From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Benjamin Marzinski <bmarzins@redhat.com>

Date: Wed, 27 Mar 2019 12:21:57 -0500

Subject: [PATCH] libmulitpath: cleanup uid_fallback code

Instead of always calling uid_fallback() if the configured method to get

the uid failed, get_uid now checks if the path supports fallbacks and if

all the retriggers have occurred. If so, it calls uid_fallback(), which

just attempts to get the uid using the appropriate fallback method. None

of these changes should make the code function any differently.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>

---

 libmultipath/discovery.c | 85 ++++++++++++++++++++++------------------

 1 file changed, 46 insertions(+), 39 deletions(-)

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c

index bece67c..3ec60d6 100644

--- a/libmultipath/discovery.c

+++ b/libmultipath/discovery.c

@@ -1755,50 +1755,50 @@ get_vpd_uid(struct path * pp)

 }

 static ssize_t uid_fallback(struct path *pp, int path_state,

-			    const char **origin, ssize_t old_len)

+			    const char **origin)

 {

-	ssize_t len = old_len;

-	int retrigger;

-	struct config *conf;

-

-	conf = get_multipath_config();

-	retrigger = conf->retrigger_tries;

-	put_multipath_config(conf);

-	if (pp->retriggers >= retrigger) {

-		if (pp->bus == SYSFS_BUS_SCSI &&

-		    !strcmp(pp->uid_attribute, DEFAULT_UID_ATTRIBUTE)) {

-			len = get_vpd_uid(pp);

-			*origin = "sysfs";

-			pp->uid_attribute = NULL;

-			if (len < 0 && path_state == PATH_UP) {

-				condlog(1, "%s: failed to get sysfs uid: %s",

-					pp->dev, strerror(-len));

-				len = get_vpd_sgio(pp->fd, 0x83, pp->wwid,

+	ssize_t len = -1;

+

+	if (pp->bus == SYSFS_BUS_SCSI &&

+	    !strcmp(pp->uid_attribute, DEFAULT_UID_ATTRIBUTE)) {

+		len = get_vpd_uid(pp);

+		*origin = "sysfs";

+		pp->uid_attribute = NULL;

+		if (len < 0 && path_state == PATH_UP) {

+			condlog(1, "%s: failed to get sysfs uid: %s",

+				pp->dev, strerror(-len));

+			len = get_vpd_sgio(pp->fd, 0x83, pp->wwid,

+					   WWID_SIZE);

+			*origin = "sgio";

+		}

+	} else if (pp->bus == SYSFS_BUS_NVME) {

+		char value[256];

+		len = sysfs_attr_get_value(pp->udev, "wwid", value,

+					   sizeof(value));

+		if (len <= 0)

+			return -1;

+		len = strlcpy(pp->wwid, value, WWID_SIZE);

+		if (len >= WWID_SIZE) {

+			len = fix_broken_nvme_wwid(pp, value,

 						   WWID_SIZE);

-				*origin = "sgio";

-			}

-		} else if (pp->bus == SYSFS_BUS_NVME) {

-			char value[256];

-			len = sysfs_attr_get_value(pp->udev, "wwid", value,

-						   sizeof(value));

-			if (len <= 0)

-				return -1;

-			len = strlcpy(pp->wwid, value, WWID_SIZE);

-			if (len >= WWID_SIZE) {

-				len = fix_broken_nvme_wwid(pp, value,

-							   WWID_SIZE);

-				if (len > 0)

-					return len;

-				condlog(0, "%s: wwid overflow", pp->dev);

-				len = WWID_SIZE;

-			}

-			*origin = "sysfs";

-			pp->uid_attribute = NULL;

+			if (len > 0)

+				return len;

+			condlog(0, "%s: wwid overflow", pp->dev);

+			len = WWID_SIZE;

 		}

+		*origin = "sysfs";

+		pp->uid_attribute = NULL;

 	}

 	return len;

 }

+static int has_uid_fallback(struct path *pp)

+{

+	return ((pp->bus == SYSFS_BUS_SCSI &&

+		 !strcmp(pp->uid_attribute, DEFAULT_UID_ATTRIBUTE)) ||

+		pp->bus == SYSFS_BUS_NVME);

+}

+

 int

 get_uid (struct path * pp, int path_state, struct udev_device *udev)

 {

@@ -1846,8 +1846,15 @@ get_uid (struct path * pp, int path_state, struct udev_device *udev)

 			len = get_vpd_uid(pp);

 			origin = "sysfs";

 		}

-		if (len <= 0)

-			len = uid_fallback(pp, path_state, &origin, len);

+		if (len <= 0 && has_uid_fallback(pp)) {

+			int retrigger_tries;

+

+			conf = get_multipath_config();

+			retrigger_tries = conf->retrigger_tries;

+			put_multipath_config(conf);

+			if (pp->retriggers >= retrigger_tries)

+				len = uid_fallback(pp, path_state, &origin);

+		}

 	}

 	if ( len < 0 ) {

 		condlog(1, "%s: failed to get %s uid: %s",

-- 

2.17.2