btrfs-progs: write down the meaning of BTRFS_ARG_BLKDEV

Although BTRFS_ARG_BLKDEV can be returned from check_arg_type(),
it's not explained the meaning.

Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/utils.c b/utils.c
index 3df8b42a..eabc36dc 100644
--- a/utils.c
+++ b/utils.c
@@ -1007,6 +1007,7 @@ static int is_reg_file(const char *path)
  * return BTRFS_ARG_UUID:	given input is uuid
  * return BTRFS_ARG_MNTPOINT:	given input is path
  * return BTRFS_ARG_REG:	given input is regular file
+ * return BTRFS_ARG_BLKDEV:	given input is block device
  */
 int check_arg_type(const char *input)
 {