Commit graph

13,616 commits

Author SHA1 Message Date
Johannes Thumshirn
6839108b66 btrfs: zoned: skip ZONE FINISH of conventional zones
[ Upstream commit f0ba0e7172 ]

Don't call ZONE FINISH for conventional zones as this will result in I/O
errors. Instead check if the zone that needs finishing is a conventional
zone and if yes skip it.

Also factor out the actual handling of finishing a single zone into a
helper function, as do_zone_finish() is growing ever bigger and the
indentations levels are getting higher.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09 18:58:03 +02:00
Filipe Manana
8446ff5a83 btrfs: avoid load/store tearing races when checking if an inode was logged
[ Upstream commit 986bf6ed44 ]

At inode_logged() we do a couple lockless checks for ->logged_trans, and
these are generally safe except the second one in case we get a load or
store tearing due to a concurrent call updating ->logged_trans (either at
btrfs_log_inode() or later at inode_logged()).

In the first case it's safe to compare to the current transaction ID since
once ->logged_trans is set the current transaction, we never set it to a
lower value.

In the second case, where we check if it's greater than zero, we are prone
to load/store tearing races, since we can have a concurrent task updating
to the current transaction ID with store tearing for example, instead of
updating with a single 64 bits write, to update with two 32 bits writes or
four 16 bits writes. In that case the reading side at inode_logged() could
see a positive value that does not match the current transaction and then
return a false negative.

Fix this by doing the second check while holding the inode's spinlock, add
some comments about it too. Also add the data_race() annotation to the
first check to avoid any reports from KCSAN (or similar tools) and comment
about it.

Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09 18:58:02 +02:00
Filipe Manana
3d9c5e1512 btrfs: fix race between setting last_dir_index_offset and inode logging
[ Upstream commit 59a0dd4ab9 ]

At inode_logged() if we find that the inode was not logged before we
update its ->last_dir_index_offset to (u64)-1 with the goal that the
next directory log operation will see the (u64)-1 and then figure out
it must check what was the index of the last logged dir index key and
update ->last_dir_index_offset to that key's offset (this is done in
update_last_dir_index_offset()).

This however has a possibility for a time window where a race can happen
and lead to directory logging skipping dir index keys that should be
logged. The race happens like this:

1) Task A calls inode_logged(), sees ->logged_trans as 0 and then checks
   that the inode item was logged before, but before it sets the inode's
   ->last_dir_index_offset to (u64)-1...

2) Task B is at btrfs_log_inode() which calls inode_logged() early, and
   that has set ->last_dir_index_offset to (u64)-1;

3) Task B then enters log_directory_changes() which calls
   update_last_dir_index_offset(). There it sees ->last_dir_index_offset
   is (u64)-1 and that the inode was logged before (ctx->logged_before is
   true), and so it searches for the last logged dir index key in the log
   tree and it finds that it has an offset (index) value of N, so it sets
   ->last_dir_index_offset to N, so that we can skip index keys that are
   less than or equal to N (later at process_dir_items_leaf());

4) Task A now sets ->last_dir_index_offset to (u64)-1, undoing the update
   that task B just did;

5) Task B will now skip every index key when it enters
   process_dir_items_leaf(), since ->last_dir_index_offset is (u64)-1.

Fix this by making inode_logged() not touch ->last_dir_index_offset and
initializing it to 0 when an inode is loaded (at btrfs_alloc_inode()) and
then having update_last_dir_index_offset() treat a value of 0 as meaning
we must check the log tree and update with the index of the last logged
index key. This is fine since the minimum possible value for
->last_dir_index_offset is 1 (BTRFS_DIR_START_INDEX - 1 = 2 - 1 = 1).
This also simplifies the management of ->last_dir_index_offset and now
all accesses to it are done under the inode's log_mutex.

Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09 18:58:02 +02:00
Filipe Manana
37c491006e btrfs: fix race between logging inode and checking if it was logged before
[ Upstream commit ef07b74e1b ]

There's a race between checking if an inode was logged before and logging
an inode that can cause us to mark an inode as not logged just after it
was logged by a concurrent task:

1) We have inode X which was not logged before neither in the current
   transaction not in past transaction since the inode was loaded into
   memory, so it's ->logged_trans value is 0;

2) We are at transaction N;

3) Task A calls inode_logged() against inode X, sees that ->logged_trans
   is 0 and there is a log tree and so it proceeds to search in the log
   tree for an inode item for inode X. It doesn't see any, but before
   it sets ->logged_trans to N - 1...

3) Task B calls btrfs_log_inode() against inode X, logs the inode and
   sets ->logged_trans to N;

4) Task A now sets ->logged_trans to N - 1;

5) At this point anyone calling inode_logged() gets 0 (inode not logged)
   since ->logged_trans is greater than 0 and less than N, but our inode
   was really logged. As a consequence operations like rename, unlink and
   link that happen afterwards in the current transaction end up not
   updating the log when they should.

Fix this by ensuring inode_logged() only updates ->logged_trans in case
the inode item is not found in the log tree if after tacking the inode's
lock (spinlock struct btrfs_inode::lock) the ->logged_trans value is still
zero, since the inode lock is what protects setting ->logged_trans at
btrfs_log_inode().

Fixes: 0f8ce49821 ("btrfs: avoid inode logging during rename and link when possible")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-09 18:58:02 +02:00
Naohiro Aota
3d61136945 btrfs: subpage: keep TOWRITE tag until folio is cleaned
[ Upstream commit b1511360c8 ]

btrfs_subpage_set_writeback() calls folio_start_writeback() the first time
a folio is written back, and it also clears the PAGECACHE_TAG_TOWRITE tag
even if there are still dirty blocks in the folio. This can break ordering
guarantees, such as those required by btrfs_wait_ordered_extents().

That ordering breakage leads to a real failure. For example, running
generic/464 on a zoned setup will hit the following ASSERT. This happens
because the broken ordering fails to flush existing dirty pages before the
file size is truncated.

  assertion failed: !list_empty(&ordered->list) :: 0, in fs/btrfs/zoned.c:1899
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/zoned.c:1899!
  Oops: invalid opcode: 0000 [#1] SMP NOPTI
  CPU: 2 UID: 0 PID: 1906169 Comm: kworker/u130:2 Kdump: loaded Not tainted 6.16.0-rc6-BTRFS-ZNS+ #554 PREEMPT(voluntary)
  Hardware name: Supermicro Super Server/H12SSL-NT, BIOS 2.0 02/22/2021
  Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
  RIP: 0010:btrfs_finish_ordered_zoned.cold+0x50/0x52 [btrfs]
  RSP: 0018:ffffc9002efdbd60 EFLAGS: 00010246
  RAX: 000000000000004c RBX: ffff88811923c4e0 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: ffffffff827e38b1 RDI: 00000000ffffffff
  RBP: ffff88810005d000 R08: 00000000ffffdfff R09: ffffffff831051c8
  R10: ffffffff83055220 R11: 0000000000000000 R12: ffff8881c2458c00
  R13: ffff88811923c540 R14: ffff88811923c5e8 R15: ffff8881c1bd9680
  FS:  0000000000000000(0000) GS:ffff88a04acd0000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007f907c7a918c CR3: 0000000004024000 CR4: 0000000000350ef0
  Call Trace:
   <TASK>
   ? srso_return_thunk+0x5/0x5f
   btrfs_finish_ordered_io+0x4a/0x60 [btrfs]
   btrfs_work_helper+0xf9/0x490 [btrfs]
   process_one_work+0x204/0x590
   ? srso_return_thunk+0x5/0x5f
   worker_thread+0x1d6/0x3d0
   ? __pfx_worker_thread+0x10/0x10
   kthread+0x118/0x230
   ? __pfx_kthread+0x10/0x10
   ret_from_fork+0x205/0x260
   ? __pfx_kthread+0x10/0x10
   ret_from_fork_asm+0x1a/0x30
   </TASK>

Consider process A calling writepages() with WB_SYNC_NONE. In zoned mode or
for compressed writes, it locks several folios for delalloc and starts
writing them out. Let's call the last locked folio folio X. Suppose the
write range only partially covers folio X, leaving some pages dirty.
Process A calls btrfs_subpage_set_writeback() when building a bio. This
function call clears the TOWRITE tag of folio X, whose size = 8K and
the block size = 4K. It is following state.

