trace:
   ? free_extent_buffer+0x46/0x90 [btrfs]
   run_delalloc_nocow+0x455/0x900 [btrfs]
   btrfs_run_delalloc_range+0x1a7/0x360 [btrfs]
   writepage_delalloc+0xf9/0x150 [btrfs]
   __extent_writepage+0x125/0x3e0 [btrfs]
   extent_write_cache_pages+0x1b6/0x3e0 [btrfs]
   ? __wake_up_common_lock+0x63/0xc0
   extent_writepages+0x50/0x80 [btrfs]
   do_writepages+0x41/0xd0
   ? __filemap_fdatawrite_range+0x9e/0xf0
   __filemap_fdatawrite_range+0xbe/0xf0
   btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
   __btrfs_write_out_cache+0x42c/0x480 [btrfs]
   btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
   btrfs_save_ino_cache+0x551/0x660 [btrfs]
   commit_fs_roots+0xc5/0x190 [btrfs]
   btrfs_commit_transaction+0x2bf/0x8d0 [btrfs]
   btrfs_mksubvol+0x48d/0x4d0 [btrfs]
   btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs]
   btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs]
   btrfs_ioctl+0x123f/0x3030 [btrfs]

The file extent generation of the free space inode is equal to the last
snapshot of the file root, so the inode will be passed to cow_file_rage.
But the inode was created and its extents were preallocated in
btrfs_save_ino_cache, there are no cow copies on disk.

The preallocated extent is not yet in the extent tree, and
btrfs_cross_ref_exist will ignore the -ENOENT returned by
check_committed_ref, so we can directly write the inode to the disk.

Fixes: 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path")
CC: stable@vger.kernel.org # 4.18+
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NLu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      e967a98f
  3. 21 11月, 2018 1 次提交
    • R
      Btrfs: fix cur_offset in the error case for nocow · db39065c
      由 Robbie Ko 提交于 
      commit 506481b20e818db40b6198815904ecd2d6daee64 upstream.

When the cow_file_range fails, the related resources are unlocked
according to the range [start..end), so the unlock cannot be repeated in
run_delalloc_nocow.

In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is
not updated correctly, so move the cur_offset update before
cow_file_range.

  kernel BUG at mm/page-writeback.c:2663!
  Internal error: Oops - BUG: 0 [#1] SMP
  CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O
  Hardware name: Realtek_RTD1296 (DT)
  Workqueue: writeback wb_workfn (flush-btrfs-1)
  task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000
  PC is at clear_page_dirty_for_io+0x1bc/0x1e8
  LR is at clear_page_dirty_for_io+0x14/0x1e8
  pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145
  sp : ffffffc02e9af4f0
  Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020)
  Call trace:
  [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8
  [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs]
  [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs]
  [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs]
  [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs]
  [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs]
  [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs]
  [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs]
  [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs]
  [<ffffffc00033d758>] do_writepages+0x30/0x88
  [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198
  [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0
  [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0
  [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0
  [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250
  [<ffffffc0002b0014>] process_one_work+0x1dc/0x388
  [<ffffffc0002b02f0>] worker_thread+0x130/0x500
  [<ffffffc0002b6344>] kthread+0x10c/0x110
  [<ffffffc000284590>] ret_from_fork+0x10/0x40
  Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000)

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NRobbie Ko <robbieko@synology.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      db39065c
  5. 14 11月, 2018 3 次提交
  7. 23 8月, 2018 1 次提交
    • F
      Btrfs: sync log after logging new name · d4682ba0
      由 Filipe Manana 提交于 
      When we add a new name for an inode which was logged in the current
transaction, we update the inode in the log so that its new name and
ancestors are added to the log. However when we do this we do not persist
the log, so the changes remain in memory only, and as a consequence, any
ancestors that were created in the current transaction are updated such
that future calls to btrfs_inode_in_log() return true. This leads to a
subsequent fsync against such new ancestor directories returning
immediately, without persisting the log, therefore after a power failure
the new ancestor directories do not exist, despite fsync being called
against them explicitly.

Example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/A
  $ mkdir /mnt/B
  $ mkdir /mnt/A/C
  $ touch /mnt/B/foo
  $ xfs_io -c "fsync" /mnt/B/foo
  $ ln /mnt/B/foo /mnt/A/C/foo
  $ xfs_io -c "fsync" /mnt/A
  <power failure>

After the power failure, directory "A" does not exist, despite the explicit
fsync on it.

Instead of fixing this by changing the behaviour of the explicit fsync on
directory "A" to persist the log instead of doing nothing, make the logging
of the new file name (which happens when creating a hard link or renaming)
persist the log. This approach not only is simpler, not requiring addition
of new fields to the inode in memory structure, but also gives us the same
behaviour as ext4, xfs and f2fs (possibly other filesystems too).

A test case for fstests follows soon.

Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes")
Reported-by: NVijay Chidambaram <vvijay03@gmail.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      d4682ba0
  9. 18 8月, 2018 1 次提交
    • R
      Btrfs: fix unexpected failure of nocow buffered writes after snapshotting when low on space · 8ecebf4d
      由 Robbie Ko 提交于 
      Commit e9894fd3 ("Btrfs: fix snapshot vs nocow writting") forced
nocow writes to fallback to COW, during writeback, when a snapshot is
created. This resulted in writes made before creating the snapshot to
unexpectedly fail with ENOSPC during writeback when success (0) was
returned to user space through the write system call.

The steps leading to this problem are:

1. When it's not possible to allocate data space for a write, the
   buffered write path checks if a NOCOW write is possible.  If it is,
   it will not reserve space and success (0) is returned to user space.

2. Then when a snapshot is created, the root's will_be_snapshotted
   atomic is incremented and writeback is triggered for all inode's that
   belong to the root being snapshotted. Incrementing that atomic forces
   all previous writes to fallback to COW during writeback (running
   delalloc).

3. This results in the writeback for the inodes to fail and therefore
   setting the ENOSPC error in their mappings, so that a subsequent
   fsync on them will report the error to user space. So it's not a
   completely silent data loss (since fsync will report ENOSPC) but it's
   a very unexpected and undesirable behaviour, because if a clean
   shutdown/unmount of the filesystem happens without previous calls to
   fsync, it is expected to have the data present in the files after
   mounting the filesystem again.

So fix this by adding a new atomic named snapshot_force_cow to the
root structure which prevents this behaviour and works the following way:

1. It is incremented when we start to create a snapshot after triggering
   writeback and before waiting for writeback to finish.

2. This new atomic is now what is used by writeback (running delalloc)
   to decide whether we need to fallback to COW or not. Because we
   incremented this new atomic after triggering writeback in the
   snapshot creation ioctl, we ensure that all buffered writes that
   happened before snapshot creation will succeed and not fallback to
   COW (which would make them fail with ENOSPC).

3. The existing atomic, will_be_snapshotted, is kept because it is used
   to force new buffered writes, that start after we started
   snapshotting, to reserve data space even when NOCOW is possible.
   This makes these writes fail early with ENOSPC when there's no
   available space to allocate, preventing the unexpected behaviour of
   writeback later failing with ENOSPC due to a fallback to COW mode.

Fixes: e9894fd3 ("Btrfs: fix snapshot vs nocow writting")
Signed-off-by: NRobbie Ko <robbieko@synology.com>
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      8ecebf4d
  11. 06 8月, 2018 18 次提交
  13. 04 8月, 2018 1 次提交
  15. 28 6月, 2018 1 次提交
    • C
      Btrfs: fix regression in btrfs_page_mkwrite() from vm_fault_t conversion · 717beb96
      由 Chris Mason 提交于 
      The vm_fault_t conversion commit introduced a ret2 variable for tracking
the integer return values from internal btrfs functions.  It was
sometimes returning VM_FAULT_LOCKED for pages that were actually invalid
and had been removed from the radix.  Something like this:

    ret2 = btrfs_delalloc_reserve_space() // returns zero on success

    lock_page(page)
    if (page->mapping != inode->i_mapping)
	goto out_unlock;

...

out_unlock:
    if (!ret2) {
	    ...
	    return VM_FAULT_LOCKED;
    }

This ends up triggering this WARNING in btrfs_destroy_inode()
    WARN_ON(BTRFS_I(inode)->block_rsv.size);

xfstests generic/095 was able to reliably reproduce the errors.

Since out_unlock: is only used for errors, this fix moves it below the
if (!ret2) check we use to return VM_FAULT_LOCKED for success.

Fixes: a528a241 (btrfs: change return type of btrfs_page_mkwrite to vm_fault_t)
Signed-off-by: NChris Mason <clm@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      717beb96
  17. 22 6月, 2018 1 次提交
    • F
      Btrfs: fix return value on rename exchange failure · c5b4a50b
      由 Filipe Manana 提交于 
      If we failed during a rename exchange operation after starting/joining a
transaction, we would end up replacing the return value, stored in the
local 'ret' variable, with the return value from btrfs_end_transaction().
So this could end up returning 0 (success) to user space despite the
operation having failed and aborted the transaction, because if there are
multiple tasks having a reference on the transaction at the time
btrfs_end_transaction() is called by the rename exchange, that function
returns 0 (otherwise it returns -EIO and not the original error value).
So fix this by not overwriting the return value on error after getting
a transaction handle.

