[dm-devel] [PATCH 3/4] libmultipath: use regular array for field widths

[Benjamin Marzinski <bmarzins@redhat.com>]

We know the size of these arrays, so we can just allocate them on the
stack. Also, show_path() doesn't use the width, so don't initialize it
in the first place.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 libmultipath/foreign.c            |  5 ++--
 libmultipath/libmultipath.version |  4 +--
 libmultipath/print.c              | 32 +++++++++++-------------
 libmultipath/print.h              |  4 +--
 multipath/main.c                  |  5 ++--
 multipathd/cli_handlers.c         | 41 ++++++++++++-------------------
 6 files changed, 38 insertions(+), 53 deletions(-)

diff --git a/libmultipath/foreign.c b/libmultipath/foreign.c
index 8981ff58..4cc2a8e3 100644
--- a/libmultipath/foreign.c
+++ b/libmultipath/foreign.c
@@ -550,10 +550,9 @@ void print_foreign_topology(int verbosity)
 	struct strbuf buf = STRBUF_INIT;
 	struct foreign *fgn;
 	int i;
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[path_layout_size()];
 
-	if ((width = alloc_path_layout()) == NULL)
-		return;
+	memset(width, 0, sizeof(width));
 	rdlock_foreigns();
 	if (foreigns == NULL) {
 		unlock_foreigns(NULL);
diff --git a/libmultipath/libmultipath.version b/libmultipath/libmultipath.version
index 8a447f7f..af7c5ed2 100644
--- a/libmultipath/libmultipath.version
+++ b/libmultipath/libmultipath.version
@@ -38,9 +38,7 @@ global:
 	add_map_with_path;
 	adopt_paths;
 	alloc_multipath;
-	alloc_multipath_layout;
 	alloc_path;
-	alloc_path_layout;
 	alloc_path_with_pathinfo;
 	change_foreign;
 	check_alias_settings;
@@ -126,6 +124,7 @@ global:
 	libmultipath_exit;
 	libmultipath_init;
 	load_config;
+	multipath_layout_size;
 	need_io_err_check;
 	orphan_path;
 	parse_prkey_flags;
@@ -133,6 +132,7 @@ global:
 	path_discovery;
 	path_get_tpgs;
 	pathinfo;
+	path_layout_size;
 	path_offline;
 	print_all_paths;
 	print_foreign_topology;
diff --git a/libmultipath/print.c b/libmultipath/print.c
index 97f9a177..87d6a329 100644
--- a/libmultipath/print.c
+++ b/libmultipath/print.c
@@ -805,6 +805,12 @@ static const struct multipath_data mpd[] = {
 	{'g', "vpd page data", snprint_multipath_vpd_data},
 };
 
+
+int multipath_layout_size(void)
+{
+	return ARRAY_SIZE(mpd);
+}
+
 static const struct path_data pd[] = {
 	{'w', "uuid",          snprint_path_uuid},
 	{'i', "hcil",          snprint_hcil},
@@ -834,6 +840,11 @@ static const struct path_data pd[] = {
 	{'L', "LUN hex",       snprint_path_lunhex},
 };
 
+int path_layout_size(void)
+{
+	return ARRAY_SIZE(pd);
+}
+
 static const struct pathgroup_data pgd[] = {
 	{'s', "selector",      snprint_pg_selector},
 	{'p', "pri",           snprint_pg_pri},
@@ -871,10 +882,6 @@ int snprint_wildcards(struct strbuf *buff)
 	return get_strbuf_len(buff) - initial_len;
 }
 
-fieldwidth_t *alloc_path_layout(void) {
-	return calloc(ARRAY_SIZE(pd), sizeof(fieldwidth_t));
-}
-
 void get_path_layout(vector pathvec, int header, fieldwidth_t *width)
 {
 	vector gpvec = vector_convert(NULL, pathvec, struct path,
@@ -929,11 +936,6 @@ void _get_path_layout (const struct _vector *gpvec, enum layout_reset reset,
 	}
 }
 
