From: Eric Sandeen <sandeen@redhat.com>

Date: Wed, 14 May 2014 17:39:07 +0000 (-0500)

Subject: btrfs-progs: mkfs: allow UUID specification at mkfs time

X-Git-Url: http://repo.or.cz/w/btrfs-progs-unstable/devel.git/commitdiff_plain/a03901849f868c65f845325fcaeb3d25c6896759

btrfs-progs: mkfs: allow UUID specification at mkfs time

Allow the specification of the filesystem UUID at mkfs time.

Non-unique unique IDs are rejected.  This includes attempting

to re-mkfs with the same UUID; if you really want to do that,

you can mkfs with a new UUID, then re-mkfs with the one you

wanted.

(Implemented only for mkfs.btrfs, not btrfs-convert).

Signed-off-by: Eric Sandeen <sandeen@redhat.com>

[converted help to asciidoc]

Signed-off-by: David Sterba <dsterba@suse.cz>

---

Index: btrfs-progs-v3.14.2/Documentation/mkfs.btrfs.txt

===================================================================

--- btrfs-progs-v3.14.2.orig/Documentation/mkfs.btrfs.txt

+++ btrfs-progs-v3.14.2/Documentation/mkfs.btrfs.txt

@@ -21,6 +21,7 @@ $$[-s|--sectorsize <sectorsize>]$$

 $$[-r|--rootdir <rootdir>]$$

 $$[-K|--nodiscard]$$

 $$[-O|--features <feature1>[,<feature2>...]]$$

+$$[-U|--uuid <UUID>]$$

 $$[-h]$$

 $$[-V|--version]$$

 $$<device> [<device>...]$$

@@ -109,6 +110,10 @@ supported by old kernels.

 To see all features run::::

 mkfs.btrfs -O list-all

+-U|--uuid <UUID>::

+Create the filesystem with the specified UUID, which must not already exist on

+the system.

+

 -V|--version::

 Print the *mkfs.btrfs* version and exit.

Index: btrfs-progs-v3.14.2/btrfs-convert.c

===================================================================

--- btrfs-progs-v3.14.2.orig/btrfs-convert.c

+++ btrfs-progs-v3.14.2/btrfs-convert.c

@@ -2240,7 +2240,7 @@ static int do_convert(const char *devnam

 		goto fail;

 	}

 	ret = make_btrfs(fd, devname, ext2_fs->super->s_volume_name,

-			 blocks, total_bytes, blocksize, blocksize,

+			 NULL, blocks, total_bytes, blocksize, blocksize,

 			 blocksize, blocksize, 0);

 	if (ret) {

 		fprintf(stderr, "unable to create initial ctree: %s\n",

Index: btrfs-progs-v3.14.2/mkfs.c

===================================================================

--- btrfs-progs-v3.14.2.orig/mkfs.c

+++ btrfs-progs-v3.14.2/mkfs.c

@@ -288,6 +288,7 @@ static void print_usage(void)

 	fprintf(stderr, "\t -r --rootdir the source directory\n");

 	fprintf(stderr, "\t -K --nodiscard do not perform whole device TRIM\n");

 	fprintf(stderr, "\t -O --features comma separated list of filesystem features\n");

+	fprintf(stderr, "\t -U --uuid specify the filesystem UUID\n");

 	fprintf(stderr, "\t -V --version print the mkfs.btrfs version and exit\n");

 	fprintf(stderr, "%s\n", BTRFS_BUILD_VERSION);

 	exit(1);

@@ -351,6 +352,7 @@ static struct option long_options[] = {

 	{ "rootdir", 1, NULL, 'r' },

 	{ "nodiscard", 0, NULL, 'K' },

 	{ "features", 1, NULL, 'O' },

+	{ "uuid", 0, NULL, 'U' },

 	{ NULL, 0, NULL, 0}

 };

@@ -1273,11 +1275,12 @@ int main(int ac, char **av)

 	int dev_cnt = 0;

 	int saved_optind;

 	char estr[100];

+	char *fs_uuid = NULL;

 	u64 features = DEFAULT_MKFS_FEATURES;

 	while(1) {

 		int c;

-		c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:O:r:VMK",

+		c = getopt_long(ac, av, "A:b:fl:n:s:m:d:L:O:r:U:VMK",

 				long_options, &option_index);

 		if (c < 0)

 			break;

@@ -1346,6 +1349,9 @@ int main(int ac, char **av)

 				source_dir = optarg;

 				source_dir_set = 1;

 				break;

+			case 'U':

+				fs_uuid = optarg;

+				break;

 			case 'K':

 				discard = 0;

 				break;

@@ -1368,6 +1374,20 @@ int main(int ac, char **av)

 			"The -r option is limited to a single device\n");

 		exit(1);

