md/raid10: allow removal of failed replacement devices.

Enhance raid10_remove_disk to be able to remove ->replacement
as well as ->rdev

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 32 insertions, 25 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 5b886218110e..b2c8998e1397 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1429,34 +1429,41 @@ static int raid10_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
         struct r10conf *conf = mddev->private;
         int err = 0;
         int number = rdev->raid_disk;
-        struct mirror_info *p = conf->mirrors+ number;
+        struct md_rdev **rdevp;
+        struct mirror_info *p = conf->mirrors + number;
 
         print_conf(conf);
-        if (rdev == p->rdev) {
-                if (test_bit(In_sync, &rdev->flags) ||
-                    atomic_read(&rdev->nr_pending)) {
-                        err = -EBUSY;
-                        goto abort;
-                }
-                /* Only remove faulty devices in recovery
-                 * is not possible.
-                 */
-                if (!test_bit(Faulty, &rdev->flags) &&
-                    mddev->recovery_disabled != p->recovery_disabled &&
-                    enough(conf, -1)) {
-                        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;
-                        goto abort;
-                }
-                err = md_integrity_register(mddev);
+        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 faulty devices if recovery
+         * is not possible.
+         */
+        if (!test_bit(Faulty, &rdev->flags) &&
+            mddev->recovery_disabled != p->recovery_disabled &&
+            enough(conf, -1)) {
+                err = -EBUSY;
+                goto abort;
         }
+        *rdevp = NULL;
+        synchronize_rcu();
+        if (atomic_read(&rdev->nr_pending)) {
+                /* lost the race, try later */
+                err = -EBUSY;
+                *rdevp = rdev;
+                goto abort;
+        }
+        err = md_integrity_register(mddev);
+
 abort:
 
         print_conf(conf);