[BUG]
When quota is enabled for TEST_DEV, generic/013 sometimes fails like this:
generic/013 14s ... _check_dmesg: something found in dmesg (see xfstests-dev/results//generic/013.dmesg)
And with the following metadata leak:
BTRFS warning (device dm-3): qgroup 0/1370 has unreleased space, type 2 rsv 49152
------------[ cut here ]------------
WARNING: CPU: 2 PID: 47912 at fs/btrfs/disk-io.c:4078 close_ctree+0x1dc/0x323 [btrfs]
Call Trace:
btrfs_put_super+0x15/0x17 [btrfs]
generic_shutdown_super+0x72/0x110
kill_anon_super+0x18/0x30
btrfs_kill_super+0x17/0x30 [btrfs]
deactivate_locked_super+0x3b/0xa0
deactivate_super+0x40/0x50
cleanup_mnt+0x135/0x190
__cleanup_mnt+0x12/0x20
task_work_run+0x64/0xb0
__prepare_exit_to_usermode+0x1bc/0x1c0
__syscall_return_slowpath+0x47/0x230
do_syscall_64+0x64/0xb0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
---[ end trace a6cfd45ba80e4e06 ]---
BTRFS error (device dm-3): qgroup reserved space leaked
BTRFS info (device dm-3): disk space caching is enabled
BTRFS info (device dm-3): has skinny extents
[CAUSE]
The qgroup preallocated meta rsv operations of that offending root are:
btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072
btrfs_delayed_inode_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=131072
btrfs_subvolume_reserve_metadata: rsv_meta_prealloc root=1370 num_bytes=49152
btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072
btrfs_delayed_inode_release_metadata: convert_meta_prealloc root=1370 num_bytes=-131072
It's pretty obvious that, we reserve qgroup meta rsv in
btrfs_subvolume_reserve_metadata(), but doesn't have corresponding
release/convert calls in btrfs_subvolume_release_metadata().
This leads to the leakage.
[FIX]
To fix this bug, we should follow what we're doing in
btrfs_delalloc_reserve_metadata(), where we reserve qgroup space, and
add it to block_rsv->qgroup_rsv_reserved.
And free the qgroup reserved metadata space when releasing the
block_rsv.
To do this, we need to change the btrfs_subvolume_release_metadata() to
accept btrfs_root, and record the qgroup_to_release number, and call
btrfs_qgroup_convert_reserved_meta() for it.
Fixes: 733e03a0b26a ("btrfs: qgroup: Split meta rsv type into meta_prealloc and meta_pertrans")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
e85fde5162