unsigned int depth;
list_splice_init(&plug->mq_list, &list);
- plug->rq_count = 0;
if (plug->rq_count > 2 && plug->multiple_queues)
list_sort(NULL, &list, plug_rq_cmp);
+ plug->rq_count = 0;
+
this_q = NULL;
this_hctx = NULL;
this_ctx = NULL;
return ret;
}
-blk_status_t blk_mq_try_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, bool last)
+ bool bypass_insert, bool last)
{
struct request_queue *q = rq->q;
bool run_queue = true;
- blk_status_t ret = BLK_STS_RESOURCE;
- int srcu_idx;
- bool force = false;
- hctx_lock(hctx, &srcu_idx);
/*
- * hctx_lock is needed before checking quiesced flag.
+ * RCU or SRCU read lock is needed before checking quiesced flag.
*
- * When queue is stopped or quiesced, ignore 'bypass', insert
- * and return BLK_STS_OK to caller, and avoid driver to try to
- * dispatch again.
+ * When queue is stopped or quiesced, ignore 'bypass_insert' from
+ * blk_mq_request_issue_directly(), and return BLK_STS_OK to caller,
+ * and avoid driver to try to dispatch again.
*/
- if (unlikely(blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q))) {
+ if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) {
run_queue = false;
- bypass = false;
- goto out_unlock;
+ bypass_insert = false;
+ goto insert;
}
- if (unlikely(q->elevator && !bypass))
- goto out_unlock;
+ if (q->elevator && !bypass_insert)
+ goto insert;
if (!blk_mq_get_dispatch_budget(hctx))
- goto out_unlock;
+ goto insert;
if (!blk_mq_get_driver_tag(rq)) {
blk_mq_put_dispatch_budget(hctx);
- goto out_unlock;
+ goto insert;
}
- /*
- * Always add a request that has been through
- *.queue_rq() to the hardware dispatch list.
- */
- force = true;
- ret = __blk_mq_issue_directly(hctx, rq, cookie, last);
-out_unlock:
+ return __blk_mq_issue_directly(hctx, rq, cookie, last);
+insert:
+ if (bypass_insert)
+ return BLK_STS_RESOURCE;
+
+ blk_mq_request_bypass_insert(rq, run_queue);
+ return BLK_STS_OK;
+}
+
+static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, blk_qc_t *cookie)
+{
+ blk_status_t ret;
+ int srcu_idx;
+
+ might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
+
+ hctx_lock(hctx, &srcu_idx);
+
+ ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false, true);
+ if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
+ blk_mq_request_bypass_insert(rq, true);
+ else if (ret != BLK_STS_OK)
+ blk_mq_end_request(rq, ret);
+
+ hctx_unlock(hctx, srcu_idx);
+}
+
+blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
+{
+ blk_status_t ret;
+ int srcu_idx;
+ blk_qc_t unused_cookie;
+ 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, last);
hctx_unlock(hctx, srcu_idx);
- switch (ret) {
- case BLK_STS_OK:
- break;
- case BLK_STS_DEV_RESOURCE:
- case BLK_STS_RESOURCE:
- if (force) {
- blk_mq_request_bypass_insert(rq, run_queue);
- /*
- * We have to return BLK_STS_OK for the DM
- * to avoid livelock. Otherwise, we return
- * the real result to indicate whether the
- * request is direct-issued successfully.
- */
- ret = bypass ? BLK_STS_OK : ret;
- } else if (!bypass) {
- blk_mq_sched_insert_request(rq, false,
- run_queue, false);
- }
- break;
- default:
- if (!bypass)
- blk_mq_end_request(rq, ret);
- break;
- }
return ret;
}
void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
struct list_head *list)
{
- blk_qc_t unused;
- blk_status_t ret = BLK_STS_OK;
-
while (!list_empty(list)) {
+ blk_status_t ret;
struct request *rq = list_first_entry(list, struct request,
queuelist);
list_del_init(&rq->queuelist);
- if (ret == BLK_STS_OK)
- ret = blk_mq_try_issue_directly(hctx, rq, &unused,
- false,
+ 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) {
+ blk_mq_request_bypass_insert(rq,
list_empty(list));
- else
- blk_mq_sched_insert_request(rq, false, true, false);
+ break;
+ }
+ blk_mq_end_request(rq, ret);
+ }
}
/*
* the driver there was more coming, but that turned out to
* be a lie.
*/
- if (ret != BLK_STS_OK && hctx->queue->mq_ops->commit_rqs)
+ if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs)
hctx->queue->mq_ops->commit_rqs(hctx);
}
plug->rq_count--;
}
blk_add_rq_to_plug(plug, rq);
+ trace_block_plug(q);
blk_mq_put_ctx(data.ctx);
if (same_queue_rq) {
data.hctx = same_queue_rq->mq_hctx;
+ trace_block_unplug(q, 1, true);
blk_mq_try_issue_directly(data.hctx, same_queue_rq,
- &cookie, false, true);
+ &cookie);
}
} else if ((q->nr_hw_queues > 1 && is_sync) || (!q->elevator &&
!data.hctx->dispatch_busy)) {
blk_mq_put_ctx(data.ctx);
blk_mq_bio_to_request(rq, bio);
- blk_mq_try_issue_directly(data.hctx, rq, &cookie, false, true);
+ blk_mq_try_issue_directly(data.hctx, rq, &cookie);
} else {
blk_mq_put_ctx(data.ctx);
blk_mq_bio_to_request(rq, bio);
return 0;
free_fq:
- kfree(hctx->fq);
+ blk_free_flush_queue(hctx->fq);
exit_hctx:
if (set->ops->exit_hctx)
set->ops->exit_hctx(hctx, hctx_idx);
projects / linux.git / blobdiff