Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md:
  md: protect against NULL reference when waiting to start a raid10.
  md: fix bug with re-adding of partially recovered device.
  md: fix possible deadlock in handling flush requests.
  md: move code in to submit_flushes.
  md: remove handling of flush_pending in md_submit_flush_data

drivers/md/md.c

@@ -371,10 +371,15 @@ static void md_end_flush(struct bio *bio, int err)
 	bio_put(bio);
 }
 
-static void submit_flushes(mddev_t *mddev)
+static void md_submit_flush_data(struct work_struct *ws);
+
+static void submit_flushes(struct work_struct *ws)
 {
+	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
 	mdk_rdev_t *rdev;
 
+	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
+	atomic_set(&mddev->flush_pending, 1);
 	rcu_read_lock();
 	list_for_each_entry_rcu(rdev, &mddev->disks, same_set)
 		if (rdev->raid_disk >= 0 &&
@@ -397,6 +402,8 @@ static void submit_flushes(mddev_t *mddev)
 			rdev_dec_pending(rdev, mddev);
 		}
 	rcu_read_unlock();
+	if (atomic_dec_and_test(&mddev->flush_pending))
+		queue_work(md_wq, &mddev->flush_work);
 }
 
 static void md_submit_flush_data(struct work_struct *ws)
@@ -404,8 +411,6 @@ static void md_submit_flush_data(struct work_struct *ws)
 	mddev_t *mddev = container_of(ws, mddev_t, flush_work);
 	struct bio *bio = mddev->flush_bio;
 
-	atomic_set(&mddev->flush_pending, 1);
-
 	if (bio->bi_size == 0)
 		/* an empty barrier - all done */
 		bio_endio(bio, 0);
@@ -414,10 +419,9 @@ static void md_submit_flush_data(struct work_struct *ws)
 		if (mddev->pers->make_request(mddev, bio))
 			generic_make_request(bio);
 	}
-	if (atomic_dec_and_test(&mddev->flush_pending)) {
+
 	mddev->flush_bio = NULL;
 	wake_up(&mddev->sb_wait);
-	}
 }
 
 void md_flush_request(mddev_t *mddev, struct bio *bio)
@@ -429,12 +433,7 @@ void md_flush_request(mddev_t *mddev, struct bio *bio)
 	mddev->flush_bio = bio;
 	spin_unlock_irq(&mddev->write_lock);
 
-	atomic_set(&mddev->flush_pending, 1);
-	INIT_WORK(&mddev->flush_work, md_submit_flush_data);
-
-	submit_flushes(mddev);
-
-	if (atomic_dec_and_test(&mddev->flush_pending))
+	INIT_WORK(&mddev->flush_work, submit_flushes);
 	queue_work(md_wq, &mddev->flush_work);
 }
 EXPORT_SYMBOL(md_flush_request);
@@ -5160,7 +5159,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
 				PTR_ERR(rdev));
 			return PTR_ERR(rdev);
 		}
-		/* set save_raid_disk if appropriate */
+		/* set saved_raid_disk if appropriate */
 		if (!mddev->persistent) {
 			if (info->state & (1<<MD_DISK_SYNC)  &&
 			    info->raid_disk < mddev->raid_disks)
@@ -5170,7 +5169,10 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
 		} else
 			super_types[mddev->major_version].
 				validate_super(mddev, rdev);
+		if (test_bit(In_sync, &rdev->flags))
 			rdev->saved_raid_disk = rdev->raid_disk;
+		else
+			rdev->saved_raid_disk = -1;
 
 		clear_bit(In_sync, &rdev->flags); /* just to be sure */
 		if (info->state & (1<<MD_DISK_WRITEMOSTLY))
@@ -6042,8 +6044,7 @@ static int md_thread(void * arg)
 			 || kthread_should_stop(),
 			 thread->timeout);
 
-		clear_bit(THREAD_WAKEUP, &thread->flags);
-
+		if (test_and_clear_bit(THREAD_WAKEUP, &thread->flags))
 			thread->run(thread->mddev);
 	}
 

drivers/md/raid10.c

@@ -2397,13 +2397,13 @@ static int run(mddev_t *mddev)
 	return 0;
 
 out_free_conf:
+	md_unregister_thread(mddev->thread);
 	if (conf->r10bio_pool)
 		mempool_destroy(conf->r10bio_pool);
 	safe_put_page(conf->tmppage);
 	kfree(conf->mirrors);
 	kfree(conf);
 	mddev->private = NULL;
-	md_unregister_thread(mddev->thread);
 out:
 	return -EIO;
 }