mdadm: introduce sysfs_get_container_devnm()

There at least two places where it is done directly, so replace them
with function. Print message about creating external array, add "/dev/"
prefix to refer directly to devnode.

Signed-off-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/mdadm.h b/mdadm.h
index cbc586f5..39b86bd0 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -777,6 +777,8 @@ enum sysfs_read_flags {
 
 #define SYSFS_MAX_BUF_SIZE 64
 
+extern void sysfs_get_container_devnm(struct mdinfo *mdi, char *buf);
+
 /* If fd >= 0, get the array it is open on,
  * else use devnm.
  */