svn commit: r350722 - stable/12/sys/cam

[Alexander Motin]

Author: mav
Date: Thu Aug  8 02:08:09 2019
New Revision: 350722
URL: https://svnweb.freebsd.org/changeset/base/350722

Log:
  MFC r349283 (by scottl):
  Refactor xpt_getattr() to make it more readable.  No outwardly
  visible functional changes, though code flow was modified a bit
  internally to lessen the need for goto jumps and chained if
  conditionals.

Modified:
  stable/12/sys/cam/cam_xpt.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/cam/cam_xpt.c
==============================================================================
--- stable/12/sys/cam/cam_xpt.c	Thu Aug  8 02:07:05 2019	(r350721)
+++ stable/12/sys/cam/cam_xpt.c	Thu Aug  8 02:08:09 2019	(r350722)
@@ -1253,6 +1253,7 @@ xpt_getattr(char *buf, size_t len, const char *attr, s
 {
 	int ret = -1, l, o;
 	struct ccb_dev_advinfo cdai;
+	struct scsi_vpd_device_id *did;
 	struct scsi_vpd_id_descriptor *idd;
 
 	xpt_path_assert(path, MA_OWNED);
@@ -1285,31 +1286,36 @@ xpt_getattr(char *buf, size_t len, const char *attr, s
 		cam_release_devq(cdai.ccb_h.path, 0, 0, 0, FALSE);
 	if (cdai.provsiz == 0)
 		goto out;
-	if (cdai.buftype == CDAI_TYPE_SCSI_DEVID) {
+	switch(cdai.buftype) {
+	case CDAI_TYPE_SCSI_DEVID:
+		did = (struct scsi_vpd_device_id *)cdai.buf;
 		if (strcmp(attr, "GEOM::lunid") == 0) {
-			idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-			    cdai.provsiz, scsi_devid_is_lun_naa);
+			idd = scsi_get_devid(did, cdai.provsiz,
+			    scsi_devid_is_lun_naa);
 			if (idd == NULL)
-				idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-				    cdai.provsiz, scsi_devid_is_lun_eui64);
+				idd = scsi_get_devid(did, cdai.provsiz,
+				    scsi_devid_is_lun_eui64);
 			if (idd == NULL)
-				idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-				    cdai.provsiz, scsi_devid_is_lun_uuid);
+				idd = scsi_get_devid(did, cdai.provsiz,
+				    scsi_devid_is_lun_uuid);
 			if (idd == NULL)
-				idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-				    cdai.provsiz, scsi_devid_is_lun_md5);
+				idd = scsi_get_devid(did, cdai.provsiz,
+				    scsi_devid_is_lun_md5);
 		} else
 			idd = NULL;
+
 		if (idd == NULL)
-			idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-			    cdai.provsiz, scsi_devid_is_lun_t10);
+			idd = scsi_get_devid(did, cdai.provsiz,
+			    scsi_devid_is_lun_t10);
 		if (idd == NULL)
-			idd = scsi_get_devid((struct scsi_vpd_device_id *)cdai.buf,
-			    cdai.provsiz, scsi_devid_is_lun_name);
+			idd = scsi_get_devid(did, cdai.provsiz,
+			    scsi_devid_is_lun_name);
 		if (idd == NULL)
-			goto out;
+			break;
+
 		ret = 0;
-		if ((idd->proto_codeset & SVPD_ID_CODESET_MASK) == SVPD_ID_CODESET_ASCII) {
+		if ((idd->proto_codeset & SVPD_ID_CODESET_MASK) ==
+		    SVPD_ID_CODESET_ASCII) {
 			if (idd->length < len) {
 				for (l = 0; l < idd->length; l++)
 					buf[l] = idd->identifier[l] ?
@@ -1317,38 +1323,46 @@ xpt_getattr(char *buf, size_t len, const char *attr, s
 				buf[l] = 0;
 			} else
 				ret = EFAULT;
-		} else if ((idd->proto_codeset & SVPD_ID_CODESET_MASK) == SVPD_ID_CODESET_UTF8) {
+			break;
+		}
+		if ((idd->proto_codeset & SVPD_ID_CODESET_MASK) ==
+		    SVPD_ID_CODESET_UTF8) {
 			l = strnlen(idd->identifier, idd->length);
 			if (l < len) {
 				bcopy(idd->identifier, buf, l);
 				buf[l] = 0;
 			} else
 				ret = EFAULT;
-		} else if ((idd->id_type & SVPD_ID_TYPE_MASK) == SVPD_ID_TYPE_UUID
-		    && idd->identifier[0] == 0x10) {
-			if ((idd->length - 2) * 2 + 4 < len) {
-				for (l = 2, o = 0; l < idd->length; l++) {
-					if (l == 6 || l == 8 || l == 10 || l == 12)
-					    o += sprintf(buf + o, "-");
-					o += sprintf(buf + o, "%02x",
-					    idd->identifier[l]);
-				}
-			} else
+			break;
+		}
+		if ((idd->id_type & SVPD_ID_TYPE_MASK) ==
+		    SVPD_ID_TYPE_UUID && idd->identifier[0] == 0x10) {
+			if ((idd->length - 2) * 2 + 4 >= len) {
 				ret = EFAULT;
-		} else {
-			if (idd->length * 2 < len) {
-				for (l = 0; l < idd->length; l++)
-					sprintf(buf + l * 2, "%02x",
-					    idd->identifier[l]);
-			} else
-				ret = EFAULT;
+				break;
+			}
+			for (l = 2, o = 0; l < idd->length; l++) {
+				if (l == 6 || l == 8 || l == 10 || l == 12)
+				    o += sprintf(buf + o, "-");
+				o += sprintf(buf + o, "%02x",
+				    idd->identifier[l]);
+			}
+			break;
 		}
-	} else {
+		if (idd->length * 2 < len) {
+			for (l = 0; l < idd->length; l++)
+				sprintf(buf + l * 2, "%02x",
+				    idd->identifier[l]);
+		} else
+				ret = EFAULT;
+		break;
+	default:
 		if (cdai.provsiz < len) {
 			cdai.buf[cdai.provsiz] = 0;
 			ret = 0;
 		} else
 			ret = EFAULT;
+		break;
 	}
 
 out: