@@ -142,12 +142,12 @@ you can add \'\+' or \'-' in front of each items, \'+' means ascending,
for --sort you can combine some items together by \',', just like
--sort=+ogen,-gen,path,rootid.
-*set-default* <id> <path>::
-Set the subvolume of the filesystem <path> which is mounted as
-default.
+*set-default* [<subvolume>|<id> <path>]::
+Set the subvolume of the filesystem which is mounted as default.
+
-The subvolume is identified by <id>, which is returned by the *subvolume list*
-command.
+If <id> and <path> is given, the subvolume is identified by <id>,
+which is returned by the *subvolume list* command. The filesystem
+is specified by <path>.
*show* <path>::
Show information of a given subvolume in the <path>.
@@ -803,8 +803,10 @@ out:
}
static const char * const cmd_subvol_set_default_usage[] = {
- "btrfs subvolume set-default <subvolid> <path>",
- "Set the default subvolume of a filesystem",
+ "btrfs subvolume set-default [<subvolume>|<subvolid> <path>]",
+ "Set the default subvolume of the filesystem mounted as default.",
+ "The subvolume can be specified by its path,",
+ "or the pair of subvolume id and path to the filesystem.",
NULL
};
@@ -818,17 +820,43 @@ static int cmd_subvol_set_default(int argc, char **argv)
clean_args_no_options(argc, argv, cmd_subvol_set_default_usage);
- if (check_argc_exact(argc - optind, 2))
+ if (check_argc_min(argc - optind, 1) ||
+ check_argc_max(argc - optind, 2))
usage(cmd_subvol_set_default_usage);
- subvolid = argv[optind];
- path = argv[optind + 1];
+ if (argc - optind == 1) {
+ /* path to the subvolume is specified */
+ path = argv[optind];
- objectid = arg_strtou64(subvolid);
+ ret = test_issubvolume(path);
+ if (ret < 0) {
+ error("stat error: %s", strerror(-ret));
+ return 1;
+ } else if (!ret) {
+ error("'%s' is not a subvolume", path);
+ return 1;
+ }
- fd = btrfs_open_dir(path, &dirstream, 1);
- if (fd < 0)
- return 1;
+ fd = btrfs_open_dir(path, &dirstream, 1);
+ if (fd < 0)
+ return 1;
+
+ ret = lookup_path_rootid(fd, &objectid);
+ if (ret) {
+ error("unable to get subvol id: %s", strerror(-ret));
+ close_file_or_dir(fd, dirstream);
+ return 1;
+ }
+ } else {
+ /* subvol id and path to the filesystem are specified */
+ subvolid = argv[optind];
+ path = argv[optind + 1];
+ objectid = arg_strtou64(subvolid);
+
+ fd = btrfs_open_dir(path, &dirstream, 1);
+ if (fd < 0)
+ return 1;
+ }
ret = ioctl(fd, BTRFS_IOC_DEFAULT_SUBVOL, &objectid);
e = errno;
This patch changes "subvol set-default" to also accept the subvolume path for convenience. This is the one of the issue on github: https://github.com/kdave/btrfs-progs/issues/35 If there are two args, they are assumed as subvol id and path to the fs (the same as current behavior), and if there is only one arg, it is assumed as the path to the subvolume. subvol id is resolved by test_issubvolume() + lookup_path_rootid(). Empty subvol (ino==2) will get error on test_issubvolume() which checks whether inode num is 256 or not. Signed-off-by: Tomohiro Misono <misono.tomohiro@jp.fujitsu.com> --- changelog v1 -> v2 : revert v1 -> v3 : use test_issubvolume() + lookup_path_rootid() instead of get_subvol_info() for getting subvol id of path. Documentation/btrfs-subvolume.asciidoc | 10 ++++---- cmds-subvolume.c | 46 +++++++++++++++++++++++++++------- 2 files changed, 42 insertions(+), 14 deletions(-)