From: Eric Sandeen 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 [converted help to asciidoc] Signed-off-by: David Sterba --- 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 @@ $$[-s|--sectorsize ]$$ $$[-r|--rootdir ]$$ $$[-K|--nodiscard]$$ $$[-O|--features [,...]]$$ +$$[-U|--uuid ]$$ $$[-h]$$ $$[-V|--version]$$ $$ [...]$$ @@ -109,6 +110,10 @@ supported by old kernels. To see all features run:::: mkfs.btrfs -O list-all +-U|--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