From patchwork Wed Dec 12 03:23:00 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1864501 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 87B67DF2EE for ; Wed, 12 Dec 2012 03:23:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753879Ab2LLDXR (ORCPT ); Tue, 11 Dec 2012 22:23:17 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:30177 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752853Ab2LLDXQ (ORCPT ); Tue, 11 Dec 2012 22:23:16 -0500 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by userp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBC3N9dt028814 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 12 Dec 2012 03:23:10 GMT Received: from acsmt356.oracle.com (acsmt356.oracle.com [141.146.40.156]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id qBC3N9E6025815 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 12 Dec 2012 03:23:09 GMT Received: from abhmt109.oracle.com (abhmt109.oracle.com [141.146.116.61]) by acsmt356.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBC3N9QB002129; Tue, 11 Dec 2012 21:23:09 -0600 Received: from [192.168.1.103] (/114.248.195.239) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 11 Dec 2012 19:23:08 -0800 Message-ID: <50C7F894.9000709@oracle.com> Date: Wed, 12 Dec 2012 11:23:00 +0800 From: Jeff Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121028 Thunderbird/16.0.2 MIME-Version: 1.0 To: linux-btrfs@vger.kernel.org CC: anand.jain@oracle.com, miaox@cn.fujitsu.com Subject: [RESEND PATCH V4 2/2] Btrfs: Add a new ioctl to change the label of a mounted filesystem X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Add a new ioctl BTRFS_FS_SETLABEL to change the label of a mounted filesystem. Signed-off-by: Jie Liu Signed-off-by: Anand Jain --- fs/btrfs/ioctl.c | 34 ++++++++++++++++++++++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 36 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index b0a5e17..ebbf634 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3711,6 +3711,38 @@ static int btrfs_ioctl_get_fslabel(struct btrfs_root *root, void __user *arg) return ret ? -EFAULT : 0; } +static int btrfs_ioctl_set_fslabel(struct btrfs_root *root, void __user *arg) +{ + struct btrfs_super_block *super_block = root->fs_info->super_copy; + struct btrfs_trans_handle *trans; + char label[BTRFS_LABEL_SIZE]; + int ret = 0; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (btrfs_root_readonly(root)) + return -EROFS; + + if (copy_from_user(label, arg, sizeof(label))) + return -EFAULT; + + label[BTRFS_LABEL_SIZE - 1] = '\0'; + + mutex_lock(&root->fs_info->volume_mutex); + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_unlock; + } + strcpy(super_block->label, label); + btrfs_end_transaction(trans, root); + +out_unlock: + mutex_unlock(&root->fs_info->volume_mutex); + return ret; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3811,6 +3843,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_limit(root, argp); case BTRFS_IOC_GET_FSLABEL: return btrfs_ioctl_get_fslabel(root, argp); + case BTRFS_IOC_SET_FSLABEL: + return btrfs_ioctl_set_fslabel(root, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 98f896f..cc4e657 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -455,4 +455,6 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_get_dev_stats) #define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 53, \ char[BTRFS_LABEL_SIZE]) +#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 54, \ + char[BTRFS_LABEL_SIZE]) #endif