block: only bdi_unregister() in del_gendisk() if !GENHD_FL_HIDDEN

device_add_disk() will only call bdi_register_owner() if !GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call bdi_unregister() if !GENHD_FL_HIDDEN. Found with code inspection. bdi_unregister() won't do any harm if bdi_register_owner() wasn't used but best to avoid the unnecessary call to bdi_unregister(). Fixes: 8ddcd65 ("block: introduce GENHD_FL_HIDDEN") Signed-off-by: Mike Snitzer <[email protected]> Reviewed-by: Ming Lei <[email protected]> Reviewed-by: Hannes Reinecke <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
CarlFK · Jan 15, 2018 · bc8d062 · bc8d062
1 parent bf9ae8c
commit bc8d062
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/block/genhd.c b/block/genhd.c
@@ -725,7 +725,8 @@ void del_gendisk(struct gendisk *disk)
 		 * Unregister bdi before releasing device numbers (as they can
 		 * get reused and we'd get clashes in sysfs).
 		 */
-		bdi_unregister(disk->queue->backing_dev_info);
+		if (!(disk->flags & GENHD_FL_HIDDEN))
+			bdi_unregister(disk->queue->backing_dev_info);
 		blk_unregister_queue(disk);
 	} else {
 		WARN_ON(1);