From patchwork Thu Sep 1 08:47:47 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1118462 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 p818lp6D009907 for ; Thu, 1 Sep 2011 08:48:19 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756696Ab1IAIsF (ORCPT ); Thu, 1 Sep 2011 04:48:05 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:34518 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756460Ab1IAIsE (ORCPT ); Thu, 1 Sep 2011 04:48:04 -0400 Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by acsinet15.oracle.com (Switch-3.4.4/Switch-3.4.4) with ESMTP id p818m0Ir002933 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 1 Sep 2011 08:48:01 GMT Received: from acsmt358.oracle.com (acsmt358.oracle.com [141.146.40.158]) by acsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id p818lwYH028323 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 1 Sep 2011 08:48:00 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 p818lrAH030659 for ; Thu, 1 Sep 2011 03:47:53 -0500 Received: from [192.168.1.103] (/221.223.117.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 01 Sep 2011 01:47:53 -0700 Message-ID: <4E5F46B3.50607@oracle.com> Date: Thu, 01 Sep 2011 16:47:47 +0800 From: Jeff Liu 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: added new ioctl to set fs label X-Source-IP: acsinet21.oracle.com [141.146.126.237] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090205.4E5F46C2.001F:SCFMA922111, ss=1, re=-4.000, fgs=0 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: 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 08:48:19 +0000 (UTC) Hello, I'd like to introduce a new ioctl to set file system label. With this feature, we can execute `btrfs filesystem label [label] [path]` through btrfs tools to set or change the label. Signed-off-by: Jie Liu --- fs/btrfs/ctree.h | 6 ++++++ fs/btrfs/ioctl.c | 37 +++++++++++++++++++++++++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 3 files changed, 45 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 03912c5..2889b5e 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1259,6 +1259,12 @@ struct btrfs_ioctl_defrag_range_args { }; +struct btrfs_ioctl_fs_label_args { + /* label length in bytes */ + __u32 len; + char label[BTRFS_LABEL_SIZE]; +}; + /* * inode items have the data typically returned from stat and store other * info about object characteristics. There is one for every file and dir in diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 970977a..9e01628 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -268,6 +268,41 @@ static int btrfs_ioctl_getversion(struct file *file, int __user *arg) return put_user(inode->i_generation, arg); } +static int btrfs_ioctl_fs_setlabel(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_super_block *super_block = &(root->fs_info->super_copy); + struct btrfs_ioctl_fs_label_args *label_args; + struct btrfs_trans_handle *trans; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (btrfs_root_readonly(root)) + return -EROFS; + + label_args = memdup_user(arg, sizeof(*label_args)); + if (IS_ERR(label_args)) + return PTR_ERR(label_args); + + if (label_args->len >= sizeof(label_args->label)) + return -EINVAL; + + mutex_lock(&root->fs_info->volume_mutex); + trans = btrfs_start_transaction(root, 0); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + if (snprintf(super_block->label, BTRFS_LABEL_SIZE, "%s", + label_args->label) != label_args->len) + return -EFAULT; + + btrfs_end_transaction(trans, root); + mutex_unlock(&root->fs_info->volume_mutex); + + kfree(label_args); + return 0; +} + static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg) { struct btrfs_root *root = fdentry(file)->d_sb->s_fs_info; @@ -2876,6 +2911,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_fs_info(root, argp); case BTRFS_IOC_DEV_INFO: return btrfs_ioctl_dev_info(root, argp); + case BTRFS_IOC_FS_SETLABEL: + return btrfs_ioctl_fs_setlabel(root, argp); case BTRFS_IOC_BALANCE: return btrfs_balance(root->fs_info->dev_root); case BTRFS_IOC_CLONE: diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index ad1ea78..1e0ca2a 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -248,4 +248,6 @@ struct btrfs_ioctl_space_args { struct btrfs_ioctl_dev_info_args) #define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \ struct btrfs_ioctl_fs_info_args) +#define BTRFS_IOC_FS_SETLABEL _IOW(BTRFS_IOCTL_MAGIC, 32, \ + struct btrfs_ioctl_fs_label_args) #endif