linux-stable.git/fs/btrfs, branch linux-6.2.y

btrfs: fix backref walking not returning all inode refs

2023-05-17T11:58:58+00:00

commit 0cad8f14d70cfeb5173dce93cafeba665a95430e upstream.

When using the logical to ino ioctl v2, if the flag to ignore offsets of
file extent items (BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET) is given, the
backref walking code ends up not returning references for all file offsets
of an inode that point to the given logical bytenr. This happens since
kernel 6.2, commit 6ce6ba534418 ("btrfs: use a single argument for extent
offset in backref walking functions") because:

1) It mistakenly skipped the search for file extent items in a leaf that
   point to the target extent if that flag is given. Instead it should
   only skip the filtering done by check_extent_in_eb() - that is, it
   should not avoid the calls to that function (or find_extent_in_eb(),
   which uses it).

2) It was also not building a list of inode extent elements (struct
   extent_inode_elem) if we have multiple inode references for an extent
   when the ignore offset flag is given to the logical to ino ioctl - it
   would leave a single element, only the last one that was found.

These stem from the confusing old interface for backref walking functions
where we had an extent item offset argument that was a pointer to a u64
and another boolean argument that indicated if the offset should be
ignored, but the pointer could be NULL. That NULL case is used by
relocation, qgroup extent accounting and fiemap, simply to avoid building
the inode extent list for each reference, as it's not necessary for those
use cases and therefore avoids memory allocations and some computations.

Fix this by adding a boolean argument to the backref walk context
structure to indicate that the inode extent list should not be built,
make relocation set that argument to true and fix the backref walking
logic to skip the calls to check_extent_in_eb() and find_extent_in_eb()
only if this new argument is true, instead of 'ignore_extent_item_pos'
being true.

A test case for fstests will be added soon, to provide cover not only
for these cases but to the logical to ino ioctl in general as well, as
currently we do not have a test case for it.

Reported-by: Vladimir Panteleev 
Link: https://lore.kernel.org/linux-btrfs/CAHhfkvwo=nmzrJSqZ2qMfF-rZB-ab6ahHnCD_sq9h4o8v+M7QQ@mail.gmail.com/
Fixes: 6ce6ba534418 ("btrfs: use a single argument for extent offset in backref walking functions")
CC: stable@vger.kernel.org # 6.2+
Tested-by: Vladimir Panteleev 
Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: zoned: fix full zone super block reading on ZNS

2023-05-17T11:58:58+00:00

commit 02ca9e6fb5f66a031df4fac508b8e477ca69e918 upstream.

When both of the superblock zones are full, we need to check which
superblock is newer. The calculation of last superblock position is wrong
as it does not consider zone_capacity and uses the length.

Fixes: 9658b72ef300 ("btrfs: zoned: locate superblock position using zone capacity")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: zoned: zone finish data relocation BG with last IO

2023-05-17T11:58:58+00:00

commit f84353c7c20536ea7e01eca79430eccdf3cc7348 upstream.

For data block groups, we zone finish a zone (or, just deactivate it) when
seeing the last IO in btrfs_finish_ordered_io(). That is only called for
IOs using ZONE_APPEND, but we use a regular WRITE command for data
relocation IOs. Detect it and call btrfs_zone_finish_endio() properly.

Fixes: be1a1d7a5d24 ("btrfs: zoned: finish fully written block group")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Naohiro Aota 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix space cache inconsistency after error loading it from disk

2023-05-17T11:58:58+00:00

commit 0004ff15ea26015a0a3a6182dca3b9d1df32e2b7 upstream.

When loading a free space cache from disk, at __load_free_space_cache(),
if we fail to insert a bitmap entry, we still increment the number of
total bitmaps in the btrfs_free_space_ctl structure, which is incorrect
since we failed to add the bitmap entry. On error we then empty the
cache by calling __btrfs_remove_free_space_cache(), which will result
in getting the total bitmaps counter set to 1.

A failure to load a free space cache is not critical, so if a failure
happens we just rebuild the cache by scanning the extent tree, which
happens at block-group.c:caching_thread(). Yet the failure will result
in having the total bitmaps of the btrfs_free_space_ctl always bigger
by 1 then the number of bitmap entries we have. So fix this by having
the total bitmaps counter be incremented only if we successfully added
the bitmap entry.

Fixes: a67509c30079 ("Btrfs: add a io_ctl struct and helpers for dealing with the space cache")
Reviewed-by: Anand Jain 
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: print-tree: parent bytenr must be aligned to sector size

2023-05-17T11:58:57+00:00

commit c87f318e6f47696b4040b58f460d5c17ea0280e6 upstream.

Check nodesize to sectorsize in alignment check in print_extent_item.
The comment states that and this is correct, similar check is done
elsewhere in the functions.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: ea57788eb76d ("btrfs: require only sector size alignment for parent eb bytenr")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Qu Wenruo 
Signed-off-by: Anastasia Belova 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: make clear_cache mount option to rebuild FST without disabling it

2023-05-17T11:58:57+00:00

commit 1d6a4fc85717677e00fefffd847a50fc5928ce69 upstream.

Previously clear_cache mount option would simply disable free-space-tree
feature temporarily then re-enable it to rebuild the whole free space
tree.

But this is problematic for block-group-tree feature, as we have an
artificial dependency on free-space-tree feature.

If we go the existing method, after clearing the free-space-tree
feature, we would flip the filesystem to read-only mode, as we detect a
super block write with block-group-tree but no free-space-tree feature.

This patch would change the behavior by properly rebuilding the free
space tree without disabling this feature, thus allowing clear_cache
mount option to work with block group tree.

Now we can mount a filesystem with block-group-tree feature and
clear_mount option:

  $ mkfs.btrfs  -O block-group-tree /dev/test/scratch1  -f
  $ sudo mount /dev/test/scratch1 /mnt/btrfs -o clear_cache
  $ sudo dmesg -t | head -n 5
  BTRFS info (device dm-1): force clearing of disk cache
  BTRFS info (device dm-1): using free space tree
  BTRFS info (device dm-1): auto enabling async discard
  BTRFS info (device dm-1): rebuilding free space tree
  BTRFS info (device dm-1): checking UUID tree

CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Qu Wenruo 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: zero the buffer before marking it dirty in btrfs_redirty_list_add

2023-05-17T11:58:57+00:00

commit c83b56d1dd87cf67492bb770c26d6f87aee70ed6 upstream.

btrfs_redirty_list_add zeroes the buffer data and sets the
EXTENT_BUFFER_NO_CHECK to make sure writeback is fine with a bogus
header.  But it does that after already marking the buffer dirty, which
means that writeback could already be looking at the buffer.

Switch the order of operations around so that the buffer is only marked
dirty when we're ready to write it.

Fixes: d3575156f662 ("btrfs: zoned: redirty released extent buffers")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: don't free qgroup space unless specified

2023-05-17T11:58:57+00:00

commit d246331b78cbef86237f9c22389205bc9b4e1cc1 upstream.

Boris noticed in his simple quotas testing that he was getting a leak
with Sweet Tea's change to subvol create that stopped doing a
transaction commit.  This was just a side effect of that change.

In the delayed inode code we have an optimization that will free extra
reservations if we think we can pack a dir item into an already modified
leaf.  Previously this wouldn't be triggered in the subvolume create
case because we'd commit the transaction, it was still possible but
much harder to trigger.  It could actually be triggered if we did a
mkdir && subvol create with qgroups enabled.

This occurs because in btrfs_insert_delayed_dir_index(), which gets
called when we're adding the dir item, we do the following:

  btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);

if we're able to skip reserving space.

The problem here is that trans->block_rsv points at the temporary block
rsv for the subvolume create, which has qgroup reservations in the block
rsv.

