kernel/linux.git/fs/btrfs, branch v6.18.34

btrfs: fix squota accounting during enable generation

2026-06-01T15:51:02+00:00

[ Upstream commit d7c600554816b8ef70adffe078a0e360c055d82b ] The first transaction that enables squotas is special and a bit tricky. We have to set BTRFS_FS_QUOTA_ENABLED after the transaction to avoid a deadlock, so any delayed refs that run before we set the bit are not squota accounted. For data this is fine, we don't get an owner_ref, so there is no real harm, it's as if the extent predated squotas. However for metadata, the tree block will have gen == enable_gen so when we free it later, we will decrement the squota accounting, which can result in an underflow. Before it is freed, btrfs check shows errors, as we have mismatched usage between the node generations/owners and the squota values. There are two angles to this fix: 1. For extents that come in delayed_refs that run during the enable_gen transaction, we must actually set enable_gen to the *next* transaction. That is the first transaction that we can really properly account in any way. 2. For extents that come in between the end of our transaction handle and the time we set the BTRFS_FS_QUOTA_ENABLED bit, we need an additional bit, BTRFS_FS_SQUOTA_ENABLING which only affects recording squota deltas, so we do pick up those extents. Otherwise, we would miss them, even for enable_gen + 1. Fixes: bd7c1ea3a302 ("btrfs: qgroup: check generation when recording simple quota delta") Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: check for subvolume before deleting squota qgroup

2026-06-01T15:51:02+00:00

[ Upstream commit 1e92637722ae4bd417f7a37e8d1485dc23b93935 ] The invariant that we want to maintain with subvolume qgroups is that the qgroup can only be deleted if there is no root. With squotas, we thought that it was sufficient to just check the usage, because we assumed that deleting a subvolume will drive it's qgroups usage to 0, and thus 0 usage implies no subvolume. However, this is false, for two reasons: - A subvol whose extents are all from before squotas was enabled. - A subvol that was created in this transaction and for which we have not yet run any delayed refs. In both cases, deleting the qgroup breaks the desired invariant and we are left with a subvolume with no qgroup but squotas are enabled. Fix this by unifying the deletion check logic between full qgroups and squotas. Squotas do all the same checks *and* the additional usage == 0 check, which is the one extra rule peculiar to squotas. Link: https://lore.kernel.org/linux-btrfs/adnBhWfJQ1n3hZC8@merlins.org/ Fixes: a8df35619948 ("btrfs: forbid deleting live subvol qgroup") Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

btrfs: relax squota parent qgroup deletion rule

2026-06-01T15:51:01+00:00

[ Upstream commit adb0af40fe89fd42f1ef277bf60d9cfa7c2ae472 ] Currently, with squotas, we do not allow removing a parent qgroup with no members if it still has usage accounted to it. This makes it really difficult to recover from accounting bugs, as we have no good way of getting back to 0 usage. Instead, allow deletion (it's safe at 0 members..) while still warning about the inconsistency by adding a squota parent check. Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: check squota parent usage on membership change

2026-06-01T15:51:01+00:00

[ Upstream commit 9c46bcda5f347febdbb4d117fb21a37ffcec5fa4 ] We could have detected the quick inherit bug more directly if we had an extra warning about squota hierarchy consistency while modifying the hierarchy. In squotas, the parent usage always simply adds up to the sum of its children, so we can just check for that when changing membership and detect more accounting bugs. Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: remaining BTRFS_PATH_AUTO_FREE conversions

2026-06-01T15:51:01+00:00

[ Upstream commit 10934c131f9bcfb616dd8be9456f11efd6b240ec ] Do the remaining btrfs_path conversion to the auto cleaning, this seems to be the last one. Most of the conversions are trivial, only adding the declaration and removing the freeing, or changing the goto patterns to return. There are some functions with many changes, like __btrfs_free_extent(), btrfs_remove_from_free_space_tree() or btrfs_add_to_free_space_tree() but it still follows the same pattern. Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: don't search back for dir inode item in INO_LOOKUP_USER

