1 files changed, 18 insertions, 64 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index d5ab4493c8be..308e87b417e0 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -498,61 +498,13 @@ void md_flush_request(struct mddev *mddev, struct bio *bio)
 }
 EXPORT_SYMBOL(md_flush_request);
 
-/* Support for plugging.
- * This mirrors the plugging support in request_queue, but does not
- * require having a whole queue or request structures.
- * We allocate an md_plug_cb for each md device and each thread it gets
- * plugged on.  This links tot the private plug_handle structure in the
- * personality data where we keep a count of the number of outstanding
- * plugs so other code can see if a plug is active.
- */
-struct md_plug_cb {
-	struct blk_plug_cb cb;
-	struct mddev *mddev;
-};
-
-static void plugger_unplug(struct blk_plug_cb *cb)
-{
-	struct md_plug_cb *mdcb = container_of(cb, struct md_plug_cb, cb);
-	if (atomic_dec_and_test(&mdcb->mddev->plug_cnt))
-		md_wakeup_thread(mdcb->mddev->thread);
-	kfree(mdcb);
-}
-
-/* Check that an unplug wakeup will come shortly.
- * If not, wakeup the md thread immediately
- */
-int mddev_check_plugged(struct mddev *mddev)
+void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
 {
-	struct blk_plug *plug = current->plug;
-	struct md_plug_cb *mdcb;
-
-	if (!plug)
-		return 0;
-
-	list_for_each_entry(mdcb, &plug->cb_list, cb.list) {
-		if (mdcb->cb.callback == plugger_unplug &&
-		    mdcb->mddev == mddev) {
-			/* Already on the list, move to top */
-			if (mdcb != list_first_entry(&plug->cb_list,
-						    struct md_plug_cb,
-						    cb.list))
-				list_move(&mdcb->cb.list, &plug->cb_list);
-			return 1;
-		}
-	}
-	/* Not currently on the callback list */
-	mdcb = kmalloc(sizeof(*mdcb), GFP_ATOMIC);
-	if (!mdcb)
-		return 0;
-
-	mdcb->mddev = mddev;
-	mdcb->cb.callback = plugger_unplug;
-	atomic_inc(&mddev->plug_cnt);
-	list_add(&mdcb->cb.list, &plug->cb_list);
-	return 1;
+	struct mddev *mddev = cb->data;
+	md_wakeup_thread(mddev->thread);
+	kfree(cb);
 }
-EXPORT_SYMBOL_GPL(mddev_check_plugged);
+EXPORT_SYMBOL(md_unplug);
 
 static inline struct mddev *mddev_get(struct mddev *mddev)
 {
@@ -602,7 +554,6 @@ void mddev_init(struct mddev *mddev)
 	atomic_set(&mddev->active, 1);
 	atomic_set(&mddev->openers, 0);
 	atomic_set(&mddev->active_io, 0);
-	atomic_set(&mddev->plug_cnt, 0);
 	spin_lock_init(&mddev->write_lock);
 	atomic_set(&mddev->flush_pending, 0);
 	init_waitqueue_head(&mddev->sb_wait);
@@ -1157,8 +1108,11 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 			ret = 0;
 	}
 	rdev->sectors = rdev->sb_start;
-	/* Limit to 4TB as metadata cannot record more than that */
-	if (rdev->sectors >= (2ULL << 32))
+	/* Limit to 4TB as metadata cannot record more than that.
+	 * (not needed for Linear and RAID0 as metadata doesn't
+	 * record this size)
+	 */
+	if (rdev->sectors >= (2ULL << 32) && sb->level >= 1)
 		rdev->sectors = (2ULL << 32) - 2;
 
 	if (rdev->sectors < ((sector_t)sb->size) * 2 && sb->level >= 1)
@@ -1449,7 +1403,7 @@ super_90_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 	/* Limit to 4TB as metadata cannot record more than that.
 	 * 4TB == 2^32 KB, or 2*2^32 sectors.
 	 */
-	if (num_sectors >= (2ULL << 32))
+	if (num_sectors >= (2ULL << 32) && rdev->mddev->level >= 1)
 		num_sectors = (2ULL << 32) - 2;
 	md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
 		       rdev->sb_page);
@@ -3942,17 +3896,13 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
 		break;
 	case clear:
 		/* stopping an active array */
-		if (atomic_read(&mddev->openers) > 0)
-			return -EBUSY;
 		err = do_md_stop(mddev, 0, NULL);
 		break;
 	case inactive:
 		/* stopping an active array */
-		if (mddev->pers) {
-			if (atomic_read(&mddev->openers) > 0)
-				return -EBUSY;
+		if (mddev->pers)
 			err = do_md_stop(mddev, 2, NULL);
-		} else
+		else
 			err = 0; /* already inactive */
 		break;
 	case suspended:
@@ -7669,6 +7619,8 @@ static int remove_and_add_spares(struct mddev *mddev)
 			}
 		}
 	}
+	if (removed)
+		set_bit(MD_CHANGE_DEVS, &mddev->flags);
 	return spares;
 }
 
@@ -7682,9 +7634,11 @@ static void reap_sync_thread(struct mddev *mddev)
 	    !test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
 		/* success...*/
 		/* activate any spares */
-		if (mddev->pers->spare_active(mddev))
+		if (mddev->pers->spare_active(mddev)) {
 			sysfs_notify(&mddev->kobj, NULL,
 				     "degraded");
+			set_bit(MD_CHANGE_DEVS, &mddev->flags);
+		}
 	}
 	if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) &&
 	    mddev->pers->finish_reshape)