summaryrefslogtreecommitdiff
path: root/block/elevator.c
diff options
context:
space:
mode:
Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 86836dd179c0..261ffaaf47bd 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -944,10 +944,14 @@ void elv_completed_request(struct request_queue *q, struct request *rq)
* drained for flush sequence.
*/
if (unlikely(q->ordseq)) {
- struct request *first_rq = list_entry_rq(q->queue_head.next);
- if (q->in_flight == 0 &&
+ struct request *next = NULL;
+
+ if (!list_empty(&q->queue_head))
+ next = list_entry_rq(q->queue_head.next);
+
+ if (!q->in_flight &&
blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
- blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
+ (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
blk_start_queueing(q);
}