I rethink this and conclude that we should only allow the absolute path to the subvolume in order to prevent setting wrong filesystem by mistake when multiple filesystems are used.
I will submit the patch again and please ignore this. Regards, Tomohiro On 2017/10/02 15:25, Misono, Tomohiro wrote: > 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. Therefore there is no ambiguity between subvol > id and subvol name, which is mentioned in the above issue page. > > subvol id is resolved by get_subvol_info() which is used by "subvol show". > > Signed-off-by: Tomohiro Misono <[email protected]> > --- > Documentation/btrfs-subvolume.asciidoc | 10 +++---- > cmds-subvolume.c | 48 > ++++++++++++++++++++++++++-------- > 2 files changed, 42 insertions(+), 16 deletions(-) > > diff --git a/Documentation/btrfs-subvolume.asciidoc > b/Documentation/btrfs-subvolume.asciidoc > index 5cfe885..df27460 100644 > --- a/Documentation/btrfs-subvolume.asciidoc > +++ b/Documentation/btrfs-subvolume.asciidoc > @@ -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>. > diff --git a/cmds-subvolume.c b/cmds-subvolume.c > index 666f6e0..5bf8295 100644 > --- a/cmds-subvolume.c > +++ b/cmds-subvolume.c > @@ -803,28 +803,54 @@ 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 > }; > > static int cmd_subvol_set_default(int argc, char **argv) > { > - int ret=0, fd, e; > - u64 objectid; > - char *path; > - char *subvolid; > - DIR *dirstream = NULL; > + int ret = 0; > + int fd, e; > + u64 objectid; > + char *path; > + char *subvolid; > + DIR *dirstream = NULL; > > 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 */ > + struct root_info ri; > + char *fullpath; > > - objectid = arg_strtou64(subvolid); > + path = argv[optind]; > + fullpath = realpath(path, NULL); > + if (!fullpath) { > + error("cannot find real path for '%s': %s", > + path, strerror(errno)); > + return 1; > + } > + > + ret = get_subvol_info(fullpath, &ri); > + free(fullpath); > + > + if (ret) > + return 1; > + > + objectid = ri.root_id; > + } 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) > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
