[PATCH 1/2] btrfs: code reorder in btrfs_prepare_sprout

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

No functional change, bring the clone of fs_devices and its
operations closer, so that it indicates its purpose.

Also add a comment to indicate why we clone the fs_devices.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
---
 fs/btrfs/volumes.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index b63aae267ebe..0e92969b1adc 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2276,18 +2276,21 @@ static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info)
 	if (!fs_devices->seeding)
 		return -EINVAL;
 
-	seed_devices = alloc_fs_devices(NULL);
-	if (IS_ERR(seed_devices))
-		return PTR_ERR(seed_devices);
-
+	/*
+	 * This step ensures the scanned seed device remains scanned,
+	 * its not a must for the sprout operation though.
+	 */
 	old_devices = clone_fs_devices(fs_devices);
 	if (IS_ERR(old_devices)) {
 		kfree(seed_devices);
 		return PTR_ERR(old_devices);
 	}
-
 	list_add(&old_devices->fs_list, &fs_uuids);
 
+	seed_devices = alloc_fs_devices(NULL);
+	if (IS_ERR(seed_devices))
+		return PTR_ERR(seed_devices);
+
 	memcpy(seed_devices, fs_devices, sizeof(*seed_devices));
 	seed_devices->opened = 1;
 	INIT_LIST_HEAD(&seed_devices->devices);
-- 
2.7.0