block: make gendisk hold a reference to its queue

[mirror_ubuntu-bionic-kernel.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index e2f67902dd024ed2f07abdfc190c73558d2ddb7b..d261b73b9744f033eb59f2b8075bc755c2d2780c 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -611,6 +611,12 @@ void add_disk(struct gendisk *disk)
        register_disk(disk);
        blk_register_queue(disk);
 
+       /*
+        * Take an extra ref on queue which will be put on disk_release()
+        * so that it sticks around as long as @disk is there.
+        */
+       WARN_ON_ONCE(blk_get_queue(disk->queue));
+
        retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
                                   "bdi");
        WARN_ON(retval);
@@ -1095,6 +1101,8 @@ static void disk_release(struct device *dev)
        disk_replace_part_tbl(disk, NULL);
        free_part_stats(&disk->part0);
        free_part_info(&disk->part0);
+       if (disk->queue)
+               blk_put_queue(disk->queue);
        kfree(disk);
 }
 struct class block_class = {