md: allow an md array to appear with 0 drives if it has external metadata
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 3975756..08e0f8d 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4647,9 +4647,10 @@
*/
/* if we are not initialised yet, only ADD_NEW_DISK, STOP_ARRAY,
* RUN_ARRAY, and GET_ and SET_BITMAP_FILE are allowed */
- if (!mddev->raid_disks && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
- && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
- && cmd != GET_BITMAP_FILE) {
+ if ((!mddev->raid_disks && !mddev->external)
+ && cmd != ADD_NEW_DISK && cmd != STOP_ARRAY
+ && cmd != RUN_ARRAY && cmd != SET_BITMAP_FILE
+ && cmd != GET_BITMAP_FILE) {
err = -ENODEV;
goto abort_unlock;
}