Small core patch to fix a corner case bug: we forgot to run the queues to handle starvation in the error exit from the scsi_queue_rq routine, which can lead to hangs on error conditions. The patch is available here: git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi.git scsi-fixes The short changelog is: Ming Lei (1): scsi: core: Run queue in case of I/O resource contention failure And the diffstat: drivers/scsi/scsi_lib.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) With full diff below. James --- diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 0ba7a65e7c8d..06056e9ec333 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -547,6 +547,15 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd) scsi_uninit_cmd(cmd); } +static void scsi_run_queue_async(struct scsi_device *sdev) +{ + if (scsi_target(sdev)->single_lun || + !list_empty(&sdev->host->starved_list)) + kblockd_schedule_work(&sdev->requeue_work); + else + blk_mq_run_hw_queues(sdev->request_queue, true); +} + /* Returns false when no more bytes to process, true if there are more */ static bool scsi_end_request(struct request *req, blk_status_t error, unsigned int bytes) @@ -591,11 +600,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error, __blk_mq_end_request(req, error); - if (scsi_target(sdev)->single_lun || - !list_empty(&sdev->host->starved_list)) - kblockd_schedule_work(&sdev->requeue_work); - else - blk_mq_run_hw_queues(q, true); + scsi_run_queue_async(sdev); percpu_ref_put(&q->q_usage_counter); return false; @@ -1702,6 +1707,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, */ if (req->rq_flags & RQF_DONTPREP) scsi_mq_uninit_cmd(cmd); + scsi_run_queue_async(sdev); break; } return ret;