commit 5037b34282 upstream.
When wait_current_trans() is called during start_transaction(), it
currently waits for a blocked transaction without considering whether
the given transaction type actually needs to wait for that particular
transaction state. The btrfs_blocked_trans_types[] array already defines
which transaction types should wait for which transaction states, but
this check was missing in wait_current_trans().
This can lead to a deadlock scenario involving two transactions and
pending ordered extents:
1. Transaction A is in TRANS_STATE_COMMIT_DOING state
2. A worker processing an ordered extent calls start_transaction()
with TRANS_JOIN
3. join_transaction() returns -EBUSY because Transaction A is in
TRANS_STATE_COMMIT_DOING
4. Transaction A moves to TRANS_STATE_UNBLOCKED and completes
5. A new Transaction B is created (TRANS_STATE_RUNNING)
6. The ordered extent from step 2 is added to Transaction B's
pending ordered extents
7. Transaction B immediately starts commit by another task and
enters TRANS_STATE_COMMIT_START
8. The worker finally reaches wait_current_trans(), sees Transaction B
in TRANS_STATE_COMMIT_START (a blocked state), and waits
unconditionally
9. However, TRANS_JOIN should NOT wait for TRANS_STATE_COMMIT_START
according to btrfs_blocked_trans_types[]
10. Transaction B is waiting for pending ordered extents to complete
11. Deadlock: Transaction B waits for ordered extent, ordered extent
waits for Transaction B
This can be illustrated by the following call stacks:
CPU0 CPU1
btrfs_finish_ordered_io()
start_transaction(TRANS_JOIN)
join_transaction()
# -EBUSY (Transaction A is
# TRANS_STATE_COMMIT_DOING)
# Transaction A completes
# Transaction B created
# ordered extent added to
# Transaction B's pending list
btrfs_commit_transaction()
# Transaction B enters
# TRANS_STATE_COMMIT_START
# waiting for pending ordered
# extents
wait_current_trans()
# waits for Transaction B
# (should not wait!)
Task bstore_kv_sync in btrfs_commit_transaction waiting for ordered
extents:
__schedule+0x2e7/0x8a0
schedule+0x64/0xe0
btrfs_commit_transaction+0xbf7/0xda0 [btrfs]
btrfs_sync_file+0x342/0x4d0 [btrfs]
__x64_sys_fdatasync+0x4b/0x80
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Task kworker in wait_current_trans waiting for transaction commit:
Workqueue: btrfs-syno_nocow btrfs_work_helper [btrfs]
__schedule+0x2e7/0x8a0
schedule+0x64/0xe0
wait_current_trans+0xb0/0x110 [btrfs]
start_transaction+0x346/0x5b0 [btrfs]
btrfs_finish_ordered_io.isra.0+0x49b/0x9c0 [btrfs]
btrfs_work_helper+0xe8/0x350 [btrfs]
process_one_work+0x1d3/0x3c0
worker_thread+0x4d/0x3e0
kthread+0x12d/0x150
ret_from_fork+0x1f/0x30
Fix this by passing the transaction type to wait_current_trans() and
checking btrfs_blocked_trans_types[cur_trans->state] against the given
type before deciding to wait. This ensures that transaction types which
are allowed to join during certain blocked states will not unnecessarily
wait and cause deadlocks.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Cc: Motiejus Jakštys <motiejus@jakstys.lt>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a11224a016 ]
In create_space_info(), the 'space_info' object is allocated at the
beginning of the function. However, there are two error paths where the
function returns an error code without freeing the allocated memory:
1. When create_space_info_sub_group() fails in zoned mode.
2. When btrfs_sysfs_add_space_info_type() fails.
In both cases, 'space_info' has not yet been added to the
fs_info->space_info list, resulting in a memory leak. Fix this by
adding an error handling label to kfree(space_info) before returning.
Fixes: 2be12ef79f ("btrfs: Separate space_info create/update")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Jiasheng Jiang <jiashengjiangcool@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 08b096c137 ]
Before accessing the disk_bytenr field of a file extent item we need
to check if we are dealing with an inline extent.
This is because for inline extents their data starts at the offset of
the disk_bytenr field. So accessing the disk_bytenr
means we are accessing inline data or in case the inline data is less
than 8 bytes we can actually cause an invalid
memory access if this inline extent item is the first item in the leaf
or access metadata from other items.
Fixes: 82bfb2e7b6 ("Btrfs: incremental send, fix unnecessary hole writes for sparse files")
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit e9e3b22ddf ]
[BUG]
For the following write sequence with 64K page size and 4K fs block size,
it will lead to file extent items to be inserted without any data
checksum:
mkfs.btrfs -s 4k -f $dev > /dev/null
mount $dev $mnt
xfs_io -f -c "pwrite 0 16k" -c "pwrite 32k 4k" -c pwrite "60k 64K" \
-c "truncate 16k" $mnt/foobar
umount $mnt
This will result the following 2 file extent items to be inserted (extra
trace point added to insert_ordered_extent_file_extent()):
btrfs_finish_one_ordered: root=5 ino=257 file_off=61440 num_bytes=4096 csum_bytes=0
btrfs_finish_one_ordered: root=5 ino=257 file_off=0 num_bytes=16384 csum_bytes=16384
Note for file offset 60K, we're inserting a file extent without any
data checksum.
Also note that range [32K, 36K) didn't reach
insert_ordered_extent_file_extent(), which is the correct behavior as
that OE is fully truncated, should not result any file extent.
Although file extent at 60K will be later dropped by btrfs_truncate(),
if the transaction got committed after file extent inserted but before
the file extent dropping, we will have a small window where we have a
file extent beyond EOF and without any data checksum.
That will cause "btrfs check" to report error.
[CAUSE]
The sequence happens like this:
- Buffered write dirtied the page cache and updated isize
Now the inode size is 64K, with the following page cache layout:
0 16K 32K 48K 64K
|/////////////| |//| |//|
- Truncate the inode to 16K
Which will trigger writeback through:
btrfs_setsize()
|- truncate_setsize()
| Now the inode size is set to 16K
|
|- btrfs_truncate()
|- btrfs_wait_ordered_range() for [16K, u64(-1)]
|- btrfs_fdatawrite_range() for [16K, u64(-1)}
|- extent_writepage() for folio 0
|- writepage_delalloc()
| Generated OE for [0, 16K), [32K, 36K] and [60K, 64K)
|
|- extent_writepage_io()
Then inside extent_writepage_io(), the dirty fs blocks are handled
differently:
- Submit write for range [0, 16K)
As they are still inside the inode size (16K).
- Mark OE [32K, 36K) as truncated
Since we only call btrfs_lookup_first_ordered_range() once, which
returned the first OE after file offset 16K.
- Mark all OEs inside range [16K, 64K) as finished
Which will mark OE ranges [32K, 36K) and [60K, 64K) as finished.
For OE [32K, 36K) since it's already marked as truncated, and its
truncated length is 0, no file extent will be inserted.
For OE [60K, 64K) it has never been submitted thus has no data
checksum, and we insert the file extent as usual.
This is the root cause of file extent at 60K to be inserted without
any data checksum.
- Clear dirty flags for range [16K, 64K)
It is the function btrfs_folio_clear_dirty() which searches and clears
any dirty blocks inside that range.
[FIX]
The bug itself was introduced a long time ago, way before subpage and
large folio support.
At that time, fs block size must match page size, thus the range
[cur, end) is just one fs block.
But later with subpage and large folios, the same range [cur, end)
can have multiple blocks and ordered extents.
Later commit 18de34daa7 ("btrfs: truncate ordered extent when skipping
writeback past i_size") was fixing a bug related to subpage/large
folios, but it's still utilizing the old range [cur, end), meaning only
the first OE will be marked as truncated.
The proper fix here is to make EOF handling block-by-block, not trying
to handle the whole range to @end.
By this we always locate and truncate the OE for every dirty block.
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: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 46a2390859 ]
Instead of repeating the expression "start + len" multiple times, store it
in a variable and use it where needed.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <asj@kernel.org>
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: e9e3b22ddf ("btrfs: fix beyond-EOF write handling")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 18de34daa7 ]
While running test case btrfs/192 from fstests with support for large
folios (needs CONFIG_BTRFS_EXPERIMENTAL=y) I ended up getting very sporadic
btrfs check failures reporting that csum items were missing. Looking into
the issue it turned out that btrfs check searches for csum items of a file
extent item with a range that spans beyond the i_size of a file and we
don't have any, because the kernel's writeback code skips submitting bios
for ranges beyond eof. It's not expected however to find a file extent item
that crosses the rounded up (by the sector size) i_size value, but there is
a short time window where we can end up with a transaction commit leaving
this small inconsistency between the i_size and the last file extent item.
Example btrfs check output when this happens:
$ btrfs check /dev/sdc
Opening filesystem to check...
Checking filesystem on /dev/sdc
UUID: 69642c61-5efb-4367-aa31-cdfd4067f713
[1/8] checking log skipped (none written)
[2/8] checking root items
[3/8] checking extents
[4/8] checking free space tree
[5/8] checking fs roots
root 5 inode 332 errors 1000, some csum missing
ERROR: errors found in fs roots
(...)
Looking at a tree dump of the fs tree (root 5) for inode 332 we have:
$ btrfs inspect-internal dump-tree -t 5 /dev/sdc
(...)
item 28 key (332 INODE_ITEM 0) itemoff 2006 itemsize 160
generation 17 transid 19 size 610969 nbytes 86016
block group 0 mode 100666 links 1 uid 0 gid 0 rdev 0
sequence 11 flags 0x0(none)
atime 1759851068.391327881 (2025-10-07 16:31:08)
ctime 1759851068.410098267 (2025-10-07 16:31:08)
mtime 1759851068.410098267 (2025-10-07 16:31:08)
otime 1759851068.391327881 (2025-10-07 16:31:08)
item 29 key (332 INODE_REF 340) itemoff 1993 itemsize 13
index 2 namelen 3 name: f1f
item 30 key (332 EXTENT_DATA 589824) itemoff 1940 itemsize 53
generation 19 type 1 (regular)
extent data disk byte 21745664 nr 65536
extent data offset 0 nr 65536 ram 65536
extent compression 0 (none)
(...)
