From patchwork Thu Sep  1 08:52:23 2011
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
X-Patchwork-Submitter: "jeff.liu" <jeff.liu@oracle.com>
X-Patchwork-Id: 1118472
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p818qfrm010497
	for <patchwork-linux-btrfs@patchwork.kernel.org>;
	Thu, 1 Sep 2011 08:52:45 GMT
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1756484Ab1IAIwi (ORCPT
	<rfc822;patchwork-linux-btrfs@patchwork.kernel.org>);
	Thu, 1 Sep 2011 04:52:38 -0400
Received: from acsinet15.oracle.com ([141.146.126.227]:60349 "EHLO
	acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1756429Ab1IAIwh (ORCPT
	<rfc822; linux-btrfs@vger.kernel.org>); Thu, 1 Sep 2011 04:52:37 -0400
Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238])
	by acsinet15.oracle.com (Switch-3.4.4/Switch-3.4.4) with ESMTP id
	p818qZZF010590
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK)
	for <linux-btrfs@vger.kernel.org>; Thu, 1 Sep 2011 08:52:37 GMT
Received: from acsmt358.oracle.com (acsmt358.oracle.com [141.146.40.158])
	by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id
	p818qZYR016199
	(version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO)
	for <linux-btrfs@vger.kernel.org>; Thu, 1 Sep 2011 08:52:35 GMT
Received: from abhmt107.oracle.com (abhmt107.oracle.com [141.146.116.59])
	by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id
	p818qTgR001253
	for <linux-btrfs@vger.kernel.org>; Thu, 1 Sep 2011 03:52:29 -0500
Received: from [192.168.1.103] (/221.223.117.210)
	by default (Oracle Beehive Gateway v4.0)
	with ESMTP ; Thu, 01 Sep 2011 01:52:29 -0700
Message-ID: <4E5F47C7.3030803@oracle.com>
Date: Thu, 01 Sep 2011 16:52:23 +0800
From: Jeff Liu <jeff.liu@oracle.com>
Reply-To: jeff.liu@oracle.com
Organization: Oracle
User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US;
	rv:1.9.2.18) Gecko/20110617 Thunderbird/3.1.11
MIME-Version: 1.0
To: linux-btrfs@vger.kernel.org
CC: chris.mason@oracle.com
Subject: [PATCH] Btrfs-progs: added btrfs filesystem label [label] [path]
	support
X-Source-IP: acsinet22.oracle.com [141.146.126.238]
X-Auth-Type: Internal IP
X-CT-RefId: str=0001.0A090202.4E5F47D5.00CA:SCFMA922111, ss=1, re=-4.000,
	fgs=0
Sender: linux-btrfs-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-btrfs.vger.kernel.org>
X-Mailing-List: linux-btrfs@vger.kernel.org
X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by
	milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]);
	Thu, 01 Sep 2011 08:52:45 +0000 (UTC)

Hello,

This patch make use of the new ioctl(2) to set Btrfs label via `btrfs 
filesystem label` command.

  Signed-off-by: Jie Liu <jeff.liu@oracle.com>
---
  btrfs.c      |    7 +++----
  btrfs_cmds.c |   27 +++++++++++++++++++++++++++
  btrfs_cmds.h |    1 +
  ctree.h      |    6 ++++++
  ioctl.h      |    2 ++
  mkfs.c       |   19 -------------------
  utils.c      |   18 ++++++++++++++++++
  utils.h      |    1 +
  8 files changed, 58 insertions(+), 23 deletions(-)

diff --git a/btrfs.c b/btrfs.c
index 46314cf..6d414f1 100644
--- a/btrfs.c
+++ b/btrfs.c
@@ -108,11 +108,10 @@ static struct Command commands[] = {
        "device delete", "<dev> [<dev>..] <path>\n"
          "Remove a device from a filesystem."
      },
-    /* coming soon
-    { 2, "filesystem label", "<label> <path>\n"
+    { do_set_label, 2,
+      "filesystem label", "<label> <path>\n"
          "Set the label of a filesystem"
-    }
-    */
+    },
      { 0, 0 , 0 }
  };

diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 8031c58..8d2b8e1 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -834,6 +834,33 @@ int do_set_default_subvol(int nargs, char **argv)
      return 0;
  }

