Remove exit points from libbache and return error messages instead.

Change-Id: Ibd238bb63354dae841c2a70e5ded550b3c603d4b
Signed-off-by: Jacob Malevich <jam@daterainc.com>

bcache.c

@@ -963,7 +963,7 @@ static void list_cacheset_devs(char *cset_dir, char *cset_name, bool parse_dev_n
 	}
 }
 
-void find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uuid) {
+char *find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uuid) {
 	/* Do a query-dev --uuid only to get the uuid
 	 * repeat on each dev until we find a matching one
 	 * append that cache# to subdir and return
@@ -974,6 +974,7 @@ void find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uui
 	struct stat cache_stat;
 	char intbuf[4];
 	char entry[MAX_PATH];
+	char *err = NULL;
 
 	snprintf(entry, MAX_PATH, "%s%s", stats_dir, subdir);
 	snprintf(intbuf, 4, "%d", i);
@@ -1010,7 +1011,7 @@ void find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uui
 			query_dev(devname, false, false, true, dev_uuid);
 			if(!strcmp(stats_dev_uuid, dev_uuid)) {
 				strcat(subdir, intbuf);
-				return;
+				return err;
 			}
 		}
 
@@ -1022,17 +1023,20 @@ void find_matching_uuid(char *stats_dir, char *subdir, const char *stats_dev_uui
 	}
 
 
-	printf("dev uuid doesn't exist in cache_set\n");
+	err = "dev uuid doesn't exist in cache_set";
-	exit(1);
+	return err;
 }
 
-int list_cachesets(char *cset_dir, bool list_devs)
+char *list_cachesets(char *cset_dir, bool list_devs)
 {
 	struct dirent *ent;
-	DIR *dir = opendir(cset_dir);
+	DIR *dir;
+	char *err = NULL;
+
+	dir = opendir(cset_dir);
 	if (!dir) {
-		fprintf(stderr, "Failed to open dir %s\n", cset_dir);
+		err = "Failed to open cacheset dir";
-		return 1;
+		goto err;
 	}
 
 	while ((ent = readdir(dir)) != NULL) {
@@ -1045,8 +1049,8 @@ int list_cachesets(char *cset_dir, bool list_devs)
 
 		snprintf(entry, MAX_PATH, "%s/%s", cset_dir, ent->d_name);
 		if(stat(entry, &statbuf) == -1) {
-			fprintf(stderr, "Failed to stat %s\n", entry);
+			err = "Failed to stat cacheset subdir";
-			return 1;
+			goto err;
 		}
 
 		if (S_ISDIR(statbuf.st_mode)) {
@@ -1058,55 +1062,63 @@ int list_cachesets(char *cset_dir, bool list_devs)
 		}
 	}
 
+err:
 	closedir(dir);
-
+	return err;
-	return 0;
 }
 
-static int get_bcache_fd(void)
+char *register_bcache(char *const *devs)
-{
-	int bcachefd = open("/dev/bcache", O_RDWR);
-
-	if (bcachefd < 0) {
-		perror("Can't open bcache device\n");
-		exit(EXIT_FAILURE);
-	}
-	return bcachefd;
-}
-
-int register_bcache(char *const *devs)
 {
 	int ret, bcachefd;
+	char *err = NULL;
 
-	bcachefd = get_bcache_fd();
+	bcachefd = open("/dev/bcache", O_RDWR);
+	if (bcachefd < 0) {
+		err = "Can't open bcache device";
+		goto err;
+	}
 
 	ret = ioctl(bcachefd, BCH_IOCTL_REGISTER, devs);
 	if (ret < 0) {
-		fprintf(stderr, "ioctl register error: %s\n", strerror(ret));
+		char tmp[64];
-		exit(EXIT_FAILURE);
+		snprintf(tmp, 64, "ioctl register error: %s\n",
+				strerror(ret));
+		err = strdup(tmp);
+		goto err;
 	}
 
+err:
+	if (bcachefd)
 		close(bcachefd);
-	return 0;
+	return err;
 }
 
-int unregister_bcache(char *const *devs)
+char *unregister_bcache(char *const *devs)
 {
 	int ret, bcachefd;
+	char *err = NULL;
 
-	bcachefd = get_bcache_fd();
+	bcachefd = open("/dev/bcache", O_RDWR);
+	if (bcachefd < 0) {
+		err = "Can't open bcache device";
+		goto err;
+	}
 
 	ret = ioctl(bcachefd, BCH_IOCTL_UNREGISTER, devs);
 	if (ret < 0) {
-		fprintf(stderr, "ioctl unregister error: %s\n", strerror(ret));
+		char tmp[64];
-		exit(EXIT_FAILURE);
+		snprintf(tmp, 64, "ioctl unregister error: %s\n",
+				strerror(ret));
+		err = strdup(tmp);
+		goto err;
 	}
 
