> On Mar 24, 2017, at 1:39 PM, Jens Axboe <[email protected]> wrote: > > 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. > > Signed-off-by: Jens Axboe <[email protected]> > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index a4546f060e80..e3b09abf9d5b 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -978,7 +978,7 @@ 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 > @@ -989,7 +989,7 @@ 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; > > @@ -1046,6 +1046,7 @@ 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; > @@ -1097,7 +1098,7 @@ 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) >
Thanks this fixed it, you can add Tested-by: Josef Bacik <[email protected]> Thanks, Josef