+int do_set_label(int nargs, char **argv)
+{
+    int    fd, ret = 0;
+    char    *path = argv[2];
+    char    *label = parse_label(argv[1]);
+    size_t    len = strlen(label);
+    struct    btrfs_ioctl_fs_label_args label_args;
+
+    fd = open_file_or_dir(path);
+    if (fd < 0) {
+        fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+        return 12;
+    }
+
+    label_args.len = len;
+    snprintf(label_args.label, BTRFS_LABEL_SIZE, "%s", label);
+    ret = ioctl(fd, BTRFS_IOC_FS_SETLABEL, &label_args);
+    close(fd);
+    free(label);
+    if(ret < 0) {
+        fprintf(stderr, "ERROR: unable to set a new label\n");
+        return 30;
+    }
+
+    return 0;
+}
+
  int do_df_filesystem(int nargs, char **argv)
  {
      struct btrfs_ioctl_space_args *sargs;
diff --git a/btrfs_cmds.h b/btrfs_cmds.h
index 7bde191..29ded22 100644
--- a/btrfs_cmds.h
+++ b/btrfs_cmds.h
@@ -32,3 +32,4 @@ int list_subvols(int fd);
  int do_df_filesystem(int nargs, char **argv);
  int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
  int do_find_newer(int argc, char **argv);
+int do_set_label(int argc, char **argv);
diff --git a/ctree.h b/ctree.h
index b79e238..4924b88 100644
--- a/ctree.h
+++ b/ctree.h
@@ -345,6 +345,12 @@ struct btrfs_super_block {
      u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
  } __attribute__ ((__packed__));

+struct btrfs_ioctl_fs_label_args {
+    /* label length in bytes */
+    __u32 len;
+    char label[BTRFS_LABEL_SIZE];
+};
+
  /*
   * Compat flags that we support.  If any incompat flags are set other 
than the
   * ones specified below then we will fail to mount
diff --git a/ioctl.h b/ioctl.h
index 776d7a9..5750f3a 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -169,4 +169,6 @@ struct btrfs_ioctl_space_args {
  #define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64)
  #define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \
                      struct btrfs_ioctl_space_args)
+#define BTRFS_IOC_FS_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 32, \
+                   struct btrfs_ioctl_fs_label_args)
  #endif
diff --git a/mkfs.c b/mkfs.c
index 1598aae..93c1636 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -303,25 +303,6 @@ static u64 parse_profile(char *s)
      return 0;
  }

-static char *parse_label(char *input)
-{
-    int i;
-    int len = strlen(input);
-
-    if (len >= BTRFS_LABEL_SIZE) {
-        fprintf(stderr, "Label %s is too long (max %d)\n", input,
-            BTRFS_LABEL_SIZE - 1);
-        exit(1);
-    }
-    for (i = 0; i < len; i++) {
-        if (input[i] == '/' || input[i] == '\\') {
-            fprintf(stderr, "invalid label %s\n", input);
-            exit(1);
-        }
-    }
-    return strdup(input);
-}
-
  static struct option long_options[] = {
      { "alloc-start", 1, NULL, 'A'},
      { "byte-count", 1, NULL, 'b' },
diff --git a/utils.c b/utils.c
index fd894f3..5d77503 100644
--- a/utils.c
+++ b/utils.c
@@ -993,3 +993,21 @@ char *pretty_sizes(u64 size)
      return pretty;
  }

+char *parse_label(const char *input)
+{
+    int i;
+    int len = strlen(input);
+
+    if (len >= BTRFS_LABEL_SIZE) {
+        fprintf(stderr, "Label %s is too long (max %d)\n", input,
+            BTRFS_LABEL_SIZE - 1);
+        exit(1);
+    }
+    for (i = 0; i < len; i++) {
+        if (input[i] == '/' || input[i] == '\\') {
+            fprintf(stderr, "invalid label %s\n", input);
+            exit(1);
+        }
+    }
+    return strdup(input);
+}
diff --git a/utils.h b/utils.h
index 9dce5b0..9212a75 100644
--- a/utils.h
+++ b/utils.h
@@ -40,4 +40,5 @@ int check_mounted(const char *devicename);
  int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
                   int super_offset);
  char *pretty_sizes(u64 size);
+char *parse_label(const char *);
  #endif