libmultipath: embed dm_info in multipath structure

Instead of having multipath allocate its dm_info structure, it should
just embed it to save on the extra allocations. This also lets us have
only one function that all callers use to fill a dm_info structure.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Reviewed-by: Martin Wilck <mwilck@suse.com>

libmultipath/configure.c

@@ -450,12 +450,12 @@ get_udev_for_mpp(const struct multipath *mpp)
 	dev_t devnum;
 	struct udev_device *udd;
 
-	if (!mpp || !mpp->dmi) {
+	if (!mpp || !has_dm_info(mpp)) {
 		condlog(1, "%s called with empty mpp", __func__);
 		return NULL;
 	}
 
-	devnum = makedev(mpp->dmi->major, mpp->dmi->minor);
+	devnum = makedev(mpp->dmi.major, mpp->dmi.minor);
 	udd = udev_device_new_from_devnum(udev, 'b', devnum);
 	if (!udd) {
 		condlog(1, "failed to get udev device for %s", mpp->alias);
@@ -574,7 +574,8 @@ sysfs_set_max_sectors_kb(struct multipath *mpp, int is_reload)
 		return 0;
 	max_sectors_kb = mpp->max_sectors_kb;
 	if (is_reload) {
-		if (!mpp->dmi && dm_get_info(mpp->alias, &mpp->dmi) != 0) {
+		if (!has_dm_info(mpp) &&
+		    dm_get_info(mpp->alias, &mpp->dmi) != 0) {
 			condlog(1, "failed to get dm info for %s", mpp->alias);
 			return 1;
 		}

libmultipath/devmapper.c

@@ -611,12 +611,21 @@ int dm_addmap_reload(struct multipath *mpp, char *params, int flush)
 	return 0;
 }
 
-static int
-do_get_info(const char *name, struct dm_info *info)
+bool
+has_dm_info(const struct multipath *mpp)
+{
+	return (mpp && mpp->dmi.exists != 0);
+}
+
+int
+dm_get_info(const char *name, struct dm_info *info)
 {
 	int r = -1;
 	struct dm_task *dmt;
 
+	if (!name || !info)
+		return r;
+
 	if (!(dmt = libmp_dm_task_create(DM_DEVICE_INFO)))
 		return r;
 
@@ -646,7 +655,7 @@ int dm_map_present(const char * str)
 {
 	struct dm_info info;
 
-	return (do_get_info(str, &info) == 0);
+	return (dm_get_info(str, &info) == 0);
 }
 
 int dm_get_map(const char *name, unsigned long long *size, char **outparams)
@@ -969,7 +978,7 @@ dm_dev_t (const char * mapname, char * dev_t, int len)
 {
 	struct dm_info info;
 
-	if (do_get_info(mapname, &info) != 0)
+	if (dm_get_info(mapname, &info) != 0)
 		return 1;
 
 	if (snprintf(dev_t, len, "%i:%i", info.major, info.minor) > len)
@@ -1013,7 +1022,7 @@ dm_get_major_minor(const char *name, int *major, int *minor)
 {
 	struct dm_info info;
 
-	if (do_get_info(name, &info) != 0)
+	if (dm_get_info(name, &info) != 0)
 		return -1;
 
 	*major = info.major;
@@ -1367,7 +1376,7 @@ dm_geteventnr (const char *name)
 {
 	struct dm_info info;
 
-	if (do_get_info(name, &info) != 0)
+	if (dm_get_info(name, &info) != 0)
 		return -1;
 
 	return info.event_nr;
@@ -1378,7 +1387,7 @@ dm_is_suspended(const char *name)
 {
 	struct dm_info info;
 
-	if (do_get_info(name, &info) != 0)
+	if (dm_get_info(name, &info) != 0)
 		return -1;
 
 	return info.suspended;
@@ -1542,7 +1551,7 @@ dm_get_deferred_remove (const char * mapname)
 {
 	struct dm_info info;
 
-	if (do_get_info(mapname, &info) != 0)
+	if (dm_get_info(mapname, &info) != 0)
 		return -1;
 
 	return info.deferred_remove;
@@ -1583,32 +1592,6 @@ dm_cancel_deferred_remove (struct multipath *mpp __attribute__((unused)))
 
