device-mapper-multipath/0051-libmultipath-add-a-protocol-subsection-to-multipath..patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Benjamin Marzinski <bmarzins@redhat.com>
Date: Wed, 13 Apr 2022 23:27:37 -0500
Subject: [PATCH] libmultipath: add a protocol subsection to multipath.conf

Some storage arrays can be accessed using multiple protocols at the same
time.  In these cases, users may want to set path attributes
differently, depending on the protocol that the path is using. To allow
this, add a protocol subsection to the overrides section in
multipath.conf, which allows select path-specific options to be set.
This commit simply adds the subsection, and handles merging matching
entries. Future patches will make use of the section.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>
---
 libmultipath/config.c | 83 ++++++++++++++++++++++++++++++++++++
 libmultipath/config.h | 10 +++++
 libmultipath/dict.c   | 99 +++++++++++++++++++++++++++++++++++++++++++
 libmultipath/print.c  | 50 ++++++++++++++++++++++
 4 files changed, 242 insertions(+)

diff --git a/libmultipath/config.c b/libmultipath/config.c
index 005d6b54..8b0e1f72 100644
--- a/libmultipath/config.c
+++ b/libmultipath/config.c
@@ -238,6 +238,18 @@ const char *get_mpe_wwid(const struct _vector *mptable, const char *alias)
 	return NULL;
 }
 
+static void
+free_pctable (vector pctable)
+{
+	int i;
+	struct pcentry *pce;
+
+	vector_foreach_slot(pctable, pce, i)
+		free(pce);
+
+	vector_free(pctable);
+}
+
 void
 free_hwe (struct hwentry * hwe)
 {
@@ -283,6 +295,9 @@ free_hwe (struct hwentry * hwe)
 	if (hwe->bl_product)
 		FREE(hwe->bl_product);
 
+	if (hwe->pctable)
+		free_pctable(hwe->pctable);
+
 	FREE(hwe);
 }
 
@@ -364,6 +379,15 @@ alloc_hwe (void)
 	return hwe;
 }
 
+struct pcentry *
+alloc_pce (void)
+{
+	struct pcentry *pce = (struct pcentry *)
+				calloc(1, sizeof(struct pcentry));
+	pce->type = -1;
+	return pce;
+}
+
 static char *
 set_param_str(const char * str)
 {
@@ -397,6 +421,13 @@ set_param_str(const char * str)
 	if (!dst->s && src->s) \
 		dst->s = src->s
 
+static void
+merge_pce(struct pcentry *dst, struct pcentry *src)
+{
+	merge_num(fast_io_fail);
+	merge_num(dev_loss);
+	merge_num(eh_deadline);
+}
 
 static void
 merge_hwe (struct hwentry * dst, struct hwentry * src)
@@ -603,6 +634,51 @@ out:
 	return 1;
 }
 
+static void
+validate_pctable(struct hwentry *ovr, int idx, const char *table_desc)
+{
+	struct pcentry *pce;
+
+	if (!ovr || !ovr->pctable)
+		return;
+
+	vector_foreach_slot_after(ovr->pctable, pce, idx) {
+		if (pce->type < 0) {
+			condlog(0, "protocol section in %s missing type",
+				table_desc);
+			vector_del_slot(ovr->pctable, idx--);
+			free(pce);
+		}
+	}
+
+	if (VECTOR_SIZE(ovr->pctable) == 0) {
+		vector_free(ovr->pctable);
+		ovr->pctable = NULL;
+	}
+}
+
+static void
+merge_pctable(struct hwentry *ovr)
+{
+	struct pcentry *pce1, *pce2;
+	int i, j;
+
+	if (!ovr || !ovr->pctable)
+		return;
+
+	vector_foreach_slot(ovr->pctable, pce1, i) {
+		j = i + 1;
+		vector_foreach_slot_after(ovr->pctable, pce2, j) {
+			if (pce1->type != pce2->type)
+				continue;
+			merge_pce(pce2,pce1);
+			vector_del_slot(ovr->pctable, i--);
+			free(pce1);
+			break;
+		}
+	}
+}
+
 static void
 factorize_hwtable (vector hw, int n, const char *table_desc)
 {
@@ -751,6 +827,7 @@ process_config_dir(struct config *conf, char *dir)
 	int i, n;
 	char path[LINE_MAX];
 	int old_hwtable_size;
+	int old_pctable_size = 0;
 