   0     4K    8K
   |/////|/////|  (flag: DIRTY, tag: DIRTY)
   <-----> Process A will write this range.

Now suppose process B concurrently calls writepages() with WB_SYNC_ALL. It
calls tag_pages_for_writeback() to tag dirty folios with
PAGECACHE_TAG_TOWRITE. Since folio X is still dirty, it gets tagged. Then,
B collects tagged folios using filemap_get_folios_tag() and must wait for
folio X to be written before returning from writepages().

   0     4K    8K
   |/////|/////|  (flag: DIRTY, tag: DIRTY|TOWRITE)

However, between tagging and collecting, process A may call
btrfs_subpage_set_writeback() and clear folio X's TOWRITE tag.
   0     4K    8K
   |     |/////|  (flag: DIRTY|WRITEBACK, tag: DIRTY)

As a result, process B won't see folio X in its batch, and returns without
waiting for it. This breaks the WB_SYNC_ALL ordering requirement.

Fix this by using btrfs_subpage_set_writeback_keepwrite(), which retains
the TOWRITE tag. We now manually clear the tag only after the folio becomes
clean, via the xas operation.

Fixes: 3470da3b7d ("btrfs: subpage: introduce helpers for writeback status")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[ Adjust context ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:07 +02:00
Filipe Manana
06eb8b95cb btrfs: send: make fs_path_len() inline and constify its argument
[ Upstream commit 920e8ee2bf ]

The helper function fs_path_len() is trivial and doesn't need to change
its path argument, so make it inline and constify the argument.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
7386d3e3dd btrfs: send: use fallocate for hole punching with send stream v2
[ Upstream commit 005b0a0c24 ]

Currently holes are sent as writes full of zeroes, which results in
unnecessarily using disk space at the receiving end and increasing the
stream size.

In some cases we avoid sending writes of zeroes, like during a full
send operation where we just skip writes for holes.

But for some cases we fill previous holes with writes of zeroes too, like
in this scenario:

1) We have a file with a hole in the range [2M, 3M), we snapshot the
   subvolume and do a full send. The range [2M, 3M) stays as a hole at
   the receiver since we skip sending write commands full of zeroes;

2) We punch a hole for the range [3M, 4M) in our file, so that now it
   has a 2M hole in the range [2M, 4M), and snapshot the subvolume.
   Now if we do an incremental send, we will send write commands full
   of zeroes for the range [2M, 4M), removing the hole for [2M, 3M) at
   the receiver.

We could improve cases such as this last one by doing additional
comparisons of file extent items (or their absence) between the parent
and send snapshots, but that's a lot of code to add plus additional CPU
and IO costs.

Since the send stream v2 already has a fallocate command and btrfs-progs
implements a callback to execute fallocate since the send stream v2
support was added to it, update the kernel to use fallocate for punching
holes for V2+ streams.

Test coverage is provided by btrfs/284 which is a version of btrfs/007
that exercises send stream v2 instead of v1, using fsstress with random
operations and fssum to verify file contents.

Link: https://github.com/kdave/btrfs-progs/issues/1001
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
039d05430e btrfs: send: avoid path allocation for the current inode when issuing commands
[ Upstream commit 374d45af64 ]

Whenever we issue a command we allocate a path and then compute it. For
the current inode this is not necessary since we have one preallocated
and computed in the send context structure, so we can use it instead
and avoid allocating and freeing a path.

For example if we have 100 extents to send (100 write commands) for a
file, we are allocating and freeing paths 100 times.

So improve on this by avoiding path allocation and freeing whenever a
command is for the current inode by using the current inode's path
stored in the send context structure.

A test was run before applying this patch and the previous one in the
series:

  "btrfs: send: keep the current inode's path cached"

The test script is the following:

  $ cat test.sh
  #!/bin/bash

  DEV=/dev/nullb0
  MNT=/mnt/nullb0

  mkfs.btrfs -f $DEV > /dev/null
  mount $DEV $MNT

  DIR="$MNT/one/two/three/four"
  FILE="$DIR/foobar"

  mkdir -p $DIR

  # Create some empty files to get a deeper btree and therefore make
  # path computations slower.
  for ((i = 1; i <= 30000; i++)); do
      echo -n > "$DIR/filler_$i"
  done

  for ((i = 0; i < 10000; i += 2)); do
     offset=$(( i * 4096 ))
     xfs_io -f -c "pwrite -S 0xab $offset 4K" $FILE > /dev/null
  done

  btrfs subvolume snapshot -r $MNT $MNT/snap

  start=$(date +%s%N)
  btrfs send -f /dev/null $MNT/snap
  end=$(date +%s%N)

  echo -e "\nsend took $(( (end - start) / 1000000 )) milliseconds"

  umount $MNT

Result before applying the 2 patches:  1121 milliseconds
Result after applying the 2 patches:    815 milliseconds  (-31.6%)

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 005b0a0c24 ("btrfs: send: use fallocate for hole punching with send stream v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
a4eac4fd1b btrfs: send: keep the current inode's path cached
[ Upstream commit fc746acb7a ]

Whenever we need to send a command for the current inode, like sending
writes, xattr updates, truncates, utimes, etc, we compute the inode's
path each time, which implies doing some memory allocations and traversing
the inode hierarchy to extract the name of the inode and each ancestor
directory, and that implies doing lookups in the subvolume tree amongst
other operations.

Most of the time, by far, the current inode's path doesn't change while
we are processing it (like if we need to issue 100 write commands, the
path remains the same and it's pointless to compute it 100 times).

To avoid this keep the current inode's path cached in the send context
and invalidate it or update it whenever it's needed (after unlinks or
renames).

A performance test, and its results, is mentioned in the next patch in
the series (subject: "btrfs: send: avoid path allocation for the current
inode when issuing commands").

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 005b0a0c24 ("btrfs: send: use fallocate for hole punching with send stream v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
eb38777ad1 btrfs: send: add and use helper to rename current inode when processing refs
[ Upstream commit ec666c84de ]

Extract the logic to rename the current inode at process_recorded_refs()
into a helper function and use it, therefore removing duplicated logic
and making it easier for an upcoming patch by avoiding yet more duplicated
logic.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 005b0a0c24 ("btrfs: send: use fallocate for hole punching with send stream v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
a7920a7ea6 btrfs: send: only use boolean variables at process_recorded_refs()
[ Upstream commit 9453fe3297 ]

We have several local variables at process_recorded_refs() that are used
as booleans, with some of them having a 'bool' type while two of them
having an 'int' type. Change this to make them all use the 'bool' type
which is more clear and to make everything more consistent.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 005b0a0c24 ("btrfs: send: use fallocate for hole punching with send stream v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
efb8eb976a btrfs: send: factor out common logic when sending xattrs
[ Upstream commit 17f6a74d0b ]

We always send xattrs for the current inode only and both callers of
send_set_xattr() pass a path for the current inode. So move the path
allocation and computation to send_set_xattr(), reducing duplicated
code. This also facilitates an upcoming patch.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 005b0a0c24 ("btrfs: send: use fallocate for hole punching with send stream v2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Naohiro Aota
4cb852e43f btrfs: zoned: requeue to unused block group list if zone finish failed
[ Upstream commit 62be7afcc1 ]

btrfs_zone_finish() can fail for several reason. If it is -EAGAIN, we need
to try it again later. So, put the block group to the retry list properly.

Failing to do so will keep the removable block group intact until remount
and can causes unnecessary ENOSPC.

Fixes: 74e91b12b1 ("btrfs: zoned: zone finish unused block group")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Boris Burkov
e663071ae9 btrfs: codify pattern for adding block_group to bg_list
[ Upstream commit 0497dfba98 ]

Similar to mark_bg_unused() and mark_bg_to_reclaim(), we have a few
places that use bg_list with refcounting, mostly for retrying failures
to reclaim/delete unused.

These have custom logic for handling locking and refcounting the bg_list
properly, but they actually all want to do the same thing, so pull that
logic out into a helper. Unfortunately, mark_bg_unused() does still need
the NEW flag to avoid prematurely marking stuff unused (even if refcount
is fine, we don't want to mess with bg creation), so it cannot use the
new helper.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 62be7afcc1 ("btrfs: zoned: requeue to unused block group list if zone finish failed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Boris Burkov
9a20e95694 btrfs: explicitly ref count block_group on new_bgs list
[ Upstream commit 7cbce3cb4c ]

All other users of the bg_list list_head increment the refcount when
adding to a list and decrement it when deleting from the list. Just for
the sake of uniformity and to try to avoid refcounting bugs, do it for
this list as well.

This does not fix any known ref-counting bug, as the reference belongs
to a single task (trans_handle is not shared and this represents
trans_handle->new_bgs linkage) and will not lose its original refcount
while that thread is running. And BLOCK_GROUP_FLAG_NEW protects against
ref-counting errors "moving" the block group to the unused list without
taking a ref.

With that said, I still believe it is simpler to just hold the extra ref
count for this list user as well.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 62be7afcc1 ("btrfs: zoned: requeue to unused block group list if zone finish failed")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:04 +02:00
Filipe Manana
da2124719f btrfs: abort transaction on unexpected eb generation at btrfs_copy_root()
[ Upstream commit 33e8f24b52 ]

If we find an unexpected generation for the extent buffer we are cloning
at btrfs_copy_root(), we just WARN_ON() and don't error out and abort the
transaction, meaning we allow to persist metadata with an unexpected
generation. Instead of warning only, abort the transaction and return
-EUCLEAN.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:03 +02:00
Filipe Manana
cd2bce7d84 btrfs: always abort transaction on failure to add block group to free space tree
[ Upstream commit 1f06c942aa ]

Only one of the callers of __add_block_group_free_space() aborts the
transaction if the call fails, while the others don't do it and it's
either never done up the call chain or much higher in the call chain.

So make sure we abort the transaction at __add_block_group_free_space()
if it fails, which brings a couple benefits:

1) If some call chain never aborts the transaction, we avoid having some
   metadata inconsistency because BLOCK_GROUP_FLAG_NEEDS_FREE_SPACE is
   cleared when we enter __add_block_group_free_space() and therefore
   __add_block_group_free_space() is never called again to add the block
   group items to the free space tree, since the function is only called
   when that flag is set in a block group;

2) If the call chain already aborts the transaction, then we get a better
   trace that points to the exact step from __add_block_group_free_space()
   which failed, which is better for analysis.

So abort the transaction at __add_block_group_free_space() if any of its
steps fails.

CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:03 +02:00
David Sterba
7eb547071c btrfs: move transaction aborts to the error site in add_block_group_free_space()
[ Upstream commit b63c8c1ede ]

Transaction aborts should be done next to the place the error happens,
which was not done in add_block_group_free_space().

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 1f06c942aa ("btrfs: always abort transaction on failure to add block group to free space tree")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:03 +02:00
Filipe Manana
dd0b28d877 btrfs: qgroup: fix race between quota disable and quota rescan ioctl
[ Upstream commit e124966775 ]

There's a race between a task disabling quotas and another running the
rescan ioctl that can result in a use-after-free of qgroup records from
the fs_info->qgroup_tree rbtree.

This happens as follows:

1) Task A enters btrfs_ioctl_quota_rescan() -> btrfs_qgroup_rescan();

2) Task B enters btrfs_quota_disable() and calls
   btrfs_qgroup_wait_for_completion(), which does nothing because at that
   point fs_info->qgroup_rescan_running is false (it wasn't set yet by
   task A);

3) Task B calls btrfs_free_qgroup_config() which starts freeing qgroups
   from fs_info->qgroup_tree without taking the lock fs_info->qgroup_lock;

4) Task A enters qgroup_rescan_zero_tracking() which starts iterating
   the fs_info->qgroup_tree tree while holding fs_info->qgroup_lock,
   but task B is freeing qgroup records from that tree without holding
   the lock, resulting in a use-after-free.

Fix this by taking fs_info->qgroup_lock at btrfs_free_qgroup_config().
Also at btrfs_qgroup_rescan() don't start the rescan worker if quotas
were already disabled.

Reported-by: cen zhang <zzzccc427@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/CAFRLqsV+cMDETFuzqdKSHk_FDm6tneea45krsHqPD6B3FetLpQ@mail.gmail.com/
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:03 +02:00
David Sterba
8efc2a4d2f btrfs: qgroup: drop unused parameter fs_info from __del_qgroup_rb()
[ Upstream commit 2651f43274 ]

We don't need fs_info here, everything is reachable from qgroup.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: e124966775 ("btrfs: qgroup: fix race between quota disable and quota rescan ioctl")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:31:03 +02:00
Kyoji Ogasawara
0c2f2fd7dc btrfs: fix printing of mount info messages for NODATACOW/NODATASUM
commit 74857fdc5d upstream.

The NODATASUM message was printed twice by mistake and the NODATACOW was
missing from the 'unset' part.  Fix the duplication and make the output
look the same.

Fixes: eddb1a433f ("btrfs: add reconfigure callback for fs_context")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Kyoji Ogasawara <sawara04.o@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Kyoji Ogasawara
7b16d89fda btrfs: restore mount option info messages during mount
commit b435ab556b upstream.

After the fsconfig migration in 6.8, mount option info messages are no
longer displayed during mount operations because btrfs_emit_options() is
only called during remount, not during initial mount.

Fix this by calling btrfs_emit_options() in btrfs_fill_super() after
open_ctree() succeeds. Additionally, prevent log duplication by ensuring
btrfs_check_options() handles validation with warn-level and err-level
messages, while btrfs_emit_options() provides info-level messages.

Fixes: eddb1a433f ("btrfs: add reconfigure callback for fs_context")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Kyoji Ogasawara <sawara04.o@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Kyoji Ogasawara
30776a735d btrfs: fix incorrect log message for nobarrier mount option
commit edf842abe4 upstream.

Fix a wrong log message that appears when the "nobarrier" mount option
is unset.  When "nobarrier" is unset, barrier is actually enabled.
However, the log incorrectly stated "turning off barriers".

Fixes: eddb1a433f ("btrfs: add reconfigure callback for fs_context")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Kyoji Ogasawara <sawara04.o@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Naohiro Aota
5abf2cec45 btrfs: zoned: fix write time activation failure for metadata block group
commit 5c4b93f4c8 upstream.

Since commit 13bb483d32 ("btrfs: zoned: activate metadata block group on
write time"), we activate a metadata block group at the write time. If the
zone capacity is small enough, we can allocate the entire region before the
first write. Then, we hit the btrfs_zoned_bg_is_full() in
btrfs_zone_activate() and the activation fails.

For a data block group, we activate it at the allocation time and we should
check the fullness condition in the caller side. Add, a WARN to check the
fullness condition.

For a metadata block group, we don't need the fullness check because we
activate it at the write time. Instead, activating it once it is written
should be invalid. Catch that with a WARN too.

Fixes: 13bb483d32 ("btrfs: zoned: activate metadata block group on write time")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28 16:30:56 +02:00
Qu Wenruo
39a93e1c9d btrfs: do not allow relocation of partially dropped subvolumes
commit 4289b494ac upstream.

