From e8f47cf068c3a4b5de7770ebb9eef37e28e09ef7 Mon Sep 17 00:00:00 2001 From: Goffredo Baroncelli Date: Sun, 5 Dec 2010 17:46:44 +0000 Subject: Add the "btrfs filesystem label" command Hi all, this patch adds the command "btrfs filesystem label" to change (or show) the label of a filesystem. This patch is a subset of the one written previously by Morey Roof. I included the user space part only. So it is possible only to change/show a label of a *single device* and *unounted* filesystem. The reason of excluding the kernel space part, is to simplify the patch in order to speed the check and then the merging of the patch itself. In fact I have to point out that in the past there was almost three attempts to propose this patch, without success neither complaints. Chris, let me know how you want to proceed. I know that you are very busy, and you prefer to work to stabilize btrfs instead adding new feature. But I think that changing a label is a *essential* feature for a filesystem managing tool. Think about a mount by LABEL. To show a label $ btrfs filesystem label To set a label $ btrfs filesystem label Please guys, give a look to the source. Comments are welcome. You can pull the source from the branch "label" of the repository http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git Regards G.Baroncelli Signed-off-by: Chris Mason --- btrfslabel.c | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 btrfslabel.c (limited to 'btrfslabel.c') diff --git a/btrfslabel.c b/btrfslabel.c new file mode 100644 index 00000000..c9f46844 --- /dev/null +++ b/btrfslabel.c @@ -0,0 +1,121 @@ +/* + * Copyright (C) 2008 Morey Roof. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#define _GNU_SOURCE + +#ifndef __CHECKER__ +#include +#include +#include "ioctl.h" +#endif /* __CHECKER__ */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "kerncompat.h" +#include "ctree.h" +#include "utils.h" +#include "version.h" +#include "disk-io.h" +#include "transaction.h" + +#define MOUNTED 1 +#define UNMOUNTED 2 +#define GET_LABEL 3 +#define SET_LABEL 4 + +static void change_label_unmounted(char *dev, char *nLabel) +{ + struct btrfs_root *root; + struct btrfs_trans_handle *trans; + + /* Open the super_block at the default location + * and as read-write. + */ + root = open_ctree(dev, 0, 1); + + trans = btrfs_start_transaction(root, 1); + strncpy(root->fs_info->super_copy.label, nLabel, BTRFS_LABEL_SIZE); + btrfs_commit_transaction(trans, root); + + /* Now we close it since we are done. */ + close_ctree(root); +} + +static void get_label_unmounted(char *dev) +{ + struct btrfs_root *root; + + /* Open the super_block at the default location + * and as read-only. + */ + root = open_ctree(dev, 0, 0); + + fprintf(stdout, "%s\n", root->fs_info->super_copy.label); + + /* Now we close it since we are done. */ + close_ctree(root); +} + +int get_label(char *btrfs_dev) +{ + + int ret; + ret = check_mounted(btrfs_dev); + if (ret < 0) + { + fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev); + return -1; + } + + if(ret != 0) + { + fprintf(stderr, "FATAL: the filesystem has to be unmounted\n"); + return -2; + } + get_label_unmounted(btrfs_dev); + return 0; +} + + +int set_label(char *btrfs_dev, char *nLabel) +{ + + int ret; + ret = check_mounted(btrfs_dev); + if (ret < 0) + { + fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev); + return -1; + } + + if(ret != 0) + { + fprintf(stderr, "FATAL: the filesystem has to be unmounted\n"); + return -2; + } + change_label_unmounted(btrfs_dev, nLabel); + return 0; +} -- cgit v1.2.3