2026-06-01T15:51:01+00:00

[ Upstream commit 70085399b1a1623ef488d96b4c2d0c67be1d0607 ] We don't need to search back to the inode item, the directory inode number is in key.offset, so simply use that. If we can't find the directory we'll get an ENOENT at the iget(). 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. Reviewed-by: Johannes Thumshirn Signed-off-by: Josef Bacik Signed-off-by: Daniel Vacek Reviewed-by: David Sterba [ add note ] Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: use the key format macros when printing keys

2026-06-01T15:51:01+00:00

[ Upstream commit af1e800c0244a04f5eb0993745c23d974f262628 ] Change all locations that print a key to use the new macros to print them in order to ensure a consistent style and avoid repetitive code. Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: add macros to facilitate printing of keys

2026-06-01T15:51:01+00:00

[ Upstream commit 95de4b097e25225d4deb5a33a4bfc27bb441f2d8 ] There's a lot of places where we need to print a key, and it's tiresome to type the format specifier, typically "(%llu %u %llu)", as well as passing 3 arguments to a prink family function (key->objectid, key->type, key->offset). So add a couple macros for this just like we have for csum values in btrfs_inode.h (CSUM_FMT and CSUM_FMT_VALUE). This also ensures that we consistently print a key in the same format, always as "(%llu %llu %llu)", which is the most common format we use, but we have a few variations such as "[%llu %llu %llu]" for no good reason. This patch introduces the macros while the next one makes use of it. This is to ease backports of future patches, since then we can backport this patch which is simple and short and then backport those future patches, as the next patch in the series that makes use of these new macros is quite large and may have some dependencies. Reviewed-by: Qu Wenruo Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Stable-dep-of: 1e92637722ae ("btrfs: check for subvolume before deleting squota qgroup") Signed-off-by: Sasha Levin

btrfs: do not mark inode incompressible after inline attempt fails

2026-05-23T11:07:20+00:00

[ Upstream commit 2e0e3716c7b6f8d71df2fbe709b922e54700f71b ] [BUG] The following sequence will set the file with nocompress flag: # mkfs.btrfs -f $dev # mount $dev $mnt -o max_inline=4,compress # xfs_io -f -c "pwrite 0 2k" -c sync $mnt/foobar The inode will have NOCOMPRESS flag, even if the content itself (all 0xcd) can still be compressed very well: item 4 key (257 INODE_ITEM 0) itemoff 15879 itemsize 160 generation 9 transid 10 size 2097152 nbytes 1052672 block group 0 mode 100600 links 1 uid 0 gid 0 rdev 0 sequence 257 flags 0x8(NOCOMPRESS) Please note that, this behavior is there even before commit 59615e2c1f63 ("btrfs: reject single block sized compression early"). [CAUSE] At compress_file_range(), after btrfs_compress_folios() call, we try making an inlined extent by calling cow_file_range_inline(). But cow_file_range_inline() calls can_cow_file_range_inline() which has more accurate checks on if the range can be inlined. One of the user configurable conditions is the "max_inline=" mount option. If that value is set low (like the example, 4 bytes, which cannot store any header), or the compressed content is just slightly larger than 2K (the default value, meaning a 50% compression ratio), cow_file_range_inline() will return 1 immediately. And since we're here only to try inline the compressed data, the range is no larger than a single fs block. Thus compression is never going to make it a win, we fall back to marking the inode incompressible unavoidably. [FIX] Just add an extra check after inline attempt, so that if the inline attempt failed, do not set the nocompress flag. As there is no way to remove that flag, and the default 50% compression ratio is way too strict for the whole inode. CC: stable@vger.kernel.org # 6.12+ Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

btrfs: only release the dirty pages io tree after successful writes

2026-05-23T11:07:18+00:00

commit 4066c55e109475a06d18a1f127c939d551211956 upstream. [WARNING] With extra warning on dirty extent buffers at umount (aka, the next patch in the series), test case generic/388 can trigger the following warning about dirty extent buffers at unmount time: BTRFS critical (device dm-2 state E): emergency shutdown BTRFS error (device dm-2 state E): error while writing out transaction: -30 BTRFS warning (device dm-2 state E): Skipping commit of aborted transaction. BTRFS error (device dm-2 state EA): Transaction 9 aborted (error -30) BTRFS: error (device dm-2 state EA) in cleanup_transaction:2068: errno=-30 Readonly filesystem BTRFS info (device dm-2 state EA): forced readonly BTRFS info (device dm-2 state EA): last unmount of filesystem 4fbf2e15-f941-49a0-bc7c-716315d2777c ------------[ cut here ]------------ WARNING: disk-io.c:3311 at invalidate_and_check_btree_folios+0xfd/0x1ca [btrfs], CPU#8: umount/914368 CPU: 8 UID: 0 PID: 914368 Comm: umount Tainted: G OE 7.1.0-rc1-custom+ #372 PREEMPT(full) 2de38db8d1deae71fde295430a0ff3ab98ccf596 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022 RIP: 0010:invalidate_and_check_btree_folios+0xfd/0x1ca [btrfs] Call Trace: close_ctree+0x52e/0x574 [btrfs d2f0b1cd330d1287e7a9919d112eadfc0e914efd] generic_shutdown_super+0x89/0x1a0 kill_anon_super+0x16/0x40 btrfs_kill_super+0x16/0x20 [btrfs d2f0b1cd330d1287e7a9919d112eadfc0e914efd] deactivate_locked_super+0x2d/0xb0 cleanup_mnt+0xdc/0x140 task_work_run+0x5a/0xa0 exit_to_user_mode_loop+0x123/0x4b0 do_syscall_64+0x243/0x7c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 ---[ end trace 0000000000000000 ]--- BTRFS warning (device dm-2 state EA): unable to release extent buffer 30539776 owner 9 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30621696 owner 257 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30638080 owner 258 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30654464 owner 7 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30703616 owner 2 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30720000 owner 10 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30736384 owner 4 gen 9 refs 2 flags 0x7 BTRFS warning (device dm-2 state EA): unable to release extent buffer 30752768 owner 11 gen 9 refs 2 flags 0x7 I'm using a stripped down version, which seems to trigger the warning more reliably: _fsstress_pid="" workload() { dmesg -C mkfs.btrfs -f -K $dev > /dev/null echo 1 > /sys/kernel/debug/clear_warn_once mount $dev $mnt $fsstress -w -n 1024 -p 4 -d $mnt & _fsstress_pid=$! sleep 0 $godown $mnt pkill --echo -PIPE fsstress > /dev/null wait $_fsstress_pid unset _fsstress_pid umount $mnt if dmesg | grep -q "WARNING"; then fail fi } for (( i = 0; i < $runtime; i++ )); do echo "=== $i/$runtime ===" workload done [CAUSE] Inside btrfs_write_and_wait_transaction(), we first try to write all dirty ebs, then wait for them to finish. After that we call btrfs_extent_io_tree_release() to free all extent states from dirty_pages io tree. However if we hit an error from btrfs_write_marked_extent(), then we still call btrfs_extent_io_tree_release() to clear that dirty_pages io tree, which may contain dirty records that we haven't yet submitted. Furthermore, the later transaction cleanup path will utilize that dirty_pages io tree to properly cleanup those dirty ebs, but since it's already empty, no dirty ebs are properly cleaned up, thus will later trigger the warnings inside invalidate_btree_folios(). [FIX] Normally such dirty ebs won't cause problems, as when the iput() is called on the btree inode, the dirty ebs will be forcibly written back, and since the fs is already in an error status, such writeback will not reach disk and finish immediately. But it's still better to get rid of such dirty ebs, if we ended up with dirty ebs but the fs is not in an error status, then such writeback at iput() time will be too late, as all workers are already stopped but writeback will utilize workers, which will lead to NULL pointer dereferences. Instead of unconditionally calling btrfs_extent_io_tree_release(), only call it if btrfs_write_and_wait_transaction() finished successfully, so that @dirty_pages extent io tree is kept untouched for transaction cleanup. CC: stable@vger.kernel.org # 6.1+ Reviewed-by: Filipe Manana Signed-off-by: Qu Wenruo Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman