diff options
Diffstat (limited to 'block/blk-barrier.c')
| -rw-r--r-- | block/blk-barrier.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/block/blk-barrier.c b/block/blk-barrier.c index b03d88013e1..c63044e9c4c 100644 --- a/block/blk-barrier.c +++ b/block/blk-barrier.c @@ -162,6 +162,14 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp) q->ordered = q->next_ordered; q->ordseq |= QUEUE_ORDSEQ_STARTED; + /* + * For an empty barrier, there's no actual BAR request, which + * in turn makes POSTFLUSH unnecessary. Mask them off. + */ + if (!rq->hard_nr_sectors) + q->ordered &= ~(QUEUE_ORDERED_DO_BAR | + QUEUE_ORDERED_DO_POSTFLUSH); + /* stash away the original request */ elv_dequeue_request(q, rq); q->orig_bar_rq = rq; @@ -171,13 +179,9 @@ static inline bool start_ordered(struct request_queue *q, struct request **rqp) * Queue ordered sequence. As we stack them at the head, we * need to queue in reverse order. Note that we rely on that * no fs request uses ELEVATOR_INSERT_FRONT and thus no fs - * request gets inbetween ordered sequence. If this request is - * an empty barrier, we don't need to do a postflush ever since - * there will be no data written between the pre and post flush. - * Hence a single flush will suffice. + * request gets inbetween ordered sequence. */ - if ((q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) && - !blk_empty_barrier(q->orig_bar_rq)) { + if (q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) { queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH); rq = &q->post_flush_rq; } else |