We can see that the file extent item for file offset 589824 has a length of
64K and its number of bytes is 64K. Looking at the inode item we see that
its i_size is 610969 bytes which falls within the range of that file extent
item [589824, 655360[.
Looking into the csum tree:
$ btrfs inspect-internal dump-tree /dev/sdc
(...)
item 15 key (EXTENT_CSUM EXTENT_CSUM 21565440) itemoff 991 itemsize 200
range start 21565440 end 21770240 length 204800
item 16 key (EXTENT_CSUM EXTENT_CSUM 1104576512) itemoff 983 itemsize 8
range start 1104576512 end 1104584704 length 8192
(..)
We see that the csum item number 15 covers the first 24K of the file extent
item - it ends at offset 21770240 and the extent's disk_bytenr is 21745664,
so we have:
21770240 - 21745664 = 24K
We see that the next csum item (number 16) is completely outside the range,
so the remaining 40K of the extent doesn't have csum items in the tree.
If we round up the i_size to the sector size, we get:
round_up(610969, 4096) = 614400
If we subtract from that the file offset for the extent item we get:
614400 - 589824 = 24K
So the missing 40K corresponds to the end of the file extent item's range
minus the rounded up i_size:
655360 - 614400 = 40K
Normally we don't expect a file extent item to span over the rounded up
i_size of an inode, since when truncating, doing hole punching and other
operations that trim a file extent item, the number of bytes is adjusted.
There is however a short time window where the kernel can end up,
temporarily,persisting an inode with an i_size that falls in the middle of
the last file extent item and the file extent item was not yet trimmed (its
number of bytes reduced so that it doesn't cross i_size rounded up by the
sector size).
The steps (in the kernel) that lead to such scenario are the following:
1) We have inode I as an empty file, no allocated extents, i_size is 0;
2) A buffered write is done for file range [589824, 655360[ (length of
64K) and the i_size is updated to 655360. Note that we got a single
large folio for the range (64K);
3) A truncate operation starts that reduces the inode's i_size down to
610969 bytes. The truncate sets the inode's new i_size at
btrfs_setsize() by calling truncate_setsize() and before calling
btrfs_truncate();
4) At btrfs_truncate() we trigger writeback for the range starting at
610304 (which is the new i_size rounded down to the sector size) and
ending at (u64)-1;
5) During the writeback, at extent_write_cache_pages(), we get from the
call to filemap_get_folios_tag(), the 64K folio that starts at file
offset 589824 since it contains the start offset of the writeback
range (610304);
6) At writepage_delalloc() we find the whole range of the folio is dirty
and therefore we run delalloc for that 64K range ([589824, 655360[),
reserving a 64K extent, creating an ordered extent, etc;
7) At extent_writepage_io() we submit IO only for subrange [589824, 614400[
because the inode's i_size is 610969 bytes (rounded up by sector size
is 614400). There, in the while loop we intentionally skip IO beyond
i_size to avoid any unnecessay work and just call
btrfs_mark_ordered_io_finished() for the range [614400, 655360[ (which
has a 40K length);
8) Once the IO finishes we finish the ordered extent by ending up at
btrfs_finish_one_ordered(), join transaction N, insert a file extent
item in the inode's subvolume tree for file offset 589824 with a number
of bytes of 64K, and update the inode's delayed inode item or directly
the inode item with a call to btrfs_update_inode_fallback(), which
results in storing the new i_size of 610969 bytes;
9) Transaction N is committed either by the transaction kthread or some
other task committed it (in response to a sync or fsync for example).
At this point we have inode I persisted with an i_size of 610969 bytes
and file extent item that starts at file offset 589824 and has a number
of bytes of 64K, ending at an offset of 655360 which is beyond the
i_size rounded up to the sector size (614400).
--> So after a crash or power failure here, the btrfs check program
reports that error about missing checksum items for this inode, as
it tries to lookup for checksums covering the whole range of the
extent;
10) Only after transaction N is committed that at btrfs_truncate() the
call to btrfs_start_transaction() starts a new transaction, N + 1,
instead of joining transaction N. And it's with transaction N + 1 that
it calls btrfs_truncate_inode_items() which updates the file extent
item at file offset 589824 to reduce its number of bytes from 64K down
to 24K, so that the file extent item's range ends at the i_size
rounded up to the sector size (614400 bytes).
Fix this by truncating the ordered extent at extent_writepage_io() when we
skip writeback because the current offset in the folio is beyond i_size.
This ensures we don't ever persist a file extent item with a number of
bytes beyond the rounded up (by sector size) value of the i_size.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Anand Jain <asj@kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: e9e3b22ddf ("btrfs: fix beyond-EOF write handling")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 530e3d4af5 ]
Coverity reported a NULL pointer dereference issue (CID 1666756) in
do_abort_log_replay(). When btrfs_alloc_path() fails in
replay_one_buffer(), wc->subvol_path is NULL, but btrfs_abort_log_replay()
calls do_abort_log_replay() which unconditionally dereferences
wc->subvol_path when attempting to print debug information. Fix this by
adding a NULL check before dereferencing wc->subvol_path in
do_abort_log_replay().
Fixes: 2753e49176 ("btrfs: dump detailed info and specific messages on log replay failures")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Suchit Karunakaran <suchitkarunakaran@gmail.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>
[ Upstream commit 30bcf4e824 ]
[BUG]
Since the introduction of btrfs bs < ps support, v1 cache was never on
the plan due to its hard coded PAGE_SIZE usage, and the future plan to
properly deprecate it.
However for bs < ps cases, even if 'nospace_cache,clear_cache' mount
option is specified, it's never respected and free space tree is always
enabled:
mkfs.btrfs -f -O ^bgt,fst $dev
mount $dev $mnt -o clear_cache,nospace_cache
umount $mnt
btrfs ins dump-super $dev
...
compat_ro_flags 0x3
( FREE_SPACE_TREE |
FREE_SPACE_TREE_VALID )
...
This means a different behavior compared to bs >= ps cases.
[CAUSE]
The forcing usage of v2 space cache is done inside
btrfs_set_free_space_cache_settings(), however it never checks if we're
even using space cache but always enabling v2 cache.
[FIX]
Instead unconditionally enable v2 cache, only forcing v2 cache if the
old v1 cache is required.
Now v2 space cache can be properly disabled on bs < ps cases:
mkfs.btrfs -f -O ^bgt,fst $dev
mount $dev $mnt -o clear_cache,nospace_cache
umount $mnt
btrfs ins dump-super $dev
...
compat_ro_flags 0x0
...
Fixes: 9f73f1aef9 ("btrfs: force v2 space cache usage for subpage mount")
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8731f2c50b ]
In btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree()
while holding a path with a read locked leaf from a subvolume tree, and
btrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can
trigger reclaim.
This can create a circular lock dependency which lockdep warns about with
the following splat:
[6.1433] ======================================================
[6.1574] WARNING: possible circular locking dependency detected
[6.1583] 6.18.0+ #4 Tainted: G U
[6.1591] ------------------------------------------------------
[6.1599] kswapd0/117 is trying to acquire lock:
[6.1606] ffff8d9b6333c5b8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1625]
but task is already holding lock:
[6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60
[6.1646]
which lock already depends on the new lock.
