scsi: introduce a result field in struct scsi_request

This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

7 files changed, 18 insertions, 19 deletions

diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 5eeab7047d1e..8a1b94816419 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -477,7 +477,7 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
 			     int error)
 {
 	or->async_error = error;
-	or->req_errors = req->errors ? : error;
+	or->req_errors = scsi_req(req)->result ? : error;
 	or->sense_len = scsi_req(req)->sense_len;
 	if (or->sense_len)
 		memcpy(or->sense, scsi_req(req)->sense, or->sense_len);
@@ -492,7 +492,7 @@ int osd_execute_request(struct osd_request *or)
 	int error;
 
 	blk_execute_rq(or->request->q, NULL, or->request, 0);
-	error = or->request->errors ? -EIO : 0;
+	error = scsi_req(or->request)->result ? -EIO : 0;
 
 	_set_error_resid(or, or->request, error);
 	return error;
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 41bc1d64bf86..67cbed92f07d 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -327,7 +327,7 @@ static void osst_end_async(struct request *req, int update)
 	struct osst_tape *STp = SRpnt->stp;
 	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 #if DEBUG
 	STp->write_pending = 0;
 #endif
diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c
index 84c9098cc089..b6e40fd4c3c1 100644
--- a/drivers/scsi/qla2xxx/qla_bsg.c
+++ b/drivers/scsi/qla2xxx/qla_bsg.c
@@ -2553,13 +2553,13 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 						ql_log(ql_log_warn, vha, 0x7089,
 						    "mbx abort_command "
 						    "failed.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = -EIO;
 					} else {
 						ql_dbg(ql_dbg_user, vha, 0x708a,
 						    "mbx abort_command "
 						    "success.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = 0;
 					}
 					spin_lock_irqsave(&ha->hardware_lock, flags);
@@ -2570,7 +2570,7 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 	}
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 	ql_log(ql_log_info, vha, 0x708b, "SRB not found to abort.\n");
-	bsg_job->req->errors = bsg_reply->result = -ENXIO;
+	scsi_req(bsg_job->req)->result = bsg_reply->result = -ENXIO;
 	return 0;
 
 done:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7bc4513bf4e4..b9298a499e19 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -229,8 +229,8 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @rq_flags:	flags for ->rq_flags
  * @resid:	optional residual length
  *
- * returns the req->errors value which is the scsi_cmnd result
- * field.
+ * Returns the scsi_cmnd result field if a command was executed, or a negative
+ * Linux error code if we didn't get that far.
  */
 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		 int data_direction, void *buffer, unsigned bufflen,
@@ -281,7 +281,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 	if (sshdr)
 		scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
-	ret = req->errors;
+	ret = rq->result;
  out:
 	blk_put_request(req);
 
@@ -797,8 +797,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		/*
 		 * __scsi_error_from_host_byte may have reset the host_byte
 		 */
-		req->errors = cmd->result;
-
+		scsi_req(req)->result = cmd->result;
 		scsi_req(req)->resid_len = scsi_get_resid(cmd);
 
 		if (scsi_bidi_cmnd(cmd)) {
@@ -835,7 +834,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 	/*
 	 * Recovered errors need reporting, but they're always treated as
 	 * success, so fiddle the result code here.  For passthrough requests
-	 * we already took a copy of the original into rq->errors which
+	 * we already took a copy of the original into sreq->result which
 	 * is what gets returned to the user
 	 */
 	if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
@@ -1281,7 +1280,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 	switch (ret) {
 	case BLKPREP_KILL:
 	case BLKPREP_INVALID:
-		req->errors = DID_NO_CONNECT << 16;
+		scsi_req(req)->result = DID_NO_CONNECT << 16;
 		/* release the command and kill it */
 		if (req->special) {
 			struct scsi_cmnd *cmd = req->special;
@@ -1905,7 +1904,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, cmd->request->errors);
+	blk_mq_complete_request(cmd->request, 0);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index cdbb293aca08..a2b279737a4b 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -184,7 +184,7 @@ static void sas_smp_request(struct request_queue *q, struct Scsi_Host *shost,
 				blk_rq_bytes(req->next_rq);
 		handler = to_sas_internal(shost->transportt)->f->smp_handler;
 		ret = handler(shost, rphy, req);
-		req->errors = ret;
+		scsi_req(req)->result = ret;
 
 		blk_end_request_all(req, ret);
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index b61cc3c512d3..90ee9d926deb 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1298,7 +1298,7 @@ sg_rq_end_io(struct request *rq, int uptodate)
 		pr_info("%s: device detaching\n", __func__);
 
 	sense = req->sense;
-	result = rq->errors;
+	result = req->result;
 	resid = req->resid_len;
 
 	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 5408643431bb..1ea34d6f5437 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -480,7 +480,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->write_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_write_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->write_byte_cnt);
@@ -494,7 +494,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->read_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_read_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->read_byte_cnt);
@@ -518,7 +518,7 @@ static void st_scsi_execute_end(struct request *req, int uptodate)
 	struct scsi_tape *STp = SRpnt->stp;
 	struct bio *tmp;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 	STp->buffer->cmdstat.residual = rq->resid_len;
 
 	st_do_stats(STp, req);