Fix recursive lock in free_uid()/free_user_ns()

[sfrench/cifs-2.6.git] / block / blk-timeout.c

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 116bbf394fb53d7a5ed8499af6fd59e76d31e94b..bbbdc4b8ccf27a9d0d1f4a9648a930b89f8761a0 100644 (file)
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -73,11 +73,7 @@ ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
  */
 void blk_delete_timer(struct request *req)
 {
-       struct request_queue *q = req->q;
-
        list_del_init(&req->timeout_list);
-       if (list_empty(&q->timeout_list))
-               del_timer(&q->timeout);
 }
 
 static void blk_rq_timed_out(struct request *req)
@@ -132,7 +128,12 @@ void blk_rq_timed_out_timer(unsigned long data)
                }
        }
 
-       if (next_set && !list_empty(&q->timeout_list))
+       /*
+        * next can never be 0 here with the list non-empty, since we always
+        * bump ->deadline to 1 so we can detect if the timer was ever added
+        * or not. See comment in blk_add_timer()
+        */
+       if (next)
                mod_timer(&q->timeout, round_jiffies_up(next));
 
        spin_unlock_irqrestore(q->queue_lock, flags);
@@ -208,12 +209,19 @@ void blk_abort_queue(struct request_queue *q)
 {
        unsigned long flags;
        struct request *rq, *tmp;
+       LIST_HEAD(list);
 
        spin_lock_irqsave(q->queue_lock, flags);
 
        elv_abort_queue(q);
 
-       list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
+       /*
+        * Splice entries to local list, to avoid deadlocking if entries
+        * get readded to the timeout list by error handling
+        */
+       list_splice_init(&q->timeout_list, &list);
+
+       list_for_each_entry_safe(rq, tmp, &list, timeout_list)
                blk_abort_request(rq);
 
        spin_unlock_irqrestore(q->queue_lock, flags);