[6.1657]
the existing dependency chain (in reverse order) is:
[6.1667]
-> #2 (fs_reclaim){+.+.}-{0:0}:
[6.1677] fs_reclaim_acquire+0x9d/0xd0
[6.1685] __kmalloc_cache_noprof+0x59/0x750
[6.1694] btrfs_init_file_extent_tree+0x90/0x100
[6.1702] btrfs_read_locked_inode+0xc3/0x6b0
[6.1710] btrfs_iget+0xbb/0xf0
[6.1716] btrfs_lookup_dentry+0x3c5/0x8e0
[6.1724] btrfs_lookup+0x12/0x30
[6.1731] lookup_open.isra.0+0x1aa/0x6a0
[6.1739] path_openat+0x5f7/0xc60
[6.1746] do_filp_open+0xd6/0x180
[6.1753] do_sys_openat2+0x8b/0xe0
[6.1760] __x64_sys_openat+0x54/0xa0
[6.1768] do_syscall_64+0x97/0x3e0
[6.1776] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[6.1784]
-> #1 (btrfs-tree-00){++++}-{3:3}:
[6.1794] lock_release+0x127/0x2a0
[6.1801] up_read+0x1b/0x30
[6.1808] btrfs_search_slot+0x8e0/0xff0
[6.1817] btrfs_lookup_inode+0x52/0xd0
[6.1825] __btrfs_update_delayed_inode+0x73/0x520
[6.1833] btrfs_commit_inode_delayed_inode+0x11a/0x120
[6.1842] btrfs_log_inode+0x608/0x1aa0
[6.1849] btrfs_log_inode_parent+0x249/0xf80
[6.1857] btrfs_log_dentry_safe+0x3e/0x60
[6.1865] btrfs_sync_file+0x431/0x690
[6.1872] do_fsync+0x39/0x80
[6.1879] __x64_sys_fsync+0x13/0x20
[6.1887] do_syscall_64+0x97/0x3e0
[6.1894] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[6.1903]
-> #0 (&delayed_node->mutex){+.+.}-{3:3}:
[6.1913] __lock_acquire+0x15e9/0x2820
[6.1920] lock_acquire+0xc9/0x2d0
[6.1927] __mutex_lock+0xcc/0x10a0
[6.1934] __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1944] btrfs_evict_inode+0x20b/0x4b0
[6.1952] evict+0x15a/0x2f0
[6.1958] prune_icache_sb+0x91/0xd0
[6.1966] super_cache_scan+0x150/0x1d0
[6.1974] do_shrink_slab+0x155/0x6f0
[6.1981] shrink_slab+0x48e/0x890
[6.1988] shrink_one+0x11a/0x1f0
[6.1995] shrink_node+0xbfd/0x1320
[6.1002] balance_pgdat+0x67f/0xc60
[6.1321] kswapd+0x1dc/0x3e0
[6.1643] kthread+0xff/0x240
[6.1965] ret_from_fork+0x223/0x280
[6.1287] ret_from_fork_asm+0x1a/0x30
[6.1616]
other info that might help us debug this:
[6.1561] Chain exists of:
&delayed_node->mutex --> btrfs-tree-00 --> fs_reclaim
[6.1503] Possible unsafe locking scenario:
[6.1110] CPU0 CPU1
[6.1411] ---- ----
[6.1707] lock(fs_reclaim);
[6.1998] lock(btrfs-tree-00);
[6.1291] lock(fs_reclaim);
[6.1581] lock(&delayed_node->mutex);
[6.1874]
*** DEADLOCK ***
[6.1716] 2 locks held by kswapd0/117:
[6.1999] #0: ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60
[6.1294] #1: ffff8d998344b0e0 (&type->s_umount_key#40){++++}- {3:3}, at: super_cache_scan+0x37/0x1d0
[6.1596]
stack backtrace:
[6.1183] CPU: 11 UID: 0 PID: 117 Comm: kswapd0 Tainted: G U 6.18.0+ #4 PREEMPT(lazy)
[6.1185] Tainted: [U]=USER
[6.1186] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[6.1187] Call Trace:
[6.1187] <TASK>
[6.1189] dump_stack_lvl+0x6e/0xa0
[6.1192] print_circular_bug.cold+0x17a/0x1c0
[6.1194] check_noncircular+0x175/0x190
[6.1197] __lock_acquire+0x15e9/0x2820
[6.1200] lock_acquire+0xc9/0x2d0
[6.1201] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1204] __mutex_lock+0xcc/0x10a0
[6.1206] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1208] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1211] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1213] __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1215] btrfs_evict_inode+0x20b/0x4b0
[6.1217] ? lock_acquire+0xc9/0x2d0
[6.1220] evict+0x15a/0x2f0
[6.1222] prune_icache_sb+0x91/0xd0
[6.1224] super_cache_scan+0x150/0x1d0
[6.1226] do_shrink_slab+0x155/0x6f0
[6.1228] shrink_slab+0x48e/0x890
[6.1229] ? shrink_slab+0x2d2/0x890
[6.1231] shrink_one+0x11a/0x1f0
[6.1234] shrink_node+0xbfd/0x1320
[6.1236] ? shrink_node+0xa2d/0x1320
[6.1236] ? shrink_node+0xbd3/0x1320
[6.1239] ? balance_pgdat+0x67f/0xc60
[6.1239] balance_pgdat+0x67f/0xc60
[6.1241] ? finish_task_switch.isra.0+0xc4/0x2a0
[6.1246] kswapd+0x1dc/0x3e0
[6.1247] ? __pfx_autoremove_wake_function+0x10/0x10
[6.1249] ? __pfx_kswapd+0x10/0x10
[6.1250] kthread+0xff/0x240
[6.1251] ? __pfx_kthread+0x10/0x10
[6.1253] ret_from_fork+0x223/0x280
[6.1255] ? __pfx_kthread+0x10/0x10
[6.1257] ret_from_fork_asm+0x1a/0x30
[6.1260] </TASK>
This is because:
1) The fsync task is holding an inode's delayed node mutex (for a
directory) while calling __btrfs_update_delayed_inode() and that needs
to do a search on the subvolume's btree (therefore read lock some
extent buffers);
2) The lookup task, at btrfs_lookup(), triggered reclaim with the
GFP_KERNEL allocation done by btrfs_init_file_extent_tree() while
holding a read lock on a subvolume leaf;
3) The reclaim triggered kswapd which is doing inode eviction for the
directory inode the fsync task is using as an argument to
btrfs_commit_inode_delayed_inode() - but in that call chain we are
trying to read lock the same leaf that the lookup task is holding
while calling btrfs_init_file_extent_tree() and doing the GFP_KERNEL
allocation.
Fix this by calling btrfs_init_file_extent_tree() after we don't need the
path anymore and release it in btrfs_read_locked_inode().
Reported-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://lore.kernel.org/linux-btrfs/6e55113a22347c3925458a5d840a18401a38b276.camel@linux.intel.com/
Fixes: 8679d2687c ("btrfs: initialize inode::file_extent_tree after i_mode has been set")
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>
[ Upstream commit 83f59076a1 ]
Previously, btrfs_get_or_create_delayed_node() set the delayed_node's
refcount before acquiring the root->delayed_nodes lock.
Commit e8513c012d ("btrfs: implement ref_tracker for delayed_nodes")
moved refcount_set inside the critical section, which means there is
no longer a memory barrier between setting the refcount and setting
btrfs_inode->delayed_node.
Without that barrier, the stores to node->refs and
btrfs_inode->delayed_node may become visible out of order. Another
thread can then read btrfs_inode->delayed_node and attempt to
increment a refcount that hasn't been set yet, leading to a
refcounting bug and a use-after-free warning.
The fix is to move refcount_set back to where it was to take
advantage of the implicit memory barrier provided by lock
acquisition.
Because the allocations now happen outside of the lock's critical
section, they can use GFP_NOFS instead of GFP_ATOMIC.
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202511262228.6dda231e-lkp@intel.com
Fixes: e8513c012d ("btrfs: implement ref_tracker for delayed_nodes")
Tested-by: kernel test robot <oliver.sang@intel.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 68d4b3fa18 ]
[BUG]
There is a bug that if a subvolume has multi-level parent qgroups, and
is able to do a quick inherit, only the direct parent qgroup got
updated:
mkfs.btrfs -f -O quota $dev
mount $dev $mnt
btrfs subv create $mnt/subv1
btrfs qgroup create 1/100 $mnt
btrfs qgroup create 2/100 $mnt
btrfs qgroup assign 1/100 2/100 $mnt
btrfs qgroup assign 0/256 1/100 $mnt
btrfs qgroup show -p --sync $mnt
Qgroupid Referenced Exclusive Parent Path
-------- ---------- --------- ------ ----
0/5 16.00KiB 16.00KiB - <toplevel>
0/256 16.00KiB 16.00KiB 1/100 subv1
1/100 16.00KiB 16.00KiB 2/100 2/100<1 member qgroup>
2/100 16.00KiB 16.00KiB - <0 member qgroups>
btrfs subv snap -i 1/100 $mnt/subv1 $mnt/snap1
btrfs qgroup show -p --sync $mnt
Qgroupid Referenced Exclusive Parent Path
-------- ---------- --------- ------ ----
0/5 16.00KiB 16.00KiB - <toplevel>
0/256 16.00KiB 16.00KiB 1/100 subv1
0/257 16.00KiB 16.00KiB 1/100 snap1
1/100 32.00KiB 32.00KiB 2/100 2/100<1 member qgroup>
2/100 16.00KiB 16.00KiB - <0 member qgroups>
# Note that 2/100 is not updated, and qgroup numbers are inconsistent
umount $mnt
[CAUSE]
If the snapshot source subvolume belongs to a parent qgroup, and the new
snapshot target is also added to the new same parent qgroup, we allow a
quick update without marking qgroup inconsistent.
But that quick update only update the parent qgroup, without checking if
there is any more parent qgroups.
[FIX]
Iterate through all parent qgroups during the quick inherit.
Reported-by: Boris Burkov <boris@bur.io>
Fixes: b20fe56cd2 ("btrfs: qgroup: allow quick inherit if snapshot is created and added to the same parent")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7ee19a59a7 ]
qgroup_snapshot_quick_inherit() detects conditions where the snapshot
destination would land in the same parent qgroup as the snapshot source
subvolume. In this case we can avoid costly qgroup calculations and just
add the nodesize of the new snapshot to the parent.
However, in the case of squotas this is actually a double count, and
also an undercount for deeper qgroup nestings.
The following annotated script shows the issue:
btrfs quota enable --simple "$mnt"
# Create 2-level qgroup hierarchy
btrfs qgroup create 2/100 "$mnt" # Q2 (level 2)
btrfs qgroup create 1/100 "$mnt" # Q1 (level 1)
btrfs qgroup assign 1/100 2/100 "$mnt"
# Create base subvolume
btrfs subvolume create "$mnt/base" >/dev/null
base_id=$(btrfs subvolume show "$mnt/base" | grep 'Subvolume ID:' | awk '{print $3}')
# Create intermediate snapshot and add to Q1
btrfs subvolume snapshot "$mnt/base" "$mnt/intermediate" >/dev/null
inter_id=$(btrfs subvolume show "$mnt/intermediate" | grep 'Subvolume ID:' | awk '{print $3}')
btrfs qgroup assign "0/$inter_id" 1/100 "$mnt"
# Create working snapshot with --inherit (auto-adds to Q1)
# src=intermediate (in only Q1)
# dst=snap (inheriting only into Q1)
# This double counts the 16k nodesize of the snapshot in Q1, and
# undercounts it in Q2.
btrfs subvolume snapshot -i 1/100 "$mnt/intermediate" "$mnt/snap" >/dev/null
snap_id=$(btrfs subvolume show "$mnt/snap" | grep 'Subvolume ID:' | awk '{print $3}')
# Fully complete snapshot creation
sync
# Delete working snapshot
# Q1 and Q2 will lose the full snap usage
btrfs subvolume delete "$mnt/snap" >/dev/null
# Delete intermediate and remove from Q1
# Q1 and Q2 will lose the full intermediate usage
btrfs qgroup remove "0/$inter_id" 1/100 "$mnt"
btrfs subvolume delete "$mnt/intermediate" >/dev/null
# Q1 should be at 0, but still has 16k. Q2 is "correct" at 0 (for now...)
# Trigger cleaner, wait for deletions
mount -o remount,sync=1 "$mnt"
btrfs subvolume sync "$mnt" "$snap_id"
btrfs subvolume sync "$mnt" "$inter_id"
# Remove Q1 from Q2
# Frees 16k more from Q2, underflowing it to 16EiB
btrfs qgroup remove 1/100 2/100 "$mnt"
# And show the bad state:
btrfs qgroup show -pc "$mnt"
Qgroupid Referenced Exclusive Parent Child Path
-------- ---------- --------- ------ ----- ----
0/5 16.00KiB 16.00KiB - - <toplevel>
0/256 16.00KiB 16.00KiB - - base
1/100 16.00KiB 16.00KiB - - <0 member qgroups>
2/100 16.00EiB 16.00EiB - - <0 member qgroups>
Fix this by simply not doing this quick inheritance with squotas.
