block: check for timeout function in blk_rq_timed_out()

rq_timed_out_fn might have been unset while the request
was in flight, so we need to check for it in blk_rq_timed_out().

Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 6e4744cbfb56..65f103563969 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -82,9 +82,10 @@ void blk_delete_timer(struct request *req)
 static void blk_rq_timed_out(struct request *req)
 {
         struct request_queue *q = req->q;
-        enum blk_eh_timer_return ret;
+        enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
 
-        ret = q->rq_timed_out_fn(req);
+        if (q->rq_timed_out_fn)
+                ret = q->rq_timed_out_fn(req);
         switch (ret) {
         case BLK_EH_HANDLED:
                 __blk_complete_request(req);