@@ -183,6 +183,11 @@ OPTIONS
you can duplicate the UUID; however, for a multi-device filesystem, the UUID
must not already exist on any currently present filesystem.
+--device-uuid <UUID>
+ Create the filesystem with the given device-uuid (also known as sub-uuid) *UUID*.
+ For a single-device filesystem, you can duplicate the device-uuid; however, used
+ for a multi-device filesystem this option will not apply presently.
+
-v|--verbose
Increase verbosity level, default is 1.
@@ -340,6 +340,7 @@ static void mkfs_blocks_remove(enum btrfs_mkfs_block *blocks, int *blocks_nr,
/*
* @fs_uuid - if NULL, generates a UUID, returns back the new filesystem UUID
+ * @dev_uuid - if NULL, generates a UUID, returns back the new device UUID
*
* The superblock signature is not valid, denotes a partially created
* filesystem, needs to be finalized.
@@ -435,7 +436,12 @@ int make_btrfs(int fd, struct btrfs_mkfs_config *cfg)
} else {
uuid_parse(cfg->fs_uuid, super.fsid);
}
- uuid_generate(super.dev_item.uuid);
+ if (!*cfg->dev_uuid) {
+ uuid_generate(super.dev_item.uuid);
+ uuid_unparse(super.dev_item.uuid, cfg->dev_uuid);
+ } else {
+ uuid_parse(cfg->dev_uuid, super.dev_item.uuid);
+ }
uuid_generate(chunk_tree_uuid);
for (i = 0; i < blocks_nr; i++) {
@@ -90,7 +90,12 @@ struct btrfs_mkfs_config {
/* Logical addresses of superblock [0] and other tree roots */
u64 blocks[MKFS_BLOCK_COUNT + 1];
+
+ /* btrfs_super_block filesystem uuid */
char fs_uuid[BTRFS_UUID_UNPARSED_SIZE];
+
+ /* btrfs_dev_item device uuid */
+ char dev_uuid[BTRFS_UUID_UNPARSED_SIZE];
char chunk_uuid[BTRFS_UUID_UNPARSED_SIZE];
/* Superblock offset after make_btrfs */
@@ -431,6 +431,7 @@ static const char * const mkfs_usage[] = {
OPTLINE("-O|--features LIST", "comma separated list of filesystem features (use '-O list-all' to list features)"),
OPTLINE("-L|--label LABEL", "set the filesystem label"),
OPTLINE("-U|--uuid UUID", "Specify the filesystem UUID (must be unique for a filesystem with multiple devices)"),
+ OPTLINE("--device-uuid UUID", "Specify the filesystem device UUID (a.k.a sub-uuid) (for single device filesystem only)"),
"Creation:",
OPTLINE("-b|--byte-count SIZE", "set size of each device to SIZE (filesystem size is sum of all device sizes)"),
OPTLINE("-r|--rootdir DIR", "copy files from DIR to the image root directory"),
@@ -1161,6 +1162,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
struct btrfs_mkfs_features features = btrfs_mkfs_default_features;
enum btrfs_csum_type csum_type = BTRFS_CSUM_TYPE_CRC32;
char fs_uuid[BTRFS_UUID_UNPARSED_SIZE] = { 0 };
+ char dev_uuid[BTRFS_UUID_UNPARSED_SIZE] = { 0 };
u32 nodesize = 0;
bool nodesize_forced = false;
u32 sectorsize = 0;
@@ -1187,6 +1189,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
GETOPT_VAL_SHRINK = GETOPT_VAL_FIRST,
GETOPT_VAL_CHECKSUM,
GETOPT_VAL_GLOBAL_ROOTS,
+ GETOPT_VAL_DEVICE_UUID,
};
static const struct option long_options[] = {
{ "byte-count", required_argument, NULL, 'b' },
@@ -1208,6 +1211,8 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
{ "features", required_argument, NULL, 'O' },
{ "runtime-features", required_argument, NULL, 'R' },
{ "uuid", required_argument, NULL, 'U' },
+ { "device-uuid", required_argument, NULL, \
+ GETOPT_VAL_DEVICE_UUID },
{ "quiet", 0, NULL, 'q' },
{ "verbose", 0, NULL, 'v' },
{ "shrink", no_argument, NULL, GETOPT_VAL_SHRINK },
@@ -1331,6 +1336,10 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
case 'q':
bconf_be_quiet();
break;
+ case GETOPT_VAL_DEVICE_UUID:
+ strncpy(dev_uuid, optarg,
+ BTRFS_UUID_UNPARSED_SIZE - 1);
+ break;
case GETOPT_VAL_SHRINK:
shrink_rootdir = true;
break;
@@ -1372,6 +1381,10 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
error("the option -r is limited to a single device");
goto error;
}
+ if (strlen(dev_uuid) != 0 && device_count > 1) {
+ error("the option --device-uuid is limited to a single device");
+ goto error;
+ }
if (shrink_rootdir && source_dir == NULL) {
error("the option --shrink must be used with --rootdir");
goto error;
@@ -1730,6 +1743,7 @@ int BOX_MAIN(mkfs)(int argc, char **argv)
mkfs_cfg.label = label;
memcpy(mkfs_cfg.fs_uuid, fs_uuid, sizeof(mkfs_cfg.fs_uuid));
+ memcpy(mkfs_cfg.dev_uuid, dev_uuid, sizeof(mkfs_cfg.dev_uuid));
mkfs_cfg.num_bytes = dev_block_count;
mkfs_cfg.nodesize = nodesize;
mkfs_cfg.sectorsize = sectorsize;
Add an option to specify the device uuid for mkfs. This is useful for creating a filesystem with a specific device uuid. This is useful for testing. Signed-off-by: Anand Jain <anand.jain@oracle.com> --- v2: Added --help. Added comments for the dev_uuid and fs_uuid. Removed short -P option instead using only long option --device-uuid. Add error if --device-uuid is used with multi-device. For example: $ mkfs.btrfs -f --device-uuid 29e708ad-6fe5-447d-8910-a9b9f79854b5 /dev/sdc5 /dev/sdc6 btrfs-progs v6.5.1 See https://btrfs.readthedocs.io for more information. ERROR: the option --device-uuid is limited to a single device Documentation/mkfs.btrfs.rst | 5 +++++ mkfs/common.c | 8 +++++++- mkfs/common.h | 5 +++++ mkfs/main.c | 14 ++++++++++++++ 4 files changed, 31 insertions(+), 1 deletion(-)