I suspect that it is also wrong in normal qgroups to not recurse up the
qgroup tree in the quick inherit case, though other consistency checks
will likely fix it anyway.
Fixes: b20fe56cd2 ("btrfs: qgroup: allow quick inherit if snapshot is created and added to the same parent")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7ba0b6461b upstream.
After rename exchanging (either with the rename exchange operation or
regular renames in multiple non-atomic steps) two inodes and at least
one of them is a directory, we can end up with a log tree that contains
only of the inodes and after a power failure that can result in an attempt
to delete the other inode when it should not because it was not deleted
before the power failure. In some case that delete attempt fails when
the target inode is a directory that contains a subvolume inside it, since
the log replay code is not prepared to deal with directory entries that
point to root items (only inode items).
1) We have directories "dir1" (inode A) and "dir2" (inode B) under the
same parent directory;
2) We have a file (inode C) under directory "dir1" (inode A);
3) We have a subvolume inside directory "dir2" (inode B);
4) All these inodes were persisted in a past transaction and we are
currently at transaction N;
5) We rename the file (inode C), so at btrfs_log_new_name() we update
inode C's last_unlink_trans to N;
6) We get a rename exchange for "dir1" (inode A) and "dir2" (inode B),
so after the exchange "dir1" is inode B and "dir2" is inode A.
During the rename exchange we call btrfs_log_new_name() for inodes
A and B, but because they are directories, we don't update their
last_unlink_trans to N;
7) An fsync against the file (inode C) is done, and because its inode
has a last_unlink_trans with a value of N we log its parent directory
(inode A) (through btrfs_log_all_parents(), called from
btrfs_log_inode_parent()).
8) So we end up with inode B not logged, which now has the old name
of inode A. At copy_inode_items_to_log(), when logging inode A, we
did not check if we had any conflicting inode to log because inode
A has a generation lower than the current transaction (created in
a past transaction);
9) After a power failure, when replaying the log tree, since we find that
inode A has a new name that conflicts with the name of inode B in the
fs tree, we attempt to delete inode B... this is wrong since that
directory was never deleted before the power failure, and because there
is a subvolume inside that directory, attempting to delete it will fail
since replay_dir_deletes() and btrfs_unlink_inode() are not prepared
to deal with dir items that point to roots instead of inodes.
When that happens the mount fails and we get a stack trace like the
following:
[87.2314] BTRFS info (device dm-0): start tree-log replay
[87.2318] BTRFS critical (device dm-0): failed to delete reference to subvol, root 5 inode 256 parent 259
[87.2332] ------------[ cut here ]------------
[87.2338] BTRFS: Transaction aborted (error -2)
[87.2346] WARNING: CPU: 1 PID: 638968 at fs/btrfs/inode.c:4345 __btrfs_unlink_inode+0x416/0x440 [btrfs]
[87.2368] Modules linked in: btrfs loop dm_thin_pool (...)
[87.2470] CPU: 1 UID: 0 PID: 638968 Comm: mount Tainted: G W 6.18.0-rc7-btrfs-next-218+ #2 PREEMPT(full)
[87.2489] Tainted: [W]=WARN
[87.2494] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[87.2514] RIP: 0010:__btrfs_unlink_inode+0x416/0x440 [btrfs]
[87.2538] Code: c0 89 04 24 (...)
[87.2568] RSP: 0018:ffffc0e741f4b9b8 EFLAGS: 00010286
[87.2574] RAX: 0000000000000000 RBX: ffff9d3ec8a6cf60 RCX: 0000000000000000
[87.2582] RDX: 0000000000000002 RSI: ffffffff84ab45a1 RDI: 00000000ffffffff
[87.2591] RBP: ffff9d3ec8a6ef20 R08: 0000000000000000 R09: ffffc0e741f4b840
[87.2599] R10: ffff9d45dc1fffa8 R11: 0000000000000003 R12: ffff9d3ee26d77e0
[87.2608] R13: ffffc0e741f4ba98 R14: ffff9d4458040800 R15: ffff9d44b6b7ca10
[87.2618] FS: 00007f7b9603a840(0000) GS:ffff9d4658982000(0000) knlGS:0000000000000000
[87.2629] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[87.2637] CR2: 00007ffc9ec33b98 CR3: 000000011273e003 CR4: 0000000000370ef0
[87.2648] Call Trace:
[87.2651] <TASK>
[87.2654] btrfs_unlink_inode+0x15/0x40 [btrfs]
[87.2661] unlink_inode_for_log_replay+0x27/0xf0 [btrfs]
[87.2669] check_item_in_log+0x1ea/0x2c0 [btrfs]
[87.2676] replay_dir_deletes+0x16b/0x380 [btrfs]
[87.2684] fixup_inode_link_count+0x34b/0x370 [btrfs]
[87.2696] fixup_inode_link_counts+0x41/0x160 [btrfs]
[87.2703] btrfs_recover_log_trees+0x1ff/0x7c0 [btrfs]
[87.2711] ? __pfx_replay_one_buffer+0x10/0x10 [btrfs]
[87.2719] open_ctree+0x10bb/0x15f0 [btrfs]
[87.2726] btrfs_get_tree.cold+0xb/0x16c [btrfs]
[87.2734] ? fscontext_read+0x15c/0x180
[87.2740] ? rw_verify_area+0x50/0x180
[87.2746] vfs_get_tree+0x25/0xd0
[87.2750] vfs_cmd_create+0x59/0xe0
[87.2755] __do_sys_fsconfig+0x4f6/0x6b0
[87.2760] do_syscall_64+0x50/0x1220
[87.2764] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[87.2770] RIP: 0033:0x7f7b9625f4aa
[87.2775] Code: 73 01 c3 48 (...)
[87.2803] RSP: 002b:00007ffc9ec35b08 EFLAGS: 00000246 ORIG_RAX: 00000000000001af
[87.2817] RAX: ffffffffffffffda RBX: 0000558bfa91ac20 RCX: 00007f7b9625f4aa
[87.2829] RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003
[87.2842] RBP: 0000558bfa91b120 R08: 0000000000000000 R09: 0000000000000000
[87.2854] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
[87.2864] R13: 00007f7b963f1580 R14: 00007f7b963f326c R15: 00007f7b963d8a23
[87.2877] </TASK>
[87.2882] ---[ end trace 0000000000000000 ]---
[87.2891] BTRFS: error (device dm-0 state A) in __btrfs_unlink_inode:4345: errno=-2 No such entry
[87.2904] BTRFS: error (device dm-0 state EAO) in do_abort_log_replay:191: errno=-2 No such entry
[87.2915] BTRFS critical (device dm-0 state EAO): log tree (for root 5) leaf currently being processed (slot 7 key (258 12 257)):
[87.2929] BTRFS info (device dm-0 state EAO): leaf 30736384 gen 10 total ptrs 7 free space 15712 owner 18446744073709551610
[87.2929] BTRFS info (device dm-0 state EAO): refs 3 lock_owner 0 current 638968
[87.2929] item 0 key (257 INODE_ITEM 0) itemoff 16123 itemsize 160
[87.2929] inode generation 9 transid 10 size 0 nbytes 0
[87.2929] block group 0 mode 40755 links 1 uid 0 gid 0
[87.2929] rdev 0 sequence 7 flags 0x0
[87.2929] atime 1765464494.678070921
[87.2929] ctime 1765464494.686606513
[87.2929] mtime 1765464494.686606513
[87.2929] otime 1765464494.678070921
[87.2929] item 1 key (257 INODE_REF 256) itemoff 16109 itemsize 14
[87.2929] index 4 name_len 4
[87.2929] item 2 key (257 DIR_LOG_INDEX 2) itemoff 16101 itemsize 8
[87.2929] dir log end 2
[87.2929] item 3 key (257 DIR_LOG_INDEX 3) itemoff 16093 itemsize 8
[87.2929] dir log end 18446744073709551615
[87.2930] item 4 key (257 DIR_INDEX 3) itemoff 16060 itemsize 33
[87.2930] location key (258 1 0) type 1
[87.2930] transid 10 data_len 0 name_len 3
[87.2930] item 5 key (258 INODE_ITEM 0) itemoff 15900 itemsize 160
[87.2930] inode generation 9 transid 10 size 0 nbytes 0
[87.2930] block group 0 mode 100644 links 1 uid 0 gid 0
[87.2930] rdev 0 sequence 2 flags 0x0
[87.2930] atime 1765464494.678456467
[87.2930] ctime 1765464494.686606513
[87.2930] mtime 1765464494.678456467
[87.2930] otime 1765464494.678456467
[87.2930] item 6 key (258 INODE_REF 257) itemoff 15887 itemsize 13
[87.2930] index 3 name_len 3
[87.2930] BTRFS critical (device dm-0 state EAO): log replay failed in unlink_inode_for_log_replay:1045 for root 5, stage 3, with error -2: failed to unlink inode 256 parent dir 259 name subvol root 5
[87.2963] BTRFS: error (device dm-0 state EAO) in btrfs_recover_log_trees:7743: errno=-2 No such entry
[87.2981] BTRFS: error (device dm-0 state EAO) in btrfs_replay_log:2083: errno=-2 No such entry (Failed to recover log tr
So fix this by changing copy_inode_items_to_log() to always detect if
there are conflicting inodes for the ref/extref of the inode being logged
even if the inode was created in a past transaction.
A test case for fstests will follow soon.
CC: stable@vger.kernel.org # 6.1+
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>
commit 0185c2292c upstream.
