From patchwork Thu Dec 20 08:43:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1898801 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 38A0740061 for ; Thu, 20 Dec 2012 08:44:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751595Ab2LTIoP (ORCPT ); Thu, 20 Dec 2012 03:44:15 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:28865 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564Ab2LTIoL (ORCPT ); Thu, 20 Dec 2012 03:44:11 -0500 Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by aserp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBK8hLTj009257 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 20 Dec 2012 08:43:22 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 qBK8hLtT009044 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 20 Dec 2012 08:43:21 GMT Received: from abhmt105.oracle.com (abhmt105.oracle.com [141.146.116.57]) by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBK8hLkv013811; Thu, 20 Dec 2012 02:43:21 -0600 Received: from [10.191.13.116] (/10.191.13.116) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 20 Dec 2012 00:43:20 -0800 Message-ID: <50D2CF9A.6040704@oracle.com> Date: Thu, 20 Dec 2012 16:43:06 +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, kreijack@inwind.it, dsterba@suse.cz Subject: [RFC PATCH v7 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org With the new ioctl(2) BTRFS_IOC_SET_FSLABEL, we can set/change the label of a mounted file system. Signed-off-by: Jie Liu Signed-off-by: Anand Jain Cc: Miao Xie Cc: Goffredo Baroncelli Cc: David Sterba Reviewed-by: Goffredo Baroncelli Reviewed-by: David Sterba --- fs/btrfs/ioctl.c | 39 +++++++++++++++++++++++++++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 41 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6a2488a..99aa812 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3712,6 +3712,43 @@ static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg) return ret ? -EFAULT : 0; } +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg) +{ + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root; + struct btrfs_super_block *super_block = root->fs_info->super_copy; + struct btrfs_trans_handle *trans; + char label[BTRFS_LABEL_SIZE]; + int ret; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (copy_from_user(label, arg, sizeof(label))) + return -EFAULT; + + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) + return -EINVAL; + + ret = mnt_want_write_file(file); + if (ret) + return ret; + + 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); + ret = btrfs_end_transaction(trans, root); + +out_unlock: + mutex_unlock(&root->fs_info->volume_mutex); + mnt_drop_write_file(file); + return ret; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3812,6 +3849,8 @@ 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(file, argp); + case BTRFS_IOC_SET_FSLABEL: + return btrfs_ioctl_set_fslabel(file, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 5b2cbef..2abe239 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -453,6 +453,8 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_limit_args) #define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \ char[BTRFS_LABEL_SIZE]) +#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 50, \ + char[BTRFS_LABEL_SIZE]) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) #endif