---

 libmultipath/propsel.c |   20 ++++++++++++++++----

 libmultipath/structs.h |    1 +

 multipathd/main.c      |   37 ++++++++++++++++++++++++++-----------

 3 files changed, 43 insertions(+), 15 deletions(-)

Index: multipath-tools-130222/libmultipath/propsel.c

===================================================================

--- multipath-tools-130222.orig/libmultipath/propsel.c

+++ multipath-tools-130222/libmultipath/propsel.c

@@ -398,9 +398,11 @@ detect_prio(struct path * pp)

 {

 	int ret;

 	struct prio *p = &pp->prio;

+	int tpgs = 0;

-	if (get_target_port_group_support(pp->fd) <= 0)

+	if ((tpgs = get_target_port_group_support(pp->fd)) <= 0)

 		return;

+	pp->tpgs = tpgs;

 	ret = get_target_port_group(pp->fd, NULL);

 	if (ret < 0)

 		return;

@@ -432,7 +434,7 @@ select_prio (struct path * pp)

 			pp->dev, prio_name(p));

 		condlog(3, "%s: prio args = %s (LUN setting)",

 			pp->dev, prio_args(p));

-		return 0;

+		goto out;

 	}

 	if (pp->hwe && pp->hwe->prio_name) {

@@ -441,7 +443,7 @@ select_prio (struct path * pp)

 			pp->dev, pp->hwe->prio_name);

 		condlog(3, "%s: prio args = %s (controller setting)",

 			pp->dev, pp->hwe->prio_args);

-		return 0;

+		goto out;

 	}

 	if (conf->prio_name) {

 		prio_get(p, conf->prio_name, conf->prio_args);

@@ -449,13 +451,23 @@ select_prio (struct path * pp)

 			pp->dev, conf->prio_name);

 		condlog(3, "%s: prio args = %s (config file default)",

 			pp->dev, conf->prio_args);

-		return 0;

+		goto out;

 	}

 	prio_get(p, DEFAULT_PRIO, DEFAULT_PRIO_ARGS);

 	condlog(3, "%s: prio = %s (internal default)",

 		pp->dev, DEFAULT_PRIO);

 	condlog(3, "%s: prio args = %s (internal default)",

 		pp->dev, DEFAULT_PRIO_ARGS);

+out:

+	/*

+ 	 * fetch tpgs mode for alua

+ 	 */

+	if (!strncmp(prio_name(p), PRIO_ALUA, PRIO_NAME_LEN)) {

+		int tpgs = 0;

+		if (!pp->tpgs &&

+		    (tpgs = get_target_port_group_support(pp->fd)) >= 0)

+			pp->tpgs = tpgs;

+	}

 	return 0;

 }

Index: multipath-tools-130222/libmultipath/structs.h

===================================================================

--- multipath-tools-130222.orig/libmultipath/structs.h

+++ multipath-tools-130222/libmultipath/structs.h

@@ -193,6 +193,7 @@ struct path {

 	int detect_prio;

 	int watch_checks;

 	int wait_checks;

+	int tpgs;

 	char * uid_attribute;

 	struct prio prio;

 	char * prio_args;

Index: multipath-tools-130222/multipathd/main.c

===================================================================

--- multipath-tools-130222.orig/multipathd/main.c

+++ multipath-tools-130222/multipathd/main.c

@@ -19,6 +19,7 @@

 #include <libudev.h>

 #include <semaphore.h>

 #include <mpath_persist.h>

+#include "prioritizers/alua_rtpg.h"

 /*

  * libcheckers

@@ -1248,6 +1249,7 @@ check_path (struct vectors * vecs, struc

 	int newstate;

 	int new_path_up = 0;

 	int chkr_new_path_up = 0;

+	int disable_reinstate = 0;

 	int oldchkrstate = pp->chkrstate;

 	if (!pp->mpp && (pp->missing_udev_info != INFO_MISSING ||

@@ -1312,6 +1314,16 @@ check_path (struct vectors * vecs, struc

 			pp->wait_checks = 0;

 	}

+	/*

+	 * don't reinstate failed path, if its in stand-by

+	 * and if target supports only implicit tpgs mode.

+	 * this will prevent unnecessary i/o by dm on stand-by

+	 * paths if there are no other active paths in map.

+	 */

+	disable_reinstate = (newstate == PATH_GHOST &&

+			    pp->mpp->nr_active == 0 &&

+			    pp->tpgs == TPGS_IMPLICIT) ? 1 : 0;

+

 	pp->chkrstate = newstate;

 	if (newstate != pp->state) {

 		int oldstate = pp->state;

@@ -1367,15 +1379,17 @@ check_path (struct vectors * vecs, struc

 		/*

 		 * reinstate this path

 		 */

-		if (oldstate != PATH_UP &&

-		    oldstate != PATH_GHOST) {

-			if (pp->mpp->delay_watch_checks > 0)

-				pp->watch_checks = pp->mpp->delay_watch_checks;

-			reinstate_path(pp, 1);

-		} else {

-			if (pp->watch_checks > 0)

-				pp->watch_checks--;

-			reinstate_path(pp, 0);

+		if (!disable_reinstate) {

+			if (oldstate != PATH_UP &&

+			    oldstate != PATH_GHOST) {

+				if (pp->mpp->delay_watch_checks > 0)

+					pp->watch_checks = pp->mpp->delay_watch_checks;

+				reinstate_path(pp, 1);

+			} else {

+				if (pp->watch_checks > 0)

+					pp->watch_checks--;

+				reinstate_path(pp, 0);

+			}

 		}

 		new_path_up = 1;

@@ -1390,8 +1404,9 @@ check_path (struct vectors * vecs, struc

 			enable_group(pp);

 	}

 	else if (newstate == PATH_UP || newstate == PATH_GHOST) {

-		if (pp->dmstate == PSTATE_FAILED ||

-		    pp->dmstate == PSTATE_UNDEF) {

+		if ((pp->dmstate == PSTATE_FAILED ||

+		    pp->dmstate == PSTATE_UNDEF) &&

+		    !disable_reinstate) {

 			/* Clear IO errors */

 			reinstate_path(pp, 0);

 		} else {