flush request is special, which borrows tag from other request. Need a special handling to get it from tag.
Signed-off-by: Shaohua Li <[email protected]> --- block/blk-flush.c | 4 +++- block/blk-mq.c | 13 +++++++++++-- drivers/block/mtip32xx/mtip32xx.c | 2 +- include/linux/blk-mq.h | 3 ++- include/linux/blkdev.h | 1 + 5 files changed, 18 insertions(+), 5 deletions(-) Index: linux/block/blk-flush.c =================================================================== --- linux.orig/block/blk-flush.c 2014-05-09 19:52:25.360415014 +0800 +++ linux/block/blk-flush.c 2014-05-09 19:53:59.795228450 +0800 @@ -231,8 +231,10 @@ static void flush_end_io(struct request struct request *rq, *n; unsigned long flags = 0; - if (q->mq_ops) + if (q->mq_ops) { spin_lock_irqsave(&q->mq_flush_lock, flags); + q->flush_rq_tag_valid = false; + } running = &q->flush_queue[q->flush_running_idx]; BUG_ON(q->flush_pending_idx == q->flush_running_idx); Index: linux/block/blk-mq.c =================================================================== --- linux.orig/block/blk-mq.c 2014-05-09 19:52:25.360415014 +0800 +++ linux/block/blk-mq.c 2014-05-09 19:57:58.432227506 +0800 @@ -336,6 +336,8 @@ void blk_mq_clone_flush_request(struct r flush_rq->mq_ctx = orig_rq->mq_ctx; flush_rq->tag = orig_rq->tag; + smp_wmb(); + orig_rq->q->flush_rq_tag_valid = true; memcpy(blk_mq_rq_to_pdu(flush_rq), blk_mq_rq_to_pdu(orig_rq), hctx->cmd_size); } @@ -481,8 +483,14 @@ void blk_mq_requeue_request(struct reque } EXPORT_SYMBOL(blk_mq_requeue_request); -struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag) +struct request *blk_mq_tag_to_rq(struct request_queue *q, + struct blk_mq_tags *tags, unsigned int tag) { + if (q->flush_rq_tag_valid) { + smp_rmb(); + if (q->flush_rq->tag == tag) + return q->flush_rq; + } return tags->rqs[tag]; } EXPORT_SYMBOL(blk_mq_tag_to_rq); @@ -512,7 +520,7 @@ static void blk_mq_timeout_check(void *_ if (tag >= hctx->tags->nr_tags) break; - rq = blk_mq_tag_to_rq(hctx->tags, tag++); + rq = blk_mq_tag_to_rq(hctx->queue, hctx->tags, tag++); if (rq->q != hctx->queue) continue; if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) @@ -1510,6 +1518,7 @@ struct request_queue *blk_mq_init_queue( GFP_KERNEL); if (!q->flush_rq) goto err_hw; + q->flush_rq_tag_valid = false; if (blk_mq_init_hw_queues(q, set)) goto err_flush_rq; Index: linux/include/linux/blk-mq.h =================================================================== --- linux.orig/include/linux/blk-mq.h 2014-05-09 19:52:25.360415014 +0800 +++ linux/include/linux/blk-mq.h 2014-05-09 19:52:25.352415140 +0800 @@ -149,7 +149,8 @@ void blk_mq_free_request(struct request bool blk_mq_can_queue(struct blk_mq_hw_ctx *); struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp); struct request *blk_mq_alloc_reserved_request(struct request_queue *q, int rw, gfp_t gfp); -struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag); +struct request *blk_mq_tag_to_rq(struct request_queue *q, + struct blk_mq_tags *tags, unsigned int tag); struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *, const int ctx_index); struct blk_mq_hw_ctx *blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set *, unsigned int); Index: linux/drivers/block/mtip32xx/mtip32xx.c =================================================================== --- linux.orig/drivers/block/mtip32xx/mtip32xx.c 2014-05-09 19:52:25.360415014 +0800 +++ linux/drivers/block/mtip32xx/mtip32xx.c 2014-05-09 19:52:25.352415140 +0800 @@ -195,7 +195,7 @@ static struct request *mtip_rq_from_tag( { struct blk_mq_hw_ctx *hctx = dd->queue->queue_hw_ctx[0]; - return blk_mq_tag_to_rq(hctx->tags, tag); + return blk_mq_tag_to_rq(dd->queue, hctx->tags, tag); } static struct mtip_cmd *mtip_cmd_from_tag(struct driver_data *dd, Index: linux/include/linux/blkdev.h =================================================================== --- linux.orig/include/linux/blkdev.h 2014-05-09 19:42:28.000000000 +0800 +++ linux/include/linux/blkdev.h 2014-05-09 19:53:07.591883317 +0800 @@ -461,6 +461,7 @@ struct request_queue { struct list_head flush_queue[2]; struct list_head flush_data_in_flight; struct request *flush_rq; + bool flush_rq_tag_valid; spinlock_t mq_flush_lock; struct mutex sysfs_lock; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
