Hello, This is the test results. 0. Kernel configs Version: 5.1-rc1 Boot parameter: dm_mod.use_blk_mq=Y scsi_mod.use_blk_mq=Y 1. Normal state : (As expected) The command succeeded $ sg_write_same --lba=100 --xferlen=512 /dev/sg5 $ 2. Immediately after bringing down the iSCSI interface at the target : (As expected) Failed with DID_TRANSPORT_DISRUPTED after a few seconds $ sg_write_same --lba=100 --xferlen=512 /dev/sg5 Write same: transport: Host_status=0x0e [DID_TRANSPORT_DISRUPTED] Driver_status=0x00 [DRIVER_OK, SUGGEST_OK] Write same(10) command failed 3. Immediately after the DID_TRANSPORT_DISRUPTED error : (As expected) Failed with DID_NO_CONNECT after a few seconds $ sg_write_same --lba=100 --xferlen=512 /dev/sg5 Write same: transport: Host_status=0x01 [DID_NO_CONNECT] Driver_status=0x00 [DRIVER_OK, SUGGEST_OK] Write same(10) command failed 4. Issued IO again : (As expected) The command failed $ sg_write_same --lba=100 --xferlen=512 /dev/sg5 Write same: pass through os error: No such device or address Write same(10) command failed Thanks, Jaesoo Lee. On Tue, Apr 9, 2019 at 2:53 PM Jaesoo Lee <jalee@xxxxxxxxxxxxxxx> wrote: > > 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. This commit also fixes another bug that the > result field is not initialized when scsi_request is allocated. > > Signed-off-by: Jaesoo Lee <jalee@xxxxxxxxxxxxxxx> > --- > block/scsi_ioctl.c | 1 + > drivers/scsi/scsi_lib.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c > index 533f4ae..f2d7979 100644 > --- a/block/scsi_ioctl.c > +++ b/block/scsi_ioctl.c > @@ -723,6 +723,7 @@ void scsi_req_init(struct scsi_request *req) > req->cmd = req->__cmd; > req->cmd_len = BLK_MAX_CDB; > req->sense_len = 0; > + req->result = 0; > } > EXPORT_SYMBOL(scsi_req_init); > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > index 2018967..af1488d 100644 > --- a/drivers/scsi/scsi_lib.c > +++ b/drivers/scsi/scsi_lib.c > @@ -1699,6 +1699,7 @@ static blk_status_t scsi_queue_rq(struct > blk_mq_hw_ctx *hctx, > ret = BLK_STS_DEV_RESOURCE; > break; > default: > + scsi_req(req)->result = DID_NO_CONNECT << 16; > /* > * Make sure to release all allocated ressources when > * we hit an error, as we will never see this command > -- > 2.7.4