 	if (dir[0] != '/') {
 		condlog(1, "config_dir '%s' must be a fully qualified path",
@@ -777,11 +854,15 @@ process_config_dir(struct config *conf, char *dir)
 			continue;
 
 		old_hwtable_size = VECTOR_SIZE(conf->hwtable);
+		old_pctable_size = conf->overrides ?
+				   VECTOR_SIZE(conf->overrides->pctable) : 0;
 		snprintf(path, LINE_MAX, "%s/%s", dir, namelist[i]->d_name);
 		path[LINE_MAX-1] = '\0';
 		process_file(conf, path);
 		factorize_hwtable(conf->hwtable, old_hwtable_size,
 				  namelist[i]->d_name);
+		validate_pctable(conf->overrides, old_pctable_size,
+				 namelist[i]->d_name);
 	}
 	pthread_cleanup_pop(1);
 }
@@ -889,6 +970,7 @@ int _init_config (const char *file, struct config *conf)
 			goto out;
 		}
 		factorize_hwtable(conf->hwtable, builtin_hwtable_size, file);
+		validate_pctable(conf->overrides, 0, file);
 	} else {
 		condlog(0, "/etc/multipath.conf does not exist, blacklisting all devices.");
 		condlog(0, "You can run \"/sbin/mpathconf --enable\" to create");
@@ -1004,6 +1086,7 @@ int _init_config (const char *file, struct config *conf)
 			goto out;
 	}
 
+	merge_pctable(conf->overrides);
 	merge_mptable(conf->mptable);
 	merge_blacklist(conf->blist_devnode);
 	merge_blacklist(conf->blist_property);
diff --git a/libmultipath/config.h b/libmultipath/config.h
index 5f01c1fc..57992604 100644
--- a/libmultipath/config.h
+++ b/libmultipath/config.h
@@ -41,6 +41,13 @@ enum force_reload_types {
 	FORCE_RELOAD_WEAK,
 };
 
+struct pcentry {
+	int type;
+	int fast_io_fail;
+	unsigned int dev_loss;
+	int eh_deadline;
+};
+
 struct hwentry {
 	char * vendor;
 	char * product;
@@ -86,6 +93,8 @@ struct hwentry {
 	int vpd_vendor_id;
 	int recheck_wwid;
 	char * bl_product;
+
+	vector pctable;
 };
 
 struct mpentry {
@@ -286,6 +295,7 @@ const char *get_mpe_wwid (const struct _vector *mptable, const char *alias);
 
 struct hwentry * alloc_hwe (void);
 struct mpentry * alloc_mpe (void);
+struct pcentry * alloc_pce (void);
 
 void free_hwe (struct hwentry * hwe);
 void free_hwtable (vector hwtable);
diff --git a/libmultipath/dict.c b/libmultipath/dict.c
index eb5a8083..46b9f225 100644
--- a/libmultipath/dict.c
+++ b/libmultipath/dict.c
@@ -414,6 +414,29 @@ snprint_mp_ ## option (struct config *conf, struct strbuf *buff,	\
 	return function(buff, mpe->option);				\
 }
 
+#define declare_pc_handler(option, function)				\
+static int								\
+pc_ ## option ## _handler (struct config *conf, vector strvec,		\
+			   const char *file, int line_nr)		\
+{									\
+	struct pcentry *pce;						\
+	if (!conf->overrides || !conf->overrides->pctable)		\
+		return 1;						\
+	pce = VECTOR_LAST_SLOT(conf->overrides->pctable);		\
+	if (!pce)							\
+		return 1;						\
+	return function (strvec, &pce->option, file, line_nr);		\
+}
+
+#define declare_pc_snprint(option, function)				\
+static int								\
+snprint_pc_ ## option (struct config *conf, struct strbuf *buff,	\
+		       const void *data)				\
+{									\
+	const struct pcentry *pce  = (const struct pcentry *)data;	\
+	return function(buff, pce->option);				\
+}
+
 static int checkint_handler(struct config *conf, vector strvec,
 			    const char *file, int line_nr)
 {
@@ -1038,6 +1061,8 @@ declare_ovr_handler(fast_io_fail, set_undef_off_zero)
 declare_ovr_snprint(fast_io_fail, print_undef_off_zero)
 declare_hw_handler(fast_io_fail, set_undef_off_zero)
 declare_hw_snprint(fast_io_fail, print_undef_off_zero)
+declare_pc_handler(fast_io_fail, set_undef_off_zero)
+declare_pc_snprint(fast_io_fail, print_undef_off_zero)
 
 static int
 set_dev_loss(vector strvec, void *ptr, const char *file, int line_nr)
@@ -1075,6 +1100,8 @@ declare_ovr_handler(dev_loss, set_dev_loss)
 declare_ovr_snprint(dev_loss, print_dev_loss)
 declare_hw_handler(dev_loss, set_dev_loss)
 declare_hw_snprint(dev_loss, print_dev_loss)
+declare_pc_handler(dev_loss, set_dev_loss)
+declare_pc_snprint(dev_loss, print_dev_loss)
 
 declare_def_handler(eh_deadline, set_undef_off_zero)
 declare_def_snprint(eh_deadline, print_undef_off_zero)
@@ -1082,6 +1109,8 @@ declare_ovr_handler(eh_deadline, set_undef_off_zero)
 declare_ovr_snprint(eh_deadline, print_undef_off_zero)
 declare_hw_handler(eh_deadline, set_undef_off_zero)
 declare_hw_snprint(eh_deadline, print_undef_off_zero)
+declare_pc_handler(eh_deadline, set_undef_off_zero)
+declare_pc_snprint(eh_deadline, print_undef_off_zero)
 
 static int
 set_pgpolicy(vector strvec, void *ptr, const char *file, int line_nr)
@@ -1889,6 +1918,69 @@ declare_mp_snprint(wwid, print_str)
 declare_mp_handler(alias, set_str_noslash)
 declare_mp_snprint(alias, print_str)
 
+
+static int
+protocol_handler(struct config *conf, vector strvec, const char *file,
+               int line_nr)
+{
+	struct pcentry *pce;
+
+	if (!conf->overrides)
+		return 1;
+
+	if (!conf->overrides->pctable &&
+	    !(conf->overrides->pctable = vector_alloc()))
+		return 1;
+
+	if (!(pce = alloc_pce()))
+		return 1;
+
+	if (!vector_alloc_slot(conf->overrides->pctable)) {
+		free(pce);
+		return 1;
+	}
+	vector_set_slot(conf->overrides->pctable, pce);
+
+	return 0;
+}
+
+static int
+set_protocol_type(vector strvec, void *ptr, const char *file, int line_nr)
+{
+	int *int_ptr = (int *)ptr;
+	char *buff;
+	int i;
+
+	buff = set_value(strvec);
+
+	if (!buff)
+		return 1;
+
+	for (i = 0; i <= LAST_BUS_PROTOCOL_ID; i++) {
+		if (protocol_name[i] && !strcmp(buff, protocol_name[i])) {
+			*int_ptr = i;
+			break;
+		}
+	}
+	if (i > LAST_BUS_PROTOCOL_ID)
+		condlog(1, "%s line %d, invalid value for type: \"%s\"",
+			file, line_nr, buff);
+
+	free(buff);
+	return 0;
+}
+
+static int
+print_protocol_type(struct strbuf *buff, int type)
+{
+	if (type < 0)
+		return 0;
+	return append_strbuf_quoted(buff, protocol_name[type]);
+}
+
+declare_pc_handler(type, set_protocol_type)
+declare_pc_snprint(type, print_protocol_type)
+
 /*
  * deprecated handlers
  */
@@ -2130,6 +2222,13 @@ init_keywords(vector keywords)
 	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("recheck_wwid", &ovr_recheck_wwid_handler, &snprint_ovr_recheck_wwid);
+	install_keyword_multi("protocol", &protocol_handler, NULL);
+	install_sublevel();
+	install_keyword("type", &pc_type_handler, &snprint_pc_type);
+	install_keyword("fast_io_fail_tmo", &pc_fast_io_fail_handler, &snprint_pc_fast_io_fail);
+	install_keyword("dev_loss_tmo", &pc_dev_loss_handler, &snprint_pc_dev_loss);
+	install_keyword("eh_deadline", &pc_eh_deadline_handler, &snprint_pc_eh_deadline);
+	install_sublevel_end();
 
