From patchwork Wed Dec 12 00:22:25 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1864171 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 2638A3FCA5 for ; Wed, 12 Dec 2012 00:23:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559Ab2LLAWi (ORCPT ); Tue, 11 Dec 2012 19:22:38 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:38545 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932541Ab2LLAWb (ORCPT ); Tue, 11 Dec 2012 19:22:31 -0500 Received: from acsinet22.oracle.com (acsinet22.oracle.com [141.146.126.238]) by userp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBC0MTSq003796 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Dec 2012 00:22:30 GMT Received: from acsmt356.oracle.com (acsmt356.oracle.com [141.146.40.156]) by acsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id qBC0MTEb021730 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 12 Dec 2012 00:22:29 GMT Received: from abhmt119.oracle.com (abhmt119.oracle.com [141.146.116.71]) by acsmt356.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBC0MTwd009568 for ; Tue, 11 Dec 2012 18:22:29 -0600 Received: from [192.168.1.103] (/114.248.195.239) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 11 Dec 2012 16:22:28 -0800 Message-ID: <50C7CE41.9050607@oracle.com> Date: Wed, 12 Dec 2012 08:22:25 +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 1/2] Btrfs: Add a new ioctl to get 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 Introduce a new ioctl BTRFS_IOC_GET_FSLABEL, which would be used to fetch 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