This is a problem because btrfs_block_rsv_release() will do the
following:

  if (block_rsv->qgroup_rsv_reserved >= block_rsv->qgroup_rsv_size) {
	  qgroup_to_release = block_rsv->qgroup_rsv_reserved -
		  block_rsv->qgroup_rsv_size;
	  block_rsv->qgroup_rsv_reserved = block_rsv->qgroup_rsv_size;
  }

The temporary block rsv just has ->qgroup_rsv_reserved set,
->qgroup_rsv_size == 0.  The optimization in
btrfs_insert_delayed_dir_index() sets ->qgroup_rsv_reserved = 0.  Then
later on when we call btrfs_subvolume_release_metadata() which has

  btrfs_block_rsv_release(fs_info, rsv, (u64)-1, &qgroup_to_release);
  btrfs_qgroup_convert_reserved_meta(root, qgroup_to_release);

qgroup_to_release is set to 0, and we do not convert the reserved
metadata space.

The problem here is that the block rsv code has been unconditionally
messing with ->qgroup_rsv_reserved, because the main place this is used
is delalloc, and any time we call btrfs_block_rsv_release() we do it
with qgroup_to_release set, and thus do the proper accounting.

The subvolume code is the only other code that uses the qgroup
reservation stuff, but it's intermingled with the above optimization,
and thus was getting its reservation freed out from underneath it and
thus leaking the reserved space.

The solution is to simply not mess with the qgroup reservations if we
don't have qgroup_to_release set.  This works with the existing code as
anything that messes with the delalloc reservations always have
qgroup_to_release set.  This fixes the leak that Boris was observing.

Reviewed-by: Qu Wenruo 
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Josef Bacik 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix encoded write i_size corruption with no-holes

2023-05-17T11:58:57+00:00

commit e7db9e5c6b9615b287d01f0231904fbc1fbde9c5 upstream.

We have observed a btrfs filesystem corruption on workloads using
no-holes and encoded writes via send stream v2. The symptom is that a
file appears to be truncated to the end of its last aligned extent, even
though the final unaligned extent and even the file extent and otherwise
correctly updated inode item have been written.

So if we were writing out a 1MiB+X file via 8 128K extents and one
extent of length X, i_size would be set to 1MiB, but the ninth extent,
nbyte, etc. would all appear correct otherwise.

The source of the race is a narrow (one line of code) window in which a
no-holes fs has read in an updated i_size, but has not yet set a shared
disk_i_size variable to write. Therefore, if two ordered extents run in
parallel (par for the course for receive workloads), the following
sequence can play out: (following "threads" a bit loosely, since there
are callbacks involved for endio but extra threads aren't needed to
cause the issue)

  ENC-WR1 (second to last)                                         ENC-WR2 (last)
  -------                                                          -------
  btrfs_do_encoded_write
    set i_size = 1M
    submit bio B1 ending at 1M
  endio B1
  btrfs_inode_safe_disk_i_size_write
    local i_size = 1M
    falls off a cliff for some reason
							      btrfs_do_encoded_write
								set i_size = 1M+X
								submit bio B2 ending at 1M+X
							      endio B2
							      btrfs_inode_safe_disk_i_size_write
								local i_size = 1M+X
								disk_i_size = 1M+X
    disk_i_size = 1M
							      btrfs_delayed_update_inode
    btrfs_delayed_update_inode

And the delayed inode ends up filled with nbytes=1M+X and isize=1M, and
writes respect i_size and present a corrupted file missing its last
extents.

Fix this by holding the inode lock in the no-holes case so that a thread
can't sneak in a write to disk_i_size that gets overwritten with an out
of date i_size.

Fixes: 41a2ee75aab0 ("btrfs: introduce per-inode file extent tree")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Josef Bacik 
Signed-off-by: Boris Burkov 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

btrfs: fix assertion of exclop condition when starting balance

2023-05-17T11:58:57+00:00

commit ac868bc9d136cde6e3eb5de77019a63d57a540ff upstream.

