The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From be549d49115422f846b6d96ee8fd7173a5f7ceb0 Mon Sep 17 00:00:00 2001

From: Jaesoo Lee jalee@purestorage.com Date: Tue, 9 Apr 2019 17:02:22 -0700 Subject: [PATCH] scsi: core: set result when the command cannot be dispatched

When SCSI blk-mq is enabled, there is a bug in handling errors in scsi_queue_rq. Specifically, the bug is not setting result field of scsi_request correctly when the dispatch of the command has been failed. Since the upper layer code including the sg_io ioctl expects to receive any error status from result field of scsi_request, the error is silently ignored and this could cause data corruptions for some applications.

Fixes: d285203cf647 ("scsi: add support for a blk-mq based I/O path.") Cc: stable@vger.kernel.org Signed-off-by: Jaesoo Lee jalee@purestorage.com Reviewed-by: Hannes Reinecke hare@suse.com Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 601b9f1de267..07dfc17d4824 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1706,8 +1706,12 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx, ret = BLK_STS_DEV_RESOURCE; break; default: + if (unlikely(!scsi_device_online(sdev))) + scsi_req(req)->result = DID_NO_CONNECT << 16; + else + scsi_req(req)->result = DID_ERROR << 16; /* - * Make sure to release all allocated ressources when + * Make sure to release all allocated resources when * we hit an error, as we will never see this command * again. */