block: call blk_mq_exit_queue from disk_release for never added disks

[linux-stable] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index 4d15f828c44988dd652af5ae4d37ed58946fd03f..89f22a677f4182672642bdb9480d3344e4e108fc 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1158,6 +1158,18 @@ static void disk_release(struct device *dev)
        might_sleep();
        WARN_ON_ONCE(disk_live(disk));
 
+       /*
+        * To undo the all initialization from blk_mq_init_allocated_queue in
+        * case of a probe failure where add_disk is never called we have to
+        * call blk_mq_exit_queue here. We can't do this for the more common
+        * teardown case (yet) as the tagset can be gone by the time the disk
+        * is released once it was added.
+        */
+       if (queue_is_mq(disk->queue) &&
+           test_bit(GD_OWNS_QUEUE, &disk->state) &&
+           !test_bit(GD_ADDED, &disk->state))
+               blk_mq_exit_queue(disk->queue);
+
        blkcg_exit_queue(disk->queue);
 
        disk_release_events(disk);
@@ -1422,6 +1434,9 @@ EXPORT_SYMBOL(__blk_alloc_disk);
  * This decrements the refcount for the struct gendisk. When this reaches 0
  * we'll have disk_release() called.
  *
+ * Note: for blk-mq disk put_disk must be called before freeing the tag_set
+ * when handling probe errors (that is before add_disk() is called).
+ *
  * Context: Any context, but the last reference must not be dropped from
  *          atomic context.
  */