Balance as exclusive state is compatible with paused balance and device
add, which makes some things more complicated. The assertion of valid
states when starting from paused balance needs to take into account two
more states, the combinations can be hit when there are several threads
racing to start balance and device add. This won't typically happen when
the commands are started from command line.

Scenario 1: With exclusive_operation state == BTRFS_EXCLOP_NONE.

Concurrently adding multiple devices to the same mount point and
btrfs_exclop_finish executed finishes before assertion in
btrfs_exclop_balance, exclusive_operation will changed to
BTRFS_EXCLOP_NONE state which lead to assertion failed:

  fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
  fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD,
  in fs/btrfs/ioctl.c:456
  Call Trace:
   
   btrfs_exclop_balance+0x13c/0x310
   ? memdup_user+0xab/0xc0
   ? PTR_ERR+0x17/0x20
   btrfs_ioctl_add_dev+0x2ee/0x320
   btrfs_ioctl+0x9d5/0x10d0
   ? btrfs_ioctl_encoded_write+0xb80/0xb80
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x3c/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

Scenario 2: With exclusive_operation state == BTRFS_EXCLOP_BALANCE_PAUSED.

Concurrently adding multiple devices to the same mount point and
btrfs_exclop_balance executed finish before the latter thread execute
assertion in btrfs_exclop_balance, exclusive_operation will changed to
BTRFS_EXCLOP_BALANCE_PAUSED state which lead to assertion failed:

  fs_info->exclusive_operation == BTRFS_EXCLOP_BALANCE ||
  fs_info->exclusive_operation == BTRFS_EXCLOP_DEV_ADD ||
  fs_info->exclusive_operation == BTRFS_EXCLOP_NONE,
  fs/btrfs/ioctl.c:458
  Call Trace:
   
   btrfs_exclop_balance+0x240/0x410
   ? memdup_user+0xab/0xc0
   ? PTR_ERR+0x17/0x20
   btrfs_ioctl_add_dev+0x2ee/0x320
   btrfs_ioctl+0x9d5/0x10d0
   ? btrfs_ioctl_encoded_write+0xb80/0xb80
   __x64_sys_ioctl+0x197/0x210
   do_syscall_64+0x3c/0xb0
   entry_SYSCALL_64_after_hwframe+0x63/0xcd

An example of the failed assertion is below, which shows that the
paused balance is also needed to be checked.

  root@syzkaller:/home/xsk# ./repro
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  [  416.611428][ T7970] BTRFS info (device loop0): fs_info exclusive_operation: 0
  Failed to add device /dev/vda, errno 14
  [  416.613973][ T7971] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.615456][ T7972] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.617528][ T7973] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.618359][ T7974] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.622589][ T7975] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.624034][ T7976] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.626420][ T7977] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.627643][ T7978] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.629006][ T7979] BTRFS info (device loop0): fs_info exclusive_operation: 3
  [  416.630298][ T7980] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  Failed to add device /dev/vda, errno 14
  [  416.632787][ T7981] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.634282][ T7982] BTRFS info (device loop0): fs_info exclusive_operation: 3
  Failed to add device /dev/vda, errno 14
  [  416.636202][ T7983] BTRFS info (device loop0): fs_info exclusive_operation: 3
  [  416.637012][ T7984] BTRFS info (device loop0): fs_info exclusive_operation: 1
  Failed to add device /dev/vda, errno 14
  [  416.637759][ T7984] assertion failed: fs_info->exclusive_operation ==
  BTRFS_EXCLOP_BALANCE || fs_info->exclusive_operation ==
  BTRFS_EXCLOP_DEV_ADD || fs_info->exclusive_operation ==
  BTRFS_EXCLOP_NONE, in fs/btrfs/ioctl.c:458
  [  416.639845][ T7984] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
  [  416.640485][ T7984] CPU: 0 PID: 7984 Comm: repro Not tainted 6.2.0 #7
  [  416.641172][ T7984] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [  416.642090][ T7984] RIP: 0010:btrfs_assertfail+0x2c/0x2e
  [  416.644423][ T7984] RSP: 0018:ffffc90003ea7e28 EFLAGS: 00010282
  [  416.645018][ T7984] RAX: 00000000000000cc RBX: 0000000000000000 RCX: 0000000000000000
  [  416.645763][ T7984] RDX: ffff88801d030000 RSI: ffffffff81637e7c RDI: fffff520007d4fb7
  [  416.646554][ T7984] RBP: ffffffff8a533de0 R08: 00000000000000cc R09: 0000000000000000
  [  416.647299][ T7984] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8a533da0
  [  416.648041][ T7984] R13: 00000000000001ca R14: 000000005000940a R15: 0000000000000000
  [  416.648785][ T7984] FS:  00007fa2985d4640(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
  [  416.649616][ T7984] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [  416.650238][ T7984] CR2: 0000000000000000 CR3: 0000000018e5e000 CR4: 0000000000750ef0
  [  416.650980][ T7984] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [  416.651725][ T7984] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [  416.652502][ T7984] PKRU: 55555554
  [  416.652888][ T7984] Call Trace:
  [  416.653241][ T7984]  
  [  416.653527][ T7984]  btrfs_exclop_balance+0x240/0x410
  [  416.654036][ T7984]  ? memdup_user+0xab/0xc0
  [  416.654465][ T7984]  ? PTR_ERR+0x17/0x20
  [  416.654874][ T7984]  btrfs_ioctl_add_dev+0x2ee/0x320
  [  416.655380][ T7984]  btrfs_ioctl+0x9d5/0x10d0
  [  416.655822][ T7984]  ? btrfs_ioctl_encoded_write+0xb80/0xb80
  [  416.656400][ T7984]  __x64_sys_ioctl+0x197/0x210
  [  416.656874][ T7984]  do_syscall_64+0x3c/0xb0
  [  416.657346][ T7984]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  [  416.657922][ T7984] RIP: 0033:0x4546af
  [  416.660170][ T7984] RSP: 002b:00007fa2985d4150 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [  416.660972][ T7984] RAX: ffffffffffffffda RBX: 00007fa2985d4640 RCX: 00000000004546af
  [  416.661714][ T7984] RDX: 0000000000000000 RSI: 000000005000940a RDI: 0000000000000003
  [  416.662449][ T7984] RBP: 00007fa2985d41d0 R08: 0000000000000000 R09: 00007ffee37a4c4f
  [  416.663195][ T7984] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2985d4640
  [  416.663951][ T7984] R13: 0000000000000009 R14: 000000000041b320 R15: 00007fa297dd4000
  [  416.664703][ T7984]  
  [  416.665040][ T7984] Modules linked in:
  [  416.665590][ T7984] ---[ end trace 0000000000000000 ]---
  [  416.666176][ T7984] RIP: 0010:btrfs_assertfail+0x2c/0x2e
  [  416.668775][ T7984] RSP: 0018:ffffc90003ea7e28 EFLAGS: 00010282
  [  416.669425][ T7984] RAX: 00000000000000cc RBX: 0000000000000000 RCX: 0000000000000000
  [  416.670235][ T7984] RDX: ffff88801d030000 RSI: ffffffff81637e7c RDI: fffff520007d4fb7
  [  416.671050][ T7984] RBP: ffffffff8a533de0 R08: 00000000000000cc R09: 0000000000000000
  [  416.671867][ T7984] R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8a533da0
  [  416.672685][ T7984] R13: 00000000000001ca R14: 000000005000940a R15: 0000000000000000
  [  416.673501][ T7984] FS:  00007fa2985d4640(0000) GS:ffff88802cc00000(0000) knlGS:0000000000000000
  [  416.674425][ T7984] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [  416.675114][ T7984] CR2: 0000000000000000 CR3: 0000000018e5e000 CR4: 0000000000750ef0
  [  416.675933][ T7984] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [  416.676760][ T7984] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Link: https://lore.kernel.org/linux-btrfs/20230324031611.98986-1-xiaoshoukui@gmail.com/
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: xiaoshoukui 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman