target: pass sense_reason as a return value

Pass the sense reason as an explicit return value from the I/O submission
path instead of storing it in struct se_cmd and using negative return
values.  This cleans up a lot of the code pathes, and with the sparse
annotations for the new sense_reason_t type allows for much better
error checking.

(nab: Convert spc_emulate_modesense + spc_emulate_modeselect to use
      sense_reason_t with Roland's MODE SELECT changes)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 18 insertions, 25 deletions

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index cf23c46185b2..e6fafc62acae 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1730,7 +1730,7 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
         uint64_t unpacked_lun;
         u64 data_len;
         enum dma_data_direction dir;
-        int ret;
+        sense_reason_t ret;
 
         BUG_ON(!send_ioctx);
 
@@ -1755,12 +1755,10 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
                 break;
         }
 
-        ret = srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len);
-        if (ret) {
+        if (srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len)) {
                 printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
                        srp_cmd->tag);
-                cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
-                cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
+                ret = TCM_INVALID_CDB_FIELD;
                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
                 goto send_sense;
         }
@@ -1769,26 +1767,26 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
         cmd->data_direction = dir;
         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
                                        sizeof(srp_cmd->lun));
-        if (transport_lookup_cmd_lun(cmd, unpacked_lun) < 0) {
+        ret = transport_lookup_cmd_lun(cmd, unpacked_lun);
+        if (ret) {
                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
                 goto send_sense;
         }
         ret = target_setup_cmd_from_cdb(cmd, srp_cmd->cdb);
-        if (ret < 0) {
+        if (ret) {
                 kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
-                if (cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT) {
+                if (ret == TCM_RESERVATION_CONFLICT) {
                         srpt_queue_status(cmd);
                         return 0;
-                } else
-                        goto send_sense;
+                }
+                goto send_sense;
         }
 
         transport_handle_cdb_direct(cmd);
         return 0;
 
 send_sense:
-        transport_send_check_condition_and_sense(cmd, cmd->scsi_sense_reason,
-                                                 0);
+        transport_send_check_condition_and_sense(cmd, ret, 0);
         return -1;
 }
 
@@ -1882,16 +1880,14 @@ static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
         send_ioctx->tag = srp_tsk->tag;
         tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
         if (tcm_tmr < 0) {
-                send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                 send_ioctx->cmd.se_tmr_req->response =
                         TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
-                goto process_tmr;
+                goto fail;
         }
         res = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
         if (res < 0) {
-                send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                 send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
-                goto process_tmr;
+                goto fail;
         }
 
         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_tsk->lun,
@@ -1899,22 +1895,19 @@ static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
         res = transport_lookup_tmr_lun(&send_ioctx->cmd, unpacked_lun);
         if (res) {
                 pr_debug("rejecting TMR for LUN %lld\n", unpacked_lun);
-                send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
                 send_ioctx->cmd.se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
-                goto process_tmr;
+                goto fail;
         }
 
         if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
                 srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
 
-process_tmr:
         kref_get(&send_ioctx->kref);
-        if (!(send_ioctx->cmd.se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
-                transport_generic_handle_tmr(&send_ioctx->cmd);
-        else
-                transport_send_check_condition_and_sense(cmd,
-                                                cmd->scsi_sense_reason, 0);
-
+        transport_generic_handle_tmr(&send_ioctx->cmd);
+        return;
+fail:
+        kref_get(&send_ioctx->kref);
+        transport_send_check_condition_and_sense(cmd, 0, 0); // XXX:
 }
 
 /**