[BUG]
There is an internal report that balance triggered transaction abort,
with the following call trace:

  item 85 key (594509824 169 0) itemoff 12599 itemsize 33
          extent refs 1 gen 197740 flags 2
          ref#0: tree block backref root 7
  item 86 key (594558976 169 0) itemoff 12566 itemsize 33
          extent refs 1 gen 197522 flags 2
          ref#0: tree block backref root 7
 ...
 BTRFS error (device loop0): extent item not found for insert, bytenr 594526208 num_bytes 16384 parent 449921024 root_objectid 934 owner 1 offset 0
 BTRFS error (device loop0): failed to run delayed ref for logical 594526208 num_bytes 16384 type 182 action 1 ref_mod 1: -117
 ------------[ cut here ]------------
 BTRFS: Transaction aborted (error -117)
 WARNING: CPU: 1 PID: 6963 at ../fs/btrfs/extent-tree.c:2168 btrfs_run_delayed_refs+0xfa/0x110 [btrfs]

And btrfs check doesn't report anything wrong related to the extent
tree.

[CAUSE]
The cause is a little complex, firstly the extent tree indeed doesn't
have the backref for 594526208.

The extent tree only have the following two backrefs around that bytenr
on-disk:

        item 65 key (594509824 METADATA_ITEM 0) itemoff 13880 itemsize 33
                refs 1 gen 197740 flags TREE_BLOCK
                tree block skinny level 0
                (176 0x7) tree block backref root CSUM_TREE
        item 66 key (594558976 METADATA_ITEM 0) itemoff 13847 itemsize 33
                refs 1 gen 197522 flags TREE_BLOCK
                tree block skinny level 0
                (176 0x7) tree block backref root CSUM_TREE

But the such missing backref item is not an corruption on disk, as the
offending delayed ref belongs to subvolume 934, and that subvolume is
being dropped:

        item 0 key (934 ROOT_ITEM 198229) itemoff 15844 itemsize 439
                generation 198229 root_dirid 256 bytenr 10741039104 byte_limit 0 bytes_used 345571328
                last_snapshot 198229 flags 0x1000000000001(RDONLY) refs 0
                drop_progress key (206324 EXTENT_DATA 2711650304) drop_level 2
                level 2 generation_v2 198229

And that offending tree block 594526208 is inside the dropped range of
that subvolume.  That explains why there is no backref item for that
bytenr and why btrfs check is not reporting anything wrong.

But this also shows another problem, as btrfs will do all the orphan
subvolume cleanup at a read-write mount.

So half-dropped subvolume should not exist after an RW mount, and
balance itself is also exclusive to subvolume cleanup, meaning we
shouldn't hit a subvolume half-dropped during relocation.

The root cause is, there is no orphan item for this subvolume.
In fact there are 5 subvolumes from around 2021 that have the same
problem.

It looks like the original report has some older kernels running, and
caused those zombie subvolumes.

Thankfully upstream commit 8d488a8c7b ("btrfs: fix subvolume/snapshot
deletion not triggered on mount") has long fixed the bug.

[ENHANCEMENT]
For repairing such old fs, btrfs-progs will be enhanced.

Considering how delayed the problem will show up (at run delayed ref
time) and at that time we have to abort transaction already, it is too
late.

Instead here we reject any half-dropped subvolume for reloc tree at the
earliest time, preventing confusion and extra time wasted on debugging
similar bugs.

CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:54 +02:00
Boris Burkov
03880ebe47 btrfs: fix iteration bug in __qgroup_excl_accounting()
commit 7b63259618 upstream.

__qgroup_excl_accounting() uses the qgroup iterator machinery to
update the account of one qgroups usage for all its parent hierarchy,
when we either add or remove a relation and have only exclusive usage.

However, there is a small bug there: we loop with an extra iteration
temporary qgroup called `cur` but never actually refer to that in the
body of the loop. As a result, we redundantly account the same usage to
the first qgroup in the list.

This can be reproduced in the following way:

  mkfs.btrfs -f -O squota <dev>
  mount <dev> <mnt>
  btrfs subvol create <mnt>/sv
  dd if=/dev/zero of=<mnt>/sv/f bs=1M count=1
  sync
  btrfs qgroup create 1/100 <mnt>
  btrfs qgroup create 2/200 <mnt>
  btrfs qgroup assign 1/100 2/200 <mnt>
  btrfs qgroup assign 0/256 1/100 <mnt>
  btrfs qgroup show <mnt>

and the broken result is (note the 2MiB on 1/100 and 0Mib on 2/100):

  Qgroupid    Referenced    Exclusive   Path
  --------    ----------    ---------   ----
  0/5           16.00KiB     16.00KiB   <toplevel>
  0/256          1.02MiB      1.02MiB   sv

  Qgroupid    Referenced    Exclusive   Path
  --------    ----------    ---------   ----
  0/5           16.00KiB     16.00KiB   <toplevel>
  0/256          1.02MiB      1.02MiB   sv
  1/100          2.03MiB      2.03MiB   2/100<1 member qgroup>
  2/100            0.00B        0.00B   <0 member qgroups>

With this fix, which simply re-uses `qgroup` as the iteration variable,
we see the expected result:

  Qgroupid    Referenced    Exclusive   Path
  --------    ----------    ---------   ----
  0/5           16.00KiB     16.00KiB   <toplevel>
  0/256          1.02MiB      1.02MiB   sv

  Qgroupid    Referenced    Exclusive   Path
  --------    ----------    ---------   ----
  0/5           16.00KiB     16.00KiB   <toplevel>
  0/256          1.02MiB      1.02MiB   sv
  1/100          1.02MiB      1.02MiB   2/100<1 member qgroup>
  2/100          1.02MiB      1.02MiB   <0 member qgroups>

The existing fstests did not exercise two layer inheritance so this bug
was missed. I intend to add that testing there, as well.

Fixes: a0bdc04b07 ("btrfs: qgroup: use qgroup_iterator in __qgroup_excl_accounting()")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:54 +02:00
Naohiro Aota
c2972df789 btrfs: zoned: do not select metadata BG as finish target
commit 3a931e9b39 upstream.

We call btrfs_zone_finish_one_bg() to zone finish one block group and make
room to activate another block group. Currently, we can choose a metadata
block group as a target. But, as we reserve an active metadata block group,
we no longer want to select a metadata block group. So, skip it in the
loop.

CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:54 +02:00
Filipe Manana
58e66d83e1 btrfs: error on missing block group when unaccounting log tree extent buffers
commit fc5799986f upstream.

Currently we only log an error message if we can't find the block group
for a log tree extent buffer when unaccounting it (while freeing a log
tree). A missing block group means something is seriously wrong and we
end up leaking space from the metadata space info. So return -ENOENT in
case we don't find the block group.

CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:54 +02:00
Filipe Manana
807c422740 btrfs: fix log tree replay failure due to file with 0 links and extents
commit 0a32e4f002 upstream.

If we log a new inode (not persisted in a past transaction) that has 0
links and extents, then log another inode with an higher inode number, we
end up with failing to replay the log tree with -EINVAL. The steps for
this are:

1) create new file A
2) write some data to file A
3) open an fd on file A
4) unlink file A
5) fsync file A using the previously open fd
6) create file B (has higher inode number than file A)
7) fsync file B
8) power fail before current transaction commits

Now when attempting to mount the fs, the log replay will fail with
-ENOENT at replay_one_extent() when attempting to replay the first
extent of file A. The failure comes when trying to open the inode for
file A in the subvolume tree, since it doesn't exist.

Before commit 5f61b96159 ("btrfs: fix inode lookup error handling
during log replay"), the returned error was -EIO instead of -ENOENT,
since we converted any errors when attempting to read an inode during
log replay to -EIO.

