This test will occasionaly fail like so: --- /tmp/fstests/tests/generic/604.out 2024-02-03 12:08:52.349924277 -0800 +++ /var/tmp/fstests/generic/604.out.bad 2024-02-05 04:35:55.020000000 -0800 @@ -1,2 +1,5 @@ QA output created by 604 -Silence is golden +mount: /opt: /dev/sda4 already mounted on /opt. + dmesg(1) may have more information after failed mount system call. +mount -o usrquota,grpquota,prjquota, /dev/sda4 /opt failed +(see /var/tmp/fstests/generic/604.full for details) As far as I can tell, the cause of this seems to be _scratch_mount getting forked and exec'd before the backgrounded umount process has a chance to enter the kernel. When this occurs, the mount() system call will return -EBUSY because this isn't an attempt to make a bind mount. Slow things down slightly by stalling the mount by 10ms. Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx> --- v1.1: indent commit message, fix busted comment --- tests/generic/604 | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/tests/generic/604 b/tests/generic/604 index cc6a4b214f..00da56dd70 100755 --- a/tests/generic/604 +++ b/tests/generic/604 @@ -24,10 +24,12 @@ _scratch_mount for i in $(seq 0 500); do $XFS_IO_PROG -f -c "pwrite 0 4K" $SCRATCH_MNT/$i >/dev/null done -# For overlayfs, avoid unmouting the base fs after _scratch_mount -# tries to mount the base fs +# For overlayfs, avoid unmouting the base fs after _scratch_mount tries to +# mount the base fs. Delay the mount attempt by a small amount in the hope +# that the mount() call will try to lock s_umount /after/ umount has already +# taken it. $UMOUNT_PROG $SCRATCH_MNT & -_scratch_mount +sleep 0.01s ; _scratch_mount wait echo "Silence is golden"