From 3e8a7069b9ded55d408e3272213a95f07036dfa5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 24 Mar 2017 12:04:19 -0600 Subject: [PATCH] blk-mq: include errors in did_work calculation Currently we return true in blk_mq_dispatch_rq_list() if we queued IO successfully, but we really want to return whether or not the we made progress. Progress includes if we got an error return. If we don't, this can lead to a hang in blk_mq_sched_dispatch_requests() when a driver is draining IO by returning BLK_MQ_QUEUE_ERROR instead of manually ending the IO in error and return BLK_MQ_QUEUE_OK. Tested-by: Josef Bacik Reviewed-by: Bart Van Assche Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/blk-mq.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 5a4a2361053e..e6ac774b0e41 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -987,7 +987,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) struct request *rq; LIST_HEAD(driver_list); struct list_head *dptr; - int queued, ret = BLK_MQ_RQ_QUEUE_OK; + int errors, queued, ret = BLK_MQ_RQ_QUEUE_OK; /* * Start off with dptr being NULL, so we start the first request @@ -998,7 +998,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) /* * Now process all the entries, sending them to the driver. */ - queued = 0; + errors = queued = 0; while (!list_empty(list)) { struct blk_mq_queue_data bd; @@ -1055,6 +1055,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) default: pr_err("blk-mq: bad return on queue: %d\n", ret); case BLK_MQ_RQ_QUEUE_ERROR: + errors++; rq->errors = -EIO; blk_mq_end_request(rq, rq->errors); break; @@ -1106,7 +1107,7 @@ bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list) blk_mq_run_hw_queue(hctx, true); } - return queued != 0; + return (queued + errors) != 0; } static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) -- 2.20.1