On Mon, Feb 26, 2024 at 06:00:47PM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong <djwong@xxxxxxxxxx> > > 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> > --- > tests/generic/604 | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > > diff --git a/tests/generic/604 b/tests/generic/604 > index cc6a4b214f..a0dcdcd58e 100755 > --- a/tests/generic/604 > +++ b/tests/generic/604 > @@ -24,10 +24,11 @@ _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 0.1s 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 0.1s or 0.01s ? Above comment says 0.1s, but it sleeps 0.01s actually :) The comment of g/604 says "Evicting dirty inodes can take a long time during umount." So how long time makes sense, how long is the bug? Thanks, Zorro > wait > > echo "Silence is golden" >
