From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:31326 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1759370Ab2FULj5 (ORCPT ); Thu, 21 Jun 2012 07:39:57 -0400 Received: from fnstmail02.fnst.cn.fujitsu.com (tang.cn.fujitsu.com [127.0.0.1]) by tang.cn.fujitsu.com (8.14.3/8.13.1) with ESMTP id q5LBdrwd016704 for ; Thu, 21 Jun 2012 19:39:54 +0800 From: Liu Bo To: Subject: [PATCH 4/4] Btrfs: do not set subvolume flags in readonly mode Date: Thu, 21 Jun 2012 19:48:17 +0800 Message-Id: <1340279297-3964-4-git-send-email-liubo2009@cn.fujitsu.com> In-Reply-To: <1340279297-3964-1-git-send-email-liubo2009@cn.fujitsu.com> References: <1340279297-3964-1-git-send-email-liubo2009@cn.fujitsu.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: $ mkfs.btrfs /dev/sdb7 $ btrfstune -S1 /dev/sdb7 $ mount /dev/sdb7 /mnt/btrfs mount: block device /dev/sdb7 is write-protected, mounting read-only $ btrfs dev add /dev/sdb8 /mnt/btrfs/ Now we get a btrfs in which mnt flags has readonly but sb flags does not. So for those ioctls that only check sb flags with MS_RDONLY, it is going to be a problem. Setting subvolume flags is such an ioctl, we should use mnt_want_write_file() to check RO flags. Signed-off-by: Liu Bo --- fs/btrfs/ioctl.c | 27 ++++++++++++++++++--------- 1 files changed, 18 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index df4c04d..ae29737 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1519,29 +1519,35 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file, u64 flags; int ret = 0; - if (root->fs_info->sb->s_flags & MS_RDONLY) - return -EROFS; + ret = mnt_want_write_file(file); + if (ret) + goto out; + ret = -EINVAL; if (btrfs_ino(inode) != BTRFS_FIRST_FREE_OBJECTID) - return -EINVAL; + goto out_drop_write; + ret = -EFAULT; if (copy_from_user(&flags, arg, sizeof(flags))) - return -EFAULT; + goto out_drop_write; + ret = -EINVAL; if (flags & BTRFS_SUBVOL_CREATE_ASYNC) - return -EINVAL; + goto out_drop_write; + ret = -EOPNOTSUPP; if (flags & ~BTRFS_SUBVOL_RDONLY) - return -EOPNOTSUPP; + goto out_drop_write; + ret = -EACCES; if (!inode_owner_or_capable(inode)) - return -EACCES; + goto out_drop_write; down_write(&root->fs_info->subvol_sem); /* nothing to do */ if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root)) - goto out; + goto out_drop_sem; root_flags = btrfs_root_flags(&root->root_item); if (flags & BTRFS_SUBVOL_RDONLY) @@ -1564,8 +1570,11 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file, out_reset: if (ret) btrfs_set_root_flags(&root->root_item, root_flags); -out: +out_drop_sem: up_write(&root->fs_info->subvol_sem); +out_drop_write: + mnt_drop_write_file(file); +out: return ret; } -- 1.6.5.2