In our user safe ino resolve ioctl we'll just turn any ret into -EACCES
from inode_permission(). This is redundant, and could potentially be
wrong if we had an ENOMEM in the security layer or some such other
error, so simply return the actual return value.
Note: The patch was taken from v5 of fscrypt patchset
(https://lore.kernel.org/linux-btrfs/cover.1706116485.git.josef@toxicpanda.com/)
which was handled over time by various people: Omar Sandoval, Sweet Tea
Dorminy, Josef Bacik.
Fixes: 23d0b79dfa ("btrfs: Add unprivileged version of ino_lookup ioctl")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Daniel Vacek <neelx@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 54df8b80cc ]
[BUG]
When a scrub failed immediately without any byte scrubbed, the returned
btrfs_scrub_progress::last_physical will always be 0, even if there is a
non-zero @start passed into btrfs_scrub_dev() for resume cases.
This will reset the progress and make later scrub resume start from the
beginning.
[CAUSE]
The function btrfs_scrub_dev() accepts a @progress parameter to copy its
updated progress to the caller, there are cases where we either don't
touch progress::last_physical at all or copy 0 into last_physical:
- last_physical not updated at all
If some error happened before scrubbing any super block or chunk, we
will not copy the progress, leaving the @last_physical untouched.
E.g. failed to allocate @sctx, scrubbing a missing device or even
there is already a running scrub and so on.
All those cases won't touch @progress at all, resulting the
last_physical untouched and will be left as 0 for most cases.
- Error out before scrubbing any bytes
In those case we allocated @sctx, and sctx->stat.last_physical is all
zero (initialized by kvzalloc()).
Unfortunately some critical errors happened during
scrub_enumerate_chunks() or scrub_supers() before any stripe is really
scrubbed.
In that case although we will copy sctx->stat back to @progress, since
no byte is really scrubbed, last_physical will be overwritten to 0.
[FIX]
Make sure the parameter @progress always has its @last_physical member
updated to @start parameter inside btrfs_scrub_dev().
At the very beginning of the function, set @progress->last_physical to
@start, so that even if we error out without doing progress copying,
last_physical is still at @start.
Then after we got @sctx allocated, set sctx->stat.last_physical to
@start, this will make sure even if we didn't get any byte scrubbed, at
the progress copying stage the @last_physical is not left as zero.
This should resolve the resume progress reset problem.
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 37343524f0 ]
If the call to btrfs_delalloc_reserve_metadata() fails we jump to the
'out_noreserve' label and there we never free the extent_changeset
allocated by the previous call to btrfs_check_data_free_space() (if
qgroups are enabled). Fix this by calling extent_changeset_free() under
the 'out_noreserve' label.
Fixes: 6599716de2 ("btrfs: fix -ENOSPC mmap write failure on NOCOW files/extents")
Reported-by: syzbot+2f8aa76e6acc9fce6638@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/693a635a.a70a0220.33cd7b.0029.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>
[ Upstream commit b57f2ddd28 ]
In open_seed_devices(), when find_fsid() fails and we're in DEGRADED
mode, a new fs_devices is allocated via alloc_fs_devices() but is never
added to the seed_list before returning. This contrasts with the normal
path where fs_devices is properly added via list_add().
If any error occurs later in read_one_dev() or btrfs_read_chunk_tree(),
the cleanup code iterates seed_list to free seed devices, but this
orphaned fs_devices is never found and never freed, causing a memory
leak. Any devices allocated via add_missing_dev() and attached to this
fs_devices are also leaked.
Fix this by adding the newly allocated fs_devices to seed_list in the
degraded path, consistent with the normal path.
Fixes: 5f37583569 ("Btrfs: move the missing device to its own fs device list")
Reported-by: syzbot+eadd98df8bceb15d7fed@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=eadd98df8bceb15d7fed
Tested-by: syzbot+eadd98df8bceb15d7fed@syzkaller.appspotmail.com
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 313ef70a9f ]
Inside print_data_reloc_error(), if extent_from_logical() failed we
return immediately.
However there are the following cases where extent_from_logical() can
return error but still holds a path:
- btrfs_search_slot() returned 0
- No backref item found in extent tree
- No flags_ret provided
This is not possible in this call site though.
So for the above two cases, we can return without releasing the path,
causing extent buffer leaks.
Fixes: b9a9a85059 ("btrfs: output affected files when relocation fails")
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5630f7557d ]
When we are logging a directory and the log context indicates that we
are logging a new name for some other file (that is or was inside that
directory), we skip logging the inodes for new dentries in the directory.
This is ok most of the time, but if after the rename or link operation
that triggered the logging of that directory, we have an explicit fsync
of that directory without the directory inode being evicted and reloaded,
we end up never logging the inodes for the new dentries that we found
during the new name logging, as the next directory fsync will only process
dentries that were added after the last time we logged the directory (we
are doing an incremental directory logging).
So make sure we always log new dentries for a directory even if we are
in a context of logging a new name.
We started skipping logging inodes for new dentries as of commit
c48792c6ee ("btrfs: do not log new dentries when logging that a new name
exists") and it was fine back then, because when logging a directory we
always iterated over all the directory entries (for leaves changed in the
current transaction) so a subsequent fsync would always log anything that
was previously skipped while logging a directory when logging a new name
(with btrfs_log_new_name()). But later support for incrementally logging
a directory was added in commit dc2872247e ("btrfs: keep track of the
last logged keys when logging a directory"), to avoid checking all dir
items every time we log a directory, so the check to skip dentry logging
added in the first commit should have been removed when the incremental
support for logging a directory was added.
A test case for fstests will follow soon.
Reported-by: Vyacheslav Kovalevsky <slava.kovalevskiy.2014@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/84c4e713-85d6-42b9-8dcf-0722ed26cb05@gmail.com/
Fixes: dc2872247e ("btrfs: keep track of the last logged keys when logging a directory")
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>
[ Upstream commit e7dd1182fc ]
If the call to btrfs_del_leaf() fails we return without decrementing the
extra ref we took on the leaf, therefore leaking it. Fix this by ensuring
we drop the ref count before returning the error.
Fixes: 751a27615d ("btrfs: do not BUG_ON() on tree mod log failures at btrfs_del_ptr()")
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>
[ Upstream commit d435c51365 ]
Unlike queue_scrub_stripe() which uses the global sctx->extent_path and
sctx->csum_path which are always released at the end of scrub_stripe(),
scrub_raid56_parity_stripe() uses local extent_path and csum_path, as
that function is going to handle the full stripe, whose bytenr may be
smaller than the bytenr in the global sctx paths.
However the cleanup of local extent/csum paths is only happening after
we have successfully submitted an rbio.
There are several error routes that we didn't release those two paths:
- scrub_find_fill_first_stripe() errored out at csum tree search
In that case extent_path is still valid, and that function itself will
not release the extent_path passed in.
And the function returns directly without releasing both paths.
- The full stripe is empty
- Some blocks failed to be recovered
- btrfs_map_block() failed
- raid56_parity_alloc_scrub_rbio() failed
The function returns directly without releasing both paths.
Fix it by covering btrfs_release_path() calls inside the out: tag.
This is just a hot fix, in the long run we will go scoped based auto
freeing for both local paths.
Fixes: 1dc4888e72 ("btrfs: scrub: avoid unnecessary extent tree search preparing stripes")
Fixes: 3c771c1944 ("btrfs: scrub: avoid unnecessary csum tree search preparing stripes")
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: Sasha Levin <sashal@kernel.org>
[ Upstream commit 38e818718c ]
From the memory-barriers.txt document regarding memory barrier ordering
guarantees:
(*) These guarantees do not apply to bitfields, because compilers often
generate code to modify these using non-atomic read-modify-write
sequences. Do not attempt to use bitfields to synchronize parallel
algorithms.
(*) Even in cases where bitfields are protected by locks, all fields
in a given bitfield must be protected by one lock. If two fields
in a given bitfield are protected by different locks, the compiler's
non-atomic read-modify-write sequences can cause an update to one
field to corrupt the value of an adjacent field.
btrfs_space_info has a bitfield sharing an underlying word consisting of
the fields full, chunk_alloc, and flush:
struct btrfs_space_info {
struct btrfs_fs_info * fs_info; /* 0 8 */
struct btrfs_space_info * parent; /* 8 8 */
...
int clamp; /* 172 4 */
unsigned int full:1; /* 176: 0 4 */
unsigned int chunk_alloc:1; /* 176: 1 4 */
unsigned int flush:1; /* 176: 2 4 */
...
Therefore, to be safe from parallel read-modify-writes losing a write to
one of the bitfield members protected by a lock, all writes to all the
bitfields must use the lock. They almost universally do, except for
btrfs_clear_space_info_full() which iterates over the space_infos and
writes out found->full = 0 without a lock.
Imagine that we have one thread completing a transaction in which we
finished deleting a block_group and are thus calling
btrfs_clear_space_info_full() while simultaneously the data reclaim
ticket infrastructure is running do_async_reclaim_data_space():
T1 T2
btrfs_commit_transaction
btrfs_clear_space_info_full
data_sinfo->full = 0
READ: full:0, chunk_alloc:0, flush:1
do_async_reclaim_data_space(data_sinfo)
spin_lock(&space_info->lock);
if(list_empty(tickets))
space_info->flush = 0;
READ: full: 0, chunk_alloc:0, flush:1
MOD/WRITE: full: 0, chunk_alloc:0, flush:0
spin_unlock(&space_info->lock);
return;
MOD/WRITE: full:0, chunk_alloc:0, flush:1
and now data_sinfo->flush is 1 but the reclaim worker has exited. This
breaks the invariant that flush is 0 iff there is no work queued or
running. Once this invariant is violated, future allocations that go
into __reserve_bytes() will add tickets to space_info->tickets but will
see space_info->flush is set to 1 and not queue the work. After this,
they will block forever on the resulting ticket, as it is now impossible
to kick the worker again.
I also confirmed by looking at the assembly of the affected kernel that
it is doing RMW operations. For example, to set the flush (3rd) bit to 0,
the assembly is:
andb $0xfb,0x60(%rbx)
and similarly for setting the full (1st) bit to 0:
andb $0xfe,-0x20(%rax)
So I think this is really a bug on practical systems. I have observed
a number of systems in this exact state, but am currently unable to
reproduce it.
