.commit_rqs() is supposed to handle partial dispatch when driver may not
see .last of flag passed to .queue_rq().
We have added .commit_rqs() in case of partial dispatch and all consumers
of bd->last have implemented .commit_rqs() callback, so it is perfect to
pass real .last flag of the request list to .queue_rq() instead of faking
it by trying to allocate driver tag for next request in the batching list.
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Cc: Baolin Wang <baolin.wang7@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 24 ++----------------------
1 file changed, 2 insertions(+), 22 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index f064e7923ea5..f8c4b59022d7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1169,16 +1169,6 @@ static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
static void blk_mq_handle_dev_resource(struct request *rq,
struct list_head *list)
{
- struct request *next =
- list_first_entry_or_null(list, struct request, queuelist);
-
- /*
- * If an I/O scheduler has been configured and we got a driver tag for
- * the next request already, free it.
- */
- if (next)
- blk_mq_put_driver_tag(next);
-
list_add(&rq->queuelist, list);
__blk_mq_requeue_request(rq);
}
@@ -1203,7 +1193,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
bool got_budget)
{
struct request_queue *q = hctx->queue;
- struct request *rq, *nxt;
+ struct request *rq;
bool no_tag = false;
int errors, queued;
blk_status_t ret = BLK_STS_OK;
@@ -1254,17 +1244,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
list_del_init(&rq->queuelist);
bd.rq = rq;
-
- /*
- * Flag last if we have no more requests, or if we have more
- * but can't assign a driver tag to it.
- */
- if (list_empty(list))
- bd.last = true;
- else {
- nxt = list_first_entry(list, struct request, queuelist);
- bd.last = !blk_mq_get_driver_tag(nxt);
- }
+ bd.last = !!list_empty(list);
ret = q->mq_ops->queue_rq(hctx, &bd);
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
--
2.25.2