The reason for this is that the log replay procedure fails to ignore
the current inode when we are at the stage LOG_WALK_REPLAY_ALL, our
current inode has 0 links and last inode we processed in the previous
stage has a non 0 link count. In other words, the issue is that at
replay_one_extent() we only update wc->ignore_cur_inode if the current
replay stage is LOG_WALK_REPLAY_INODES.

Fix this by updating wc->ignore_cur_inode whenever we find an inode item
regardless of the current replay stage. This is a simple solution and easy
to backport, but later we can do other alternatives like avoid logging
extents or inode items other than the inode item for inodes with a link
count of 0.

The problem with the wc->ignore_cur_inode logic has been around since
commit f2d72f42d5 ("Btrfs: fix warning when replaying log after fsync
of a tmpfile") but it only became frequent to hit since the more recent
commit 5e85262e54 ("btrfs: fix fsync of files with no hard links not
persisting deletion"), because we stopped skipping inodes with a link
count of 0 when logging, while before the problem would only be triggered
if trying to replay a log tree created with an older kernel which has a
logged inode with 0 links.

A test case for fstests will be submitted soon.

Reported-by: Peter Jung <ptr1337@cachyos.org>
Link: https://lore.kernel.org/linux-btrfs/fce139db-4458-4788-bb97-c29acf6cb1df@cachyos.org/
Reported-by: burneddi <burneddi@protonmail.com>
Link: https://lore.kernel.org/linux-btrfs/lh4W-Lwc0Mbk-QvBhhQyZxf6VbM3E8VtIvU3fPIQgweP_Q1n7wtlUZQc33sYlCKYd-o6rryJQfhHaNAOWWRKxpAXhM8NZPojzsJPyHMf2qY=@protonmail.com/#t
Reported-by: Russell Haley <yumpusamongus@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/598ecc75-eb80-41b3-83c2-f2317fbb9864@gmail.com/
Fixes: f2d72f42d5 ("Btrfs: fix warning when replaying log after fsync of a tmpfile")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:54 +02:00
Filipe Manana
16c5f89071 btrfs: clear dirty status from extent buffer on error at insert_new_root()
commit c0d013495a upstream.

If we failed to insert the tree mod log operation, we are not removing the
dirty status from the allocated and dirtied extent buffer before we free
it. Removing the dirty status is needed for several reasons such as to
adjust the fs_info->dirty_metadata_bytes counter and remove the dirty
status from the respective folios. So add the missing call to
btrfs_clear_buffer_dirty().

Fixes: f61aa7ba08 ("btrfs: do not BUG_ON() on tree mod log failure at insert_new_root()")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Filipe Manana
d115fc9e96 btrfs: don't skip remaining extrefs if dir not found during log replay
commit 24e066ded4 upstream.

During log replay, at add_inode_ref(), if we have an extref item that
contains multiple extrefs and one of them points to a directory that does
not exist in the subvolume tree, we are supposed to ignore it and process
the remaining extrefs encoded in the extref item, since each extref can
point to a different parent inode. However when that happens we just
return from the function and ignore the remaining extrefs.

The problem has been around since extrefs were introduced, in commit
f186373fef ("btrfs: extended inode refs"), but it's hard to hit in
practice because getting extref items encoding multiple extref requires
getting a hash collision when computing the offset of the extref's
key. The offset if computed like this:

  key.offset = btrfs_extref_hash(dir_ino, name->name, name->len);

and btrfs_extref_hash() is just a wrapper around crc32c().

Fix this by moving to next iteration of the loop when we don't find
the parent directory that an extref points to.

Fixes: f186373fef ("btrfs: extended inode refs")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Filipe Manana
38bb34617b btrfs: qgroup: fix qgroup create ioctl returning success after quotas disabled
commit 08530d6e63 upstream.

When quotas are disabled qgroup ioctls are supposed to return -ENOTCONN,
but the qgroup create ioctl stopped doing that when it races with a quota
disable operation, returning 0 instead. This change of behaviour happened
in commit 6ed05643dd ("btrfs: create qgroup earlier in snapshot
creation").

The issue happens as follows:

1) Task A enters btrfs_ioctl_qgroup_create(), qgroups are enabled and so
   qgroup_enabled() returns true since fs_info->quota_root is not NULL;

2) Task B enters btrfs_ioctl_quota_ctl() -> btrfs_quota_disable() and
   disables qgroups, so now fs_info->quota_root is NULL;

3) Task A enters btrfs_create_qgroup() and calls btrfs_qgroup_mode(),
   which returns BTRFS_QGROUP_MODE_DISABLED since quotas are disabled,
   and then btrfs_create_qgroup() returns 0 to the caller, which makes
   the ioctl return 0 instead of -ENOTCONN.

   The check for fs_info->quota_root and returning -ENOTCONN if it's NULL
   is made only after the call btrfs_qgroup_mode().

Fix this by moving the check for disabled quotas with btrfs_qgroup_mode()
into transaction.c:create_pending_snapshot(), so that we don't abort the
transaction if btrfs_create_qgroup() returns -ENOTCONN and quotas are
disabled.

Fixes: 6ed05643dd ("btrfs: create qgroup earlier in snapshot creation")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Qu Wenruo
f21928dba2 btrfs: populate otime when logging an inode item
commit 1ef94169db upstream.

[TEST FAILURE WITH EXPERIMENTAL FEATURES]
When running test case generic/508, the test case will fail with the new
btrfs shutdown support:

generic/508       - output mismatch (see /home/adam/xfstests/results//generic/508.out.bad)
#    --- tests/generic/508.out	2022-05-11 11:25:30.806666664 +0930
#    +++ /home/adam/xfstests/results//generic/508.out.bad	2025-07-02 14:53:22.401824212 +0930
#    @@ -1,2 +1,6 @@
#     QA output created by 508
#     Silence is golden
#    +Before:
#    +After : stat.btime = Thu Jan  1 09:30:00 1970
#    +Before:
#    +After : stat.btime = Wed Jul  2 14:53:22 2025
#    ...
#    (Run 'diff -u /home/adam/xfstests/tests/generic/508.out /home/adam/xfstests/results//generic/508.out.bad'  to see the entire diff)
Ran: generic/508
Failures: generic/508
Failed 1 of 1 tests

Please note that the test case requires shutdown support, thus the test
case will be skipped using the current upstream kernel, as it doesn't
have shutdown ioctl support.

[CAUSE]
The direct cause the 0 time stamp in the log tree:

leaf 30507008 items 2 free space 16057 generation 9 owner TREE_LOG
leaf 30507008 flags 0x1(WRITTEN) backref revision 1
checksum stored e522548d
checksum calced e522548d
fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0
chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398
	item 0 key (257 INODE_ITEM 0) itemoff 16123 itemsize 160
		generation 9 transid 9 size 0 nbytes 0
		block group 0 mode 100644 links 1 uid 0 gid 0 rdev 0
		sequence 1 flags 0x0(none)
		atime 1751432947.492000000 (2025-07-02 14:39:07)
		ctime 1751432947.492000000 (2025-07-02 14:39:07)
		mtime 1751432947.492000000 (2025-07-02 14:39:07)
		otime 0.0 (1970-01-01 09:30:00) <<<

But the old fs tree has all the correct time stamp:

btrfs-progs v6.12
fs tree key (FS_TREE ROOT_ITEM 0)
leaf 30425088 items 2 free space 16061 generation 5 owner FS_TREE
leaf 30425088 flags 0x1(WRITTEN) backref revision 1
checksum stored 48f6c57e
checksum calced 48f6c57e
fs uuid 57d45451-481e-43e4-aa93-289ad707a3a0
chunk uuid d52bd3fd-5163-4337-98a7-7986993ad398
	item 0 key (256 INODE_ITEM 0) itemoff 16123 itemsize 160
		generation 3 transid 0 size 0 nbytes 16384
		block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0
		sequence 0 flags 0x0(none)
		atime 1751432947.0 (2025-07-02 14:39:07)
		ctime 1751432947.0 (2025-07-02 14:39:07)
		mtime 1751432947.0 (2025-07-02 14:39:07)
		otime 1751432947.0 (2025-07-02 14:39:07) <<<

The root cause is that fill_inode_item() in tree-log.c is only
populating a/c/m time, not the otime (or btime in statx output).

