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-rw-r--r--block/blk-barrier.c16
-rw-r--r--block/elevator.c8
-rw-r--r--include/linux/blkdev.h1
3 files changed, 10 insertions, 15 deletions
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index b03d880..c63044e 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
diff --git a/block/elevator.c b/block/elevator.c
index 261ffaa..ff60177 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -755,14 +755,6 @@ struct request *elv_next_request(struct request_queue *q)
int ret;
while ((rq = __elv_next_request(q)) != NULL) {
- /*
- * Kill the empty barrier place holder, the driver must
- * not ever see it.
- */
- if (blk_empty_barrier(rq)) {
- __blk_end_request(rq, 0, blk_rq_bytes(rq));
- continue;
- }
if (!(rq->cmd_flags & REQ_STARTED)) {
/*
* This is the first time the device driver
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 3c7078e..41bbadf 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -596,7 +596,6 @@ enum {
#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
#define blk_discard_rq(rq) ((rq)->cmd_flags & REQ_DISCARD)
#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
-#define blk_empty_barrier(rq) (blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
/* rq->queuelist of dequeued request must be list_empty() */
#define blk_queued_rq(rq) (!list_empty(&(rq)->queuelist))
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