-fieldwidth_t *alloc_multipath_layout(void) {
-
-	return calloc(ARRAY_SIZE(mpd), sizeof(fieldwidth_t));
-}
-
 void get_multipath_layout (vector mpvec, int header, fieldwidth_t *width) {
 	vector gmvec = vector_convert(NULL, mpvec, struct multipath,
 				      dm_multipath_to_gen);
@@ -1187,12 +1189,11 @@ int _snprint_pathgroup(const struct gen_pathgroup *ggp, struct strbuf *line,
 void _print_multipath_topology(const struct gen_multipath *gmp, int verbosity)
 {
 	struct strbuf buff = STRBUF_INIT;
-	fieldwidth_t *p_width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t p_width[ARRAY_SIZE(pd)] = {0};
 	const struct gen_pathgroup *gpg;
 	const struct _vector *pgvec, *pathvec;
 	int j;
 
-	p_width = alloc_path_layout();
 	pgvec = gmp->ops->get_pathgroups(gmp);
 
 	if (pgvec != NULL) {
@@ -1236,14 +1237,11 @@ int _snprint_multipath_topology(const struct gen_multipath *gmp,
 	const struct gen_pathgroup *gpg;
 	struct strbuf style = STRBUF_INIT;
 	size_t initial_len = get_strbuf_len(buff);
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[ARRAY_SIZE(mpd)] = {0};
 
 	if (verbosity <= 0)
 		return 0;
 
-	if ((width = alloc_multipath_layout()) == NULL)
-		return -ENOMEM;
-
 	if (verbosity == 1)
 		return _snprint_multipath(gmp, buff, "%n", width);
 
@@ -2027,7 +2025,7 @@ static void print_all_paths_custo(vector pathvec, int banner, const char *fmt)
 	int i;
 	struct path * pp;
 	struct strbuf line = STRBUF_INIT;
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[ARRAY_SIZE(pd)] = {0};
 
 	if (!VECTOR_SIZE(pathvec)) {
 		if (banner)
@@ -2035,8 +2033,6 @@ static void print_all_paths_custo(vector pathvec, int banner, const char *fmt)
 		return;
 	}
 
-	if ((width = alloc_path_layout()) == NULL)
-		return;
 	get_path_layout(pathvec, 1, width);
 
 	pthread_cleanup_push_cast(reset_strbuf, &line);
diff --git a/libmultipath/print.h b/libmultipath/print.h
index 52f5b256..4e50827d 100644
--- a/libmultipath/print.h
+++ b/libmultipath/print.h
@@ -16,11 +16,11 @@ enum layout_reset {
 };
 
 /* fieldwidth_t is defined in generic.h */
-fieldwidth_t *alloc_path_layout(void);
+int multipath_layout_size(void);
+int path_layout_size(void);
 void _get_path_layout (const struct _vector *gpvec, enum layout_reset,
 		       fieldwidth_t *width);
 void get_path_layout (vector pathvec, int header, fieldwidth_t *width);
-fieldwidth_t *alloc_multipath_layout(void);
 void _get_multipath_layout (const struct _vector *gmvec, enum layout_reset,
 			    fieldwidth_t *width);
 void get_multipath_layout (vector mpvec, int header, fieldwidth_t *width);
diff --git a/multipath/main.c b/multipath/main.c
index 7b69a3ce..f4c85409 100644
--- a/multipath/main.c
+++ b/multipath/main.c
@@ -457,7 +457,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
 	int di_flag = 0;
 	char * refwwid = NULL;
 	char * dev = NULL;
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[path_layout_size()];
 
 	/*
 	 * allocate core vectors to store paths and multipaths
@@ -544,8 +544,7 @@ configure (struct config *conf, enum mpath_cmds cmd,
 	if (libmp_verbosity > 2)
 		print_all_paths(pathvec, 1);
 
-	if ((width = alloc_path_layout()) == NULL)
-		goto out;
+	memset(width, 0, sizeof(width));
 	get_path_layout(pathvec, 0, width);
 	foreign_path_layout(width);
 
diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
index 5b8f647b..ddc807a1 100644
--- a/multipathd/cli_handlers.c
+++ b/multipathd/cli_handlers.c
@@ -38,11 +38,10 @@ show_paths (struct strbuf *reply, struct vectors *vecs, char *style, int pretty)
 	int i;
 	struct path * pp;
 	int hdr_len = 0;
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[path_layout_size()];
 