 	}

+

+	if (fs_uuid) {

+		uuid_t dummy_uuid;

+

+		if (uuid_parse(fs_uuid, dummy_uuid) != 0) {

+			fprintf(stderr, "could not parse UUID: %s\n", fs_uuid);

+			exit(1);

+		}

+		if (!test_uuid_unique(fs_uuid)) {

+			fprintf(stderr, "non-unique UUID: %s\n", fs_uuid);

+			exit(1);

+		}

+	}

+	

 	while (dev_cnt-- > 0) {

 		file = av[optind++];

 		if (is_block_device(file))

@@ -1514,7 +1534,7 @@ int main(int ac, char **av)

 	process_fs_features(features);

-	ret = make_btrfs(fd, file, label, blocks, dev_block_count,

+	ret = make_btrfs(fd, file, label, fs_uuid, blocks, dev_block_count,

 			 nodesize, leafsize,

 			 sectorsize, stripesize, features);

 	if (ret) {

Index: btrfs-progs-v3.14.2/utils.c

===================================================================

--- btrfs-progs-v3.14.2.orig/utils.c

+++ btrfs-progs-v3.14.2/utils.c

@@ -93,12 +93,41 @@ static u64 reference_root_table[] = {

 	[6] =	BTRFS_CSUM_TREE_OBJECTID,

 };

-int make_btrfs(int fd, const char *device, const char *label,

+int test_uuid_unique(char *fs_uuid)

+{

+	int unique = 1;

+	blkid_dev_iterate iter = NULL;

+	blkid_dev dev = NULL;

+	blkid_cache cache = NULL;

+

+	if (blkid_get_cache(&cache, 0) < 0) {

+		printf("ERROR: lblkid cache get failed\n");

+		return 1;

+	}

+	blkid_probe_all(cache);

+	iter = blkid_dev_iterate_begin(cache);

+	blkid_dev_set_search(iter, "UUID", fs_uuid);

+

+	while (blkid_dev_next(iter, &dev) == 0) {

+		dev = blkid_verify(cache, dev);

+		if (dev) {

+			unique = 0;

+			break;

+		}

+	}

+

+	blkid_dev_iterate_end(iter);

+	blkid_put_cache(cache);

+

+	return unique;

+}

+

+int make_btrfs(int fd, const char *device, const char *label, char *fs_uuid,

 	       u64 blocks[7], u64 num_bytes, u32 nodesize,

 	       u32 leafsize, u32 sectorsize, u32 stripesize, u64 features)

 {

 	struct btrfs_super_block super;

-	struct extent_buffer *buf;

+	struct extent_buffer *buf = NULL;

 	struct btrfs_root_item root_item;

 	struct btrfs_disk_key disk_key;

 	struct btrfs_extent_item *extent_item;

@@ -125,7 +154,20 @@ int make_btrfs(int fd, const char *devic

 	memset(&super, 0, sizeof(super));

 	num_bytes = (num_bytes / sectorsize) * sectorsize;

-	uuid_generate(super.fsid);

+	if (fs_uuid) {

+		if (uuid_parse(fs_uuid, super.fsid) != 0) {

+			fprintf(stderr, "could not parse UUID: %s\n", fs_uuid);

+			ret = -EINVAL;

+			goto out;

+		}

+		if (!test_uuid_unique(fs_uuid)) {

+			fprintf(stderr, "non-unique UUID: %s\n", fs_uuid);

+			ret = -EBUSY;

+			goto out;

+		}

+	} else {

+		uuid_generate(super.fsid);

+	}

 	uuid_generate(super.dev_item.uuid);

 	uuid_generate(chunk_tree_uuid);

Index: btrfs-progs-v3.14.2/utils.h

===================================================================

--- btrfs-progs-v3.14.2.orig/utils.h

+++ btrfs-progs-v3.14.2/utils.h

@@ -40,7 +40,7 @@

 #define BTRFS_UUID_UNPARSED_SIZE	37

 int make_btrfs(int fd, const char *device, const char *label,

-	       u64 blocks[6], u64 num_bytes, u32 nodesize,

+	       char *fs_uuid, u64 blocks[6], u64 num_bytes, u32 nodesize,

 	       u32 leafsize, u32 sectorsize, u32 stripesize, u64 features);

 int btrfs_make_root_dir(struct btrfs_trans_handle *trans,

 			struct btrfs_root *root, u64 objectid);

@@ -101,5 +101,5 @@ int get_btrfs_mount(const char *dev, cha

 int find_mount_root(const char *path, char **mount_root);

 int get_device_info(int fd, u64 devid,

 		struct btrfs_ioctl_dev_info_args *di_args);

-

+int test_uuid_unique(char *fs_uuid);

 #endif