@@ -1067,9 +1067,8 @@ static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q,
* @q: request_queue new bio is being queued at
* @bio: new bio being queued
* @nr_segs: number of segments in @bio
- * @same_queue_rq: pointer to &struct request that gets filled in when
- * another request associated with @q is found on the plug list
- * (optional, may be %NULL)
+ * @same_queue_rq: output value, will be true if there's an existing request
+ * from the passed in @q already in the plug list
*
* Determine whether @bio being queued on @q can be merged with the previous
* request on %current's plugged list. Returns %true if merge was successful,
@@ -1085,7 +1084,7 @@ static enum bio_merge_status blk_attempt_bio_merge(struct request_queue *q,
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- unsigned int nr_segs, struct request **same_queue_rq)
+ unsigned int nr_segs, bool *same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
@@ -1096,12 +1095,12 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
/* check the previously added entry for a quick merge attempt */
rq = list_last_entry(&plug->mq_list, struct request, queuelist);
- if (rq->q == q && same_queue_rq) {
+ if (rq->q == q) {
/*
* Only blk-mq multiple hardware queues case checks the rq in
* the same queue, there should be only one such rq in a queue
*/
- *same_queue_rq = rq;
+ *same_queue_rq = true;
}
if (blk_attempt_bio_merge(q, rq, bio, nr_segs, false) == BIO_MERGE_OK)
return true;
@@ -2422,7 +2422,7 @@ void blk_mq_submit_bio(struct bio *bio)
const int is_flush_fua = op_is_flush(bio->bi_opf);
struct request *rq;
struct blk_plug *plug;
- struct request *same_queue_rq = NULL;
+ bool same_queue_rq = false;
unsigned int nr_segs = 1;
blk_status_t ret;
@@ -2515,6 +2515,8 @@ void blk_mq_submit_bio(struct bio *bio)
/* Insert the request at the IO scheduler queue */
blk_mq_sched_insert_request(rq, false, true, true);
} else if (plug && !blk_queue_nomerges(q)) {
+ struct request *next_rq = NULL;
+
/*
* We do limited plugging. If the bio can be merged, do that.
* Otherwise the existing request in the plug list will be
@@ -2522,19 +2524,19 @@ void blk_mq_submit_bio(struct bio *bio)
* The plug list might get flushed before this. If that happens,
* the plug list is empty, and same_queue_rq is invalid.
*/
- if (list_empty(&plug->mq_list))
- same_queue_rq = NULL;
if (same_queue_rq) {
- list_del_init(&same_queue_rq->queuelist);
+ next_rq = list_last_entry(&plug->mq_list,
+ struct request,
+ queuelist);
+ list_del_init(&next_rq->queuelist);
plug->rq_count--;
}
blk_add_rq_to_plug(plug, rq);
trace_block_plug(q);
- if (same_queue_rq) {
+ if (next_rq) {
trace_block_unplug(q, 1, true);
- blk_mq_try_issue_directly(same_queue_rq->mq_hctx,
- same_queue_rq);
+ blk_mq_try_issue_directly(next_rq->mq_hctx, next_rq);
}
} else if ((q->nr_hw_queues > 1 && is_sync) ||
!rq->mq_hctx->dispatch_busy) {
@@ -218,7 +218,7 @@ void blk_add_timer(struct request *req);
void blk_print_req_error(struct request *req, blk_status_t status);
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- unsigned int nr_segs, struct request **same_queue_rq);
+ unsigned int nr_segs, bool *same_queue_rq);
bool blk_bio_list_merge(struct request_queue *q, struct list_head *list,
struct bio *bio, unsigned int nr_segs);
Instead of returning the same queue request through a request pointer, use a boolean to accomplish the same. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/blk-merge.c | 11 +++++------ block/blk-mq.c | 16 +++++++++------- block/blk.h | 2 +- 3 files changed, 15 insertions(+), 14 deletions(-)