btrfs: properly shutdown subvolume stress worker to avoid umount failures
When killing a test that is using the subvolume stress worker, we may end
up in a situation where we end up leaving a subvolume mounted which makes
the shutdown sequence fail. Example when killing a script that keeps
running fstests in a loop:
FSTYP -- btrfs
PLATFORM -- Linux/x86_64 debian0 6.10.0-rc7-btrfs-next-167+ #1 SMP PREEMPT_DYNAMIC Thu Jul 11 17:54:07 WEST 2024
MKFS_OPTIONS -- /dev/sdc
MOUNT_OPTIONS -- /dev/sdc /home/fdmanana/btrfs-tests/scratch_1
(...)
btrfs/065 23s ... ^C^C^C
Iteration 134, errors 1, leaks 0, Wed Jul 24 12:14:33 PM WEST 2024, flakey errors: 0 MKFS_OPTIONS="" MOUNT_OPTIONS=""
SCRATCH_DEV=/dev/sdc is mounted but not on SCRATCH_MNT=/home/fdmanana/btrfs-tests/scratch_1 - aborting
Already mounted result:
/dev/sdc /home/fdmanana/btrfs-tests/scratch_1 /dev/sdc /home/fdmanana/btrfs-tests/dev/065.mnt
grep: results/btrfs/065.out.bad: No such file or directory
Error iteration 134, total errors 2, leaks 0
'results/btrfs/065.full' -> '/home/fdmanana/failures/btrfs_065/134/065.full'
Running 'mount' to see what's going on:
$ mount
(...)
/dev/sdb on /home/fdmanana/btrfs-tests/dev type btrfs (rw,relatime,discard=async,space_cache=v2,subvolid=5,subvol=/)
/dev/sdc on /home/fdmanana/btrfs-tests/scratch_1 type btrfs (rw,relatime,discard=async,space_cache=v2,subvolid=5,subvol=/)
/dev/sdc on /home/fdmanana/btrfs-tests/dev/065.mnt type btrfs (rw,relatime,discard=async,space_cache=v2,subvolid=2627,subvol=/subvol_3395330)
Then this makes the next attempt to run a test (./check) always fail due
to the extra mount of the subvolume, requiring one to manually umount the
subvolume before running fstests again.
So update _btrfs_kill_stress_subvolume_pid() to also unmount the subvolume.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
6 files changed
