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  1. 17 4月, 2019 1 次提交
  3. 13 2月, 2019 1 次提交
    • E
      btrfs: use tagged writepage to mitigate livelock of snapshot · f5d5b543
      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>
      f5d5b543
  5. 21 11月, 2018 2 次提交
    • F
      Btrfs: fix data corruption due to cloning of eof block · ec6d90a4
      由 Filipe Manana 提交于 
      commit ac765f83f1397646c11092a032d4f62c3d478b81 upstream.

We currently allow cloning a range from a file which includes the last
block of the file even if the file's size is not aligned to the block
size. This is fine and useful when the destination file has the same size,
but when it does not and the range ends somewhere in the middle of the
destination file, it leads to corruption because the bytes between the EOF
and the end of the block have undefined data (when there is support for
discard/trimming they have a value of 0x00).

Example:

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

 $ export foo_size=$((256 * 1024 + 100))
 $ xfs_io -f -c "pwrite -S 0x3c 0 $foo_size" /mnt/foo
 $ xfs_io -f -c "pwrite -S 0xb5 0 1M" /mnt/bar

 $ xfs_io -c "reflink /mnt/foo 0 512K $foo_size" /mnt/bar

 $ od -A d -t x1 /mnt/bar
 0000000 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 0524288 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c
 *
 0786528 3c 3c 3c 3c 00 00 00 00 00 00 00 00 00 00 00 00
 0786544 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 *
 0790528 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5
 *
 1048576

The bytes in the range from 786532 (512Kb + 256Kb + 100 bytes) to 790527
(512Kb + 256Kb + 4Kb - 1) got corrupted, having now a value of 0x00 instead
of 0xb5.

This is similar to the problem we had for deduplication that got recently
fixed by commit de02b9f6 ("Btrfs: fix data corruption when
deduplicating between different files").

Fix this by not allowing such operations to be performed and return the
errno -EINVAL to user space. This is what XFS is doing as well at the VFS
level. This change however now makes us return -EINVAL instead of
-EOPNOTSUPP for cases where the source range maps to an inline extent and
the destination range's end is smaller then the destination file's size,
since the detection of inline extents is done during the actual process of
dropping file extent items (at __btrfs_drop_extents()). Returning the
-EINVAL error is done early on and solely based on the input parameters
(offsets and length) and destination file's size. This makes us consistent
with XFS and anyone else supporting cloning since this case is now checked
at a higher level in the VFS and is where the -EINVAL will be returned
from starting with kernel 4.20 (the VFS changed was introduced in 4.20-rc1
by commit 07d19dc9fbe9 ("vfs: avoid problematic remapping requests into
partial EOF block"). So this change is more geared towards stable kernels,
as it's unlikely the new VFS checks get removed intentionally.

A test case for fstests follows soon, as well as an update to filter
existing tests that expect -EOPNOTSUPP to accept -EINVAL as well.

CC: <stable@vger.kernel.org> # 4.4+
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>
      ec6d90a4
    • F
      Btrfs: fix infinite loop on inode eviction after deduplication of eof block · bafd5b78
      由 Filipe Manana 提交于 
      commit 11023d3f5fdf89bba5e1142127701ca6e6014587 upstream.

If we attempt to deduplicate the last block of a file A into the middle of
a file B, and file A's size is not a multiple of the block size, we end
rounding the deduplication length to 0 bytes, to avoid the data corruption
issue fixed by commit de02b9f6 ("Btrfs: fix data corruption when
deduplicating between different files"). However a length of zero will
cause the insertion of an extent state with a start value greater (by 1)
then the end value, leading to a corrupt extent state that will trigger a
warning and cause chaos such as an infinite loop during inode eviction.
Example trace:

 [96049.833585] ------------[ cut here ]------------
 [96049.833714] WARNING: CPU: 0 PID: 24448 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
 [96049.833767] CPU: 0 PID: 24448 Comm: xfs_io Not tainted 4.19.0-rc7-btrfs-next-39 #1
 [96049.833768] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [96049.833780] RIP: 0010:insert_state+0x101/0x120 [btrfs]
 [96049.833783] RSP: 0018:ffffafd2c3707af0 EFLAGS: 00010282
 [96049.833785] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
 [96049.833786] RDX: 0000000000000007 RSI: ffff99045c143230 RDI: ffff99047b2168a0
 [96049.833787] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
 [96049.833787] R10: ffffafd2c3707ab8 R11: 0000000000000000 R12: ffff9903b93b12c8
 [96049.833788] R13: 000000000004e000 R14: ffffafd2c3707b80 R15: ffffafd2c3707b78
 [96049.833790] FS:  00007f5c14e7d700(0000) GS:ffff99047b200000(0000) knlGS:0000000000000000
 [96049.833791] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [96049.833792] CR2: 00007f5c146abff8 CR3: 0000000115f4c004 CR4: 00000000003606f0
 [96049.833795] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [96049.833796] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [96049.833796] Call Trace:
 [96049.833809]  __set_extent_bit+0x46c/0x6a0 [btrfs]
 [96049.833823]  lock_extent_bits+0x6b/0x210 [btrfs]
 [96049.833831]  ? _raw_spin_unlock+0x24/0x30
 [96049.833841]  ? test_range_bit+0xdf/0x130 [btrfs]
 [96049.833853]  lock_extent_range+0x8e/0x150 [btrfs]
 [96049.833864]  btrfs_double_extent_lock+0x78/0xb0 [btrfs]
 [96049.833875]  btrfs_extent_same_range+0x14e/0x550 [btrfs]
 [96049.833885]  ? rcu_read_lock_sched_held+0x3f/0x70
 [96049.833890]  ? __kmalloc_node+0x2b0/0x2f0
 [96049.833899]  ? btrfs_dedupe_file_range+0x19a/0x280 [btrfs]
 [96049.833909]  btrfs_dedupe_file_range+0x270/0x280 [btrfs]
 [96049.833916]  vfs_dedupe_file_range_one+0xd9/0xe0
 [96049.833919]  vfs_dedupe_file_range+0x131/0x1b0
 [96049.833924]  do_vfs_ioctl+0x272/0x6e0
 [96049.833927]  ? __fget+0x113/0x200
 [96049.833931]  ksys_ioctl+0x70/0x80
 [96049.833933]  __x64_sys_ioctl+0x16/0x20
 [96049.833937]  do_syscall_64+0x60/0x1b0
 [96049.833939]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [96049.833941] RIP: 0033:0x7f5c1478ddd7
 [96049.833943] RSP: 002b:00007ffe15b196a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [96049.833945] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1478ddd7
 [96049.833946] RDX: 00005625ece322d0 RSI: 00000000c0189436 RDI: 0000000000000004
 [96049.833947] RBP: 0000000000000000 R08: 00007f5c14a46f48 R09: 0000000000000040
 [96049.833948] R10: 0000000000000541 R11: 0000000000000202 R12: 0000000000000000
 [96049.833949] R13: 0000000000000000 R14: 0000000000000004 R15: 00005625ece322d0
 [96049.833954] irq event stamp: 6196
 [96049.833956] hardirqs last  enabled at (6195): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.833958] hardirqs last disabled at (6196): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.833959] softirqs last  enabled at (6114): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.833964] softirqs last disabled at (6095): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.833965] ---[ end trace db7b05f01b7fa10c ]---
 [96049.935816] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.935822] irq event stamp: 6584
 [96049.935823] hardirqs last  enabled at (6583): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.935825] hardirqs last disabled at (6584): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.935827] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.935828] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.935829] ---[ end trace db7b05f01b7fa123 ]---
 [96049.935840] ------------[ cut here ]------------
 [96049.936065] WARNING: CPU: 1 PID: 24463 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs]
 [96049.936107] CPU: 1 PID: 24463 Comm: umount Tainted: G        W         4.19.0-rc7-btrfs-next-39 #1
 [96049.936108] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [96049.936117] RIP: 0010:insert_state+0x101/0x120 [btrfs]
 [96049.936119] RSP: 0018:ffffafd2c3637bc0 EFLAGS: 00010282
 [96049.936120] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006
 [96049.936121] RDX: 0000000000000007 RSI: ffff990445cf88e0 RDI: ffff99047b2968a0
 [96049.936122] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000
 [96049.936123] R10: ffffafd2c3637b88 R11: 0000000000000000 R12: ffff9904574301e8
 [96049.936124] R13: 000000000004e000 R14: ffffafd2c3637c50 R15: ffffafd2c3637c48
 [96049.936125] FS:  00007fe4b87e72c0(0000) GS:ffff99047b280000(0000) knlGS:0000000000000000
 [96049.936126] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [96049.936128] CR2: 00005562e52618d8 CR3: 00000001151c8005 CR4: 00000000003606e0
 [96049.936129] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [96049.936131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [96049.936131] Call Trace:
 [96049.936141]  __set_extent_bit+0x46c/0x6a0 [btrfs]
 [96049.936154]  lock_extent_bits+0x6b/0x210 [btrfs]
 [96049.936167]  btrfs_evict_inode+0x1e1/0x5a0 [btrfs]
 [96049.936172]  evict+0xbf/0x1c0
 [96049.936174]  dispose_list+0x51/0x80
 [96049.936176]  evict_inodes+0x193/0x1c0
 [96049.936180]  generic_shutdown_super+0x3f/0x110
 [96049.936182]  kill_anon_super+0xe/0x30
 [96049.936189]  btrfs_kill_super+0x13/0x100 [btrfs]
 [96049.936191]  deactivate_locked_super+0x3a/0x70
 [96049.936193]  cleanup_mnt+0x3b/0x80
 [96049.936195]  task_work_run+0x93/0xc0
 [96049.936198]  exit_to_usermode_loop+0xfa/0x100
 [96049.936201]  do_syscall_64+0x17f/0x1b0
 [96049.936202]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [96049.936204] RIP: 0033:0x7fe4b80cfb37
 [96049.936206] RSP: 002b:00007ffff092b688 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
 [96049.936207] RAX: 0000000000000000 RBX: 00005562e5259060 RCX: 00007fe4b80cfb37
 [96049.936208] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00005562e525faa0
 [96049.936209] RBP: 00005562e525faa0 R08: 00005562e525f770 R09: 0000000000000015
 [96049.936210] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fe4b85d1e64
 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910
 [96049.936216] irq event stamp: 6616
 [96049.936219] hardirqs last  enabled at (6615): [<ffffffff91b00663>] console_unlock+0x503/0x640
 [96049.936219] hardirqs last disabled at (6616): [<ffffffff91a037dd>] trace_hardirqs_off_thunk+0x1a/0x1c
 [96049.936222] softirqs last  enabled at (6328): [<ffffffff92600370>] __do_softirq+0x370/0x421
 [96049.936222] softirqs last disabled at (6313): [<ffffffff91a8dd4d>] irq_exit+0xcd/0xe0
 [96049.936223] ---[ end trace db7b05f01b7fa124 ]---

The second stack trace, from inode eviction, is repeated forever due to
the infinite loop during eviction.

This is the same type of problem fixed way back in 2015 by commit
113e8283 ("Btrfs: fix inode eviction infinite loop after extent_same
ioctl") and commit ccccf3d6 ("Btrfs: fix inode eviction infinite loop
after cloning into it").

So fix this by returning immediately if the deduplication range length
gets rounded down to 0 bytes, as there is nothing that needs to be done in
such case.

Example reproducer:

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

 $ xfs_io -f -c "pwrite -S 0xe6 0 100" /mnt/foo
 $ xfs_io -f -c "pwrite -S 0xe6 0 1M" /mnt/bar

 # Unmount the filesystem and mount it again so that we start without any
 # extent state records when we ask for the deduplication.
 $ umount /mnt
 $ mount /dev/sdb /mnt

 $ xfs_io -c "dedupe /mnt/foo 0 500K 100" /mnt/bar

 # This unmount triggers the infinite loop.
 $ umount /mnt

A test case for fstests will follow soon.

Fixes: de02b9f6 ("Btrfs: fix data corruption when deduplicating between different files")
CC: <stable@vger.kernel.org> # 4.19+
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>
      bafd5b78
  7. 14 11月, 2018 1 次提交
    • Q
      btrfs: Ensure btrfs_trim_fs can trim the whole filesystem · d147f4dc
      由 Qu Wenruo 提交于 
      commit 6ba9fc8e628becf0e3ec94083450d089b0dec5f5 upstream.

[BUG]
fstrim on some btrfs only trims the unallocated space, not trimming any
space in existing block groups.

[CAUSE]
Before fstrim_range passed to btrfs_trim_fs(), it gets truncated to
range [0, super->total_bytes).  So later btrfs_trim_fs() will only be
able to trim block groups in range [0, super->total_bytes).

While for btrfs, any bytenr aligned to sectorsize is valid, since btrfs
uses its logical address space, there is nothing limiting the location
where we put block groups.

For filesystem with frequent balance, it's quite easy to relocate all
block groups and bytenr of block groups will start beyond
super->total_bytes.

In that case, btrfs will not trim existing block groups.

[FIX]
Just remove the truncation in btrfs_ioctl_fitrim(), so btrfs_trim_fs()
can get the unmodified range, which is normally set to [0, U64_MAX].
Reported-by: NChris Murphy <lists@colorremedies.com>
Fixes: f4c697e6 ("btrfs: return EINVAL if start > total_bytes in fitrim ioctl")
CC: <stable@vger.kernel.org> # v4.4+
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NNikolay Borisov <nborisov@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>
      d147f4dc
  9. 23 8月, 2018 1 次提交
    • F
      Btrfs: fix data corruption when deduplicating between different files · de02b9f6
      由 Filipe Manana 提交于 
      If we deduplicate extents between two different files we can end up
corrupting data if the source range ends at the size of the source file,
the source file's size is not aligned to the filesystem's block size
and the destination range does not go past the size of the destination
file size.

Example:

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

  $ xfs_io -f -c "pwrite -S 0x6b 0 2518890" /mnt/foo
  # The first byte with a value of 0xae starts at an offset (2518890)
  # which is not a multiple of the sector size.
  $ xfs_io -c "pwrite -S 0xae 2518890 102398" /mnt/foo

  # Confirm the file content is full of bytes with values 0x6b and 0xae.
  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
  11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # Create a second file with a length not aligned to the sector size,
  # whose bytes all have the value 0x6b, so that its extent(s) can be
  # deduplicated with the first file.
  $ xfs_io -f -c "pwrite -S 0x6b 0 557771" /mnt/bar

  # Now deduplicate the entire second file into a range of the first file
  # that also has all bytes with the value 0x6b. The destination range's
  # end offset must not be aligned to the sector size and must be less
  # then the offset of the first byte with the value 0xae (byte at offset
  # 2518890).
  $ xfs_io -c "dedupe /mnt/bar 0 1957888 557771" /mnt/foo

  # The bytes in the range starting at offset 2515659 (end of the
  # deduplication range) and ending at offset 2519040 (start offset
  # rounded up to the block size) must all have the value 0xae (and not
  # replaced with 0x00 values). In other words, we should have exactly
  # the same data we had before we asked for deduplication.
  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
  11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # Unmount the filesystem and mount it again. This guarantees any file
  # data in the page cache is dropped.
  $ umount /dev/sdb
  $ mount /dev/sdb /mnt

  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11461300 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 00
  11461320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  *
  11470000 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # The bytes in range 2515659 to 2519040 have a value of 0x00 and not a
  # value of 0xae, data corruption happened due to the deduplication
  # operation.

So fix this by rounding down, to the sector size, the length used for the
deduplication when the following conditions are met:

  1) Source file's range ends at its i_size;
  2) Source file's i_size is not aligned to the sector size;
  3) Destination range does not cross the i_size of the destination file.

Fixes: e1d227a4 ("btrfs: Handle unaligned length in extent_same")
CC: stable@vger.kernel.org # 4.2+
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      de02b9f6
  11. 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
  13. 06 8月, 2018 14 次提交
  15. 13 7月, 2018 1 次提交
  17. 07 7月, 2018 2 次提交
  19. 22 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
  23. 05 6月, 2018 1 次提交
  25. 31 5月, 2018 3 次提交
  27. 30 5月, 2018 5 次提交
  29. 29 5月, 2018 5 次提交