Rather than leaving this footgun lying around for the future, take
advantage of the fact that there is room in the struct anyway, and that
it is already quite large and simply change the three bitfield members to
bools. This avoids writes to space_info->full having any effect on
writes to space_info->flush, regardless of locking.
Fixes: 957780eb27 ("Btrfs: introduce ticketed enospc infrastructure")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 725e462988 ]
In the previous code it was possible to incur into a double kfree()
scenario when calling add_delayed_ref_head(). This could happen if the
record was reported to already exist in the
btrfs_qgroup_trace_extent_nolock() call, but then there was an error
later on add_delayed_ref_head(). In this case, since
add_delayed_ref_head() returned an error, the caller went to free the
record. Since add_delayed_ref_head() couldn't set this kfree'd pointer
to NULL, then kfree() would have acted on a non-NULL 'record' object
which was pointing to memory already freed by the callee.
The problem comes from the fact that the responsibility to kfree the
object is on both the caller and the callee at the same time. Hence, the
fix for this is to shift the ownership of the 'qrecord' object out of
the add_delayed_ref_head(). That is, we will never attempt to kfree()
the given object inside of this function, and will expect the caller to
act on the 'qrecord' object on its own. The only exception where the
'qrecord' object cannot be kfree'd is if it was inserted into the
tracing logic, for which we already have the 'qrecord_inserted_ret'
boolean to account for this. Hence, the caller has to kfree the object
only if add_delayed_ref_head() reports not to have inserted it on the
tracing logic.
As a side-effect of the above, we must guarantee that
'qrecord_inserted_ret' is properly initialized at the start of the
function, not at the end, and then set when an actual insert
happens. This way we avoid 'qrecord_inserted_ret' having an invalid
value on an early exit.
The documentation from the add_delayed_ref_head() has also been updated
to reflect on the exact ownership of the 'qrecord' object.
Fixes: 6ef8fbce01 ("btrfs: fix missing error handling when adding delayed ref with qgroups enabled")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.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>
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Merge tag 'for-6.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix new inode name tracking in tree-log
- fix conventional zone and stripe calculations in zoned mode
- fix bio reference counts on error paths in relocation and scrub
* tag 'for-6.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: release root after error in data_reloc_print_warning_inode()
btrfs: scrub: put bio after errors in scrub_raid56_parity_stripe()
btrfs: do not update last_log_commit when logging inode due to a new name
btrfs: zoned: fix stripe width calculation
btrfs: zoned: fix conventional zone capacity calculation
data_reloc_print_warning_inode() calls btrfs_get_fs_root() to obtain
local_root, but fails to release its reference when paths_from_inode()
returns an error. This causes a potential memory leak.
Add a missing btrfs_put_root() call in the error path to properly
decrease the reference count of local_root.
Fixes: b9a9a85059 ("btrfs: output affected files when relocation fails")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
scrub_raid56_parity_stripe() allocates a bio with bio_alloc(), but
fails to release it on some error paths, leading to a potential
memory leak.
Add the missing bio_put() calls to properly drop the bio reference
in those error cases.
Fixes: 1009254bf2 ("btrfs: scrub: use scrub_stripe to implement RAID56 P/Q scrub")
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When logging that a new name exists, we skip updating the inode's
last_log_commit field to prevent a later explicit fsync against the inode
from doing nothing (as updating last_log_commit makes btrfs_inode_in_log()
return true). We are detecting, at btrfs_log_inode(), that logging a new
name is happening by checking the logging mode is not LOG_INODE_EXISTS,
but that is not enough because we may log parent directories when logging
a new name of a file in LOG_INODE_ALL mode - we need to check that the
logging_new_name field of the log context too.
An example scenario where this results in an explicit fsync against a
directory not persisting changes to the directory is the following:
$ mkfs.btrfs -f /dev/sdc
$ mount /dev/sdc /mnt
$ touch /mnt/foo
$ sync
$ mkdir /mnt/dir
# Write some data to our file and fsync it.
$ xfs_io -c "pwrite -S 0xab 0 64K" -c "fsync" /mnt/foo
# Add a new link to our file. Since the file was logged before, we
# update it in the log tree by calling btrfs_log_new_name().
$ ln /mnt/foo /mnt/dir/bar
# fsync the root directory - we expect it to persist the dentry for
# the new directory "dir".
$ xfs_io -c "fsync" /mnt
<power fail>
After mounting the fs the entry for directory "dir" does not exists,
despite the explicit fsync on the root directory.
Here's why this happens:
1) When we fsync the file we log the inode, so that it's present in the
log tree;
2) When adding the new link we enter btrfs_log_new_name(), and since the
inode is in the log tree we proceed to updating the inode in the log
tree;
3) We first set the inode's last_unlink_trans to the current transaction
(early in btrfs_log_new_name());
4) We then eventually enter btrfs_log_inode_parent(), and after logging
the file's inode, we call btrfs_log_all_parents() because the inode's
last_unlink_trans matches the current transaction's ID (updated in the
previous step);
5) So btrfs_log_all_parents() logs the root directory by calling
btrfs_log_inode() for the root's inode with a log mode of LOG_INODE_ALL
so that new dentries are logged;
6) At btrfs_log_inode(), because the log mode is LOG_INODE_ALL, we
update root inode's last_log_commit to the last transaction that
changed the inode (->last_sub_trans field of the inode), which
corresponds to the current transaction's ID;
7) Then later when user space explicitly calls fsync against the root
directory, we enter btrfs_sync_file(), which calls skip_inode_logging()
and that returns true, since its call to btrfs_inode_in_log() returns
true and there are no ordered extents (it's a directory, never has
ordered extents). This results in btrfs_sync_file() returning without
syncing the log or committing the current transaction, so all the
updates we did when logging the new name, including logging the root
directory, are not persisted.
So fix this by but updating the inode's last_log_commit if we are sure
we are not logging a new name (if ctx->logging_new_name is false).
A test case for fstests will follow soon.
Reported-by: Vyacheslav Kovalevsky <slava.kovalevskiy.2014@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/03c5d7ec-5b3d-49d1-95bc-8970a7f82d87@gmail.com/
Fixes: 130341be7f ("btrfs: always update the logged transaction when logging new names")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The stripe offset calculation in the zoned code for raid0 and raid10
wrongly uses map->stripe_size to calculate it. In fact, map->stripe_size is
the size of the device extent composing the block group, which always is
the zone_size on the zoned setup.
Fix it by using BTRFS_STRIPE_LEN and BTRFS_STRIPE_LEN_SHIFT. Also, optimize
the calculation a bit by doing the common calculation only once.
Fixes: c0d90a79e8 ("btrfs: zoned: fix alloc_offset calculation for partly conventional block groups")
CC: stable@vger.kernel.org # 6.17+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a block group contains both conventional zone and sequential zone, the
capacity of the block group is wrongly set to the block group's full
length. The capacity should be calculated in btrfs_load_block_group_* using
the last allocation offset.
Fixes: 568220fa96 ("btrfs: zoned: support RAID0/1/10 on top of raid stripe tree")
CC: stable@vger.kernel.org # v6.12+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.18-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix memory leak in qgroup relation ioctl when qgroup levels are
invalid
- don't write back dirty metadata on filesystem with errors
- properly log renamed links
- properly mark prealloc extent range beyond inode size as dirty (when
no-noles is not enabled)
* tag 'for-6.18-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: mark dirty extent range for out of bound prealloc extents
btrfs: set inode flag BTRFS_INODE_COPY_EVERYTHING when logging new name
btrfs: fix memory leak of qgroup_list in btrfs_add_qgroup_relation
btrfs: ensure no dirty metadata is written back for an fs with errors
In btrfs_fallocate(), when the allocated range overlaps with a prealloc
extent and the extent starts after i_size, the range doesn't get marked
dirty in file_extent_tree. This results in persisting an incorrect
disk_i_size for the inode when not using the no-holes feature.
This is reproducible since commit 41a2ee75aa ("btrfs: introduce
per-inode file extent tree"), then became hidden since commit 3d7db6e8bd
("btrfs: don't allocate file extent tree for non regular files") and then
visible again after commit 8679d2687c ("btrfs: initialize
inode::file_extent_tree after i_mode has been set"), which fixes the
previous commit.
The following reproducer triggers the problem:
$ cat test.sh
MNT=/mnt/test
DEV=/dev/vdb
mkdir -p $MNT
mkfs.btrfs -f -O ^no-holes $DEV
mount $DEV $MNT
touch $MNT/file1
fallocate -n -o 1M -l 2M $MNT/file1
umount $MNT
mount $DEV $MNT
len=$((1 * 1024 * 1024))
fallocate -o 1M -l $len $MNT/file1
du --bytes $MNT/file1
umount $MNT
mount $DEV $MNT
du --bytes $MNT/file1
umount $MNT
Running the reproducer gives the following result:
$ ./test.sh
(...)
2097152 /mnt/test/file1
1048576 /mnt/test/file1
The difference is exactly 1048576 as we assigned.
Fix by adding a call to btrfs_inode_set_file_extent_range() in
btrfs_fallocate_update_isize().
Fixes: 41a2ee75aa ("btrfs: introduce per-inode file extent tree")
Signed-off-by: austinchang <austinchang@synology.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we are logging a new name make sure our inode has the runtime flag
BTRFS_INODE_COPY_EVERYTHING set so that at btrfs_log_inode() we will find
new inode refs/extrefs in the subvolume tree and copy them into the log
tree.
We are currently doing it when adding a new link but we are missing it
when renaming.
