fstests: filter mount error message for EUCLEAN and ESTALE

util-linux commit ea848180dd34 ("libmount: add
mnt_context_get_excode()") since v2.30 changed the error message on
EUCLEAN and ESTALE again (and maybe other errno too):

 - mount: <device> on <mountpoint> failed: Structure needs cleaning
 + mount: <mountpoint>: mount(2) system call failed: Structure needs cleaning.

and it causes xfs/005, overlay/037 to fail (and probably xfs/333 too,
but it's always _notrun for now).

And what's more, the mentioned tests would also fail when testing
with util-linux prior to v2.21, no one complained just because the
tests are usually _notrun on such old distributions that ship
util-linux < v2.21.

So let's filter out the changing parts and keep the error message
simple.

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

common/filter

@@ -390,6 +390,13 @@ _filter_fstrim()
 	egrep -o "[0-9]+ bytes" | $AWK_PROG '{print $1}'
 }
 
+# Remove the ending dot appended to mount error message, util-linux 2.30
+# starts to do so.
+_filter_ending_dot()
+{
+	sed -e "s/\.$//"
+}
+
 # Older mount output referred to "block device" when mounting RO devices
 # It's gone in newer versions
 _filter_ro_mount() {
@@ -397,6 +404,25 @@ _filter_ro_mount() {
 	    -e "s/mount: cannot mount block device/mount: cannot mount/g"
 }
 
+# Filter a failed mount output due to EUCLEAN and USTALE, util-linux changed
+# the message several times.
+#
+# prior to v2.21:
+# mount: Structure needs cleaning
+# v2.21 to v2.29:
+# mount: mount <device> on <mountpoint> failed: Structure needs cleaning
+# v2.30 and later:
+# mount: <mountpoint>: mount(2) system call failed: Structure needs cleaning.
+#
+# This is also true for ESTALE error. So let's remove all the changing parts
+# and keep the 'prior to v2.21' format:
+# mount: Structure needs cleaning
+# mount: Stale file handle
+_filter_error_mount()
+{
+	sed -e "s/mount:\(.*failed:\)/mount:/" | _filter_ending_dot
+}
+
 _filter_od()
 {
 	BLOCK_SIZE=$(_get_block_size $SCRATCH_MNT)