+err:
 	close(bcachefd);
-	return 0;
+	return err;
 }
 
-int probe(char *dev, int udev)
+char *probe(char *dev, int udev)
 {
 	struct cache_sb sb;
 	char uuid[40];
@@ -1164,9 +1176,8 @@ int probe(char *dev, int udev)
 
 	return 0;
 
-	err:
+err:
-		fprintf(stderr, "Probe exit with error: %s", err);
+	return err;
-		return -1;
 }
 
 void sb_state(struct cache_sb *sb, char *dev)
@@ -1181,15 +1192,18 @@ void sb_state(struct cache_sb *sb, char *dev)
 
 }
 
-void read_stat_dir(DIR *dir, char *stats_dir, char *stat_name, bool print_val)
+char *read_stat_dir(DIR *dir, char *stats_dir, char *stat_name, bool print_val)
 {
 	struct stat statbuf;
 	char entry[MAX_PATH];
+	char *err = NULL;
 
 	snprintf(entry, MAX_PATH, "%s/%s", stats_dir, stat_name);
 	if(stat(entry, &statbuf) == -1) {
-		fprintf(stderr, "Failed to stat %s\n", entry);
+		char tmp[MAX_PATH];
-		return;
+		snprintf(tmp, MAX_PATH, "Failed to stat %s\n", entry);
+		err = strdup(tmp);
+		goto err;
 	}
 
 	if (S_ISREG(statbuf.st_mode)) {
@@ -1200,7 +1214,7 @@ void read_stat_dir(DIR *dir, char *stats_dir, char *stat_name, bool print_val)
 		if(!fp) {
 			/* If we can't open the file, this is probably because
 			 * of permissions, just move to the next file */
-			return;
+			return NULL;
 		}
 
 		while(fgets(buf, MAX_PATH, fp));
@@ -1211,4 +1225,6 @@ void read_stat_dir(DIR *dir, char *stats_dir, char *stat_name, bool print_val)
 			printf("%s\n", stat_name);
 		fclose(fp);
 	}
+err:
+	return err;
 }

bcache.h

@@ -59,14 +59,14 @@ void show_super_backingdev(struct cache_sb *, bool);
 void show_super_cache(struct cache_sb *, bool);
 
 struct cache_sb *query_dev(char *, bool, bool, bool, char *dev_uuid);
-int list_cachesets(char *, bool);
+char *list_cachesets(char *, bool);
 char *parse_array_to_list(char *const *);
-int register_bcache(char *const *);
+char *register_bcache(char *const *);
-int unregister_bcache(char *const *);
+char *unregister_bcache(char *const *);
-int probe(char *, int);
+char *probe(char *, int);
 void sb_state(struct cache_sb *, char *);
-void read_stat_dir(DIR *, char *, char *, bool);
+char *read_stat_dir(DIR *, char *, char *, bool);
-void find_matching_uuid(char *, char *, const char*);
+char *find_matching_uuid(char *, char *, const char*);
 //int add_device(char *);
 //int remove_device(char *);
 

bcacheadm.c

@@ -112,14 +112,12 @@ static int set_block_size(NihOption *option, const char *arg)
 static int set_cache(NihOption *option, const char *arg)
 {
 	bdev = 0;
-	cache_devices[nr_cache_devices] = (char *)malloc(sizeof(char *) *
-			strlen(arg) + 1);
 	cache_devices[nr_cache_devices] = strdup(arg);
 	if(!tier)
 		tier_mapping[nr_cache_devices] = 0;
 	else {
 		int ntier = atoi(tier);
-		if(tier == 0 || tier == 1)
+		if(ntier == 0 || ntier == 1)
 			tier_mapping[nr_cache_devices] = ntier;
 		else
 			printf("Invalid tier\n");
@@ -133,14 +131,9 @@ static int set_bdev(NihOption *option, const char *arg)
 {
 	bdev = 1;
 
-	if(label) {
+	if(label)
-		backing_dev_labels[nr_backing_devices] =
-			(char *)malloc(sizeof(char *) * strlen(label) + 1);
 		backing_dev_labels[nr_backing_devices] = strdup(label);
-	}
 
-	backing_devices[nr_backing_devices] = (char *)malloc(sizeof(char *) *
-			strlen(arg) + 1);
 	backing_devices[nr_backing_devices] = strdup(arg);
 
 	nr_backing_devices++;
@@ -350,9 +343,14 @@ int make_bcache(NihCommand *command, char *const *args)
 int probe_bcache(NihCommand *command, char *const *args)
 {
 	int i;
+	char *err = NULL;
 
 	for (i = 0; args[i] != NULL; i++) {
-		probe(args[i], udev);
+		err = probe(args[i], udev);
+		if(err) {
+			printf("probe_bcache error: %s\n", err);
+			return -1;
+		}
 	}
 
 	return 0;
@@ -360,21 +358,40 @@ int probe_bcache(NihCommand *command, char *const *args)
 
 int bcache_register(NihCommand *command, char *const *args)
 {
-	int ret = register_bcache(args);
+	char *err = NULL;
 
-	return ret;
+	err = register_bcache(args);
+	if (err) {
+		printf("bcache_register error: %s\n", err);
+		return -1;
+	}
+
+	return 0;
 }
 
 int bcache_unregister(NihCommand *command, char *const *args)
 {
-	int ret = unregister_bcache(args);
+	char *err = NULL;
 
-	return ret;
+	err = unregister_bcache(args);
+	if (err) {
+		printf("bcache_unregister error: %s\n", err);
+		return -1;
+	}
+
+	return 0;
 }
 
 int bcache_list_cachesets(NihCommand *command, char *const *args)
 {
-	return list_cachesets(cset_dir, list_devs);
+	char *err = NULL;
+	err = list_cachesets(cset_dir, list_devs);
+	if (err) {
+		printf("bcache_list_cachesets error :%s\n", err);
+		return -1;
+	}
+
+	return 0;
 }
 
 int bcache_query_devs(NihCommand *command, char *const *args)
@@ -416,12 +433,15 @@ int bcache_status(NihCommand *command, char *const *args)
 	if (sb_tier1) sb_state(sb_tier1, dev1);
 }
 
-static void stats_subdir(char* stats_dir)
+static char *stats_subdir(char* stats_dir)
 {
 	char tmp[50] = "/";
+	char *err = NULL;
 	if(stats_dev_uuid) {
 		strcat(tmp, "cache");
-		find_matching_uuid(stats_dir, tmp, stats_dev_uuid);
+		err = find_matching_uuid(stats_dir, tmp, stats_dev_uuid);
+		if(err)
+			goto err;
 	} else if(stats_cache_num) {
 		strcat(tmp, "cache");
 		strcat(tmp, stats_cache_num);
@@ -434,9 +454,12 @@ static void stats_subdir(char* stats_dir)
 	else if (stats_total)
 		strcat(tmp, "stats_total");
 	else
-		return;
+		return err;
 
 	strcat(stats_dir, tmp);
+
+err:
+	return err;
 }
 
 int bcache_stats(NihCommand *command, char *const *args)
@@ -445,29 +468,46 @@ int bcache_stats(NihCommand *command, char *const *args)
 	char stats_dir[MAX_PATH];
 	DIR *dir = NULL;
 	struct dirent *ent = NULL;
+	char *err = NULL;
 
 	if (stats_uuid) {
 		snprintf(stats_dir, MAX_PATH, "%s/%s", cset_dir, stats_uuid);
-		stats_subdir(stats_dir);
+		err = stats_subdir(stats_dir);
+		if(err)
+			goto err;
+
 		dir = opendir(stats_dir);
 		if (!dir) {
-			fprintf(stderr, "Failed to open dir %s\n", cset_dir);
+			err = "Failed to open dir";
-			return 1;
+			goto err;
 		}
 	} else {
-		printf("Must provide a cacheset uuid\n");
+		err = "Must provide a cacheset uuid";
-		exit(EXIT_FAILURE);
+		goto err;
 	}
 
-	if(stats_list || stats_all)
+	if(stats_list || stats_all) {
-		while ((ent = readdir(dir)) != NULL)
+		while ((ent = readdir(dir)) != NULL) {
-			read_stat_dir(dir, stats_dir, ent->d_name, stats_all);
+			err = read_stat_dir(dir, stats_dir, ent->d_name, stats_all);
+			if (err)
+				goto err;
+		}
+	}
 
 
-	for (i = 0; args[i] != NULL; i++)
+	for (i = 0; args[i] != NULL; i++) {
-		read_stat_dir(dir, stats_dir, args[i], true);
+		err = read_stat_dir(dir, stats_dir, args[i], true);
+		if (err)
+			goto err;
+	}
 
 	closedir(dir);
+	return 0;
+
+err:
+	closedir(dir);
+	printf("bcache_stats error: %s\n", err);
+	return -1;
 }
 
 static NihCommand commands[] = {