The built-in flush request shares tag with the request inserted to flush machinery, turns out its .end_io callback has to touch the built-in flush request's internal tag or tag. On the other hand, we have to make sure that driver tag is released from __blk_mq_end_request(), since this request may not be completed via blk_mq_complete_request(). Given we have moved blk_mq_put_driver_tag() out of header file, fix this issue by releasing driver tag before calling .end_io(). Cc: Christoph Hellwig <hch@xxxxxx> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Fixes: 36a3df5a4574("blk-mq: put driver tag when this request is completed") Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- block/blk-mq.c | 46 ++++++++++++++++++++++++---------------------- 1 file changed, 24 insertions(+), 22 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 948987e9b6ab..6b36969220c1 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -532,6 +532,26 @@ void blk_mq_free_request(struct request *rq) } EXPORT_SYMBOL_GPL(blk_mq_free_request); +static void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, + struct request *rq) +{ + blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); + rq->tag = BLK_MQ_NO_TAG; + + if (rq->rq_flags & RQF_MQ_INFLIGHT) { + rq->rq_flags &= ~RQF_MQ_INFLIGHT; + atomic_dec(&hctx->nr_active); + } +} + +static inline void blk_mq_put_driver_tag(struct request *rq) +{ + if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) + return; + + __blk_mq_put_driver_tag(rq->mq_hctx, rq); +} + inline void __blk_mq_end_request(struct request *rq, blk_status_t error) { u64 now = 0; @@ -551,6 +571,7 @@ inline void __blk_mq_end_request(struct request *rq, blk_status_t error) if (rq->end_io) { rq_qos_done(rq->q, rq); + blk_mq_put_driver_tag(rq); rq->end_io(rq, error); } else { blk_mq_free_request(rq); @@ -660,26 +681,6 @@ static inline bool blk_mq_complete_need_ipi(struct request *rq) return cpu_online(rq->mq_ctx->cpu); } -static void __blk_mq_put_driver_tag(struct blk_mq_hw_ctx *hctx, - struct request *rq) -{ - blk_mq_put_tag(hctx->tags, rq->mq_ctx, rq->tag); - rq->tag = BLK_MQ_NO_TAG; - - if (rq->rq_flags & RQF_MQ_INFLIGHT) { - rq->rq_flags &= ~RQF_MQ_INFLIGHT; - atomic_dec(&hctx->nr_active); - } -} - -static inline void blk_mq_put_driver_tag(struct request *rq) -{ - if (rq->tag == BLK_MQ_NO_TAG || rq->internal_tag == BLK_MQ_NO_TAG) - return; - - __blk_mq_put_driver_tag(rq->mq_hctx, rq); -} - bool blk_mq_complete_request_remote(struct request *rq) { WRITE_ONCE(rq->state, MQ_RQ_COMPLETE); @@ -983,9 +984,10 @@ static bool blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, if (blk_mq_req_expired(rq, next)) blk_mq_rq_timed_out(rq, reserved); - if (is_flush_rq(rq, hctx)) + if (is_flush_rq(rq, hctx)) { + blk_mq_put_driver_tag(rq); rq->end_io(rq, 0); - else if (refcount_dec_and_test(&rq->ref)) + } else if (refcount_dec_and_test(&rq->ref)) __blk_mq_free_request(rq); return true; -- 2.25.2