An example where this makes a new name not persisted:
1) create symlink with name foo in directory A
2) fsync directory A, which persists the symlink
3) rename the symlink from foo to bar
4) fsync directory A to persist the new symlink name
Step 4 isn't working correctly as it's not logging the new name and also
leaving the old inode ref in the log tree, so after a power failure the
symlink still has the old name of "foo". This is because when we first
fsync directoy A we log the symlink's inode (as it's a new entry) and at
btrfs_log_inode() we set the log mode to LOG_INODE_ALL and then because
we are using that mode and the inode has the runtime flag
BTRFS_INODE_NEEDS_FULL_SYNC set, we clear that flag as well as the flag
BTRFS_INODE_COPY_EVERYTHING. That means the next time we log the inode,
during the rename through the call to btrfs_log_new_name() (calling
btrfs_log_inode_parent() and then btrfs_log_inode()), we will not search
the subvolume tree for new refs/extrefs and jump directory to the
'log_extents' label.
Fix this by making sure we set BTRFS_INODE_COPY_EVERYTHING on an inode
when we are about to log a new name. A test case for fstests will follow
soon.
Reported-by: Vyacheslav Kovalevsky <slava.kovalevskiy.2014@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/ac949c74-90c2-4b9a-b7fd-1ffc5c3175c7@gmail.com/
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>
When btrfs_add_qgroup_relation() is called with invalid qgroup levels
(src >= dst), the function returns -EINVAL directly without freeing the
preallocated qgroup_list structure passed by the caller. This causes a
memory leak because the caller unconditionally sets the pointer to NULL
after the call, preventing any cleanup.
The issue occurs because the level validation check happens before the
mutex is acquired and before any error handling path that would free
the prealloc pointer. On this early return, the cleanup code at the
'out' label (which includes kfree(prealloc)) is never reached.
In btrfs_ioctl_qgroup_assign(), the code pattern is:
prealloc = kzalloc(sizeof(*prealloc), GFP_KERNEL);
ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst, prealloc);
prealloc = NULL; // Always set to NULL regardless of return value
...
kfree(prealloc); // This becomes kfree(NULL), does nothing
When the level check fails, 'prealloc' is never freed by either the
callee or the caller, resulting in a 64-byte memory leak per failed
operation. This can be triggered repeatedly by an unprivileged user
with access to a writable btrfs mount, potentially exhausting kernel
memory.
Fix this by freeing prealloc before the early return, ensuring prealloc
is always freed on all error paths.
Fixes: 4addc1ffd6 ("btrfs: qgroup: preallocate memory before adding a relation")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Shardul Bankar <shardulsb08@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
During development of a minor feature (make sure all btrfs_bio::end_io()
is called in task context), I noticed a crash in generic/388, where
metadata writes triggered new works after btrfs_stop_all_workers().
It turns out that it can even happen without any code modification, just
using RAID5 for metadata and the same workload from generic/388 is going
to trigger the use-after-free.
[CAUSE]
If btrfs hits an error, the fs is marked as error, no new
transaction is allowed thus metadata is in a frozen state.
But there are some metadata modifications before that error, and they are
still in the btree inode page cache.
Since there will be no real transaction commit, all those dirty folios
are just kept as is in the page cache, and they can not be invalidated
by invalidate_inode_pages2() call inside close_ctree(), because they are
dirty.
And finally after btrfs_stop_all_workers(), we call iput() on btree
inode, which triggers writeback of those dirty metadata.
And if the fs is using RAID56 metadata, this will trigger RMW and queue
new works into rmw_workers, which is already stopped, causing warning
from queue_work() and use-after-free.
[FIX]
Add a special handling for write_one_eb(), that if the fs is already in
an error state, immediately mark the bbio as failure, instead of really
submitting them.
Then during close_ctree(), iput() will just discard all those dirty
tree blocks without really writing them back, thus no more new jobs for
already stopped-and-freed workqueues.
The extra discard in write_one_eb() also acts as an extra safenet.
E.g. the transaction abort is triggered by some extent/free space
tree corruptions, and since extent/free space tree is already corrupted
some tree blocks may be allocated where they shouldn't be (overwriting
existing tree blocks). In that case writing them back will further
corrupting the fs.
CC: stable@vger.kernel.org # 6.6+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- in send, fix duplicated rmdir operations when using extrefs
(hardlinks), receive can fail with ENOENT
- fixup of error check when reading extent root in ref-verify and
damaged roots are allowed by mount option (found by smatch)
- fix freeing partially initialized fs info (found by syzkaller)
- fix use-after-free when printing ref_tracking status of delayed
inodes
* tag 'for-6.18-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: ref-verify: fix IS_ERR() vs NULL check in btrfs_build_ref_tree()
btrfs: fix delayed_node ref_tracker use after free
btrfs: send: fix duplicated rmdir operations when using extrefs
btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()
Move the print before releasing the delayed node.
In my initial testing there was a bug that was causing delayed_nodes
to not get freed which is why I put the print after the release. This
obviously neglects the case where the delayed node is properly freed.
Add condition to make sure we only print if we have more than one
reference to the delayed_node to prevent printing when we only have
the reference taken in btrfs_kill_all_delayed_nodes().
Fixes: b767a28d61 ("btrfs: print leaked references in kill_all_delayed_nodes()")
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Leo Martins <loemra.dev@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Commit 29d6d30f5c ("Btrfs: send, don't send rmdir for same target
multiple times") has fixed an issue that a send stream contained a rmdir
operation for the same directory multiple times. After that fix we keep
track of the last directory for which we sent a rmdir operation and
compare with it before sending a rmdir for the parent inode of a deleted
hardlink we are processing. But there is still a corner case that in
between rmdir dir operations for the same inode we find deleted hardlinks
for other parent inodes, so tracking just the last inode for which we sent
a rmdir operation is not enough.
Hardlinks of a file in the same directory are stored in the same INODE_REF
item, but if the number of hardlinks is too large and can not fit in a
leaf, we use INODE_EXTREF items to store them. The key of an INODE_EXTREF
item is (inode_id, INODE_EXTREF, hash[name, parent ino]), so between two
hardlinks for the same parent directory, we can find others for other
parent directories. For example for the reproducer below we get the
following (from a btrfs inspect-internal dump-tree output):
item 0 key (259 INODE_EXTREF 2309449) itemoff 16257 itemsize 26
index 6925 parent 257 namelen 8 name: foo.6923
item 1 key (259 INODE_EXTREF 2311350) itemoff 16231 itemsize 26
index 6588 parent 258 namelen 8 name: foo.6587
item 2 key (259 INODE_EXTREF 2457395) itemoff 16205 itemsize 26
index 6611 parent 257 namelen 8 name: foo.6609
(...)
So tracking the last directory's inode number does not work in this case
since we process a link for parent inode 257, then for 258 and then back
again for 257, and that second time we process a deleted link for 257 we
think we have not yet sent a rmdir operation.
Fix this by using a rbtree to keep track of all the directories for which
we have already sent rmdir operations, and add those directories to the
'check_dirs' ref list in process_recorded_refs() only if the directory is
not yet in the rbtree, otherwise skip it since it means we have already
sent a rmdir operation for that directory.
The following test script reproduces the problem:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdi
MNT=/mnt/sdi
mkfs.btrfs -f $DEV
mount $DEV $MNT
mkdir $MNT/a $MNT/b
echo 123 > $MNT/a/foo
for ((i = 1; i <= 1000; i++)); do
ln $MNT/a/foo $MNT/a/foo.$i
ln $MNT/a/foo $MNT/b/foo.$i
done
btrfs subvolume snapshot -r $MNT $MNT/snap1
btrfs send $MNT/snap1 -f /tmp/base.send
rm -r $MNT/a $MNT/b
btrfs subvolume snapshot -r $MNT $MNT/snap2
btrfs send -p $MNT/snap1 $MNT/snap2 -f /tmp/incremental.send
umount $MNT
mkfs.btrfs -f $DEV
mount $DEV $MNT
btrfs receive $MNT -f /tmp/base.send
btrfs receive $MNT -f /tmp/incremental.send
rm -f /tmp/base.send /tmp/incremental.send
umount $MNT
When running it, it fails like this:
$ ./test.sh
(...)
At subvol snap1
At snapshot snap2
ERROR: rmdir o257-9-0 failed: No such file or directory
CC: <stable@vger.kernel.org>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Ting-Chang Hou <tchou@synology.com>
[ Updated changelog ]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-6.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- in tree-checker fix extref bounds check
- reorder send context structure to avoid
-Wflex-array-member-not-at-end warning
- fix extent readahead length for compressed extents
- fix memory leaks on error paths (qgroup assign ioctl, zone loading
with raid stripe tree enabled)
- fix how device specific mount options are applied, in particular the
'ssd' option will be set unexpectedly
- fix tracking of relocation state when tasks are running and
cancellation is attempted
- adjust assertion condition for folios allocated for scrub
- remove incorrect assertion checking for block group when populating
free space tree
* tag 'for-6.18-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: send: fix -Wflex-array-member-not-at-end warning in struct send_ctx
btrfs: tree-checker: fix bounds check in check_inode_extref()
btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST
btrfs: fix incorrect readahead expansion length
btrfs: do not assert we found block group item when creating free space tree
btrfs: do not use folio_test_partial_kmap() in ASSERT()s
btrfs: only set the device specific options after devices are opened
btrfs: fix memory leak on duplicated memory in the qgroup assign ioctl
btrfs: fix clearing of BTRFS_FS_RELOC_RUNNING if relocation already running
The warning -Wflex-array-member-not-at-end was introduced in GCC-14, and
we are getting ready to enable it, globally.
Fix the following warning:
fs/btrfs/send.c:181:24: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
and move the declaration of send_ctx::cur_inode_path to the end.
Notice that struct fs_path contains a flexible array member inline_buf,
but also a padding array and a limit calculated for the usable space of
inline_buf (FS_PATH_INLINE_SIZE). It is not the pattern where flexible
array is in the middle of a structure and could potentially overwrite
other members.
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The parentheses for the unlikely() annotation were put in the wrong
place so it means that the condition is basically never true and the
bounds checking is skipped.
Fixes: aab9458b9f ("btrfs: tree-checker: add inode extref checks")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At the end of btrfs_load_block_group_zone_info() the first thing we do
is to ensure that if the mapping type is not a SINGLE one and there is
no RAID stripe tree, then we return early with an error.