 #endif
 
-static struct dm_info *
-alloc_dminfo (void)
-{
-	return calloc(1, sizeof(struct dm_info));
-}
-
-int
-dm_get_info (const char * mapname, struct dm_info ** dmi)
-{
-	if (!mapname)
-		return 1;
-
-	if (!*dmi)
-		*dmi = alloc_dminfo();
-
-	if (!*dmi)
-		return 1;
-
-	if (do_get_info(mapname, *dmi) != 0) {
-		free(*dmi);
-		*dmi = NULL;
-		return 1;
-	}
-	return 0;
-}
-
 struct rename_data {
 	const char *old;
 	char *new;

libmultipath/devmapper.h

@@ -70,7 +70,8 @@ char * dm_mapname(int major, int minor);
 int dm_remove_partmaps (const char * mapname, int need_sync,
 			int deferred_remove);
 int dm_get_uuid(const char *name, char *uuid, int uuid_len);
-int dm_get_info (const char * mapname, struct dm_info ** dmi);
+bool has_dm_info(const struct multipath *mpp);
+int dm_get_info (const char * mapname, struct dm_info *dmi);
 int dm_rename (const char * old, char * new, char * delim, int skip_kpartx);
 int dm_reassign(const char * mapname);
 int dm_reassign_table(const char *name, char *old, char *new);

libmultipath/libmultipath.version

@@ -121,6 +121,7 @@ global:
 	get_used_hwes;
 	get_vpd_sgio;
 	group_by_prio;
+	has_dm_info;
 	init_checkers;
 	init_config;
 	init_foreign;

libmultipath/print.c

@@ -171,18 +171,18 @@ snprint_name (struct strbuf *buff, const struct multipath * mpp)
 static int
 snprint_sysfs (struct strbuf *buff, const struct multipath * mpp)
 {
-	if (mpp->dmi)
-		return print_strbuf(buff, "dm-%i", mpp->dmi->minor);
+	if (has_dm_info(mpp))
+		return print_strbuf(buff, "dm-%i", mpp->dmi.minor);
 	else
 		return append_strbuf_str(buff, "undef");
 }
 
 static int
 snprint_ro (struct strbuf *buff, const struct multipath * mpp)
 {
-	if (!mpp->dmi)
+	if (!has_dm_info(mpp))
 		return append_strbuf_str(buff, "undef");
-	if (mpp->dmi->read_only)
+	if (mpp->dmi.read_only)
 		return append_strbuf_str(buff, "ro");
 	else
 		return append_strbuf_str(buff, "rw");
@@ -256,7 +256,9 @@ snprint_nb_paths (struct strbuf *buff, const struct multipath * mpp)
 static int
 snprint_dm_map_state (struct strbuf *buff, const struct multipath * mpp)
 {
-	if (mpp->dmi && mpp->dmi->suspended)
+	if (!has_dm_info(mpp))
+		return append_strbuf_str(buff, "undef");
+	else if (mpp->dmi.suspended)
 		return append_strbuf_str(buff, "suspend");
 	else
 		return append_strbuf_str(buff, "active");

libmultipath/structs.c

@@ -18,6 +18,7 @@
 #include "prio.h"
 #include "prioritizers/alua_spc3.h"
 #include "dm-generic.h"
+#include "devmapper.h"
 
 struct adapter_group *
 alloc_adaptergroup(void)
@@ -278,11 +279,6 @@ free_multipath (struct multipath * mpp, enum free_path_mode free_paths)
 		mpp->alias = NULL;
 	}
 
-	if (mpp->dmi) {
-		free(mpp->dmi);
-		mpp->dmi = NULL;
-	}
-
 	if (!free_paths && mpp->pg) {
 		struct pathgroup *pgp;
 		struct path *pp;
@@ -407,10 +403,10 @@ find_mp_by_minor (const struct _vector *mpvec, unsigned int minor)
 		return NULL;
 
 	vector_foreach_slot (mpvec, mpp, i) {
-		if (!mpp->dmi)
+		if (!has_dm_info(mpp))
 			continue;
 
-		if (mpp->dmi->minor == minor)
+		if (mpp->dmi.minor == minor)
 			return mpp;
 	}
 	return NULL;

libmultipath/structs.h

@@ -4,6 +4,7 @@
 #include <sys/types.h>
 #include <inttypes.h>
 #include <stdbool.h>
+#include <libdevmapper.h>
 
 #include "prio.h"
 #include "byteorder.h"
@@ -386,7 +387,7 @@ struct multipath {
 	unsigned long long size;
 	vector paths;
 	vector pg;
-	struct dm_info * dmi;
+	struct dm_info dmi;
 
 	/* configlet pointers */
 	char * alias;

multipathd/main.c

@@ -908,7 +908,7 @@ ev_remove_map (char * devname, char * alias, int minor, struct vectors * vecs)
 	}
 	if (strcmp(mpp->alias, alias)) {
 		condlog(2, "%s: minor number mismatch (map %d, event %d)",
-			mpp->alias, mpp->dmi->minor, minor);
+			mpp->alias, mpp->dmi.minor, minor);
 		return 1;
 	}
 	return flush_map(mpp, vecs, 0);