diff --git a/block/blk-core.c b/block/blk-core.c index 7ba607527487..55f338020254 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2500,8 +2500,7 @@ blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request * * bypass a potential scheduler on the bottom device for * insert. */ - blk_mq_request_bypass_insert(rq, true); - return BLK_STS_OK; + return blk_mq_request_direct_issue(rq); } spin_lock_irqsave(q->queue_lock, flags); diff --git a/block/blk-mq.c b/block/blk-mq.c index ddc46f215bfa..e383a20809f4 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1775,15 +1775,19 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx, static void __blk_mq_fallback_to_insert(struct blk_mq_hw_ctx *hctx, struct request *rq, - bool run_queue) + bool run_queue, bool bypass_insert) { - blk_mq_sched_insert_request(rq, false, run_queue, false, - hctx->flags & BLK_MQ_F_BLOCKING); + if (!bypass_insert) + blk_mq_sched_insert_request(rq, false, run_queue, false, + hctx->flags & BLK_MQ_F_BLOCKING); + else + blk_mq_request_bypass_insert(rq, run_queue); } static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, struct request *rq, - blk_qc_t *cookie) + blk_qc_t *cookie, + bool bypass_insert) { struct request_queue *q = rq->q; bool run_queue = true; @@ -1794,7 +1798,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, goto insert; } - if (q->elevator) + if (q->elevator && !bypass_insert) goto insert; if (!blk_mq_get_driver_tag(rq, NULL, false)) @@ -1807,7 +1811,9 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, return __blk_mq_issue_directly(hctx, rq, cookie); insert: - __blk_mq_fallback_to_insert(hctx, rq, run_queue); + __blk_mq_fallback_to_insert(hctx, rq, run_queue, bypass_insert); + if (bypass_insert) + return BLK_STS_RESOURCE; return BLK_STS_OK; } @@ -1822,15 +1828,30 @@ 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); + ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false); if (ret == BLK_STS_RESOURCE) - __blk_mq_fallback_to_insert(hctx, rq, true); + __blk_mq_fallback_to_insert(hctx, rq, true, false); else if (ret != BLK_STS_OK) blk_mq_end_request(rq, ret); hctx_unlock(hctx, srcu_idx); } +blk_status_t blk_mq_request_direct_issue(struct request *rq) +{ + blk_status_t ret; + int srcu_idx; + blk_qc_t unused_cookie; + struct blk_mq_ctx *ctx = rq->mq_ctx; + struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu); + + hctx_lock(hctx, &srcu_idx); + ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true); + hctx_unlock(hctx, srcu_idx); + + return ret; +} + static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio) { const int is_sync = op_is_sync(bio->bi_opf); diff --git a/block/blk-mq.h b/block/blk-mq.h index 8591a54d989b..e3ebc93646ca 100644 --- a/block/blk-mq.h +++ b/block/blk-mq.h @@ -74,6 +74,9 @@ void blk_mq_request_bypass_insert(struct request *rq, bool run_queue); 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_direct_issue(struct request *rq); + /* * CPU -> queue mappings */ diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c index c28357f5cb0e..b7d175e94a02 100644 --- a/drivers/md/dm-rq.c +++ b/drivers/md/dm-rq.c @@ -395,7 +395,7 @@ static void end_clone_request(struct request *clone, blk_status_t error) dm_complete_request(tio->orig, error); } -static void dm_dispatch_clone_request(struct request *clone, struct request *rq) +static blk_status_t dm_dispatch_clone_request(struct request *clone, struct request *rq) { blk_status_t r; @@ -404,9 +404,10 @@ static void dm_dispatch_clone_request(struct request *clone, struct request *rq) clone->start_time = jiffies; r = blk_insert_cloned_request(clone->q, clone); - if (r) + if (r != BLK_STS_OK && r != BLK_STS_RESOURCE) /* must complete clone in terms of original request */ dm_complete_request(rq, r); + return r; } static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig, @@ -476,8 +477,10 @@ static int map_request(struct dm_rq_target_io *tio) struct mapped_device *md = tio->md; struct request *rq = tio->orig; struct request *clone = NULL; + blk_status_t ret; r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone); +check_again: switch (r) { case DM_MAPIO_SUBMITTED: /* The target has taken the I/O to submit by itself later */ @@ -492,7 +495,17 @@ static int map_request(struct dm_rq_target_io *tio) /* The target has remapped the I/O so dispatch it */ trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)), blk_rq_pos(rq)); - dm_dispatch_clone_request(clone, rq); + ret = dm_dispatch_clone_request(clone, rq); + if (ret == BLK_STS_RESOURCE) { + blk_rq_unprep_clone(clone); + tio->ti->type->release_clone_rq(clone); + tio->clone = NULL; + if (!rq->q->mq_ops) + r = DM_MAPIO_DELAY_REQUEUE; + else + r = DM_MAPIO_REQUEUE; + goto check_again; + } break; case DM_MAPIO_REQUEUE: /* The target wants to requeue the I/O */