Doing that, though, prevents the code from running the last calls from
this function which are about freeing memory allocated during its
run. Hence, in this case, instead of returning early, we set the ret
value and fall through the rest of the cleanup code.
Fixes: 5906333cc4 ("btrfs: zoned: don't skip block group profile checks on conventional zones")
CC: stable@vger.kernel.org # 6.8+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The intent of btrfs_readahead_expand() was to expand to the length of
the current compressed extent being read. However, "ram_bytes" is *not*
that, in the case where a single physical compressed extent is used for
multiple file extents.
Consider this case with a large compressed extent C and then later two
non-compressed extents N1 and N2 written over C, leaving C1 and C2
pointing to offset/len pairs of C:
[ C ]
[ N1 ][ C1 ][ N2 ][ C2 ]
In such a case, ram_bytes for both C1 and C2 is the full uncompressed
length of C. So starting readahead in C1 will expand the readahead past
the end of C1, past N2, and into C2. This will then expand readahead
again, to C2_start + ram_bytes, way past EOF. First of all, this is
totally undesirable, we don't want to read the whole file in arbitrary
chunks of the large underlying extent if it happens to exist. Secondly,
it results in zeroing the range past the end of C2 up to ram_bytes. This
is particularly unpleasant with fs-verity as it can zero and set
uptodate pages in the verity virtual space past EOF. This incorrect
readahead behavior can lead to verity verification errors, if we iterate
in a way that happens to do the wrong readahead.
Fix this by using em->len for readahead expansion, not em->ram_bytes,
resulting in the expected behavior of stopping readahead at the extent
boundary.
Reported-by: Max Chernoff <git@maxchernoff.ca>
Link: https://bugzilla.redhat.com/show_bug.cgi?id=2399898
Fixes: 9e9ff875e4 ("btrfs: use readahead_expand() on compressed extents")
CC: stable@vger.kernel.org # 6.17
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, when building a free space tree at populate_free_space_tree(),
if we are not using the block group tree feature, we always expect to find
block group items (either extent items or a block group item with key type
BTRFS_BLOCK_GROUP_ITEM_KEY) when we search the extent tree with
btrfs_search_slot_for_read(), so we assert that we found an item. However
this expectation is wrong since we can have a new block group created in
the current transaction which is still empty and for which we still have
not added the block group's item to the extent tree, in which case we do
not have any items in the extent tree associated to the block group.
The insertion of a new block group's block group item in the extent tree
happens at btrfs_create_pending_block_groups() when it calls the helper
insert_block_group_item(). This typically is done when a transaction
handle is released, committed or when running delayed refs (either as
part of a transaction commit or when serving tickets for space reservation
if we are low on free space).
So remove the assertion at populate_free_space_tree() even when the block
group tree feature is not enabled and update the comment to mention this
case.
Syzbot reported this with the following stack trace:
BTRFS info (device loop3 state M): rebuilding free space tree
assertion failed: ret == 0 :: 0, in fs/btrfs/free-space-tree.c:1115
------------[ cut here ]------------
kernel BUG at fs/btrfs/free-space-tree.c:1115!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 6352 Comm: syz.3.25 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:populate_free_space_tree+0x700/0x710 fs/btrfs/free-space-tree.c:1115
Code: ff ff e8 d3 (...)
RSP: 0018:ffffc9000430f780 EFLAGS: 00010246
RAX: 0000000000000043 RBX: ffff88805b709630 RCX: fea61d0e2e79d000
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000430f8b0 R08: ffffc9000430f4a7 R09: 1ffff92000861e94
R10: dffffc0000000000 R11: fffff52000861e95 R12: 0000000000000001
R13: 1ffff92000861f00 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007f424d9fe6c0(0000) GS:ffff888125afc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd78ad212c0 CR3: 0000000076d68000 CR4: 00000000003526f0
Call Trace:
<TASK>
btrfs_rebuild_free_space_tree+0x1ba/0x6d0 fs/btrfs/free-space-tree.c:1364
btrfs_start_pre_rw_mount+0x128f/0x1bf0 fs/btrfs/disk-io.c:3062
btrfs_remount_rw fs/btrfs/super.c:1334 [inline]
btrfs_reconfigure+0xaed/0x2160 fs/btrfs/super.c:1559
reconfigure_super+0x227/0x890 fs/super.c:1076
do_remount fs/namespace.c:3279 [inline]
path_mount+0xd1a/0xfe0 fs/namespace.c:4027
do_mount fs/namespace.c:4048 [inline]
__do_sys_mount fs/namespace.c:4236 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4213
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f424e39066a
Code: d8 64 89 02 (...)
RSP: 002b:00007f424d9fde68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f424d9fdef0 RCX: 00007f424e39066a
RDX: 0000200000000180 RSI: 0000200000000380 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007f424d9fdef0 R09: 0000000000000020
R10: 0000000000000020 R11: 0000000000000246 R12: 0000200000000380
R13: 00007f424d9fdeb0 R14: 0000000000000000 R15: 00002000000002c0
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
Reported-by: syzbot+884dc4621377ba579a6f@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-btrfs/68dc3dab.a00a0220.102ee.004e.GAE@google.com/
Fixes: a5ed918285 ("Btrfs: implement the free space B-tree")
CC: <stable@vger.kernel.org> # 6.1.x: 1961d20f6f: btrfs: fix assertion when building free space tree
CC: <stable@vger.kernel.org> # 6.1.x
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
Syzbot reported an ASSERT() triggered inside scrub:
BTRFS info (device loop0): scrub: started on devid 1
assertion failed: !folio_test_partial_kmap(folio) :: 0, in fs/btrfs/scrub.c:697
------------[ cut here ]------------
kernel BUG at fs/btrfs/scrub.c:697!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6077 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:scrub_stripe_get_kaddr+0x1bb/0x1c0 fs/btrfs/scrub.c:697
Call Trace:
<TASK>
scrub_bio_add_sector fs/btrfs/scrub.c:932 [inline]
scrub_submit_initial_read+0xf21/0x1120 fs/btrfs/scrub.c:1897
submit_initial_group_read+0x423/0x5b0 fs/btrfs/scrub.c:1952
flush_scrub_stripes+0x18f/0x1150 fs/btrfs/scrub.c:1973
scrub_stripe+0xbea/0x2a30 fs/btrfs/scrub.c:2516
scrub_chunk+0x2a3/0x430 fs/btrfs/scrub.c:2575
scrub_enumerate_chunks+0xa70/0x1350 fs/btrfs/scrub.c:2839
btrfs_scrub_dev+0x6e7/0x10e0 fs/btrfs/scrub.c:3153
btrfs_ioctl_scrub+0x249/0x4b0 fs/btrfs/ioctl.c:3163
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
---[ end trace 0000000000000000 ]---
Which doesn't make much sense, as all the folios we allocated for scrub
should not be highmem.
[CAUSE]
Thankfully syzbot has a detailed kernel config file, showing that
CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP is set to y.
And that debug option will force all folio_test_partial_kmap() to return
true, to improve coverage on highmem tests.
But in our case we really just want to make sure the folios we allocated
are not highmem (and they are indeed not). Such incorrect result from
folio_test_partial_kmap() is just screwing up everything.
[FIX]
Replace folio_test_partial_kmap() to folio_test_highmem() so that we
won't bother those highmem specific debuging options.
Fixes: 5fbaae4b85 ("btrfs: prepare scrub to support bs > ps cases")
Reported-by: syzbot+bde59221318c592e6346@syzkaller.appspotmail.com
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
With v6.17-rc kernels, btrfs will always set 'ssd' mount option even if
the block device is not a rotating one:
# cat /sys/block/sdd/queue/rotational
1
# cat /etc/fstab:
LABEL=DATA2 /data2 btrfs rw,relatime,space_cache=v2,subvolid=5,subvol=/,nofail,nosuid,nodev 0 0
# mount
[...]
/dev/sdd on /data2 type btrfs (rw,nosuid,nodev,relatime,ssd,space_cache=v2,subvolid=5,subvol=/)
[CAUSE]
The 'ssd' mount option is set by set_device_specific_options(), and it
expects that if there is any rotating device in the btrfs, it will set
fs_devices::rotating.
However after commit bddf57a707 ("btrfs: delay btrfs_open_devices()
until super block is created"), the device opening is delayed until the
super block is created.
But the timing of set_device_specific_options() is still left as is,
this makes the function be called without any device opened.
Since no device is opened, thus fs_devices::rotating will never be set,
making btrfs incorrectly set 'ssd' mount option.
[FIX]
Only call set_device_specific_options() after btrfs_open_devices().
Also only call set_device_specific_options() after a new mount, if we're
mounting a mounted btrfs, there is no need to set the device specific
mount options again.
Reported-by: HAN Yuwei <hrx@bupt.moe>
Link: https://lore.kernel.org/linux-btrfs/C8FF75669DFFC3C5+5f93bf8a-80a0-48a6-81bf-4ec890abc99a@bupt.moe/
Fixes: bddf57a707 ("btrfs: delay btrfs_open_devices() until super block is created")
CC: stable@vger.kernel.org # 6.17
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
On 'btrfs_ioctl_qgroup_assign' we first duplicate the argument as
provided by the user, which is kfree'd in the end. But this was not the
case when allocating memory for 'prealloc'. In this case, if it somehow
failed, then the previous code would go directly into calling
'mnt_drop_write_file', without freeing the string duplicated from the
user space.
Fixes: 4addc1ffd6 ("btrfs: qgroup: preallocate memory before adding a relation")
CC: stable@vger.kernel.org # 6.12+
Reviewed-by: Boris Burkov <boris@bur.io>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Robbie Ko
Jiasheng Jiang
Qu Wenruo
Filipe Manana
Suchit Karunakaran
Leo Martins
Boris Burkov
Josef Bacik
Deepanshu Kartikey
Miquel Sabaté Solà
Linus Torvalds
Zilin Guan
Naohiro Aota
austinchang
Shardul Bankar
Amit Dhingra
Ting-Chang Hou
Dewei Meng
Gustavo A. R. Silva
Dan Carpenter