xfstests: loop devices vs umount stupidity

Unmounting a fileystem mounted on a loop device doesn't always tear
down the loop device. Its racy, and it causes tests to randomly
fail.

To avoid that, we have to use umount -d to ensure that we destroy
loop devices under filesystems in case the kernel doesn't tear it
down automatically to prevent the test from failing.  However, if
the kernel does tear it down automatically, umount now issues a
warning that it couldn't tear down the loop device because it
couldn't find it, and that causes the test to fail. *facepalm*

So, convert all the loop device unmounts to use -d, and direct the
output of all of them to /dev/null.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Rich Johnston <rjohnston@sgi.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>

049

@@ -30,8 +30,8 @@ echo "QA output created by $seq"
 _cleanup()
 {
     cd /
-    umount $SCRATCH_MNT/test2 > /dev/null 2>&1
-    umount $SCRATCH_MNT/test > /dev/null 2>&1
+    umount -d $SCRATCH_MNT/test2 > /dev/null 2>&1
+    umount -d $SCRATCH_MNT/test > /dev/null 2>&1
     rm -f $tmp.*
 
     if [ -w $seq.full ]
@@ -124,11 +124,11 @@ rm -rf $SCRATCH_MNT/test/* >> $seq.full 2>&1 \
     || _fail "!!! clean failed"
 
 _log "umount ext2 on xfs"
-umount $SCRATCH_MNT/test2 >> $seq.full 2>&1 \
+umount -d $SCRATCH_MNT/test2 >> $seq.full 2>&1 \
     || _fail "!!! umount ext2 failed"
 
 _log "umount xfs"
-umount $SCRATCH_MNT/test >> $seq.full 2>&1 \
+umount -d $SCRATCH_MNT/test >> $seq.full 2>&1 \
     || _fail "!!! umount xfs failed"
 
 echo "--- mounts at end (before cleanup)" >> $seq.full

073

@@ -120,7 +120,7 @@ _verify_copy()
 
 	echo unmounting and removing new image
 	umount $source_dir
-	umount -d $target_dir
+	umount -d $target_dir > /dev/null 2>&1
 	rm -f $target
 }
 

078

@@ -37,7 +37,7 @@ _cleanup()
 {
     cd /
     rm -f $tmp.*
-    umount $LOOP_MNT 2>/dev/null
+    umount -d $LOOP_MNT 2>/dev/null
     rmdir $LOOP_MNT
     _cleanup_testdir
 }
@@ -98,7 +98,7 @@ _grow_loop()
 	$XFS_GROWFS_PROG $LOOP_MNT 2>&1 |  _filter_growfs 2>&1
 
 	echo "*** unmount"
-	umount $LOOP_MNT
+	umount -d $LOOP_MNT > /dev/null 2>&1
 
 	# Large grows takes forever to check..
 	if [ "$check" -gt "0" ]

216

@@ -63,7 +63,7 @@ _do_mkfs()
 			-d name=$LOOP_DEV,size=${i}g |grep log
 		mount -o loop -t xfs $LOOP_DEV $LOOP_MNT
 		echo "test write" > $LOOP_MNT/test
-		umount $LOOP_MNT
+		umount -d $LOOP_MNT > /dev/null 2>&1
 	done
 }
 # make large holey file

217

@@ -65,7 +65,7 @@ _do_mkfs()
 			-d name=$LOOP_DEV,size=${i}g |grep log
 		mount -o loop -t xfs $LOOP_DEV $LOOP_MNT
 		echo "test write" > $LOOP_MNT/test
-		umount $LOOP_MNT
+		umount -d $LOOP_MNT > /dev/null 2>&1
 	done
 }
 # make large holey file

250

@@ -34,7 +34,7 @@ trap "_cleanup; exit \$status" 0 1 2 3 15
 _cleanup()
 {
 	cd /
-	umount $LOOP_MNT 2>/dev/null
+	umount -d $LOOP_MNT 2>/dev/null
 	rm -f $LOOP_DEV
 	rmdir $LOOP_MNT
 	_cleanup_testdir
@@ -85,7 +85,7 @@ _test_loop()
 	xfs_io -f -c "resvsp 0 $fsize" $LOOP_MNT/foo | _filter_io
 
 	echo "*** unmount loop filesystem"
-	umount $LOOP_MNT
+	umount -d $LOOP_MNT > /dev/null 2>&1
 
 	echo "*** check loop filesystem"
 	 _check_xfs_filesystem $LOOP_DEV none none