Part of the reason is that, the vfs inode only has a/c/m time, no native
btime support yet.

[FIX]
Thankfully btrfs has its otime stored in btrfs_inode::i_otime_sec and
btrfs_inode::i_otime_nsec.

So what we really need is just fill the otime time stamp in
fill_inode_item() of tree-log.c

There is another fill_inode_item() in inode.c, which is doing the proper
otime population.

Fixes: 94edf4ae43 ("Btrfs: don't bother committing delayed inode updates when fsyncing")
CC: stable@vger.kernel.org
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Boris Burkov
acc48b7046 btrfs: fix ssd_spread overallocation
commit 807d9023e7 upstream.

If the ssd_spread mount option is enabled, then we run the so called
clustered allocator for data block groups. In practice, this results in
creating a btrfs_free_cluster which caches a block_group and borrows its
free extents for allocation.

Since the introduction of allocation size classes in 6.1, there has been
a bug in the interaction between that feature and ssd_spread.
find_free_extent() has a number of nested loops. The loop going over the
allocation stages, stored in ffe_ctl->loop and managed by
find_free_extent_update_loop(), the loop over the raid levels, and the
loop over all the block_groups in a space_info. The size class feature
relies on the block_group loop to ensure it gets a chance to see a
block_group of a given size class.  However, the clustered allocator
uses the cached cluster block_group and breaks that loop. Each call to
do_allocation() will really just go back to the same cached block_group.
Normally, this is OK, as the allocation either succeeds and we don't
want to loop any more or it fails, and we clear the cluster and return
its space to the block_group.

But with size classes, the allocation can succeed, then later fail,
outside of do_allocation() due to size class mismatch. That latter
failure is not properly handled due to the highly complex multi loop
logic. The result is a painful loop where we continue to allocate the
same num_bytes from the cluster in a tight loop until it fails and
releases the cluster and lets us try a new block_group. But by then, we
have skipped great swaths of the available block_groups and are likely
to fail to allocate, looping the outer loop. In pathological cases like
the reproducer below, the cached block_group is often the very last one,
in which case we don't perform this tight bg loop but instead rip
through the ffe stages to LOOP_CHUNK_ALLOC and allocate a chunk, which
is now the last one, and we enter the tight inner loop until an
allocation failure. Then allocation succeeds on the final block_group
and if the next allocation is a size mismatch, the exact same thing
happens again.

Triggering this is as easy as mounting with -o ssd_spread and then
running:

  mount -o ssd_spread $dev $mnt
  dd if=/dev/zero of=$mnt/big bs=16M count=1 &>/dev/null
  dd if=/dev/zero of=$mnt/med bs=4M count=1 &>/dev/null
  sync

if you do the two writes + sync in a loop, you can force btrfs to spin
an excessive amount on semi-successful clustered allocations, before
ultimately failing and advancing to the stage where we force a chunk
allocation. This results in 2G of data allocated per iteration, despite
only using ~20M of data. By using a small size classed extent, the inner
loop takes longer and we can spin for longer.

The simplest, shortest term fix to unbreak this is to make the clustered
allocator size_class aware in the dumbest way, where it fails on size
class mismatch. This may hinder the operation of the clustered
allocator, but better hindered than completely broken and terribly
overallocating.

Further re-design improvements are also in the works.

Fixes: 52bb7a2166 ("btrfs: introduce size class to block group allocator")
CC: stable@vger.kernel.org # 6.1+
Reported-by: David Sterba <dsterba@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Filipe Manana
6c25acf3a0 btrfs: don't ignore inode missing when replaying log tree
commit 7ebf381a69 upstream.

During log replay, at add_inode_ref(), we return -ENOENT if our current
inode isn't found on the subvolume tree or if a parent directory isn't
found. The error comes from btrfs_iget_logging() <- btrfs_iget() <-
btrfs_read_locked_inode().

The single caller of add_inode_ref(), replay_one_buffer(), ignores an
-ENOENT error because it expects that error to mean only that a parent
directory wasn't found and that is ok.

Before commit 5f61b96159 ("btrfs: fix inode lookup error handling during
log replay") we were converting any error when getting a parent directory
to -ENOENT and any error when getting the current inode to -EIO, so our
caller would fail log replay in case we can't find the current inode.
After that commit however in case the current inode is not found we return
-ENOENT to the caller and therefore it ignores the critical fact that the
current inode was not found in the subvolume tree.

Fix this by converting -ENOENT to 0 when we don't find a parent directory,
returning -ENOENT when we don't find the current inode and making the
caller, replay_one_buffer(), not ignore -ENOENT anymore.

Fixes: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
CC: stable@vger.kernel.org # 6.16
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Filipe Manana
3c87ae17b7 btrfs: qgroup: set quota enabled bit if quota disable fails flushing reservations
commit e41c75ca31 upstream.

Before waiting for the rescan worker to finish and flushing reservations,
we clear the BTRFS_FS_QUOTA_ENABLED flag from fs_info. If we fail flushing
reservations we leave with the flag not set which is not correct since
quotas are still enabled - we must set back the flag on error paths, such
as when we fail to start a transaction, except for error paths that abort
a transaction. The reservation flushing happens very early before we do
any operation that actually disables quotas and before we start a
transaction, so set back BTRFS_FS_QUOTA_ENABLED if it fails.

Fixes: af0e2aab3b ("btrfs: qgroup: flush reservations during quota disable")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Naohiro Aota
7e1dfc3245 btrfs: zoned: do not remove unwritten non-data block group
commit 3061801420 upstream.

There are some reports of "unable to find chunk map for logical 2147483648
length 16384" error message appears in dmesg. This means some IOs are
occurring after a block group is removed.

When a metadata tree node is cleaned on a zoned setup, we keep that node
still dirty and write it out not to create a write hole. However, this can
make a block group's used bytes == 0 while there is a dirty region left.

Such an unused block group is moved into the unused_bg list and processed
for removal. When the removal succeeds, the block group is removed from the
transaction->dirty_bgs list, so the unused dirty nodes in the block group
are not sent at the transaction commit time. It will be written at some
later time e.g, sync or umount, and causes "unable to find chunk map"
errors.

This can happen relatively easy on SMR whose zone size is 256MB. However,
calling do_zone_finish() on such block group returns -EAGAIN and keep that
block group intact, which is why the issue is hidden until now.

Fixes: afba2bc036 ("btrfs: zoned: implement active zone tracking")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Filipe Manana
f044b84928 btrfs: abort transaction during log replay if walk_log_tree() failed
commit 2a5898c4aa upstream.

If we failed walking a log tree during replay, we have a missing
transaction abort to prevent committing a transaction where we didn't
fully replay all the changes from a log tree and therefore can leave the
respective subvolume tree in some inconsistent state. So add the missing
transaction abort.

CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:53 +02:00
Johannes Thumshirn
eb2114b98f btrfs: zoned: use filesystem size not disk size for reclaim decision
commit 55f7c65b2f upstream.

When deciding if a zoned filesystem is reaching the threshold to reclaim
data block groups, look at the size of the filesystem not to potentially
total available size of all drives in the filesystem.

Especially if a filesystem was created with mkfs' -b option, constraining
it to only a portion of the block device, the numbers won't match and
potentially garbage collection is kicking in too late.

Fixes: 3687fcb075 ("btrfs: zoned: make auto-reclaim less aggressive")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20 18:30:52 +02:00
Boris Burkov
ee56da95f8 btrfs: fix block group refcount race in btrfs_create_pending_block_groups()
commit 2d8e5168d4 upstream.

