[PATCH v3 07/10] btrfs: introduce helper for creating cloned devices with mkfs

[Anand Jain <anand.jain@oracle.com>]

Use newer mkfs.btrfs option to generate two cloned devices,
used in test cases.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
v3:
 call
 _require_btrfs_command inspect-internal dump-super
 _require_btrfs_mkfs_uuid_option
 in the function mkfs_clone()
 Remove the conflict fix metadata line

v2:
 Organize changes to its right patch.
 Fix _fail erorr message.
 Declare local variables for fsid and uuid.

 common/btrfs | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/common/btrfs b/common/btrfs
index 55847733b20e..04ecff6ada71 100644
--- a/common/btrfs
+++ b/common/btrfs
@@ -840,3 +840,26 @@ check_fsid()
 	echo -e -n "Tempfsid status:\t"
 	cat /sys/fs/btrfs/$tempfsid/temp_fsid
 }
+
+mkfs_clone()
+{
+	local fsid
+	local uuid
+	local dev1=$1
+	local dev2=$2
+
+	_require_btrfs_command inspect-internal dump-super
+	_require_btrfs_mkfs_uuid_option
+
+	[[ -z $dev1 || -z $dev2 ]] && \
+		_fail "mkfs_clone requires two devices as arguments"
+
+	_mkfs_dev -fq $dev1
+
+	fsid=$($BTRFS_UTIL_PROG inspect-internal dump-super $dev1 | \
+					grep -E ^fsid | $AWK_PROG '{print $2}')
+	uuid=$($BTRFS_UTIL_PROG inspect-internal dump-super $dev1 | \
+				grep -E ^dev_item.uuid | $AWK_PROG '{print $2}')
+
+	_mkfs_dev -fq --uuid $fsid --device-uuid $uuid $dev2
+}
-- 
2.39.3