+	memset(width, 0, sizeof(width));
 	if (pretty) {
-		if ((width = alloc_path_layout()) == NULL)
-			return 1;
 		get_path_layout(vecs->pathvec, 1, width);
 		foreign_path_layout(width);
 	}
@@ -50,10 +49,10 @@ show_paths (struct strbuf *reply, struct vectors *vecs, char *style, int pretty)
 		return 1;
 
 	vector_foreach_slot(vecs->pathvec, pp, i) {
-		if (snprint_path(reply, style, pp, width) < 0)
+		if (snprint_path(reply, style, pp, pretty? width : NULL) < 0)
 			return 1;
 	}
-	if (snprint_foreign_paths(reply, style, width) < 0)
+	if (snprint_foreign_paths(reply, style, pretty? width : NULL) < 0)
 		return 1;
 
 	if (pretty && get_strbuf_len(reply) == (size_t)hdr_len)
@@ -67,12 +66,7 @@ static int
 show_path (struct strbuf *reply, struct vectors *vecs, struct path *pp,
 	   char *style)
 {
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
-
-	if ((width = alloc_path_layout()) == NULL)
-		return 1;
-	get_path_layout(vecs->pathvec, 1, width);
-	if (snprint_path(reply, style, pp, 0) < 0)
+	if (snprint_path(reply, style, pp, NULL) < 0)
 		return 1;
 	return 0;
 }
@@ -95,10 +89,9 @@ show_maps_topology (struct strbuf *reply, struct vectors * vecs)
 {
 	int i;
 	struct multipath * mpp;
-	fieldwidth_t *p_width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t p_width[path_layout_size()];
 
-	if ((p_width = alloc_path_layout()) == NULL)
-		return 1;
+	memset(p_width, 0, sizeof(p_width));
 	get_path_layout(vecs->pathvec, 0, p_width);
 	foreign_path_layout(p_width);
 
@@ -258,10 +251,9 @@ cli_list_map_topology (void *v, struct strbuf *reply, void *data)
 	struct multipath * mpp;
 	struct vectors * vecs = (struct vectors *)data;
 	char * param = get_keyparam(v, MAP);
-	fieldwidth_t *p_width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t p_width[path_layout_size()];
 
-	if ((p_width = alloc_path_layout()) == NULL)
-		return 1;
+	memset(p_width, 0, sizeof(p_width));
 	get_path_layout(vecs->pathvec, 0, p_width);
 	param = convert_dev(param, 0);
 	mpp = find_mp_by_str(vecs->mpvec, param);
@@ -357,11 +349,10 @@ show_maps (struct strbuf *reply, struct vectors *vecs, char *style,
 	int i;
 	struct multipath * mpp;
 	int hdr_len = 0;
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[multipath_layout_size()];
 
+	memset(width, 0, sizeof(width));
 	if (pretty) {
-		if ((width = alloc_multipath_layout()) == NULL)
-			return 1;
 		get_multipath_layout(vecs->mpvec, 1, width);
 		foreign_multipath_layout(width);
 	}
@@ -374,10 +365,11 @@ show_maps (struct strbuf *reply, struct vectors *vecs, char *style,
 			i--;
 			continue;
 		}
-		if (snprint_multipath(reply, style, mpp, width) < 0)
+		if (snprint_multipath(reply, style, mpp,
+				      pretty? width : NULL) < 0)
 			return 1;
 	}
-	if (snprint_foreign_multipaths(reply, style, width) < 0)
+	if (snprint_foreign_multipaths(reply, style, pretty? width : NULL) < 0)
 		return 1;
 
 	if (pretty && get_strbuf_len(reply) == (size_t)hdr_len)
@@ -416,10 +408,9 @@ cli_list_map_fmt (void *v, struct strbuf *reply, void *data)
 	struct vectors * vecs = (struct vectors *)data;
 	char * param = get_keyparam(v, MAP);
 	char * fmt = get_keyparam(v, FMT);
-	fieldwidth_t *width __attribute__((cleanup(cleanup_ucharp))) = NULL;
+	fieldwidth_t width[multipath_layout_size()];
 
-	if ((width = alloc_multipath_layout()) == NULL)
-		return 1;
+	memset(width, 0, sizeof(width));
 	get_multipath_layout(vecs->mpvec, 1, width);
 	param = convert_dev(param, 0);
 	mpp = find_mp_by_str(vecs->mpvec, param);
-- 
2.17.2

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