From patchwork Wed Dec 12 00:30:29 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "jeff.liu" X-Patchwork-Id: 1864211 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 ECF9FDFAC4 for ; Wed, 12 Dec 2012 00:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933089Ab2LLAbQ (ORCPT ); Tue, 11 Dec 2012 19:31:16 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:18624 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755499Ab2LLAag (ORCPT ); Tue, 11 Dec 2012 19:30:36 -0500 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by userp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id qBC0UZA4009719 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Dec 2012 00:30:36 GMT Received: from acsmt358.oracle.com (acsmt358.oracle.com [141.146.40.158]) by ucsinet22.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id qBC0UY3m017421 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 12 Dec 2012 00:30:35 GMT Received: from abhmt120.oracle.com (abhmt120.oracle.com [141.146.116.72]) by acsmt358.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id qBC0UYVT012953 for ; Tue, 11 Dec 2012 18:30:34 -0600 Received: from [192.168.1.103] (/114.248.195.239) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 11 Dec 2012 16:30:34 -0800 Message-ID: <50C7D025.6050708@oracle.com> Date: Wed, 12 Dec 2012 08:30:29 +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 2/3] Btrfs-progs: change the label of a mounted filesystem X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org Change the label of a mounted file system through the new ioctl BTRFS_IOCTL_FS_SETLABEL. Signed-off-by: Jie Liu Signed-off-by: Anand Jain --- btrfslabel.c | 84 ++++++++++++++++++++++++++++++++++------------------------ ioctl.h | 2 ++ 2 files changed, 51 insertions(+), 35 deletions(-) diff --git a/btrfslabel.c b/btrfslabel.c index 761a312..65388e5 100644 --- a/btrfslabel.c +++ b/btrfslabel.c @@ -46,25 +46,52 @@ #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; + } + + /* 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 get label %s\n", strerror(errno)); + close(fd); + return -1; + } + + return 0; } static int get_label_unmounted(const char *dev) @@ -125,22 +152,9 @@ 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 ed6784d..07259f9 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, 53, \ char[BTRFS_LABEL_SIZE]) +#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 54, \ + char[BTRFS_LABEL_SIZE]) #endif