From cd72f9d114da206baa01fd56ff2d8ffcc08f3239 Mon Sep 17 00:00:00 2001

From: NeilBrown <neilb@suse.com>

Date: Fri, 9 Nov 2018 17:12:33 +1100

Subject: [RHEL7.7 PATCH 03/21] policy: support devices with multiple paths.

As new releases of Linux some time change the name of

a path, some distros keep "legacy" names as well.  This

is useful, but confuses mdadm which assumes each device has

precisely one path.

So change this assumption:  allow a disk to have several

paths, and allow any to match when looking for a policy

which matches a disk.

Reported-and-tested-by: Mariusz Tkaczyk <mariusz.tkaczyk@intel.com>

Signed-off-by: NeilBrown <neilb@suse.com>

Signed-off-by: Jes Sorensen <jsorensen@fb.com>

---

 Incremental.c |   5 +-

 mdadm.h       |   2 +-

 policy.c      | 163 ++++++++++++++++++++++++++++++++--------------------------

 3 files changed, 95 insertions(+), 75 deletions(-)

diff --git a/Incremental.c b/Incremental.c

index a4ff7d4..d4d3c35 100644

--- a/Incremental.c

+++ b/Incremental.c

@@ -1080,6 +1080,7 @@ static int partition_try_spare(char *devname, int *dfdp, struct dev_policy *pol,

 		struct supertype *st2 = NULL;

 		char *devname = NULL;

 		unsigned long long devsectors;

+		char *pathlist[2];

 		if (de->d_ino == 0 || de->d_name[0] == '.' ||

 		    (de->d_type != DT_LNK && de->d_type != DT_UNKNOWN))

@@ -1094,7 +1095,9 @@ static int partition_try_spare(char *devname, int *dfdp, struct dev_policy *pol,

 			/* This is a partition - skip it */

 			goto next;

-		pol2 = path_policy(de->d_name, type_disk);

+		pathlist[0] = de->d_name;

+		pathlist[1] = NULL;

+		pol2 = path_policy(pathlist, type_disk);

 		domain_merge(&domlist, pol2, st ? st->ss->name : NULL);

 		if (domain_test(domlist, pol, st ? st->ss->name : NULL) != 1)

diff --git a/mdadm.h b/mdadm.h

index 387e681..705bd9b 100644

--- a/mdadm.h

+++ b/mdadm.h

@@ -1247,7 +1247,7 @@ extern void policyline(char *line, char *type);

 extern void policy_add(char *type, ...);

 extern void policy_free(void);

-extern struct dev_policy *path_policy(char *path, char *type);

+extern struct dev_policy *path_policy(char **paths, char *type);

 extern struct dev_policy *disk_policy(struct mdinfo *disk);

 extern struct dev_policy *devid_policy(int devid);

 extern void dev_policy_free(struct dev_policy *p);

diff --git a/policy.c b/policy.c

index 258f393..fa67d55 100644

--- a/policy.c

+++ b/policy.c

@@ -189,15 +189,17 @@ struct dev_policy *pol_find(struct dev_policy *pol, char *name)

 	return pol;

 }

-static char *disk_path(struct mdinfo *disk)

+static char **disk_paths(struct mdinfo *disk)

 {

 	struct stat stb;

 	int prefix_len;

 	DIR *by_path;

 	char symlink[PATH_MAX] = "/dev/disk/by-path/";

-	char nm[PATH_MAX];

+	char **paths;

+	int cnt = 0;

 	struct dirent *ent;

-	int rv;

+

+	paths = xmalloc(sizeof(*paths) * (cnt+1));

 	by_path = opendir(symlink);

 	if (by_path) {

@@ -214,22 +216,13 @@ static char *disk_path(struct mdinfo *disk)

 				continue;

 			if (stb.st_rdev != makedev(disk->disk.major, disk->disk.minor))

 				continue;

-			closedir(by_path);

-			return xstrdup(ent->d_name);

