dm: factor out a common cleanup_mapped_device()

Introduce a single common method for cleaning up a DM device's
mapped_device.  No functional change, just eliminates duplication of
delicate mapped_device cleanup code.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

drivers/md/dm.c

@@ -2166,6 +2166,40 @@ static void dm_init_old_md_queue(struct mapped_device *md)
 	blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
 }
 
+static void cleanup_mapped_device(struct mapped_device *md)
+{
+	cleanup_srcu_struct(&md->io_barrier);
+
+	if (md->wq)
+		destroy_workqueue(md->wq);
+	if (md->kworker_task)
+		kthread_stop(md->kworker_task);
+	if (md->io_pool)
+		mempool_destroy(md->io_pool);
+	if (md->rq_pool)
+		mempool_destroy(md->rq_pool);
+	if (md->bs)
+		bioset_free(md->bs);
+
+	if (md->disk) {
+		spin_lock(&_minor_lock);
+		md->disk->private_data = NULL;
+		spin_unlock(&_minor_lock);
+		if (blk_get_integrity(md->disk))
+			blk_integrity_unregister(md->disk);
+		del_gendisk(md->disk);
+		put_disk(md->disk);
+	}
+
+	if (md->queue)
+		blk_cleanup_queue(md->queue);
+
+	if (md->bdev) {
+		bdput(md->bdev);
+		md->bdev = NULL;
+	}
+}
+
 /*
  * Allocate and initialise a blank device with a given minor.
  */
@@ -2211,13 +2245,13 @@ static struct mapped_device *alloc_dev(int minor)
 
 	md->queue = blk_alloc_queue(GFP_KERNEL);
 	if (!md->queue)
-		goto bad_queue;
+		goto bad;
 
 	dm_init_md_queue(md);
 
 	md->disk = alloc_disk(1);
 	if (!md->disk)
-		goto bad_disk;
+		goto bad;
 
 	atomic_set(&md->pending[0], 0);
 	atomic_set(&md->pending[1], 0);
@@ -2238,11 +2272,11 @@ static struct mapped_device *alloc_dev(int minor)
 
 	md->wq = alloc_workqueue("kdmflush", WQ_MEM_RECLAIM, 0);
 	if (!md->wq)
-		goto bad_thread;
+		goto bad;
 
 	md->bdev = bdget_disk(md->disk, 0);
 	if (!md->bdev)
-		goto bad_bdev;
+		goto bad;
 
 	bio_init(&md->flush_bio);
 	md->flush_bio.bi_bdev = md->bdev;
@@ -2259,15 +2293,8 @@ static struct mapped_device *alloc_dev(int minor)
 
 	return md;
 
-bad_bdev:
-	destroy_workqueue(md->wq);
-bad_thread:
-	del_gendisk(md->disk);
-	put_disk(md->disk);
-bad_disk:
-	blk_cleanup_queue(md->queue);
-bad_queue:
-	cleanup_srcu_struct(&md->io_barrier);
+bad:
+	cleanup_mapped_device(md);
 bad_io_barrier:
 	free_minor(minor);
 bad_minor:
@@ -2284,32 +2311,13 @@ static void free_dev(struct mapped_device *md)
 	int minor = MINOR(disk_devt(md->disk));
 
 	unlock_fs(md);
-	destroy_workqueue(md->wq);
 
-	if (md->kworker_task)
-		kthread_stop(md->kworker_task);
-	if (md->io_pool)
-		mempool_destroy(md->io_pool);
-	if (md->rq_pool)
-		mempool_destroy(md->rq_pool);
-	if (md->bs)
-		bioset_free(md->bs);
+	cleanup_mapped_device(md);
+	if (md->use_blk_mq)
+		blk_mq_free_tag_set(&md->tag_set);
 
-	cleanup_srcu_struct(&md->io_barrier);
 	free_table_devices(&md->table_devices);
 	dm_stats_cleanup(&md->stats);
-
-	spin_lock(&_minor_lock);
-	md->disk->private_data = NULL;
-	spin_unlock(&_minor_lock);
-	if (blk_get_integrity(md->disk))
-		blk_integrity_unregister(md->disk);
-	del_gendisk(md->disk);
-	put_disk(md->disk);
-	blk_cleanup_queue(md->queue);
-	if (md->use_blk_mq)
-		blk_mq_free_tag_set(&md->tag_set);
-	bdput(md->bdev);
 	free_minor(minor);
 
 	module_put(THIS_MODULE);