[PATCH] fstests: generic/741: make cleanup to handle test failure properly

Qu Wenruo
2025-06-04T23:55:45Z

[BUG]
When I was tinkering the bdev open holder parameter, it caused a bug
that it no longer rejects mounting the underlying device of a
device-mapper.

And the test case properly detects the regression:

generic/741 1s ... umount: /mnt/test: target is busy.
_check_btrfs_filesystem: filesystem on /dev/mapper/test-test is inconsistent
(see /home/adam/xfstests/results//generic/741.full for details)
Trying to repair broken TEST_DEV file system
_check_btrfs_filesystem: filesystem on /dev/mapper/test-scratch1 is inconsistent
(see /home/adam/xfstests/results//generic/741.full for details)
- output mismatch (see /home/adam/xfstests/results//generic/741.out.bad)
--- tests/generic/741.out 2024-04-06 08:10:44.773333344 +1030
+++ /home/adam/xfstests/results//generic/741.out.bad 2025-06-05 09:18:03.675049206 +0930
@@ -1,3 +1,2 @@
QA output created by 741
-mount: TEST_DIR/extra_mnt: SCRATCH_DEV already mounted or mount point busy
-mount: TEST_DIR/extra_mnt: SCRATCH_DEV already mounted or mount point busy
+rm: cannot remove '/mnt/test/extra_mnt': Device or resource busy
...
(Run 'diff -u /home/adam/xfstests/tests/generic/741.out /home/adam/xfstests/results//generic/741.out.bad' to see the entire diff)

The problem is, all later test will fail, because the $SCRATCH_DEV is
still mounted at $extra_mnt:

TEST_DEV=/dev/mapper/test-test is mounted but not on TEST_DIR=/mnt/test - aborting
Already mounted result:
/dev/mapper/test-test /mnt/test /dev/mapper/test-test /mnt/test

[CAUSE]
The test case itself is doing two expected-to-fail mounts, but the
cleanup function is only doing unmount once, if the mount succeeded
unexpectedly, the $SCRATCH_DEV will be mounted at $extra_mnt forever.

[ENHANCEMENT]
To avoid screwing up later test cases, do the $extra_mnt cleanup twice
to handle the unexpected mount success.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
tests/generic/741 | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/tests/generic/741 b/tests/generic/741
index cac7045e..c15dc434 100755
--- a/tests/generic/741
+++ b/tests/generic/741
@@ -13,6 +13,10 @@ _begin_fstest auto quick volume tempfsid
# Override the default cleanup function.
_cleanup()
{
+ # If by somehow the fs mounted the underlying device (twice), we have
+ # to make sure $extra_mnt is not mounted, or TEST_DEV can not be
+ # unmounted for fsck.
+ _unmount $extra_mnt &> /dev/null
_unmount $extra_mnt &> /dev/null
rm -rf $extra_mnt
_unmount_flakey
--
2.49.0