Commit Graph

8101 Commits

Author SHA1 Message Date
Josef Bacik
280c290881 btrfs: move the space_info handling code to space-info.c
These are the basic init and lookup functions and some helper functions,
fairly straightforward before the bad stuff starts.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
d44b72aa12 btrfs: export space_info_add_*_bytes
Prep work for consolidating all of the space_info code into one file.
We need to export these so multiple files can use them.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:52 +02:00
Josef Bacik
fc471cb0c8 btrfs: rename do_chunk_alloc to btrfs_chunk_alloc
Really we just need the enum, but as we break more things up it'll help
to have this external to extent-tree.c.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
Josef Bacik
8719aaae8d btrfs: move space_info to space-info.h
Migrate the struct definition and the one helper that's in ctree.h into
space-info.h

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
e749af443f btrfs: lift bio_set_dev from bio allocation helpers
The block device is passed around for the only purpose to set it in new
bios. Move the assignment one level up. This is a preparatory patch for
further bdev cleanups.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
e1ea2beee2 btrfs: use raid_attr for minimum stripe count in btrfs_calc_avail_data_space
Minimum stripe count matches the minimum devices required for a given
profile. The open coded assignments match the raid_attr table.

What's changed here is the meaning for RAID5/6. Previously their
min_stripes would be 1, while newly it's devs_min. This however shold be
the same as before because it's not possible to create filesystem on
fewer devices than the raid_attr table allows.

There's no adjustment regarding the parity stripes (like
calc_data_stripes does), because we're interested in overall space that
would fit on the devices.

Missing devices make no difference for the whole calculation, we have
the size stored in the structures.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
4f080f5711 btrfs: use raid_attr to adjust minimal stripe size in btrfs_calc_avail_data_space
Special case for DUP can be replaced by lookup to the attribute table,
where the dev_stripes is the right coefficient.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:51 +02:00
David Sterba
f262fa8de6 btrfs: drop default value assignments in enums
A few more instances whre we don't need to specify the values as long as
they are the same that enum assigns automatically. All of the enums are
in-memory only and nothing relies on the exact values.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
David Sterba
2792237d0c btrfs: use common helpers for extent IO state insertion messages
Print the error messages using the helpers that also print the
filesystem identification.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Josef Bacik
63611e738a btrfs: run delayed iput at unlink time
We have been seeing issues in production where a cleaner script will end
up unlinking a bunch of files that have pending iputs.  This means they
will get their final iput's run at btrfs-cleaner time and thus are not
throttled, which impacts the workload.

Since we are unlinking these files we can just drop the delayed iput at
unlink time.  We are already holding a reference to the inode so this
will not be the final iput and thus is completely safe to do at this
point.  Doing this means we are more likely to be doing the final iput
at unlink time, and thus will get the IO charged to the caller and get
throttled appropriately without affecting the main workload.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Filipe Manana
179006688a Btrfs: add missing inode version, ctime and mtime updates when punching hole
If the range for which we are punching a hole covers only part of a page,
we end up updating the inode item but we skip the update of the inode's
iversion, mtime and ctime. Fix that by ensuring we update those properties
of the inode.

A patch for fstests test case generic/059 that tests this as been sent
along with this fix.

Fixes: 2aaa665581 ("Btrfs: add hole punching")
Fixes: e8c1c76e80 ("Btrfs: add missing inode update when punching hole")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Filipe Manana
803f0f64d1 Btrfs: fix fsync not persisting dentry deletions due to inode evictions
In order to avoid searches on a log tree when unlinking an inode, we check
if the inode being unlinked was logged in the current transaction, as well
as the inode of its parent directory. When any of the inodes are logged,
we proceed to delete directory items and inode reference items from the
log, to ensure that if a subsequent fsync of only the inode being unlinked
or only of the parent directory when the other is not fsync'ed as well,
does not result in the entry still existing after a power failure.

That check however is not reliable when one of the inodes involved (the
one being unlinked or its parent directory's inode) is evicted, since the
logged_trans field is transient, that is, it is not stored on disk, so it
is lost when the inode is evicted and loaded into memory again (which is
set to zero on load). As a consequence the checks currently being done by
btrfs_del_dir_entries_in_log() and btrfs_del_inode_ref_in_log() always
return true if the inode was evicted before, regardless of the inode
having been logged or not before (and in the current transaction), this
results in the dentry being unlinked still existing after a log replay
if after the unlink operation only one of the inodes involved is fsync'ed.

Example:

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

  $ mkdir /mnt/dir
  $ touch /mnt/dir/foo
  $ xfs_io -c fsync /mnt/dir/foo

  # Keep an open file descriptor on our directory while we evict inodes.
  # We just want to evict the file's inode, the directory's inode must not
  # be evicted.
  $ ( cd /mnt/dir; while true; do :; done ) &
  $ pid=$!

