From patchwork Wed Dec 12 00:22:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1864181 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 3186E402E1 for ; Wed, 12 Dec 2012 00:23:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756668Ab2LLAXD (ORCPT ); Tue, 11 Dec 2012 19:23:03 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:23355 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932485Ab2LLAWc (ORCPT ); Tue, 11 Dec 2012 19:22:32 -0500 Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by aserp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBC0MVNd003960 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Dec 2012 00:22:32 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 qBC0MVYj021771 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 12 Dec 2012 00:22:31 GMT Received: from abhmt108.oracle.com (abhmt108.oracle.com [141.146.116.60]) by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBC0MVG0008552 for ; Tue, 11 Dec 2012 18:22:31 -0600 Received: from [192.168.1.103] (/114.248.195.239) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 11 Dec 2012 16:22:31 -0800 Message-ID: <50C7CE44.3010405@oracle.com> Date: Wed, 12 Dec 2012 08:22:28 +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 Subject: [PATCH V4 2/2] Btrfs: Add a new ioctl to change the label of a mounted filesystem X-Source-IP: acsinet22.oracle.com [141.146.126.238] 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 | 14 ++++++++++++++ fs/btrfs/ioctl.h | 2 ++ 2 files changed, 16 insertions(+) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8fcf9a5..b0a5e17 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3699,6 +3699,18 @@ out: return ret; } +static int btrfs_ioctl_get_fslabel(struct btrfs_root *root, void __user *arg) +{ + const char *label = root->fs_info->super_copy->label; + int ret; + + mutex_lock(&root->fs_info->volume_mutex); + ret = copy_to_user(arg, label, strlen(label)); + mutex_unlock(&root->fs_info->volume_mutex); + + return ret ? -EFAULT : 0; +} + long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { @@ -3797,6 +3809,8 @@ long btrfs_ioctl(struct file *file, unsigned int return btrfs_ioctl_qgroup_create(root, argp); case BTRFS_IOC_QGROUP_LIMIT: return btrfs_ioctl_qgroup_limit(root, argp); + case BTRFS_IOC_GET_FSLABEL: + return btrfs_ioctl_get_fslabel(root, argp); } return -ENOTTY; diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h index 731e287..98f896f 100644 --- a/fs/btrfs/ioctl.h +++ b/fs/btrfs/ioctl.h @@ -453,4 +453,6 @@ struct btrfs_ioctl_send_args { struct btrfs_ioctl_qgroup_limit_args) #define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \ struct btrfs_ioctl_get_dev_stats) +#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 53, \ + char[BTRFS_LABEL_SIZE]) #endif -- 1.7.9.5 jeff@koala:/usr/src/linux$ cat btrfs_label_v3/0002-set-label.patch Signed-off-by: Jie Liu --- 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