Block group creation is done in two phases, which results in a slightly
unintuitive property: a block group can be allocated/deallocated from
after btrfs_make_block_group() adds it to the space_info with
btrfs_add_bg_to_space_info(), but before creation is completely completed
in btrfs_create_pending_block_groups(). As a result, it is possible for a
block group to go unused and have 'btrfs_mark_bg_unused' called on it
concurrently with 'btrfs_create_pending_block_groups'. This causes a
number of issues, which were fixed with the block group flag
'BLOCK_GROUP_FLAG_NEW'.

However, this fix is not quite complete. Since it does not use the
unused_bg_lock, it is possible for the following race to occur:

btrfs_create_pending_block_groups            btrfs_mark_bg_unused
                                           if list_empty // false
        list_del_init
        clear_bit
                                           else if (test_bit) // true
                                                list_move_tail

And we get into the exact same broken ref count and invalid new_bgs
state for transaction cleanup that BLOCK_GROUP_FLAG_NEW was designed to
prevent.

The broken refcount aspect will result in a warning like:

  [1272.943527] refcount_t: underflow; use-after-free.
  [1272.943967] WARNING: CPU: 1 PID: 61 at lib/refcount.c:28 refcount_warn_saturate+0xba/0x110
  [1272.944731] Modules linked in: btrfs virtio_net xor zstd_compress raid6_pq null_blk [last unloaded: btrfs]
  [1272.945550] CPU: 1 UID: 0 PID: 61 Comm: kworker/u32:1 Kdump: loaded Tainted: G        W          6.14.0-rc5+ #108
  [1272.946368] Tainted: [W]=WARN
  [1272.946585] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
  [1272.947273] Workqueue: btrfs_discard btrfs_discard_workfn [btrfs]
  [1272.947788] RIP: 0010:refcount_warn_saturate+0xba/0x110
  [1272.949532] RSP: 0018:ffffbf1200247df0 EFLAGS: 00010282
  [1272.949901] RAX: 0000000000000000 RBX: ffffa14b00e3f800 RCX: 0000000000000000
  [1272.950437] RDX: 0000000000000000 RSI: ffffbf1200247c78 RDI: 00000000ffffdfff
  [1272.950986] RBP: ffffa14b00dc2860 R08: 00000000ffffdfff R09: ffffffff90526268
  [1272.951512] R10: ffffffff904762c0 R11: 0000000063666572 R12: ffffa14b00dc28c0
  [1272.952024] R13: 0000000000000000 R14: ffffa14b00dc2868 R15: 000001285dcd12c0
  [1272.952850] FS:  0000000000000000(0000) GS:ffffa14d33c40000(0000) knlGS:0000000000000000
  [1272.953458] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [1272.953931] CR2: 00007f838cbda000 CR3: 000000010104e000 CR4: 00000000000006f0
  [1272.954474] Call Trace:
  [1272.954655]  <TASK>
  [1272.954812]  ? refcount_warn_saturate+0xba/0x110
  [1272.955173]  ? __warn.cold+0x93/0xd7
  [1272.955487]  ? refcount_warn_saturate+0xba/0x110
  [1272.955816]  ? report_bug+0xe7/0x120
  [1272.956103]  ? handle_bug+0x53/0x90
  [1272.956424]  ? exc_invalid_op+0x13/0x60
  [1272.956700]  ? asm_exc_invalid_op+0x16/0x20
  [1272.957011]  ? refcount_warn_saturate+0xba/0x110
  [1272.957399]  btrfs_discard_cancel_work.cold+0x26/0x2b [btrfs]
  [1272.957853]  btrfs_put_block_group.cold+0x5d/0x8e [btrfs]
  [1272.958289]  btrfs_discard_workfn+0x194/0x380 [btrfs]
  [1272.958729]  process_one_work+0x130/0x290
  [1272.959026]  worker_thread+0x2ea/0x420
  [1272.959335]  ? __pfx_worker_thread+0x10/0x10
  [1272.959644]  kthread+0xd7/0x1c0
  [1272.959872]  ? __pfx_kthread+0x10/0x10
  [1272.960172]  ret_from_fork+0x30/0x50
  [1272.960474]  ? __pfx_kthread+0x10/0x10
  [1272.960745]  ret_from_fork_asm+0x1a/0x30
  [1272.961035]  </TASK>
  [1272.961238] ---[ end trace 0000000000000000 ]---

Though we have seen them in the async discard workfn as well. It is
most likely to happen after a relocation finishes which cancels discard,
tears down the block group, etc.

Fix this fully by taking the lock around the list_del_init + clear_bit
so that the two are done atomically.

Fixes: 0657b20c5a ("btrfs: fix use-after-free of new block group that became unused")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Alva Lan <alvalan9@foxmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-07-24 08:56:36 +02:00
Filipe Manana
0bcc14f36c btrfs: fix assertion when building free space tree
[ Upstream commit 1961d20f6f ]

When building the free space tree with the block group tree feature
enabled, we can hit an assertion failure like this:

  BTRFS info (device loop0 state M): rebuilding free space tree
  assertion failed: ret == 0, in fs/btrfs/free-space-tree.c:1102
  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/free-space-tree.c:1102!
  Internal error: Oops - BUG: 00000000f2000800 [#1]  SMP
  Modules linked in:
  CPU: 1 UID: 0 PID: 6592 Comm: syz-executor322 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
  pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
  lr : populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102
  sp : ffff8000a4ce7600
  x29: ffff8000a4ce76e0 x28: ffff0000c9bc6000 x27: ffff0000ddfff3d8
  x26: ffff0000ddfff378 x25: dfff800000000000 x24: 0000000000000001
  x23: ffff8000a4ce7660 x22: ffff70001499cecc x21: ffff0000e1d8c160
  x20: ffff0000e1cb7800 x19: ffff0000e1d8c0b0 x18: 00000000ffffffff
  x17: ffff800092f39000 x16: ffff80008ad27e48 x15: ffff700011e740c0
  x14: 1ffff00011e740c0 x13: 0000000000000004 x12: ffffffffffffffff
  x11: ffff700011e740c0 x10: 0000000000ff0100 x9 : 94ef24f55d2dbc00
  x8 : 94ef24f55d2dbc00 x7 : 0000000000000001 x6 : 0000000000000001
  x5 : ffff8000a4ce6f98 x4 : ffff80008f415ba0 x3 : ffff800080548ef0
  x2 : 0000000000000000 x1 : 0000000100000000 x0 : 000000000000003e
  Call trace:
   populate_free_space_tree+0x514/0x518 fs/btrfs/free-space-tree.c:1102 (P)
   btrfs_rebuild_free_space_tree+0x14c/0x54c fs/btrfs/free-space-tree.c:1337
   btrfs_start_pre_rw_mount+0xa78/0xe10 fs/btrfs/disk-io.c:3074
   btrfs_remount_rw fs/btrfs/super.c:1319 [inline]
   btrfs_reconfigure+0x828/0x2418 fs/btrfs/super.c:1543
   reconfigure_super+0x1d4/0x6f0 fs/super.c:1083
   do_remount fs/namespace.c:3365 [inline]
   path_mount+0xb34/0xde0 fs/namespace.c:4200
   do_mount fs/namespace.c:4221 [inline]
   __do_sys_mount fs/namespace.c:4432 [inline]
   __se_sys_mount fs/namespace.c:4409 [inline]
   __arm64_sys_mount+0x3e8/0x468 fs/namespace.c:4409
   __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
   invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
   el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
   do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
   el0_svc+0x58/0x17c arch/arm64/kernel/entry-common.c:767
   el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
   el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
  Code: f0047182 91178042 528089c3 9771d47b (d4210000)
  ---[ end trace 0000000000000000 ]---

This happens because we are processing an empty block group, which has
no extents allocated from it, there are no items for this block group,
including the block group item since block group items are stored in a
dedicated tree when using the block group tree feature. It also means
this is the block group with the highest start offset, so there are no
higher keys in the extent root, hence btrfs_search_slot_for_read()
returns 1 (no higher key found).