  # Wait a bit to give time to background process to chdir to our test
  # directory.
  $ sleep 0.5

  # Trigger eviction of the file's inode.
  $ echo 2 > /proc/sys/vm/drop_caches

  # Unlink our file and fsync the parent directory. After a power failure
  # we don't expect to see the file anymore, since we fsync'ed the parent
  # directory.
  $ rm -f $SCRATCH_MNT/dir/foo
  $ xfs_io -c fsync /mnt/dir

  <power failure>

  $ mount /dev/sdb /mnt
  $ ls /mnt/dir
  foo
  $
   --> file still there, unlink not persisted despite explicit fsync on dir

Fix this by checking if the inode has the full_sync bit set in its runtime
flags as well, since that bit is set everytime an inode is loaded from
disk, or for other less common cases such as after a shrinking truncate
or failure to allocate extent maps for holes, and gets cleared after the
first fsync. Also consider the inode as possibly logged only if it was
last modified in the current transaction (besides having the full_fsync
flag set).

Fixes: 3a5f1d458a ("Btrfs: Optimize btree walking while logging inodes")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Nikolay Borisov
89b798ad1b btrfs: Use btrfs_get_io_geometry appropriately
Presently btrfs_map_block is used not only to do everything necessary to
map a bio to the underlying allocation profile but it's also used to
identify how much data could be written based on btrfs' stripe logic
without actually submitting anything. This is achieved by passing NULL
for 'bbio_ret' parameter.

This patch refactors all callers that require just the mapping length
by switching them to using btrfs_io_geometry instead of calling
btrfs_map_block with a special NULL value for 'bbio_ret'. No functional
change.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:50 +02:00
Nikolay Borisov
5f1411265e btrfs: Introduce btrfs_io_geometry infrastructure
Add a structure that holds various parameters for IO calculations and a
helper that fills the values. This will help further refactoring and
reduction of functions that in some way open-coded the calculations.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
c9d713d5b5 btrfs: improve messages when updating feature flags
Currently the messages printed after setting an incompat feature are
cryptis, we can easily make it better as the textual description is
passed to the helpers. Old:

  setting 128 feature flag

updated:

  setting incompat feature flag for RAID56 (0x80)

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
Arnd Bergmann
6c64460cdc btrfs: shut up bogus -Wmaybe-uninitialized warning
gcc sometimes can't determine whether a variable has been initialized
when both the initialization and the use are conditional:

fs/btrfs/props.c: In function 'inherit_props':
fs/btrfs/props.c:389:4: error: 'num_bytes' may be used uninitialized in this function [-Werror=maybe-uninitialized]
    btrfs_block_rsv_release(fs_info, trans->block_rsv,

This code is fine. Unfortunately, I cannot think of a good way to
rephrase it in a way that makes gcc understand this, so I add a bogus
initialization the way one should not.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ gcc 8 and 9 don't emit the warning ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
Filipe Manana
9e967495e0 Btrfs: prevent send failures and crashes due to concurrent relocation
Send always operates on read-only trees and always expected that while it
is in progress, nothing changes in those trees. Due to that expectation
and the fact that send is a read-only operation, it operates on commit
roots and does not hold transaction handles. However relocation can COW
nodes and leafs from read-only trees, which can cause unexpected failures
and crashes (hitting BUG_ONs). while send using a node/leaf, it gets
COWed, the transaction used to COW it is committed, a new transaction
starts, the extent previously used for that node/leaf gets allocated,
possibly for another tree, and the respective extent buffer' content
changes while send is still using it. When this happens send normally
fails with EIO being returned to user space and messages like the
following are found in dmesg/syslog:

  [ 3408.699121] BTRFS error (device sdc): parent transid verify failed on 58703872 wanted 250 found 253
  [ 3441.523123] BTRFS error (device sdc): did not find backref in send_root. inode=63211, offset=0, disk_byte=5222825984 found extent=5222825984

Other times, less often, we hit a BUG_ON() because an extent buffer that
send is using used to be a node, and while send is still using it, it
got COWed and got reused as a leaf while send is still using, producing
the following trace:

