common/dmthin: make this work with external log devices

Provide a mkfs helper to format the dm thin device when external devices
are in use, and fix the dmthin mount helper to support them.  This fixes
regressions in generic/347 and generic/500 when external logs are in
use.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>

common/dmthin

@@ -218,10 +218,17 @@ _dmthin_set_fail()
 
 _dmthin_mount_options()
 {
-	echo `_common_dev_mount_options $*` $DMTHIN_VOL_DEV $SCRATCH_MNT
+	_scratch_options mount
+	echo `_common_dev_mount_options $*` $SCRATCH_OPTIONS $DMTHIN_VOL_DEV $SCRATCH_MNT
 }
 
 _dmthin_mount()
 {
 	_mount -t $FSTYP `_dmthin_mount_options $*`
 }
+
+_dmthin_mkfs()
+{
+	_scratch_options mkfs
+	_mkfs_dev $SCRATCH_OPTIONS $@ $DMTHIN_VOL_DEV
+}

tests/generic/347

@@ -31,7 +31,7 @@ _setup_thin()
 {
 	_dmthin_init $BACKING_SIZE $VIRTUAL_SIZE
 	_dmthin_set_queue
-	_mkfs_dev $DMTHIN_VOL_DEV
+	_dmthin_mkfs
 	_dmthin_mount
 }
 

tests/generic/500

@@ -68,7 +68,7 @@ CLUSTER_SIZE=$((64 * 1024 / 512))		# 64K
 
 _dmthin_init $BACKING_SIZE $VIRTUAL_SIZE $CLUSTER_SIZE 0
 _dmthin_set_fail
-_mkfs_dev $DMTHIN_VOL_DEV
+_dmthin_mkfs
 _dmthin_mount
 
 # There're two bugs at here, one is dm-thin bug, the other is filesystem