+			paths[cnt++] = xstrdup(ent->d_name);

+			paths = xrealloc(paths, sizeof(*paths) * (cnt+1));

 		}

 		closedir(by_path);

 	}

-	/* A NULL path isn't really acceptable - use the devname.. */

-	sprintf(symlink, "/sys/dev/block/%d:%d", disk->disk.major, disk->disk.minor);

-	rv = readlink(symlink, nm, sizeof(nm)-1);

-	if (rv > 0) {

-		char *dname;

-		nm[rv] = 0;

-		dname = strrchr(nm, '/');

-		if (dname)

-			return xstrdup(dname + 1);

-	}

-	return xstrdup("unknown");

+	paths[cnt] = NULL;

+	return paths;

 }

 char type_part[] = "part";

@@ -246,18 +239,53 @@ static char *disk_type(struct mdinfo *disk)

 		return type_disk;

 }

-static int pol_match(struct rule *rule, char *path, char *type)

+static int path_has_part(char *path, char **part)

+{

+	/* check if path ends with "-partNN" and

+	 * if it does, place a pointer to "-pathNN"

+	 * in 'part'.

+	 */

+	int l;

+	if (!path)

+		return 0;

+	l = strlen(path);

+	while (l > 1 && isdigit(path[l-1]))

+		l--;

+	if (l < 5 || strncmp(path+l-5, "-part", 5) != 0)

+		return 0;

+	*part = path+l-5;

+	return 1;

+}

+

+static int pol_match(struct rule *rule, char **paths, char *type, char **part)

 {

-	/* check if this rule matches on path and type */

+	/* Check if this rule matches on any path and type.

+	 * If 'part' is not NULL, then 'path' must end in -partN, which

+	 * we ignore for matching, and return in *part on success.

+	 */

 	int pathok = 0; /* 0 == no path, 1 == match, -1 == no match yet */

 	int typeok = 0;

-	while (rule) {

+	for (; rule; rule = rule->next) {

 		if (rule->name == rule_path) {

+			char *p;

+			int i;

 			if (pathok == 0)

 				pathok = -1;

-			if (path && fnmatch(rule->value, path, 0) == 0)

-				pathok = 1;

+			if (!paths)

+				continue;

+			for (i = 0; paths[i]; i++) {

+				if (part) {

+					if (!path_has_part(paths[i], &p))

+						continue;

+					*p = '\0';

+					*part = p+1;

+				}

+				if (fnmatch(rule->value, paths[i], 0) == 0)

+					pathok = 1;

+				if (part)

+					*p = '-';

+			}

 		}

 		if (rule->name == rule_type) {

 			if (typeok == 0)

@@ -265,7 +293,6 @@ static int pol_match(struct rule *rule, char *path, char *type)

 			if (type && strcmp(rule->value, type) == 0)

 				typeok = 1;

 		}

-		rule = rule->next;

 	}

 	return pathok >= 0 && typeok >= 0;

 }

@@ -286,24 +313,6 @@ static void pol_merge(struct dev_policy **pol, struct rule *rule)

 			pol_new(pol, r->name, r->value, metadata);

 }

-static int path_has_part(char *path, char **part)

-{

-	/* check if path ends with "-partNN" and

-	 * if it does, place a pointer to "-pathNN"

-	 * in 'part'.

-	 */

-	int l;

-	if (!path)

-		return 0;

-	l = strlen(path);

-	while (l > 1 && isdigit(path[l-1]))

-		l--;

-	if (l < 5 || strncmp(path+l-5, "-part", 5) != 0)

-		return 0;

-	*part = path+l-5;

-	return 1;

-}

-

 static void pol_merge_part(struct dev_policy **pol, struct rule *rule, char *part)

 {

 	/* copy any name assignments from rule into pol, appending

@@ -352,7 +361,7 @@ static int config_rules_has_path = 0;

  * path_policy() gathers policy information for the

  * disk described in the given a 'path' and a 'type'.

