target/user: Use sense_reason_t in tcmu_queue_cmd_ring

BugLink: http://bugs.launchpad.net/bugs/1646204

Instead of using -ERROR-style returns, use sense_reason_t. This lets us
remove tcmu_pass_op(), and return more correct sense values.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
(cherry picked from linux-next commit 02eb924f)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/target/target_core_user.c

@@ -380,7 +380,8 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, size_t cmd_size, size_t d
 	return true;
 }
 
-static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
+static sense_reason_t
+tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 {
 	struct tcmu_dev *udev = tcmu_cmd->tcmu_dev;
 	struct se_cmd *se_cmd = tcmu_cmd->se_cmd;
@@ -394,7 +395,7 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 	bool copy_to_data_area;
 
 	if (test_bit(TCMU_DEV_BIT_BROKEN, &udev->flags))
-		return -EINVAL;
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 
 	/*
 	 * Must be a certain minimum size for response sense info, but
@@ -434,7 +435,7 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 		finish_wait(&udev->wait_cmdr, &__wait);
 		if (!ret) {
 			pr_warn("tcmu: command timed out\n");
-			return -ETIMEDOUT;
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 		}
 
 		spin_lock_irq(&udev->cmdr_lock);
@@ -504,10 +505,11 @@ static int tcmu_queue_cmd_ring(struct tcmu_cmd *tcmu_cmd)
 	mod_timer(&udev->timeout,
 		round_jiffies_up(jiffies + msecs_to_jiffies(TCMU_TIME_OUT)));
 
-	return 0;
+	return TCM_NO_SENSE;
 }
 
-static int tcmu_queue_cmd(struct se_cmd *se_cmd)
+static sense_reason_t
+tcmu_queue_cmd(struct se_cmd *se_cmd)
 {
 	struct se_device *se_dev = se_cmd->se_dev;
 	struct tcmu_dev *udev = TCMU_DEV(se_dev);
@@ -516,10 +518,10 @@ static int tcmu_queue_cmd(struct se_cmd *se_cmd)
 
 	tcmu_cmd = tcmu_alloc_cmd(se_cmd);
 	if (!tcmu_cmd)
-		return -ENOMEM;
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 
 	ret = tcmu_queue_cmd_ring(tcmu_cmd);
-	if (ret < 0) {
+	if (ret != TCM_NO_SENSE) {
 		pr_err("TCMU: Could not queue command\n");
 		spin_lock_irq(&udev->commands_lock);
 		idr_remove(&udev->commands, tcmu_cmd->cmd_id);
@@ -1094,21 +1096,10 @@ static sector_t tcmu_get_blocks(struct se_device *dev)
 		       dev->dev_attrib.block_size);
 }
 
-static sense_reason_t
-tcmu_pass_op(struct se_cmd *se_cmd)
-{
-	int ret = tcmu_queue_cmd(se_cmd);
-
-	if (ret != 0)
-		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
-	else
-		return TCM_NO_SENSE;
-}
-
 static sense_reason_t
 tcmu_parse_cdb(struct se_cmd *cmd)
 {
-	return passthrough_parse_cdb(cmd, tcmu_pass_op);
+	return passthrough_parse_cdb(cmd, tcmu_queue_cmd);
 }
 
 static void tcmu_transport_complete(struct se_cmd *cmd, struct scatterlist *sg,