2 files changed, 24 insertions, 12 deletions

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 283da7fbe034..27aceab1cc31 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -777,24 +777,25 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 }
 
 /**
- * blk_release_queue: - release a &struct request_queue when it is no longer needed
- * @kobj:    the kobj belonging to the request queue to be released
+ * __blk_release_queue - release a request queue when it is no longer needed
+ * @work: pointer to the release_work member of the request queue to be released
  *
  * Description:
- *     blk_release_queue is the pair to blk_init_queue() or
- *     blk_queue_make_request().  It should be called when a request queue is
- *     being released; typically when a block device is being de-registered.
- *     Currently, its primary task it to free all the &struct request
- *     structures that were allocated to the queue and the queue itself.
+ *     blk_release_queue is the counterpart of blk_init_queue(). It should be
+ *     called when a request queue is being released; typically when a block
+ *     device is being de-registered. Its primary task it to free the queue
+ *     itself.
  *
- * Note:
+ * Notes:
  *     The low level driver must have finished any outstanding requests first
  *     via blk_cleanup_queue().
- **/
-static void blk_release_queue(struct kobject *kobj)
+ *
+ *     Although blk_release_queue() may be called with preemption disabled,
+ *     __blk_release_queue() may sleep.
+ */
+static void __blk_release_queue(struct work_struct *work)
 {
-        struct request_queue *q =
-                container_of(kobj, struct request_queue, kobj);
+        struct request_queue *q = container_of(work, typeof(*q), release_work);
 
         if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
                 blk_stat_remove_callback(q, q->poll_cb);
@@ -834,6 +835,15 @@ static void blk_release_queue(struct kobject *kobj)
         call_rcu(&q->rcu_head, blk_free_queue_rcu);
 }
 
+static void blk_release_queue(struct kobject *kobj)
+{
+        struct request_queue *q =
+                container_of(kobj, struct request_queue, kobj);
+
+        INIT_WORK(&q->release_work, __blk_release_queue);
+        schedule_work(&q->release_work);
+}
+
 static const struct sysfs_ops queue_sysfs_ops = {
         .show   = queue_attr_show,
         .store  = queue_attr_store,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index ab92c4ea138b..b74a3edcb3da 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -586,6 +586,8 @@ struct request_queue {
 
         size_t                  cmd_size;
         void                    *rq_alloc_data;
+
+        struct work_struct      release_work;
 };
 
 #define QUEUE_FLAG_QUEUED       1       /* uses generic tag queueing */