  */

-struct dev_policy *path_policy(char *path, char *type)

+struct dev_policy *path_policy(char **paths, char *type)

 {

 	struct pol_rule *rules;

 	struct dev_policy *pol = NULL;

@@ -361,27 +370,24 @@ struct dev_policy *path_policy(char *path, char *type)

 	rules = config_rules;

 	while (rules) {

-		char *part;

+		char *part = NULL;

 		if (rules->type == rule_policy)

-			if (pol_match(rules->rule, path, type))

+			if (pol_match(rules->rule, paths, type, NULL))

 				pol_merge(&pol, rules->rule);

 		if (rules->type == rule_part && strcmp(type, type_part) == 0)

-			if (path_has_part(path, &part)) {

-				*part = 0;

-				if (pol_match(rules->rule, path, type_disk))

-					pol_merge_part(&pol, rules->rule, part+1);

-				*part = '-';

-			}

+			if (pol_match(rules->rule, paths, type_disk, &part))

+					pol_merge_part(&pol, rules->rule, part);

 		rules = rules->next;

 	}

 	/* Now add any metadata-specific internal knowledge

 	 * about this path

 	 */

-	for (i=0; path && superlist[i]; i++)

+	for (i=0; paths[0] && superlist[i]; i++)

 		if (superlist[i]->get_disk_controller_domain) {

 			const char *d =

-				superlist[i]->get_disk_controller_domain(path);

+				superlist[i]->get_disk_controller_domain(

+					paths[0]);

 			if (d)

 				pol_new(&pol, pol_domain, d, superlist[i]->name);

 		}

@@ -400,22 +406,34 @@ void pol_add(struct dev_policy **pol,

 	pol_dedup(*pol);

 }

+static void free_paths(char **paths)

+{

+	int i;

+

+	if (!paths)

+		return;

+

+	for (i = 0; paths[i]; i++)

+		free(paths[i]);

+	free(paths);

+}

+

 /*

  * disk_policy() gathers policy information for the

  * disk described in the given mdinfo (disk.{major,minor}).

  */

 struct dev_policy *disk_policy(struct mdinfo *disk)

 {

-	char *path = NULL;

+	char **paths = NULL;

 	char *type = disk_type(disk);

 	struct dev_policy *pol = NULL;

 	if (config_rules_has_path)

-		path = disk_path(disk);

+		paths = disk_paths(disk);

-	pol = path_policy(path, type);

+	pol = path_policy(paths, type);

-	free(path);

+	free_paths(paths);

 	return pol;

 }

@@ -756,27 +774,26 @@ int policy_check_path(struct mdinfo *disk, struct map_ent *array)

 {

 	char path[PATH_MAX];

 	FILE *f = NULL;

-	char *id_path = disk_path(disk);

-	int rv;

+	char **id_paths = disk_paths(disk);

+	int i;

+	int rv = 0;

-	if (!id_path)

-		return 0;

+	for (i = 0; id_paths[i]; i++) {

+		snprintf(path, PATH_MAX, FAILED_SLOTS_DIR "/%s", id_paths[i]);

+		f = fopen(path, "r");

+		if (!f)

+			continue;

-	snprintf(path, PATH_MAX, FAILED_SLOTS_DIR "/%s", id_path);

-	f = fopen(path, "r");

-	if (!f) {

-		free(id_path);

-		return 0;

+		rv = fscanf(f, " %s %x:%x:%x:%x\n",

+			    array->metadata,

+			    array->uuid,

+			    array->uuid+1,

+			    array->uuid+2,

+			    array->uuid+3);

+		fclose(f);

+		break;

 	}

-

-	rv = fscanf(f, " %s %x:%x:%x:%x\n",

-		    array->metadata,

-		    array->uuid,

-		    array->uuid+1,

-		    array->uuid+2,

-		    array->uuid+3);

-	fclose(f);

-	free(id_path);

+	free_paths(id_paths);

 	return rv == 5;

 }

-- 

2.7.5