blk-mq: use bd->last == true for list inserts

If we are issuing a list of requests, we know if we're at the last one.
If we fail issuing, ensure that we call ->commits_rqs() to flush any
potential previous requests.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-core.c b/block/blk-core.c
index d107d016b92b11eefa969ab910bb213143004962..3f6f5e6c2fe43cd9ef667d47d4998c2a54811338 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1334,7 +1334,7 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *
         * bypass a potential scheduler on the bottom device for
         * insert.
         */
-       return blk_mq_request_issue_directly(rq);
+       return blk_mq_request_issue_directly(rq, true);
 }
 EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
 

diff --git a/block/blk-mq.c b/block/blk-mq.c
index d8534107bb6fd80453011cc8e033f21a925c36b5..14e31e93a950f6c1ab7997e65e4daae7155e2cf5 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1743,12 +1743,12 @@ static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
 
 static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
                                            struct request *rq,
-                                           blk_qc_t *cookie)
+                                           blk_qc_t *cookie, bool last)
 {
        struct request_queue *q = rq->q;
        struct blk_mq_queue_data bd = {
                .rq = rq,
-               .last = true,
+               .last = last,
        };
        blk_qc_t new_cookie;
        blk_status_t ret;
@@ -1783,7 +1783,7 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
 static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
                                                struct request *rq,
                                                blk_qc_t *cookie,
-                                               bool bypass_insert)
+                                               bool bypass_insert, bool last)
 {
        struct request_queue *q = rq->q;
        bool run_queue = true;
@@ -1812,7 +1812,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
                goto insert;
        }
 
-       return __blk_mq_issue_directly(hctx, rq, cookie);
+       return __blk_mq_issue_directly(hctx, rq, cookie, last);
 insert:
        if (bypass_insert)
                return BLK_STS_RESOURCE;
@@ -1831,7 +1831,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 
        hctx_lock(hctx, &srcu_idx);
 
-       ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false);
+       ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true);
        if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
                blk_mq_sched_insert_request(rq, false, true, false);
        else if (ret != BLK_STS_OK)
@@ -1840,7 +1840,7 @@ static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
        hctx_unlock(hctx, srcu_idx);
 }
 
-blk_status_t blk_mq_request_issue_directly(struct request *rq)
+blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
 {
        blk_status_t ret;
        int srcu_idx;
@@ -1848,7 +1848,7 @@ blk_status_t blk_mq_request_issue_directly(struct request *rq)
        struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
 
        hctx_lock(hctx, &srcu_idx);
-       ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true);
+       ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true, last);
        hctx_unlock(hctx, srcu_idx);
 
        return ret;
@@ -1863,7 +1863,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
                                queuelist);
 
                list_del_init(&rq->queuelist);
-               ret = blk_mq_request_issue_directly(rq);
+               ret = blk_mq_request_issue_directly(rq, list_empty(list));
                if (ret != BLK_STS_OK) {
                        if (ret == BLK_STS_RESOURCE ||
                                        ret == BLK_STS_DEV_RESOURCE) {

diff --git a/block/blk-mq.h b/block/blk-mq.h
index 9ae8e9f8f8b1b69605ed12e107d12da8655cb7e4..7291e5379358e4a302da56ab0597d888c81dbf83 100644 (file)
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -69,7 +69,7 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
                                struct list_head *list);
 
 /* Used by blk_insert_cloned_request() to issue request directly */
-blk_status_t blk_mq_request_issue_directly(struct request *rq);
+blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last);
 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
                                    struct list_head *list);