target: simplify code around transport_get_sense_data

The error conditions in transport_get_sense_data are superfluous
and complicate the code unnecessarily:

* SCF_TRANSPORT_TASK_SENSE is checked in the caller;

* it's simply part of the invariants of dev->transport->get_sense_buffer
  that it must be there if transport_complete ever returns 1, and that
  it must not return NULL.  Besides, the entire callback will disappear
  with the next patch.

* similarly in the caller we can expect that sense data is only sent
  for non-zero cmd->scsi_status.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 13 insertions, 36 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index d0afdaa0625..040f05fde4d 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -570,7 +570,7 @@ static void target_complete_failure_work(struct work_struct *work)
 /*
  * Used to obtain Sense Data from underlying Linux/SCSI struct scsi_cmnd
  */
-static int transport_get_sense_data(struct se_cmd *cmd)
+static void transport_get_sense_data(struct se_cmd *cmd)
 {
         unsigned char *buffer = cmd->sense_buffer, *sense_buffer = NULL;
         struct se_device *dev = cmd->se_dev;
@@ -580,30 +580,15 @@ static int transport_get_sense_data(struct se_cmd *cmd)
         WARN_ON(!cmd->se_lun);
 
         if (!dev)
-                return 0;
+                return;
 
         spin_lock_irqsave(&cmd->t_state_lock, flags);
         if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
                 spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-                return 0;
-        }
-
-        if (!(cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
-                goto out;
-
-        if (!dev->transport->get_sense_buffer) {
-                pr_err("dev->transport->get_sense_buffer is NULL\n");
-                goto out;
+                return;
         }
 
         sense_buffer = dev->transport->get_sense_buffer(cmd);
-        if (!sense_buffer) {
-                pr_err("ITT 0x%08x cmd %p: Unable to locate"
-                        " sense buffer for task with sense\n",
-                        cmd->se_tfo->get_task_tag(cmd), cmd);
-                goto out;
-        }
-
         spin_unlock_irqrestore(&cmd->t_state_lock, flags);
 
         offset = cmd->se_tfo->set_fabric_sense_len(cmd, TRANSPORT_SENSE_BUFFER);
@@ -615,11 +600,6 @@ static int transport_get_sense_data(struct se_cmd *cmd)
 
         pr_debug("HBA_[%u]_PLUG[%s]: Set SAM STATUS: 0x%02x and sense\n",
                 dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
-        return 0;
-
-out:
-        spin_unlock_irqrestore(&cmd->t_state_lock, flags);
-        return -1;
 }
 
 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
@@ -1990,7 +1970,7 @@ static void transport_handle_queue_full(
 static void target_complete_ok_work(struct work_struct *work)
 {
         struct se_cmd *cmd = container_of(work, struct se_cmd, work);
-        int reason = 0, ret;
+        int ret;
 
         /*
          * Check if we need to move delayed/dormant tasks from cmds on the
@@ -2011,19 +1991,16 @@ static void target_complete_ok_work(struct work_struct *work)
          * the struct se_cmd in question.
          */
         if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
-                if (transport_get_sense_data(cmd) < 0)
-                        reason = TCM_NON_EXISTENT_LUN;
-
-                if (cmd->scsi_status) {
-                        ret = transport_send_check_condition_and_sense(
-                                        cmd, reason, 1);
-                        if (ret == -EAGAIN || ret == -ENOMEM)
-                                goto queue_full;
+                WARN_ON(!cmd->scsi_status);
+                transport_get_sense_data(cmd);
+                ret = transport_send_check_condition_and_sense(
+                                        cmd, 0, 1);
+                if (ret == -EAGAIN || ret == -ENOMEM)
+                        goto queue_full;
 
-                        transport_lun_remove_cmd(cmd);
-                        transport_cmd_check_stop_to_fabric(cmd);
-                        return;
-                }
+                transport_lun_remove_cmd(cmd);
+                transport_cmd_check_stop_to_fabric(cmd);
+                return;
         }
         /*
          * Check for a callback, used by amongst other things