Fixes: cdd1fedf ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT")
CC: stable@vger.kernel.org # 4.9+
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      c5b4a50b
  19. 07 6月, 2018 1 次提交
  21. 06 6月, 2018 1 次提交
    • D
      vfs: change inode times to use struct timespec64 · 95582b00
      由 Deepa Dinamani 提交于 
      struct timespec is not y2038 safe. Transition vfs to use
y2038 safe struct timespec64 instead.

The change was made with the help of the following cocinelle
script. This catches about 80% of the changes.
All the header file and logic changes are included in the
first 5 rules. The rest are trivial substitutions.
I avoid changing any of the function signatures or any other
filesystem specific data structures to keep the patch simple
for review.

The script can be a little shorter by combining different cases.
But, this version was sufficient for my usecase.

virtual patch

@ depends on patch @
identifier now;
@@
- struct timespec
+ struct timespec64
  current_time ( ... )
  {
- struct timespec now = current_kernel_time();
+ struct timespec64 now = current_kernel_time64();
  ...
- return timespec_trunc(
+ return timespec64_trunc(
  ... );
  }

@ depends on patch @
identifier xtime;
@@
 struct \( iattr \| inode \| kstat \) {
 ...
-       struct timespec xtime;
+       struct timespec64 xtime;
 ...
 }

@ depends on patch @
identifier t;
@@
 struct inode_operations {
 ...
int (*update_time) (...,
-       struct timespec t,
+       struct timespec64 t,
...);
 ...
 }

@ depends on patch @
identifier t;
identifier fn_update_time =~ "update_time$";
@@
 fn_update_time (...,
- struct timespec *t,
+ struct timespec64 *t,
 ...) { ... }

@ depends on patch @
identifier t;
@@
lease_get_mtime( ... ,
- struct timespec *t
+ struct timespec64 *t
  ) { ... }

@te depends on patch forall@
identifier ts;
local idexpression struct inode *inode_node;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn_update_time =~ "update_time$";
identifier fn;
expression e, E3;
local idexpression struct inode *node1;
local idexpression struct inode *node2;
local idexpression struct iattr *attr1;
local idexpression struct iattr *attr2;
local idexpression struct iattr attr;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
@@
(
(
- struct timespec ts;
+ struct timespec64 ts;
|
- struct timespec ts = current_time(inode_node);
+ struct timespec64 ts = current_time(inode_node);
)

<+... when != ts
(
- timespec_equal(&inode_node->i_xtime, &ts)
+ timespec64_equal(&inode_node->i_xtime, &ts)
|
- timespec_equal(&ts, &inode_node->i_xtime)
+ timespec64_equal(&ts, &inode_node->i_xtime)
|
- timespec_compare(&inode_node->i_xtime, &ts)
+ timespec64_compare(&inode_node->i_xtime, &ts)
|
- timespec_compare(&ts, &inode_node->i_xtime)
+ timespec64_compare(&ts, &inode_node->i_xtime)
|
ts = current_time(e)
|
fn_update_time(..., &ts,...)
|
inode_node->i_xtime = ts
|
node1->i_xtime = ts
|
ts = inode_node->i_xtime
|
<+... attr1->ia_xtime ...+> = ts
|
ts = attr1->ia_xtime
|
ts.tv_sec
|
ts.tv_nsec
|
btrfs_set_stack_timespec_sec(..., ts.tv_sec)
|
btrfs_set_stack_timespec_nsec(..., ts.tv_nsec)
|
- ts = timespec64_to_timespec(
+ ts =
...
-)
|
- ts = ktime_to_timespec(
+ ts = ktime_to_timespec64(
...)
|
- ts = E3
+ ts = timespec_to_timespec64(E3)
|
- ktime_get_real_ts(&ts)
+ ktime_get_real_ts64(&ts)
|
fn(...,
- ts
+ timespec64_to_timespec(ts)
,...)
)
...+>
(
<... when != ts
- return ts;
+ return timespec64_to_timespec(ts);
...>
)
|
- timespec_equal(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_equal(&node1->i_xtime2, &node2->i_xtime2)
|
- timespec_equal(&node1->i_xtime1, &attr2->ia_xtime2)
+ timespec64_equal(&node1->i_xtime2, &attr2->ia_xtime2)
|
- timespec_compare(&node1->i_xtime1, &node2->i_xtime2)
+ timespec64_compare(&node1->i_xtime1, &node2->i_xtime2)
|
node1->i_xtime1 =
- timespec_trunc(attr1->ia_xtime1,
+ timespec64_trunc(attr1->ia_xtime1,
...)
|
- attr1->ia_xtime1 = timespec_trunc(attr2->ia_xtime2,
+ attr1->ia_xtime1 =  timespec64_trunc(attr2->ia_xtime2,
...)
|
- ktime_get_real_ts(&attr1->ia_xtime1)
+ ktime_get_real_ts64(&attr1->ia_xtime1)
|
- ktime_get_real_ts(&attr.ia_xtime1)
+ ktime_get_real_ts64(&attr.ia_xtime1)
)