Fix this by asserting 'ret' is 0 only if the block group tree feature
is not enabled, in which case we should find a block group item for
the block group since it's stored in the extent root and block group
item keys are greater than extent item keys (the value for
BTRFS_BLOCK_GROUP_ITEM_KEY is 192 and for BTRFS_EXTENT_ITEM_KEY and
BTRFS_METADATA_ITEM_KEY the values are 168 and 169 respectively).
In case 'ret' is 1, we just need to add a record to the free space
tree which spans the whole block group, and we can achieve this by
making 'ret == 0' as the while loop's condition.

Reported-by: syzbot+36fae25c35159a763a2a@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/6841dca8.a00a0220.d4325.0020.GAE@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-17 18:37:22 +02:00
Filipe Manana
2dc82f0d78 btrfs: fix wrong start offset for delalloc space release during mmap write
[ Upstream commit 17a85f5204 ]

If we're doing a mmap write against a folio that has i_size somewhere in
the middle and we have multiple sectors in the folio, we may have to
release excess space previously reserved, for the range going from the
rounded up (to sector size) i_size to the folio's end offset. We are
calculating the right amount to release and passing it to
btrfs_delalloc_release_space(), but we are passing the wrong start offset
of that range - we're passing the folio's start offset instead of the
end offset, plus 1, of the range for which we keep the reservation. This
may result in releasing more space then we should and eventually trigger
an underflow of the data space_info's bytes_may_use counter.

So fix this by passing the start offset as 'end + 1' instead of
'page_start' to btrfs_delalloc_release_space().

Fixes: d0b7da88f6 ("Btrfs: btrfs_page_mkwrite: Reserve space in sectorsized units")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:56 +02:00
Qu Wenruo
5ff2ed0f0a btrfs: prepare btrfs_page_mkwrite() for large folios
[ Upstream commit 49990d8fa2 ]

This changes the assumption that the folio is always page sized.
(Although the ASSERT() for folio order is still kept as-is).

Just replace the PAGE_SIZE with folio_size().

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 17a85f5204 ("btrfs: fix wrong start offset for delalloc space release during mmap write")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:56 +02:00
Filipe Manana
735ac80fa9 btrfs: use btrfs_record_snapshot_destroy() during rmdir
[ Upstream commit 157501b046 ]

We are setting the parent directory's last_unlink_trans directly which
may result in a concurrent task starting to log the directory not see the
update and therefore can log the directory after we removed a child
directory which had a snapshot within instead of falling back to a
transaction commit. Replaying such a log tree would result in a mount
failure since we can't currently delete snapshots (and subvolumes) during
log replay. This is the type of failure described in commit 1ec9a1ae1e
("Btrfs: fix unreplayable log after snapshot delete + parent dir fsync").

Fix this by using btrfs_record_snapshot_destroy() which updates the
last_unlink_trans field while holding the inode's log_mutex lock.

Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:48 +02:00
Filipe Manana
bfd5c9e83d btrfs: propagate last_unlink_trans earlier when doing a rmdir
[ Upstream commit c466e33e72 ]

In case the removed directory had a snapshot that was deleted, we are
propagating its inode's last_unlink_trans to the parent directory after
we removed the entry from the parent directory. This leaves a small race
window where someone can log the parent directory after we removed the
entry and before we updated last_unlink_trans, and as a result if we ever
try to replay such a log tree, we will fail since we will attempt to
remove a snapshot during log replay, which is currently not possible and
results in the log replay (and mount) to fail. This is the type of failure
described in commit 1ec9a1ae1e ("Btrfs: fix unreplayable log after
snapshot delete + parent dir fsync").

So fix this by propagating the last_unlink_trans to the parent directory
before we remove the entry from it.

Fixes: 44f714dae5 ("Btrfs: improve performance on fsync against new inode after rename/unlink")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:48 +02:00
Filipe Manana
1728fef7ca btrfs: record new subvolume in parent dir earlier to avoid dir logging races
[ Upstream commit bf5bcf9a6f ]

Instead of recording that a new subvolume was created in a directory after
we add the entry do the directory, record it before adding the entry. This
is to avoid races where after creating the entry and before recording the
new subvolume in the directory (the call to btrfs_record_new_subvolume()),
another task logs the directory, so we end up with a log tree where we
logged a directory that has an entry pointing to a root that was not yet
committed, resulting in an invalid entry if the log is persisted and
replayed later due to a power failure or crash.

Also state this requirement in the function comment for
btrfs_record_new_subvolume(), similar to what we do for the
btrfs_record_unlink_dir() and btrfs_record_snapshot_destroy().

Fixes: 45c4102f0d ("btrfs: avoid transaction commit on any fsync after subvolume creation")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:48 +02:00
Filipe Manana
d6d8060046 btrfs: fix inode lookup error handling during log replay
[ Upstream commit 5f61b96159 ]

When replaying log trees we use read_one_inode() to get an inode, which is
just a wrapper around btrfs_iget_logging(), which in turn is a wrapper for
btrfs_iget(). But read_one_inode() always returns NULL for any error
that btrfs_iget_logging() / btrfs_iget() may return and this is a problem
because:

1) In many callers of read_one_inode() we convert the NULL into -EIO,
   which is not accurate since btrfs_iget() may return -ENOMEM and -ENOENT
   for example, besides -EIO and other errors. So during log replay we
   may end up reporting a false -EIO, which is confusing since we may
   not have had any IO error at all;

2) When replaying directory deletes, at replay_dir_deletes(), we assume
   the NULL returned from read_one_inode() means that the inode doesn't
   exist and then proceed as if no error had happened. This is wrong
   because unless btrfs_iget() returned ERR_PTR(-ENOENT), we had an
   actual error and the target inode may exist in the target subvolume
   root - this may later result in the log replay code failing at a
   later stage (if we are "lucky") or succeed but leaving some
   inconsistency in the filesystem.

So fix this by not ignoring errors from btrfs_iget_logging() and as
a consequence remove the read_one_inode() wrapper and just use
btrfs_iget_logging() directly. Also since btrfs_iget_logging() is
supposed to be called only against subvolume roots, just like
read_one_inode() which had a comment about it, add an assertion to
btrfs_iget_logging() to check that the target root corresponds to a
subvolume root.

Fixes: 5d4f98a28c ("Btrfs: Mixed back reference  (FORWARD ROLLING FORMAT CHANGE)")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:47 +02:00
Filipe Manana
401d098f92 btrfs: fix invalid inode pointer dereferences during log replay
[ Upstream commit 2dcf838cf5 ]

In a few places where we call read_one_inode(), if we get a NULL pointer
we end up jumping into an error path, or fallthrough in case of
__add_inode_ref(), where we then do something like this:

   iput(&inode->vfs_inode);

which results in an invalid inode pointer that triggers an invalid memory
access, resulting in a crash.

Fix this by making sure we don't do such dereferences.

Fixes: b4c50cbb01 ("btrfs: return a btrfs_inode from read_one_inode()")
CC: stable@vger.kernel.org # 6.15+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:47 +02:00
Filipe Manana
0502d11274 btrfs: return a btrfs_inode from read_one_inode()
[ Upstream commit b4c50cbb01 ]

All callers of read_one_inode() are mostly interested in the btrfs_inode
structure rather than the VFS inode, so make read_one_inode() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:47 +02:00
Filipe Manana
56e9882ba2 btrfs: return a btrfs_inode from btrfs_iget_logging()
[ Upstream commit a488d8ac2c ]

All callers of btrfs_iget_logging() are interested in the btrfs_inode
structure rather than the VFS inode, so make btrfs_iget_logging() return
the btrfs_inode instead, avoiding lots of BTRFS_I() calls.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 5f61b96159 ("btrfs: fix inode lookup error handling during log replay")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-07-10 16:04:47 +02:00