From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <bmarzins@redhat.com>
Date: Thu, 31 May 2018 17:47:11 -0500
Subject: [PATCH] mpathpersist: add all_tg_pt option

Some arrays, such as the EMC VNX, don't follow the scsi persistent
reservations spec in making key registrations per I_T NEXUS. Instead,
the registration is shared by all target ports connected to a given
host.  This causes mpathpersist to fail whenever it tries to register a
key, since it will receive a registration conflict on some of the paths.

To deal with this, mpathpersist needs to track the hosts that it has
done a registration on, and only register once per host. The new
"all_tg_pt" multipath.conf option is used to set which arrays need this
feature.  I currently don't know if all EMC VNX arrays handle persistent
reservations like this, or if it is configurable. A future patch will
update the VNX built-in config, if this is indeed their default (or
only) setting.

Multipathd doesn't need to worry about this. It is often the case that
when a path device comes back, it will still have the keys registered to
it. Because of this, multipathd uses register-and-ignore, which means
that it won't cause an error if the registration has already happened
down a different target port.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 libmpathpersist/mpath_persist.c | 28 ++++++++++++++++++++++------
 libmultipath/config.c           |  2 ++
 libmultipath/config.h           |  2 ++
 libmultipath/defaults.h         |  1 +
 libmultipath/dict.c             | 10 ++++++++++
 libmultipath/propsel.c          | 15 +++++++++++++++
 libmultipath/propsel.h          |  1 +
 libmultipath/structs.h          |  7 +++++++
 multipath/multipath.conf.5      | 11 +++++++++++
 9 files changed, 71 insertions(+), 6 deletions(-)

diff --git a/libmpathpersist/mpath_persist.c b/libmpathpersist/mpath_persist.c
index 907a17c..ca91c55 100644
--- a/libmpathpersist/mpath_persist.c
+++ b/libmpathpersist/mpath_persist.c
@@ -335,6 +335,7 @@ int mpath_persistent_reserve_out ( int fd, int rq_servact, int rq_scope,
 
 	conf = get_multipath_config();
 	select_reservation_key(conf, mpp);
+	select_all_tg_pt(conf, mpp);
 	put_multipath_config(conf);
 
 	memcpy(&prkey, paramp->sa_key, 8);
@@ -456,7 +457,7 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 	unsigned int rq_type, struct prout_param_descriptor * paramp, int noisy)
 {
 
-	int i, j;
+	int i, j, k;
 	struct pathgroup *pgp = NULL;
 	struct path *pp = NULL;
 	int rollback = 0;
@@ -481,11 +482,13 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 	}
 
 	struct threadinfo thread[active_pathcount];
+	int hosts[active_pathcount];
 
 	memset(thread, 0, sizeof(thread));
 
 	/* init thread parameter */
 	for (i =0; i< active_pathcount; i++){
+		hosts[i] = -1;
 		thread[i].param.rq_servact = rq_servact;
 		thread[i].param.rq_scope = rq_scope;
 		thread[i].param.rq_type = rq_type;
@@ -514,6 +517,17 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 				condlog (1, "%s: %s path not up. Skip.", mpp->wwid, pp->dev);
 				continue;
 			}
+			if (mpp->all_tg_pt == ALL_TG_PT_ON &&
+			    pp->sg_id.host_no != -1) {
+				for (k = 0; k < count; k++) {
+					if (pp->sg_id.host_no == hosts[k]) {
+						condlog(3, "%s: %s host %d matches skip.", pp->wwid, pp->dev, pp->sg_id.host_no);
+						break;
+					}
+				}
+				if (k < count)
+					continue;
+			}
 			strncpy(thread[count].param.dev, pp->dev,
 				FILE_NAME_SIZE - 1);
 
@@ -531,10 +545,12 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 				condlog (0, "%s: failed to create thread %d", mpp->wwid, rc);
 				thread[count].param.status = MPATH_PR_THREAD_ERROR;
 			}
+			else
+				hosts[count] = pp->sg_id.host_no;
 			count = count + 1;
 		}
 	}
-	for( i=0; i < active_pathcount ; i++){
+	for( i=0; i < count ; i++){
 		if (thread[i].param.status != MPATH_PR_THREAD_ERROR) {
 			rc = pthread_join(thread[i].id, NULL);
 			if (rc){
@@ -557,7 +573,7 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 	}
 	if (rollback && ((rq_servact == MPATH_PROUT_REG_SA) && sa_key != 0 )){
 		condlog (3, "%s: ERROR: initiating pr out rollback", mpp->wwid);
-		for( i=0 ; i < active_pathcount ; i++){
+		for( i=0 ; i < count ; i++){
 			if(thread[i].param.status == MPATH_PR_SUCCESS) {
 				memcpy(&thread[i].param.paramp->key, &thread[i].param.paramp->sa_key, 8);
 				memset(&thread[i].param.paramp->sa_key, 0, 8);
@@ -571,7 +587,7 @@ int mpath_prout_reg(struct multipath *mpp,int rq_servact, int rq_scope,
 			} else
 				thread[i].param.status = MPATH_PR_SKIP;
 		}
-		for(i=0; i < active_pathcount ; i++){
+		for(i=0; i < count ; i++){
 			if (thread[i].param.status != MPATH_PR_SKIP &&
 			    thread[i].param.status != MPATH_PR_THREAD_ERROR) {
 				rc = pthread_join(thread[i].id, NULL);
@@ -720,7 +736,7 @@ int mpath_prout_rel(struct multipath *mpp,int rq_servact, int rq_scope,
 		}
 	}
 	pthread_attr_destroy (&attr);
-	for (i = 0; i < active_pathcount; i++){
+	for (i = 0; i < count; i++){
 		if (thread[i].param.status != MPATH_PR_THREAD_ERROR) {
 			rc = pthread_join (thread[i].id, NULL);
 			if (rc){
@@ -729,7 +745,7 @@ int mpath_prout_rel(struct multipath *mpp,int rq_servact, int rq_scope,
 		}
 	}
 
-	for (i = 0; i < active_pathcount; i++){
+	for (i = 0; i < count; i++){
 		/*  check thread status here and return the status */
 
 		if (thread[i].param.status == MPATH_PR_RESERV_CONFLICT)
diff --git a/libmultipath/config.c b/libmultipath/config.c
index 085a3e1..5872927 100644
--- a/libmultipath/config.c
+++ b/libmultipath/config.c
@@ -352,6 +352,7 @@ merge_hwe (struct hwentry * dst, struct hwentry * src)
 	merge_num(skip_kpartx);
 	merge_num(max_sectors_kb);
 	merge_num(ghost_delay);
+	merge_num(all_tg_pt);
 
 	snprintf(id, sizeof(id), "%s/%s", dst->vendor, dst->product);
 	reconcile_features_with_options(id, &dst->features,
@@ -622,6 +623,7 @@ load_config (char * file)
 	conf->disable_changed_wwids = DEFAULT_DISABLE_CHANGED_WWIDS;
 	conf->remove_retries = 0;
 	conf->ghost_delay = DEFAULT_GHOST_DELAY;
+	conf->all_tg_pt = DEFAULT_ALL_TG_PT;
 
 	/*
 	 * preload default hwtable
diff --git a/libmultipath/config.h b/libmultipath/config.h
index 6e69a37..1bf708a 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -82,6 +82,7 @@ struct hwentry {
 	int skip_kpartx;
 	int max_sectors_kb;
 	int ghost_delay;
+	int all_tg_pt;
 	char * bl_product;
 };
 
@@ -194,6 +195,7 @@ struct config {
 	char * partition_delim;
 	char * config_dir;
 	int prkey_source;
+	int all_tg_pt;
 	struct be64 reservation_key;
 
 	vector keywords;
diff --git a/libmultipath/defaults.h b/libmultipath/defaults.h
index d7b87b4..f076b4b 100644
--- a/libmultipath/defaults.h
+++ b/libmultipath/defaults.h
@@ -43,6 +43,7 @@
 #define DEFAULT_GHOST_DELAY GHOST_DELAY_OFF
 #define DEFAULT_FIND_MULTIPATHS_TIMEOUT -10
 #define DEFAULT_UNKNOWN_FIND_MULTIPATHS_TIMEOUT 1
+#define DEFAULT_ALL_TG_PT ALL_TG_PT_OFF
 
 #define DEFAULT_CHECKINT	5
 #define MAX_CHECKINT(a)		(a << 2)
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index 3e7c5d6..2557b8a 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -1178,6 +1178,13 @@ declare_hw_snprint(ghost_delay, print_off_int_undef)
 declare_mp_handler(ghost_delay, set_off_int_undef)
 declare_mp_snprint(ghost_delay, print_off_int_undef)
 
+declare_def_handler(all_tg_pt, set_yes_no_undef)
+declare_def_snprint_defint(all_tg_pt, print_yes_no_undef, DEFAULT_ALL_TG_PT)
+declare_ovr_handler(all_tg_pt, set_yes_no_undef)
+declare_ovr_snprint(all_tg_pt, print_yes_no_undef)
+declare_hw_handler(all_tg_pt, set_yes_no_undef)
+declare_hw_snprint(all_tg_pt, print_yes_no_undef)
+
 
 static int
 def_uxsock_timeout_handler(struct config *conf, vector strvec)
@@ -1509,6 +1516,7 @@ init_keywords(vector keywords)
 	install_keyword("prkeys_file", &def_prkeys_file_handler, &snprint_def_prkeys_file);
 	install_keyword("log_checker_err", &def_log_checker_err_handler, &snprint_def_log_checker_err);
 	install_keyword("reservation_key", &def_reservation_key_handler, &snprint_def_reservation_key);
+	install_keyword("all_tg_pt", &def_all_tg_pt_handler, &snprint_def_all_tg_pt);
 	install_keyword("retain_attached_hw_handler", &def_retain_hwhandler_handler, &snprint_def_retain_hwhandler);
 	install_keyword("detect_prio", &def_detect_prio_handler, &snprint_def_detect_prio);
 	install_keyword("detect_checker", &def_detect_checker_handler, &snprint_def_detect_checker);
@@ -1618,6 +1626,7 @@ init_keywords(vector keywords)
 	install_keyword("skip_kpartx", &hw_skip_kpartx_handler, &snprint_hw_skip_kpartx);
 	install_keyword("max_sectors_kb", &hw_max_sectors_kb_handler, &snprint_hw_max_sectors_kb);
 	install_keyword("ghost_delay", &hw_ghost_delay_handler, &snprint_hw_ghost_delay);
+	install_keyword("all_tg_pt", &hw_all_tg_pt_handler, &snprint_hw_all_tg_pt);
 	install_sublevel_end();
 
 	install_keyword_root("overrides", &overrides_handler);
@@ -1654,6 +1663,7 @@ init_keywords(vector keywords)
 	install_keyword("skip_kpartx", &ovr_skip_kpartx_handler, &snprint_ovr_skip_kpartx);
 	install_keyword("max_sectors_kb", &ovr_max_sectors_kb_handler, &snprint_ovr_max_sectors_kb);
 	install_keyword("ghost_delay", &ovr_ghost_delay_handler, &snprint_ovr_ghost_delay);
+	install_keyword("all_tg_pt", &ovr_all_tg_pt_handler, &snprint_ovr_all_tg_pt);
 
 	install_keyword_root("multipaths", &multipaths_handler);
 	install_keyword_multi("multipath", &multipath_handler, NULL);
diff --git a/libmultipath/propsel.c b/libmultipath/propsel.c
index 627d366..9ca1355 100644
--- a/libmultipath/propsel.c
+++ b/libmultipath/propsel.c
@@ -978,3 +978,18 @@ out:
 		pp->dev, pp->find_multipaths_timeout, origin);
 	return 0;
 }
+
+int select_all_tg_pt (struct config *conf, struct multipath * mp)
+{
+	const char *origin;
+
+	mp_set_ovr(all_tg_pt);
+	mp_set_hwe(all_tg_pt);
+	mp_set_conf(all_tg_pt);
+	mp_set_default(all_tg_pt, DEFAULT_ALL_TG_PT);
+out:
+	condlog(3, "%s: all_tg_pt = %s %s", mp->alias,
+		(mp->all_tg_pt == ALL_TG_PT_ON)? "yes" : "no",
+		origin);
+	return 0;
+}
diff --git a/libmultipath/propsel.h b/libmultipath/propsel.h
index a022bee..ae99b92 100644
--- a/libmultipath/propsel.h
+++ b/libmultipath/propsel.h
@@ -34,3 +34,4 @@ int select_ghost_delay(struct config *conf, struct multipath * mp);
 void reconcile_features_with_options(const char *id, char **features,
 				     int* no_path_retry,
 				     int *retain_hwhandler);
+int select_all_tg_pt (struct config *conf, struct multipath * mp);
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index e424b15..0194b1e 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -217,6 +217,12 @@ enum prkey_sources {
 	PRKEY_SOURCE_FILE,
 };
 
+enum all_tg_pt_states {
+	ALL_TG_PT_UNDEF = YNU_UNDEF,
+	ALL_TG_PT_OFF = YNU_NO,
+	ALL_TG_PT_ON = YNU_YES,
+};
+
 struct sg_id {
 	int host_no;
 	int channel;
@@ -362,6 +368,7 @@ struct multipath {
 	int prkey_source;
 	struct be64 reservation_key;
 	unsigned char prflag;
+	int all_tg_pt;
 	struct gen_multipath generic_mp;
 };
 
diff --git a/multipath/multipath.conf.5 b/multipath/multipath.conf.5
index 96d1b66..0c1f174 100644
--- a/multipath/multipath.conf.5
+++ b/multipath/multipath.conf.5
@@ -743,6 +743,17 @@ The default is: \fB<unset>\fR
 .
 .
 .TP
+.B all_tg_pt
+This must be set to \fByes\fR to successfully use mpathpersist on arrays that
+automatically set and clear registration keys on all target ports from a
+host, instead of per target port per host.
+.RS
+.TP
+The default is: \fBno\fR
+.RE
+.
+.
+.TP
 .B retain_attached_hw_handler
 (Obsolete for kernels >= 4.3) If set to
 .I yes
-- 
2.7.4