diff options
| -rw-r--r-- | Documentation/btrfs-subvolume.asciidoc | 11 | ||||
| -rw-r--r-- | cmds-subvolume.c | 45 |
2 files changed, 43 insertions, 13 deletions
diff --git a/Documentation/btrfs-subvolume.asciidoc b/Documentation/btrfs-subvolume.asciidoc index 5cfe8856..d33fee5a 100644 --- a/Documentation/btrfs-subvolume.asciidoc +++ b/Documentation/btrfs-subvolume.asciidoc @@ -142,12 +142,13 @@ 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 default subvolume of the (mounted) filesystem. + -The subvolume is identified by <id>, which is returned by the *subvolume list* -command. +There are two ways how to specify the subvolume, by <id> or by the <subvolume> +path. +The id can be obtained from *btrfs subvolume list*, *btrfs subvolume show* or +*btrfs inspect-internal rootid*. *show* <path>:: Show information of a given subvolume in the <path>. diff --git a/cmds-subvolume.c b/cmds-subvolume.c index e7caa05a..dc626a64 100644 --- a/cmds-subvolume.c +++ b/cmds-subvolume.c @@ -858,8 +858,11 @@ out: } static const char * const cmd_subvol_set_default_usage[] = { + "btrfs subvolume set-default <subvolume>\n" "btrfs subvolume set-default <subvolid> <path>", - "Set the default subvolume of a filesystem", + "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 }; @@ -873,17 +876,43 @@ 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; |