1 files changed, 11 insertions, 14 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 360f2b98f62..23ac880bba9 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -208,11 +208,10 @@ static void __release_stripe(struct r5conf *conf, struct stripe_head *sh)
 			md_wakeup_thread(conf->mddev->thread);
 		} else {
 			BUG_ON(stripe_operations_active(sh));
-			if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
-				atomic_dec(&conf->preread_active_stripes);
-				if (atomic_read(&conf->preread_active_stripes) < IO_THRESHOLD)
+			if (test_and_clear_bit(STRIPE_PREREAD_ACTIVE, &sh->state))
+				if (atomic_dec_return(&conf->preread_active_stripes)
+				    < IO_THRESHOLD)
 					md_wakeup_thread(conf->mddev->thread);
-			}
 			atomic_dec(&conf->active_stripes);
 			if (!test_bit(STRIPE_EXPANDING, &sh->state)) {
 				list_add_tail(&sh->lru, &conf->inactive_list);
@@ -4843,7 +4842,7 @@ static struct r5conf *setup_conf(struct mddev *mddev)
 
 	pr_debug("raid456: run(%s) called.\n", mdname(mddev));
 
-	list_for_each_entry(rdev, &mddev->disks, same_set) {
+	rdev_for_each(rdev, mddev) {
 		raid_disk = rdev->raid_disk;
 		if (raid_disk >= max_disks
 		    || raid_disk < 0)
@@ -5178,7 +5177,7 @@ static int run(struct mddev *mddev)
 		blk_queue_io_opt(mddev->queue, chunk_size *
 				 (conf->raid_disks - conf->max_degraded));
 
-		list_for_each_entry(rdev, &mddev->disks, same_set)
+		rdev_for_each(rdev, mddev)
 			disk_stack_limits(mddev->gendisk, rdev->bdev,
 					  rdev->data_offset << 9);
 	}
@@ -5362,7 +5361,7 @@ static int raid5_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	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;
 
@@ -5501,7 +5500,7 @@ static int raid5_start_reshape(struct mddev *mddev)
 	if (!check_stripe_cache(mddev))
 		return -ENOSPC;
 
-	list_for_each_entry(rdev, &mddev->disks, same_set)
+	rdev_for_each(rdev, mddev)
 		if (!test_bit(In_sync, &rdev->flags)
 		    && !test_bit(Faulty, &rdev->flags))
 			spares++;
@@ -5547,16 +5546,14 @@ static int raid5_start_reshape(struct mddev *mddev)
 	 * such devices during the reshape and confusion could result.
 	 */
 	if (mddev->delta_disks >= 0) {
-		int added_devices = 0;
-		list_for_each_entry(rdev, &mddev->disks, same_set)
+		rdev_for_each(rdev, mddev)
 			if (rdev->raid_disk < 0 &&
 			    !test_bit(Faulty, &rdev->flags)) {
 				if (raid5_add_disk(mddev, rdev) == 0) {
 					if (rdev->raid_disk
-					    >= conf->previous_raid_disks) {
+					    >= conf->previous_raid_disks)
 						set_bit(In_sync, &rdev->flags);
-						added_devices++;
-					} else
+					else
 						rdev->recovery_offset = 0;
 
 					if (sysfs_link_rdev(mddev, rdev))
@@ -5566,7 +5563,6 @@ static int raid5_start_reshape(struct mddev *mddev)
 				   && !test_bit(Faulty, &rdev->flags)) {
 				/* This is a spare that was manually added */
 				set_bit(In_sync, &rdev->flags);
-				added_devices++;
 			}
 
 		/* When a reshape changes the number of devices,
@@ -5592,6 +5588,7 @@ static int raid5_start_reshape(struct mddev *mddev)
 		spin_lock_irq(&conf->device_lock);
 		mddev->raid_disks = conf->raid_disks = conf->previous_raid_disks;
 		conf->reshape_progress = MaxSector;
+		mddev->reshape_position = MaxSector;
 		spin_unlock_irq(&conf->device_lock);
 		return -EAGAIN;
 	}