 [ 3478.466280] ------------[ cut here ]------------
 [ 3478.466282] kernel BUG at fs/btrfs/ctree.c:1806!
 [ 3478.466965] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 [ 3478.467635] CPU: 0 PID: 2165 Comm: btrfs Not tainted 5.0.0-btrfs-next-46 #1
 [ 3478.468311] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [ 3478.469681] RIP: 0010:read_node_slot+0x122/0x130 [btrfs]
 (...)
 [ 3478.471758] RSP: 0018:ffffa437826bfaa0 EFLAGS: 00010246
 [ 3478.472457] RAX: ffff961416ed7000 RBX: 000000000000003d RCX: 0000000000000002
 [ 3478.473151] RDX: 000000000000003d RSI: ffff96141e387408 RDI: ffff961599b30000
 [ 3478.473837] RBP: ffffa437826bfb8e R08: 0000000000000001 R09: ffffa437826bfb8e
 [ 3478.474515] R10: ffffa437826bfa70 R11: 0000000000000000 R12: ffff9614385c8708
 [ 3478.475186] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 [ 3478.475840] FS:  00007f8e0e9cc8c0(0000) GS:ffff9615b6a00000(0000) knlGS:0000000000000000
 [ 3478.476489] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 3478.477127] CR2: 00007f98b67a056e CR3: 0000000005df6005 CR4: 00000000003606f0
 [ 3478.477762] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [ 3478.478385] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [ 3478.479003] Call Trace:
 [ 3478.479600]  ? do_raw_spin_unlock+0x49/0xc0
 [ 3478.480202]  tree_advance+0x173/0x1d0 [btrfs]
 [ 3478.480810]  btrfs_compare_trees+0x30c/0x690 [btrfs]
 [ 3478.481388]  ? process_extent+0x1280/0x1280 [btrfs]
 [ 3478.481954]  btrfs_ioctl_send+0x1037/0x1270 [btrfs]
 [ 3478.482510]  _btrfs_ioctl_send+0x80/0x110 [btrfs]
 [ 3478.483062]  btrfs_ioctl+0x13fe/0x3120 [btrfs]
 [ 3478.483581]  ? rq_clock_task+0x2e/0x60
 [ 3478.484086]  ? wake_up_new_task+0x1f3/0x370
 [ 3478.484582]  ? do_vfs_ioctl+0xa2/0x6f0
 [ 3478.485075]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
 [ 3478.485552]  do_vfs_ioctl+0xa2/0x6f0
 [ 3478.486016]  ? __fget+0x113/0x200
 [ 3478.486467]  ksys_ioctl+0x70/0x80
 [ 3478.486911]  __x64_sys_ioctl+0x16/0x20
 [ 3478.487337]  do_syscall_64+0x60/0x1b0
 [ 3478.487751]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [ 3478.488159] RIP: 0033:0x7f8e0d7d4dd7
 (...)
 [ 3478.489349] RSP: 002b:00007ffcf6fb4908 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
 [ 3478.489742] RAX: ffffffffffffffda RBX: 0000000000000105 RCX: 00007f8e0d7d4dd7
 [ 3478.490142] RDX: 00007ffcf6fb4990 RSI: 0000000040489426 RDI: 0000000000000005
 [ 3478.490548] RBP: 0000000000000005 R08: 00007f8e0d6f3700 R09: 00007f8e0d6f3700
 [ 3478.490953] R10: 00007f8e0d6f39d0 R11: 0000000000000202 R12: 0000000000000005
 [ 3478.491343] R13: 00005624e0780020 R14: 0000000000000000 R15: 0000000000000001
 (...)
 [ 3478.493352] ---[ end trace d5f537302be4f8c8 ]---

Another possibility, much less likely to happen, is that send will not
fail but the contents of the stream it produces may not be correct.

To avoid this, do not allow send and relocation (balance) to run in
parallel. In the long term the goal is to allow for both to be able to
run concurrently without any problems, but that will take a significant
effort in development and testing.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
71a9c4885e btrfs: document BTRFS_MAX_MIRRORS
The real meaning of that constant is not clear from the context due to
the target device inclusion.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:49 +02:00
David Sterba
a07e8a468e btrfs: use mask for RAID56 profiles
We don't need to enumerate the profiles, use the mask for consistency.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
David Sterba
c7369b3fae btrfs: add mask for all RAID1 types
Preparatory patch for additional RAID1 profiles with more copies. The
mask will contain 3-copy and 4-copy, most of the checks for plain RAID1
work the same for the other profiles.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
Qu Wenruo
e88439debd btrfs: qgroup: Don't hold qgroup_ioctl_lock in btrfs_qgroup_inherit()
[BUG]
Lockdep will report the following circular locking dependency:

  WARNING: possible circular locking dependency detected
  5.2.0-rc2-custom #24 Tainted: G           O
  ------------------------------------------------------
  btrfs/8631 is trying to acquire lock:
  000000002536438c (&fs_info->qgroup_ioctl_lock#2){+.+.}, at: btrfs_qgroup_inherit+0x40/0x620 [btrfs]

  but task is already holding lock:
  000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (&fs_info->tree_log_mutex){+.+.}:
         __mutex_lock+0x76/0x940
         mutex_lock_nested+0x1b/0x20
         btrfs_commit_transaction+0x475/0xa00 [btrfs]
         btrfs_commit_super+0x71/0x80 [btrfs]
         close_ctree+0x2bd/0x320 [btrfs]
         btrfs_put_super+0x15/0x20 [btrfs]
         generic_shutdown_super+0x72/0x110
         kill_anon_super+0x18/0x30
         btrfs_kill_super+0x16/0xa0 [btrfs]
         deactivate_locked_super+0x3a/0x80
         deactivate_super+0x51/0x60
         cleanup_mnt+0x3f/0x80
         __cleanup_mnt+0x12/0x20
         task_work_run+0x94/0xb0
         exit_to_usermode_loop+0xd8/0xe0
         do_syscall_64+0x210/0x240
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  -> #1 (&fs_info->reloc_mutex){+.+.}:
         __mutex_lock+0x76/0x940
         mutex_lock_nested+0x1b/0x20
         btrfs_commit_transaction+0x40d/0xa00 [btrfs]
         btrfs_quota_enable+0x2da/0x730 [btrfs]
         btrfs_ioctl+0x2691/0x2b40 [btrfs]
         do_vfs_ioctl+0xa9/0x6d0
         ksys_ioctl+0x67/0x90
         __x64_sys_ioctl+0x1a/0x20
         do_syscall_64+0x65/0x240
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  -> #0 (&fs_info->qgroup_ioctl_lock#2){+.+.}:
         lock_acquire+0xa7/0x190
         __mutex_lock+0x76/0x940
         mutex_lock_nested+0x1b/0x20
         btrfs_qgroup_inherit+0x40/0x620 [btrfs]
         create_pending_snapshot+0x9d7/0xe60 [btrfs]
         create_pending_snapshots+0x94/0xb0 [btrfs]
         btrfs_commit_transaction+0x415/0xa00 [btrfs]
         btrfs_mksubvol+0x496/0x4e0 [btrfs]
         btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs]
         btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs]
         btrfs_ioctl+0xa90/0x2b40 [btrfs]
         do_vfs_ioctl+0xa9/0x6d0
         ksys_ioctl+0x67/0x90
         __x64_sys_ioctl+0x1a/0x20
         do_syscall_64+0x65/0x240
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:

  Chain exists of:
    &fs_info->qgroup_ioctl_lock#2 --> &fs_info->reloc_mutex --> &fs_info->tree_log_mutex

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&fs_info->tree_log_mutex);
                                 lock(&fs_info->reloc_mutex);
                                 lock(&fs_info->tree_log_mutex);
    lock(&fs_info->qgroup_ioctl_lock#2);

   *** DEADLOCK ***

  6 locks held by btrfs/8631:
   #0: 00000000ed8f23f6 (sb_writers#12){.+.+}, at: mnt_want_write_file+0x28/0x60
   #1: 000000009fb1597a (&type->i_mutex_dir_key#10/1){+.+.}, at: btrfs_mksubvol+0x70/0x4e0 [btrfs]
   #2: 0000000088c5ad88 (&fs_info->subvol_sem){++++}, at: btrfs_mksubvol+0x128/0x4e0 [btrfs]
   #3: 000000009606fc3e (sb_internal#2){.+.+}, at: start_transaction+0x37a/0x520 [btrfs]
   #4: 00000000f82bbdf5 (&fs_info->reloc_mutex){+.+.}, at: btrfs_commit_transaction+0x40d/0xa00 [btrfs]
   #5: 000000003d52cc23 (&fs_info->tree_log_mutex){+.+.}, at: create_pending_snapshot+0x8b6/0xe60 [btrfs]

[CAUSE]
Due to the delayed subvolume creation, we need to call
btrfs_qgroup_inherit() inside commit transaction code, with a lot of
other mutex hold.
This hell of lock chain can lead to above problem.

[FIX]
On the other hand, we don't really need to hold qgroup_ioctl_lock if
we're in the context of create_pending_snapshot().
As in that context, we're the only one being able to modify qgroup.

All other qgroup functions which needs qgroup_ioctl_lock are either
holding a transaction handle, or will start a new transaction:
  Functions will start a new transaction():
  * btrfs_quota_enable()
  * btrfs_quota_disable()
  Functions hold a transaction handler:
  * btrfs_add_qgroup_relation()
  * btrfs_del_qgroup_relation()
  * btrfs_create_qgroup()
  * btrfs_remove_qgroup()
  * btrfs_limit_qgroup()
  * btrfs_qgroup_inherit() call inside create_subvol()

So we have a higher level protection provided by transaction, thus we
don't need to always hold qgroup_ioctl_lock in btrfs_qgroup_inherit().

Only the btrfs_qgroup_inherit() call in create_subvol() needs to hold
qgroup_ioctl_lock, while the btrfs_qgroup_inherit() call in
create_pending_snapshot() is already protected by transaction.

So the fix is to detect the context by checking
trans->transaction->state.
If we're at TRANS_STATE_COMMIT_DOING, then we're in commit transaction
context and no need to get the mutex.

Reported-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
Johannes Thumshirn
aa53e3bfac btrfs: correctly validate compression type
Nikolay reported the following KASAN splat when running btrfs/048:

[ 1843.470920] ==================================================================
[ 1843.471971] BUG: KASAN: slab-out-of-bounds in strncmp+0x66/0xb0
[ 1843.472775] Read of size 1 at addr ffff888111e369e2 by task btrfs/3979

[ 1843.473904] CPU: 3 PID: 3979 Comm: btrfs Not tainted 5.2.0-rc3-default #536
[ 1843.475009] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 1843.476322] Call Trace:
[ 1843.476674]  dump_stack+0x7c/0xbb
[ 1843.477132]  ? strncmp+0x66/0xb0
[ 1843.477587]  print_address_description+0x114/0x320
[ 1843.478256]  ? strncmp+0x66/0xb0
[ 1843.478740]  ? strncmp+0x66/0xb0
[ 1843.479185]  __kasan_report+0x14e/0x192
[ 1843.479759]  ? strncmp+0x66/0xb0
[ 1843.480209]  kasan_report+0xe/0x20
[ 1843.480679]  strncmp+0x66/0xb0
[ 1843.481105]  prop_compression_validate+0x24/0x70
[ 1843.481798]  btrfs_xattr_handler_set_prop+0x65/0x160
[ 1843.482509]  __vfs_setxattr+0x71/0x90
[ 1843.483012]  __vfs_setxattr_noperm+0x84/0x130
[ 1843.483606]  vfs_setxattr+0xac/0xb0
[ 1843.484085]  setxattr+0x18c/0x230
[ 1843.484546]  ? vfs_setxattr+0xb0/0xb0
[ 1843.485048]  ? __mod_node_page_state+0x1f/0xa0
[ 1843.485672]  ? _raw_spin_unlock+0x24/0x40
[ 1843.486233]  ? __handle_mm_fault+0x988/0x1290
[ 1843.486823]  ? lock_acquire+0xb4/0x1e0
[ 1843.487330]  ? lock_acquire+0xb4/0x1e0
[ 1843.487842]  ? mnt_want_write_file+0x3c/0x80
[ 1843.488442]  ? debug_lockdep_rcu_enabled+0x22/0x40
[ 1843.489089]  ? rcu_sync_lockdep_assert+0xe/0x70
[ 1843.489707]  ? __sb_start_write+0x158/0x200
[ 1843.490278]  ? mnt_want_write_file+0x3c/0x80
[ 1843.490855]  ? __mnt_want_write+0x98/0xe0
[ 1843.491397]  __x64_sys_fsetxattr+0xba/0xe0
[ 1843.492201]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[ 1843.493201]  do_syscall_64+0x6c/0x230
[ 1843.493988]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1843.495041] RIP: 0033:0x7fa7a8a7707a
[ 1843.495819] Code: 48 8b 0d 21 de 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 be 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d ee dd 2b 00 f7 d8 64 89 01 48
[ 1843.499203] RSP: 002b:00007ffcb73bca38 EFLAGS: 00000202 ORIG_RAX: 00000000000000be
[ 1843.500210] RAX: ffffffffffffffda RBX: 00007ffcb73bda9d RCX: 00007fa7a8a7707a
[ 1843.501170] RDX: 00007ffcb73bda9d RSI: 00000000006dc050 RDI: 0000000000000003
[ 1843.502152] RBP: 00000000006dc050 R08: 0000000000000000 R09: 0000000000000000
[ 1843.503109] R10: 0000000000000002 R11: 0000000000000202 R12: 00007ffcb73bda91
[ 1843.504055] R13: 0000000000000003 R14: 00007ffcb73bda82 R15: ffffffffffffffff

[ 1843.505268] Allocated by task 3979:
[ 1843.505771]  save_stack+0x19/0x80
[ 1843.506211]  __kasan_kmalloc.constprop.5+0xa0/0xd0
[ 1843.506836]  setxattr+0xeb/0x230
[ 1843.507264]  __x64_sys_fsetxattr+0xba/0xe0
[ 1843.507886]  do_syscall_64+0x6c/0x230
[ 1843.508429]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

[ 1843.509558] Freed by task 0:
[ 1843.510188] (stack is not available)

[ 1843.511309] The buggy address belongs to the object at ffff888111e369e0
                which belongs to the cache kmalloc-8 of size 8
[ 1843.514095] The buggy address is located 2 bytes inside of
                8-byte region [ffff888111e369e0, ffff888111e369e8)
[ 1843.516524] The buggy address belongs to the page:
[ 1843.517561] page:ffff88813f478d80 refcount:1 mapcount:0 mapping:ffff88811940c300 index:0xffff888111e373b8 compound_mapcount: 0
[ 1843.519993] flags: 0x4404000010200(slab|head)
[ 1843.520951] raw: 0004404000010200 ffff88813f48b008 ffff888119403d50 ffff88811940c300
[ 1843.522616] raw: ffff888111e373b8 000000000016000f 00000001ffffffff 0000000000000000
[ 1843.524281] page dumped because: kasan: bad access detected

[ 1843.525936] Memory state around the buggy address:
[ 1843.526975]  ffff888111e36880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1843.528479]  ffff888111e36900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1843.530138] >ffff888111e36980: fc fc fc fc fc fc fc fc fc fc fc fc 02 fc fc fc
[ 1843.531877]                                                        ^
[ 1843.533287]  ffff888111e36a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1843.534874]  ffff888111e36a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 1843.536468] ==================================================================

This is caused by supplying a too short compression value ('lz') in the
test-case and comparing it to 'lzo' with strncmp() and a length of 3.
strncmp() read past the 'lz' when looking for the 'o' and thus caused an
out-of-bounds read.

Introduce a new check 'btrfs_compress_is_valid_type()' which not only
checks the user-supplied value against known compression types, but also
employs checks for too short values.

Reported-by: Nikolay Borisov <nborisov@suse.com>
Fixes: 272e5326c7 ("btrfs: prop: fix vanished compression property after failed set")
CC: stable@vger.kernel.org # 5.1+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
Filipe Manana
d1d832a0b5 Btrfs: fix data loss after inode eviction, renaming it, and fsync it
When we log an inode, regardless of logging it completely or only that it
exists, we always update it as logged (logged_trans and last_log_commit
fields of the inode are updated). This is generally fine and avoids future
attempts to log it from having to do repeated work that brings no value.

However, if we write data to a file, then evict its inode after all the
dealloc was flushed (and ordered extents completed), rename the file and
fsync it, we end up not logging the new extents, since the rename may
result in logging that the inode exists in case the parent directory was
logged before. The following reproducer shows and explains how this can
happen:

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

  $ mkdir /mnt/dir
  $ touch /mnt/dir/foo
  $ touch /mnt/dir/bar

  # Do a direct IO write instead of a buffered write because with a
  # buffered write we would need to make sure dealloc gets flushed and
  # complete before we do the inode eviction later, and we can not do that
  # from user space with call to things such as sync(2) since that results
  # in a transaction commit as well.
  $ xfs_io -d -c "pwrite -S 0xd3 0 4K" /mnt/dir/bar

  # Keep the directory dir in use while we evict inodes. We want our file
  # bar's inode to be evicted but we don't want our directory's inode to
  # be evicted (if it were evicted too, we would not be able to reproduce
  # the issue since the first fsync below, of file foo, would result in a
  # transaction commit.
  $ ( cd /mnt/dir; while true; do :; done ) &
  $ pid=$!

  # Wait a bit to give time for the background process to chdir.
  $ sleep 0.1

  # Evict all inodes, except the inode for the directory dir because it is
  # currently in use by our background process.
  $ echo 2 > /proc/sys/vm/drop_caches

  # fsync file foo, which ends up persisting information about the parent
  # directory because it is a new inode.
  $ xfs_io -c fsync /mnt/dir/foo

  # Rename bar, this results in logging that this inode exists (inode item,
  # names, xattrs) because the parent directory is in the log.
  $ mv /mnt/dir/bar /mnt/dir/baz

  # Now fsync baz, which ends up doing absolutely nothing because of the
  # rename operation which logged that the inode exists only.
  $ xfs_io -c fsync /mnt/dir/baz

  <power failure>

  $ mount /dev/sdb /mnt
  $ od -t x1 -A d /mnt/dir/baz
  0000000

    --> Empty file, data we wrote is missing.

Fix this by not updating last_sub_trans of an inode when we are logging
only that it exists and the inode was not yet logged since it was loaded
from disk (full_sync bit set), this is enough to make btrfs_inode_in_log()
return false for this scenario and make us log the inode. The logged_trans
of the inode is still always setsince that alone is used to track if names
need to be deleted as part of unlink operations.

Fixes: 257c62e1bc ("Btrfs: avoid tree log commit when there are no changes")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
David Sterba
6d58a55a89 btrfs: raid56: clear incompat block group flags after removing the last one
The incompat bit for RAID56 is set either at mount time or automatically
when the profile is used by balance. The part where the bit is removed
is missing and can be unexpected or undesired when an older kernel is
needed.

This patch will drop the incompat bit after this command, assuming
that RAID5 profile is not used by system or metadata:

 $ btrfs balance start -dconvert=raid5 /mnt
 $ btrfs balance start -dconvert=raid1 /mnt

This will print "clearing 128 feature flag" to the system log.

The patch is safe for backporting to older kernels.

Reported-by: Hugo Mills <hugo@carfax.org.uk>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:48 +02:00
David Sterba
00801ae4bb btrfs: switch extent_buffer write_locks from atomic to int
The write_locks is either 0 or 1 and always updated under the lock,
so we don't need the atomic_t semantics.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:47 +02:00
David Sterba
f3dc24c52a btrfs: switch extent_buffer spinning_writers from atomic to int
The spinning_writers is either 0 or 1 and always updated under the lock,
so we don't need the atomic_t semantics.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:47 +02:00
David Sterba
06297d8cef btrfs: switch extent_buffer blocking_writers from atomic to int
The blocking_writers is either 0 or 1 and always updated under the lock,
so we don't need the atomic_t semantics.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:47 +02:00
David Sterba
38e9372e39 btrfs: assert delayed ref lock in btrfs_find_delayed_ref_head
Turn the comment about required lock into an assertion.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-02 12:30:47 +02:00
David Sterba
93ead46b03 btrfs: tests: add locks around add_extent_mapping
There are no concerns about locking during the selftests so the locks
are not necessary, but following patches will add lockdep assertions to
add_extent_mapping so this is needed in tests too.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:03 +02:00
Nikolay Borisov
8666e638b0 btrfs: Document __etree_search
The function has a lot of return values and specific conventions making
it cumbersome to understand what's returned. Have a go at documenting
its parameters and return values.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:03 +02:00
Nikolay Borisov
1eaebb341d btrfs: Don't trim returned range based on input value in find_first_clear_extent_bit
Currently find_first_clear_extent_bit always returns a range whose
starting value is >= passed 'start'. This implicit trimming behavior is
somewhat subtle and an implementation detail.

Instead, this patch modifies the function such that now it always
returns the range which contains passed 'start' and has the given bits
unset. This range could either be due to presence of existing records
which contains 'start' but have the bits unset or because there are no
records that contain the given starting offset.

This patch also adds test cases which cover find_first_clear_extent_bit
since they were missing up until now.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Nikolay Borisov
53460a4572 btrfs: trim: make reserved device area adjustments more explicit
Currently the first megabyte on a device housing a btrfs filesystem is
exempt from allocation and trimming. Currently this is not a problem
since 'start' is set to 1M at the beginning of btrfs_trim_free_extents
and find_first_clear_extent_bit always returns a range that is >= start.

However, in a follow up patch find_first_clear_extent_bit will be
changed such that it will return a range containing 'start' and this
range may very well be 0...>=1M so 'start'.

Future proof the sole user of find_first_clear_extent_bit by setting
'start' after the function is called. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
David Sterba
6f8e4fd430 btrfs: use file:line format for assertion report
The filename:line format is commonly understood by editors and can be
copy&pasted more easily than the current format.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn
ea41d6b278 btrfs: remove assumption about csum type form btrfs_print_data_csum_error()
btrfs_print_data_csum_error() still assumed checksums to be 32 bit in
size.  Make it size agnostic.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn
d5178578bc btrfs: directly call into crypto framework for checksumming
Currently btrfs_csum_data() relied on the crc32c() wrapper around the
crypto framework for calculating the CRCs.

As we have our own crypto_shash structure in the fs_info now, we can
directly call into the crypto framework without going trough the wrapper.

This way we can even remove the btrfs_csum_data() and btrfs_csum_final()
wrappers.

The module dependency on crc32c is preserved via MODULE_SOFTDEP("pre:
crc32c"), which was previously provided by LIBCRC32C config option doing
the same.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:02 +02:00
Johannes Thumshirn
6d97c6e31b btrfs: add boilerplate code for directly including the crypto framework
Add boilerplate code for directly including the crypto framework.  This
helps us flipping the switch for new algorithms.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
51bce6c9b9 btrfs: Simplify btrfs_check_super_csum() and get rid of size assumptions
Now that we have already checked for a valid checksum type before
calling btrfs_check_super_csum(), it can be simplified even further.

While at it get rid of the implicit size assumption of the resulting
checksum as well.

This is a preparation for changing all checksum functionality to use the
crypto layer later.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
8dc3f22c8b btrfs: check for supported superblock checksum type before checksum validation
Now that we have factorerd out the superblock checksum type validation,
we can check for supported superblock checksum types before doing the
actual validation of the superblock read from disk.

This leads the path to further simplifications of
btrfs_check_super_csum() later on.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
e7e16f4882 btrfs: add common checksum type validation
Currently btrfs is only supporting CRC32C as checksumming algorithm. As
this is about to change provide a function to validate the checksum type
in the superblock against all possible algorithms.

This makes adding new algorithms easier as there are fewer places to
adjust when adding new algorithms.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
7ebc7e5f2c btrfs: format checksums according to type for printing
Add a small helper for btrfs_print_data_csum_error() which formats the
checksum according to it's type for pretty printing.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ shorten macro name ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
10fe6ca80d btrfs: don't assume compressed_bio sums to be 4 bytes
BTRFS has the implicit assumption that a checksum in compressed_bio is 4
bytes. While this is true for CRC32C, it is not for any other checksum.

Change the data type to be a byte array and adjust loop index calculation
accordingly.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:01 +02:00
Johannes Thumshirn
1e25a2e3ca btrfs: don't assume ordered sums to be 4 bytes
BTRFS has the implicit assumption that a checksum in btrfs_orderd_sums
is 4 bytes. While this is true for CRC32C, it is not for any other
checksum.

Change the data type to be a byte array and adjust loop index
calculation accordingly.

This includes moving the adjustment of 'index' by 'ins_size' in
btrfs_csum_file_blocks() before dividing 'ins_size' by the checksum
size, because before this patch the 'sums' member of 'struct
btrfs_ordered_sum' was 4 Bytes in size and afterwards it is only one
byte.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Johannes Thumshirn
4bb3c2e2b5 btrfs: use btrfs_crc32c{,_final}() in for free space cache
The CRC checksum in the free space cache is not dependant on the super
block's csum_type field but always a CRC32C.

So use btrfs_crc32c() and btrfs_crc32c_final() instead of
btrfs_csum_data() and btrfs_csum_final() for computing these checksums.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Johannes Thumshirn
65019df8c3 btrfs: resurrect btrfs_crc32c()
Commit 9678c54388 ("btrfs: Remove custom crc32c init code") removed
the btrfs_crc32c() function, because it was a duplicate of the crc32c()
library function we already have in the kernel.

Resurrect it as a shim wrapper over crc32c() to make following
transformations of the checksumming code in btrfs easier.

Also provide a btrfs_crc32_final() to ease following transformations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Johannes Thumshirn
5852c8b961 btrfs: use btrfs_csum_data() instead of directly calling crc32c
btrfsic_test_for_metadata() directly calls the crc32c() library function
for calculating the CRC32C checksum, but then uses btrfs_csum_final() to
invert the result.

To ease further refactoring and development around checksumming in BTRFS
convert to calling btrfs_csum_data(), which is a wrapper around
crc32c().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Qu Wenruo
a94d1d0cb3 btrfs: Flush before reflinking any extent to prevent NOCOW write falling back to COW without data reservation
[BUG]
The following script can cause unexpected fsync failure:

  #!/bin/bash

  dev=/dev/test/test
  mnt=/mnt/btrfs

  mkfs.btrfs -f $dev -b 512M > /dev/null
  mount $dev $mnt -o nospace_cache

  # Prealloc one extent
  xfs_io -f -c "falloc 8k 64m" $mnt/file1
  # Fill the remaining data space
  xfs_io -f -c "pwrite 0 -b 4k 512M" $mnt/padding
  sync

  # Write into the prealloc extent
  xfs_io -c "pwrite 1m 16m" $mnt/file1

  # Reflink then fsync, fsync would fail due to ENOSPC
  xfs_io -c "reflink $mnt/file1 8k 0 4k" -c "fsync" $mnt/file1
  umount $dev

The fsync fails with ENOSPC, and the last page of the buffered write is
lost.

[CAUSE]
This is caused by:
- Btrfs' back reference only has extent level granularity
  So write into shared extent must be COWed even only part of the extent
  is shared.

So for above script we have:
- fallocate
  Create a preallocated extent where we can do NOCOW write.

- fill all the remaining data and unallocated space

- buffered write into preallocated space
  As we have not enough space available for data and the extent is not
  shared (yet) we fall into NOCOW mode.

- reflink
  Now part of the large preallocated extent is shared, later write
  into that extent must be COWed.

- fsync triggers writeback
  But now the extent is shared and therefore we must fallback into COW
  mode, which fails with ENOSPC since there's not enough space to
  allocate data extents.

[WORKAROUND]
The workaround is to ensure any buffered write in the related extents
(not just the reflink source range) get flushed before reflink/dedupe,
so that NOCOW writes succeed that happened before reflinking succeed.

The workaround is expensive, we could do it better by only flushing
NOCOW range, but that needs extra accounting for NOCOW range.
For now, fix the possible data loss first.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:35:00 +02:00
Nikolay Borisov
5f791ec31f btrfs: Return EAGAIN if we can't start no snpashot write in check_can_nocow
The first thing code does in check_can_nocow is trying to block
concurrent snapshots. If this fails (due to snpashot already being in
progress) the function returns ENOSPC which makes no sense. Instead
return EAGAIN. Despite this return value not being propagated to callers
it's good practice to return the closest in terms of semantics error
code. No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov
0b6f5d408b btrfs: Add comments on locking of several device-related fields
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov
bd80d94efb btrfs: Always use a cached extent_state in btrfs_lock_and_flush_ordered_range
In case no cached_state argument is passed to
btrfs_lock_and_flush_ordered_range use one locally in the function. This
optimises the case when an ordered extent is found since the unlock
function will be able to unlock that state directly without searching
for it again.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00
Nikolay Borisov
23d31bd476 btrfs: Use newly introduced btrfs_lock_and_flush_ordered_range
There several functions which open code
btrfs_lock_and_flush_ordered_range, just replace them with a call to the
function. No functional changes.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-07-01 13:34:59 +02:00