@ depends on patch @
struct inode *node;
struct iattr *attr;
identifier fn;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
expression e;
@@
(
- fn(node->i_xtime);
+ fn(timespec64_to_timespec(node->i_xtime));
|
 fn(...,
- node->i_xtime);
+ timespec64_to_timespec(node->i_xtime));
|
- e = fn(attr->ia_xtime);
+ e = fn(timespec64_to_timespec(attr->ia_xtime));
)

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
identifier i_xtime =~ "^i_[acm]time$";
identifier ia_xtime =~ "^ia_[acm]time$";
identifier fn;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
fn (...,
- &attr->ia_xtime,
+ &ts,
...);
)
...+>
}

@ depends on patch forall @
struct inode *node;
struct iattr *attr;
struct kstat *stat;
identifier ia_xtime =~ "^ia_[acm]time$";
identifier i_xtime =~ "^i_[acm]time$";
identifier xtime =~ "^[acm]time$";
identifier fn, ret;
@@
{
+ struct timespec ts;
<+...
(
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(node->i_xtime);
ret = fn (...,
- &node->i_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime,
+ &ts,
...);
|
+ ts = timespec64_to_timespec(attr->ia_xtime);
ret = fn (...,
- &attr->ia_xtime);
+ &ts);
|
+ ts = timespec64_to_timespec(stat->xtime);
ret = fn (...,
- &stat->xtime);
+ &ts);
)
...+>
}

@ depends on patch @
struct inode *node;
struct inode *node2;
identifier i_xtime1 =~ "^i_[acm]time$";
identifier i_xtime2 =~ "^i_[acm]time$";
identifier i_xtime3 =~ "^i_[acm]time$";
struct iattr *attrp;
struct iattr *attrp2;
struct iattr attr ;
identifier ia_xtime1 =~ "^ia_[acm]time$";
identifier ia_xtime2 =~ "^ia_[acm]time$";
struct kstat *stat;
struct kstat stat1;
struct timespec64 ts;
identifier xtime =~ "^[acmb]time$";
expression e;
@@
(
( node->i_xtime2 \| attrp->ia_xtime2 \| attr.ia_xtime2 \) = node->i_xtime1  ;
|
 node->i_xtime2 = \( node2->i_xtime1 \| timespec64_trunc(...) \);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 node->i_xtime1 = node->i_xtime3 = \(ts \| current_time(...) \);
|
 stat->xtime = node2->i_xtime1;
|
 stat1.xtime = node2->i_xtime1;
|
( node->i_xtime2 \| attrp->ia_xtime2 \) = attrp->ia_xtime1  ;
|
( attrp->ia_xtime1 \| attr.ia_xtime1 \) = attrp2->ia_xtime2;
|
- e = node->i_xtime1;
+ e = timespec64_to_timespec( node->i_xtime1 );
|
- e = attrp->ia_xtime1;
+ e = timespec64_to_timespec( attrp->ia_xtime1 );
|
node->i_xtime1 = current_time(...);
|
 node->i_xtime2 = node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
 node->i_xtime1 = node->i_xtime3 =
- e;
+ timespec_to_timespec64(e);
|
- node->i_xtime1 = e;
+ node->i_xtime1 = timespec_to_timespec64(e);
)
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Cc: <anton@tuxera.com>
Cc: <balbi@kernel.org>
Cc: <bfields@fieldses.org>
Cc: <darrick.wong@oracle.com>
Cc: <dhowells@redhat.com>
Cc: <dsterba@suse.com>
Cc: <dwmw2@infradead.org>
Cc: <hch@lst.de>
Cc: <hirofumi@mail.parknet.co.jp>
Cc: <hubcap@omnibond.com>
Cc: <jack@suse.com>
Cc: <jaegeuk@kernel.org>
Cc: <jaharkes@cs.cmu.edu>
Cc: <jslaby@suse.com>
Cc: <keescook@chromium.org>
Cc: <mark@fasheh.com>
Cc: <miklos@szeredi.hu>
Cc: <nico@linaro.org>
Cc: <reiserfs-devel@vger.kernel.org>
Cc: <richard@nod.at>
Cc: <sage@redhat.com>
Cc: <sfrench@samba.org>
Cc: <swhiteho@redhat.com>
Cc: <tj@kernel.org>
Cc: <trond.myklebust@primarydata.com>
Cc: <tytso@mit.edu>
Cc: <viro@zeniv.linux.org.uk>
      95582b00