md/raid5: allow removal for failed replacement devices.

Enhance raid5_remove_disk to be able to remove ->replacement
as well as ->rdev.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2ae63c5..e5795d3 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5086,36 +5086,42 @@ static int raid5_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
        struct r5conf *conf = mddev->private;
        int err = 0;
        int number = rdev->raid_disk;
+       struct md_rdev **rdevp;
        struct disk_info *p = conf->disks + number;
 
        print_raid5_conf(conf);
-       if (rdev == p->rdev) {
-               if (number >= conf->raid_disks &&
-                   conf->reshape_progress == MaxSector)
-                       clear_bit(In_sync, &rdev->flags);
+       if (rdev == p->rdev)
+               rdevp = &p->rdev;
+       else if (rdev == p->replacement)
+               rdevp = &p->replacement;
+       else
+               return 0;
 
-               if (test_bit(In_sync, &rdev->flags) ||
-                   atomic_read(&rdev->nr_pending)) {
-                       err = -EBUSY;
-                       goto abort;
-               }
-               /* Only remove non-faulty devices if recovery
-                * isn't possible.
-                */
-               if (!test_bit(Faulty, &rdev->flags) &&
-                   mddev->recovery_disabled != conf->recovery_disabled &&
-                   !has_failed(conf) &&
-                   number < conf->raid_disks) {
-                       err = -EBUSY;
-                       goto abort;
-               }
-               p->rdev = NULL;
-               synchronize_rcu();
-               if (atomic_read(&rdev->nr_pending)) {
-                       /* lost the race, try later */
-                       err = -EBUSY;
-                       p->rdev = rdev;
-               }
+       if (number >= conf->raid_disks &&
+           conf->reshape_progress == MaxSector)
+               clear_bit(In_sync, &rdev->flags);
+
+       if (test_bit(In_sync, &rdev->flags) ||
+           atomic_read(&rdev->nr_pending)) {
+               err = -EBUSY;
+               goto abort;
+       }
+       /* Only remove non-faulty devices if recovery
+        * isn't possible.
+        */
+       if (!test_bit(Faulty, &rdev->flags) &&
+           mddev->recovery_disabled != conf->recovery_disabled &&
+           !has_failed(conf) &&
+           number < conf->raid_disks) {
+               err = -EBUSY;
+               goto abort;
+       }
+       *rdevp = NULL;
+       synchronize_rcu();
+       if (atomic_read(&rdev->nr_pending)) {
+               /* lost the race, try later */
+               err = -EBUSY;
+               *rdevp = rdev;
        }
 abort: