target: simplify XCOPY wwn->se_dev lookup helper

target_xcopy_locate_se_dev_e4() is used to locate an se_dev, based on
the WWN provided with the XCOPY request. Remove a couple of unneeded
arguments, and rely on the caller for the src/dst test.

Signed-off-by: David Disseldorp <ddiss@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>

drivers/target/target_core_xcopy.c

@@ -53,18 +53,13 @@ static int target_xcopy_gen_naa_ieee(struct se_device *dev, unsigned char *buf)
 	return 0;
 }
 
-static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
-					bool src)
+static int target_xcopy_locate_se_dev_e4(const unsigned char *dev_wwn,
+					struct se_device **found_dev)
 {
 	struct se_device *se_dev;
-	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN], *dev_wwn;
+	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
 	int rc;
 
-	if (src)
-		dev_wwn = &xop->dst_tid_wwn[0];
-	else
-		dev_wwn = &xop->src_tid_wwn[0];
-
 	mutex_lock(&g_device_mutex);
 	list_for_each_entry(se_dev, &g_device_list, g_dev_node) {
 
@@ -78,15 +73,8 @@ static int target_xcopy_locate_se_dev_e4(struct se_cmd *se_cmd, struct xcopy_op
 		if (rc != 0)
 			continue;
 
-		if (src) {
-			xop->dst_dev = se_dev;
-			pr_debug("XCOPY 0xe4: Setting xop->dst_dev: %p from located"
-				" se_dev\n", xop->dst_dev);
-		} else {
-			xop->src_dev = se_dev;
-			pr_debug("XCOPY 0xe4: Setting xop->src_dev: %p from located"
-				" se_dev\n", xop->src_dev);
-		}
+		*found_dev = se_dev;
+		pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);
 
 		rc = target_depend_item(&se_dev->dev_group.cg_item);
 		if (rc != 0) {
@@ -247,9 +235,11 @@ static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
 	}
 
 	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
-		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, true);
+		rc = target_xcopy_locate_se_dev_e4(xop->dst_tid_wwn,
+						&xop->dst_dev);
 	else
-		rc = target_xcopy_locate_se_dev_e4(se_cmd, xop, false);
+		rc = target_xcopy_locate_se_dev_e4(xop->src_tid_wwn,
+						&xop->src_dev);
 	/*
 	 * If a matching IEEE NAA 0x83 descriptor for the requested device
 	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC