fstests: allow overlay SCRATCH_DEV to be a base fs mount point

When configure SCRATCH_DEV to a mount point (and not to a directory therein)
then user will get a false positive error in scratch tests:

 $SCRATCH_DEV=/mnt/base/scratch is mounted but not on $SCRATCH_MNT=/mnt/scratch
 Already mounted result:
 /dev/sda6 on /mnt/base/scratch type xfs (rw,relatime,attr2,inode64,noquota)

This is due to the wrong `grep -F $SCRATCH_DEV` which matches the mount
point instead of the device in that mount.
Fix _check_mounted_on() to grep the pattern "$dev on " and "$dev on $mnt"
instead of just grepping for "$dev" and "$mnt" without the " on " anchor.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>

diff --git a/common/rc b/common/rc
index df0a04549976c272de6cb73b3212212a70955868..551a7e9869cf9909fe28fb55df007160b5bf67c8 100644 (file)
--- a/common/rc
+++ b/common/rc
@@ -1368,12 +1368,14 @@ _check_mounted_on()
        local type=$5
 
        # Note that we use -F here so grep doesn't try to interpret an NFS over
-       # IPv6 server as a regular expression
-       local mount_rec=`_mount | grep -F "$dev"`
+       # IPv6 server as a regular expression.  Because of that, we cannot use
+       # ^$dev so we use "$dev on " to avoid matching $dev to mount point field
+       # for overlay case, where $dev is a directory.
+       local mount_rec=`_mount | grep -F "$dev on "`
        [ -n "$mount_rec" ] || return 1 # 1 = not mounted
 
        # if it's mounted, make sure its on $mnt
-       if ! (echo $mount_rec | grep -q "$mnt")
+       if ! (echo $mount_rec | grep -q "$dev on $mnt")
        then
                echo "$devname=$dev is mounted but not on $mntname=$mnt - aborting"
                echo "Already mounted result:"