From patchwork Mon Dec 17 11:35:23 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1886711 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 2F70BDF266 for ; Mon, 17 Dec 2012 11:35:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752321Ab2LQLfa (ORCPT ); Mon, 17 Dec 2012 06:35:30 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:28321 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752267Ab2LQLf3 (ORCPT ); Mon, 17 Dec 2012 06:35:29 -0500 Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by userp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBHBZS5h019485 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 17 Dec 2012 11:35:29 GMT Received: from acsmt357.oracle.com (acsmt357.oracle.com [141.146.40.157]) by acsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id qBHBZRWr014846 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Mon, 17 Dec 2012 11:35:28 GMT Received: from abhmt108.oracle.com (abhmt108.oracle.com [141.146.116.60]) by acsmt357.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBHBZRJJ021915 for ; Mon, 17 Dec 2012 05:35:27 -0600 Received: from [10.191.9.229] (/10.191.9.229) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 17 Dec 2012 03:35:27 -0800 Message-ID: <50CF037B.8070408@oracle.com> Date: Mon, 17 Dec 2012 19:35:23 +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 V5 2/4] Btrfs-progs: 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 this new ioctl(2), we can set/change the label for a mounted file system. It still does normal process for an umounted file system. Signed-off-by: Jie Liu Signed-off-by: Anand Jain --- btrfslabel.c | 90 +++++++++++++++++++++++++++++++++++----------------------- ioctl.h | 2 ++ 2 files changed, 57 insertions(+), 35 deletions(-) diff --git a/btrfslabel.c b/btrfslabel.c index 443eff6..938e8b4 100644 --- a/btrfslabel.c +++ b/btrfslabel.c @@ -46,25 +46,58 @@ #define GET_LABEL 3 #define SET_LABEL 4 -static void change_label_unmounted(char *dev, char *nLabel) +static int set_label_unmounted(const char *dev, const char *label) { - struct btrfs_root *root; - struct btrfs_trans_handle *trans; - - /* Open the super_block at the default location - * and as read-write. - */ - root = open_ctree(dev, 0, 1); - if (!root) /* errors are printed by open_ctree() */ - return; - - trans = btrfs_start_transaction(root, 1); - strncpy(root->fs_info->super_copy.label, nLabel, BTRFS_LABEL_SIZE); - root->fs_info->super_copy.label[BTRFS_LABEL_SIZE-1] = 0; - btrfs_commit_transaction(trans, root); - - /* Now we close it since we are done. */ - close_ctree(root); + struct btrfs_trans_handle *trans; + struct btrfs_root *root; + int ret; + + ret = check_mounted(dev); + if (ret < 0) { + fprintf(stderr, "FATAL: error checking %s mount status\n", dev); + return -1; + } + if (ret > 0) { + fprintf(stderr, "ERROR: dev %s is mounted, use mount point\n", + dev); + return -1; + } + + /* Open the super_block at the default location + * and as read-write. + */ + root = open_ctree(dev, 0, 1); + if (!root) /* errors are printed by open_ctree() */ + return -1; + + trans = btrfs_start_transaction(root, 1); + strncpy(root->fs_info->super_copy.label, label, BTRFS_LABEL_SIZE); + root->fs_info->super_copy.label[BTRFS_LABEL_SIZE-1] = 0; + btrfs_commit_transaction(trans, root); + + /* Now we close it since we are done. */ + close_ctree(root); + return 0; +} + +static int set_label_mounted(const char *mount_path, const char *label) +{ + int fd; + + fd = open(mount_path, O_RDONLY | O_NOATIME); + if (fd < 0) { + fprintf(stderr, "ERROR: unable access to '%s'\n", mount_path); + return -1; + } + + if (ioctl(fd, BTRFS_IOC_SET_FSLABEL, label) < 0) { + fprintf(stderr, "ERROR: unable to set label %s\n", + strerror(errno)); + close(fd); + return -1; + } + + return 0; } static int get_label_unmounted(const char *dev) @@ -131,22 +164,9 @@ int get_label(const char *btrfs_dev) get_label_mounted(btrfs_dev); } -int set_label(char *btrfs_dev, char *nLabel) +int set_label(char *btrfs_dev, char *label) { - - int ret; - ret = check_mounted(btrfs_dev); - if (ret < 0) - { - fprintf(stderr, "FATAL: error checking %s mount status\n", btrfs_dev); - return -1; - } - - if(ret != 0) - { - fprintf(stderr, "FATAL: the filesystem has to be unmounted\n"); - return -2; - } - change_label_unmounted(btrfs_dev, nLabel); - return 0; + return is_existing_blk_or_reg_file(btrfs_dev) ? + set_label_unmounted(btrfs_dev, label) : + set_label_mounted(btrfs_dev, label); } diff --git a/ioctl.h b/ioctl.h index 0807b05..0882d6c 100644 --- a/ioctl.h +++ b/ioctl.h @@ -434,4 +434,6 @@ struct btrfs_ioctl_clone_range_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]) #endif