md: allow re-add to failed arrays.
When an array is failed (some data inaccessible) then there is no
point attempting to add a spare as it could not possibly be recovered.
However that may be value in re-adding a recently removed device.
e.g. if there is a write-intent-bitmap and it is clear, then access
to the data could be restored by this action.
So don't reject a re-add to a failed array for RAID10 and RAID5 (the
only arrays types that check for a failed array).
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 99b2bbf..d38d235 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5361,7 +5361,7 @@
if (mddev->recovery_disabled == conf->recovery_disabled)
return -EBUSY;
- if (has_failed(conf))
+ if (rdev->saved_raid_disk < 0 && has_failed(conf))
/* no point adding a device */
return -EINVAL;