From 285a4cd8538c74ccdd03a704e0b806bc3222ba8c Mon Sep 17 00:00:00 2001
From: Christophe Varoqui <root@xa-s05.(none)>
Date: Thu, 17 Nov 2005 11:51:15 +0100
Subject: [PATCH] [libmultipath] store the pgpolicy function pointer in struct
 multipath

- setup the pointer in libmultipath/propsel.c:select_pgpolicy
- use in multipath/main.c:setup_map()

Edward Goggin, EMC, patch-chest
---
 libmultipath/propsel.c | 17 ++++++++++++++---
 libmultipath/structs.h |  3 +++
 multipath/main.c       | 42 ++++++++++++++++--------------------------
 3 files changed, 33 insertions(+), 29 deletions(-)

diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 1c7b12b..5817617 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -14,6 +14,15 @@
 
 #include "../libcheckers/checkers.h"
 
+pgpolicyfn *pgpolicies[] = {
+	NULL,
+	one_path_per_group,
+	one_group,
+	group_by_serial,
+	group_by_prio,
+	group_by_node_name
+};
+
 /*
  * selectors :
  * traverse the configuration layers from most specific to most generic
@@ -74,13 +83,11 @@ select_pgfailback (struct multipath * mp)
 extern int
 select_pgpolicy (struct multipath * mp)
 {
-	struct path * pp;
 	char pgpolicy_name[POLICY_NAME_SIZE];
 
-	pp = VECTOR_SLOT(mp->paths, 0);
-
 	if (conf->pgpolicy_flag > 0) {
 		mp->pgpolicy = conf->pgpolicy_flag;
+		mp->pgpolicyfn = pgpolicies[mp->pgpolicy];
 		if (get_pgpolicy_name(pgpolicy_name, mp->pgpolicy))
 			return 1;
 		condlog(3, "pgpolicy = %s (cmd line flag)", pgpolicy_name);
@@ -88,6 +95,7 @@ select_pgpolicy (struct multipath * mp)
 	}
 	if (mp->mpe && mp->mpe->pgpolicy > 0) {
 		mp->pgpolicy = mp->mpe->pgpolicy;
+		mp->pgpolicyfn = pgpolicies[mp->pgpolicy];
 		if (get_pgpolicy_name(pgpolicy_name, mp->pgpolicy))
 			return 1;
 		condlog(3, "pgpolicy = %s (LUN setting)", pgpolicy_name);
@@ -95,6 +103,7 @@ select_pgpolicy (struct multipath * mp)
 	}
 	if (mp->hwe && mp->hwe->pgpolicy > 0) {
 		mp->pgpolicy = mp->hwe->pgpolicy;
+		mp->pgpolicyfn = pgpolicies[mp->pgpolicy];
 		if (get_pgpolicy_name(pgpolicy_name, mp->pgpolicy))
 			return 1;
 		condlog(3, "pgpolicy = %s (controler setting)", pgpolicy_name);
@@ -102,12 +111,14 @@ select_pgpolicy (struct multipath * mp)
 	}
 	if (conf->default_pgpolicy > 0) {
 		mp->pgpolicy = conf->default_pgpolicy;
+		mp->pgpolicyfn = pgpolicies[mp->pgpolicy];
 		if (get_pgpolicy_name(pgpolicy_name, mp->pgpolicy))
 			return 1;
 		condlog(3, "pgpolicy = %s (config file default)", pgpolicy_name);
 		return 0;
 	}
 	mp->pgpolicy = FAILOVER;
+	mp->pgpolicyfn = pgpolicies[mp->pgpolicy];
 	if (get_pgpolicy_name(pgpolicy_name, mp->pgpolicy))
 		return 1;
 	condlog(3, "pgpolicy = %s (internal default)", pgpolicy_name);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index d53f04e..2ba1053 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -109,9 +109,12 @@ struct path {
 	struct hwentry * hwe;
 };
 
+typedef int (pgpolicyfn) (struct multipath *);
+
 struct multipath {
 	char wwid[WWID_SIZE];
 	int pgpolicy;
+	pgpolicyfn *pgpolicyfn;
 	int nextpg;
 	int bestpg;
 	int queuedio;
diff --git a/multipath/main.c b/multipath/main.c
index 1efe53e..8b14ca1 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -308,52 +308,42 @@ filter_pathvec (vector pathvec, char * refwwid)
 static int
 setup_map (struct multipath * mpp)
 {
+	struct pathgroup * pgp;
+	int i;
+	
 	/*
 	 * don't bother if devmap size is unknown
 	 */
 	if (mpp->size <= 0) {
-		condlog(3, "%s devmap size is unknown", mpp->alias);
+		condlog(3, "%s: devmap size is unknown", mpp->alias);
 		return 1;
 	}
 
 	/*
 	 * properties selectors
 	 */
+	select_pgfailback(mpp);
 	select_pgpolicy(mpp);
 	select_selector(mpp);
 	select_features(mpp);
 	select_hwhandler(mpp);
 	select_rr_weight(mpp);
-	select_no_path_retry(mpp);
 	select_minio(mpp);
+	select_no_path_retry(mpp);
 
 	/*
-	 * apply selected grouping policy to valid paths
+	 * assign paths to path groups -- start with no groups and all paths
+	 * in mpp->paths
 	 */
-	switch (mpp->pgpolicy) {
-	case MULTIBUS:
-		one_group(mpp);
-		break;
-	case FAILOVER:
-		one_path_per_group(mpp);
-		break;
-	case GROUP_BY_SERIAL:
-		group_by_serial(mpp);
-		break;
-	case GROUP_BY_PRIO:
-		group_by_prio(mpp);
-		break;
-	case GROUP_BY_NODE_NAME:
-		group_by_node_name(mpp);
-		break;
-	default:
-		break;
-	}
+	if (mpp->pg) {
+		vector_foreach_slot (mpp->pg, pgp, i)
+			free_pathgroup(pgp, KEEP_PATHS);
 
-	if (mpp->pg == NULL) {
-		condlog(3, "pgpolicy failed to produce a pg vector");
-		return 1;
+		vector_free(mpp->pg);
+		mpp->pg = NULL;
 	}
+	if (mpp->pgpolicyfn && mpp->pgpolicyfn(mpp))
+		return 1;
 
 	/*
 	 * ponders each path group and determine highest prio pg
@@ -366,7 +356,7 @@ setup_map (struct multipath * mpp)
 	 * into a mp->params strings to feed the device-mapper
 	 */
 	if (assemble_map(mpp)) {
-		condlog(3, "problem assembing map");
+		condlog(0, "%s: problem assembing map", mpp->alias);
 		return 1;
 	}
 	return 0;
-- 
2.7.4