 	install_keyword_root("multipaths", &multipaths_handler);
 	install_keyword_multi("multipath", &multipath_handler, NULL);
diff --git a/libmultipath/print.c b/libmultipath/print.c
index 0dbd34e4..46e3d32e 100644
--- a/libmultipath/print.c
+++ b/libmultipath/print.c
@@ -1318,6 +1318,52 @@ int snprint_multipath_topology_json (struct strbuf *buff,
 	return get_strbuf_len(buff) - initial_len;
 }
 
+static int
+snprint_pcentry (const struct config *conf, struct strbuf *buff,
+		 const struct pcentry *pce)
+{
+	int i, rc;
+	struct keyword *kw;
+	struct keyword * rootkw;
+	size_t initial_len = get_strbuf_len(buff);
+
+	rootkw = find_keyword(conf->keywords, NULL, "overrides");
+	assert(rootkw && rootkw->sub);
+	rootkw = find_keyword(conf->keywords, rootkw->sub, "protocol");
+	assert(rootkw);
+
+	if ((rc = append_strbuf_str(buff, "\tprotocol {\n")) < 0)
+		return rc;
+
+	iterate_sub_keywords(rootkw, kw, i) {
+		if ((rc = snprint_keyword(buff, "\t\t%k %v\n", kw, pce)) < 0)
+			return rc;
+	}
+
+	if ((rc = append_strbuf_str(buff, "\t}\n")) < 0)
+		return rc;
+	return get_strbuf_len(buff) - initial_len;
+}
+
+static int
+snprint_pctable (const struct config *conf, struct strbuf *buff,
+		 const struct _vector *pctable)
+{
+	int i, rc;
+	struct pcentry *pce;
+	struct keyword * rootkw;
+	size_t initial_len = get_strbuf_len(buff);
+
+	rootkw = find_keyword(conf->keywords, NULL, "overrides");
+	assert(rootkw);
+
+	vector_foreach_slot(pctable, pce, i) {
+		if ((rc = snprint_pcentry(conf, buff, pce)) < 0)
+			return rc;
+	}
+	return get_strbuf_len(buff) - initial_len;
+}
+
 static int
 snprint_hwentry (const struct config *conf,
 		 struct strbuf *buff, const struct hwentry * hwe)
@@ -1472,6 +1518,10 @@ static int snprint_overrides(const struct config *conf, struct strbuf *buff,
 		if ((rc = snprint_keyword(buff, "\t%k %v\n", kw, NULL)) < 0)
 			return rc;
 	}
+
+	if (overrides->pctable &&
+	    (rc = snprint_pctable(conf, buff, overrides->pctable)) < 0)
+		return rc;
 out:
 	if ((rc = append_strbuf_str(buff, "}\n")) < 0)
 		return rc;