From: "Duane Griffin" Subject: [PATCH 4/6] ext2: tighten restrictions on inode flags Date: Wed, 11 Jun 2008 01:04:07 +0100 Message-ID: <1213142649-32685-5-git-send-email-duaneg@dghda.com> References: <1213142649-32685-1-git-send-email-duaneg@dghda.com> <1213142649-32685-2-git-send-email-duaneg@dghda.com> <1213142649-32685-3-git-send-email-duaneg@dghda.com> <1213142649-32685-4-git-send-email-duaneg@dghda.com> Cc: Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Duane Griffin To: akpm@linux-foundation.org Return-path: Received: from kumera.dghda.com ([80.68.90.171]:3331 "EHLO kumera.dghda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757612AbYFKAEU (ORCPT ); Tue, 10 Jun 2008 20:04:20 -0400 In-Reply-To: <1213142649-32685-4-git-send-email-duaneg@dghda.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: At the moment there are few restrictions on which flags may be set on which inodes. Specifically DIRSYNC may only be set on directories and IMMUTABLE and APPEND may not be set on links. Tighten that to disallow TOPDIR being set on non-directories and SECRM, UNRM, COMPR, SYNC, DIRTY, COMPRBLK, NOCOMP, ECOMPR, INDEX, JOURNAL_DATA and NOTAIL being set on anything but regular files or directories. Introduce a flags masking function which masks flags based on mode and use it during inode creation and when flags are set via the ioctl to facilitate future consistency. Signed-off-by: Duane Griffin -- The specific flags masked out here are those suggested by Andreas, as well as IMMUTABLE, which I included to match the behaviour of the existing code. It would be good to get some review of these. --- fs/ext2/ialloc.c | 8 ++------ fs/ext2/ioctl.c | 3 +-- include/linux/ext2_fs.h | 22 ++++++++++++++++++++++ 3 files changed, 25 insertions(+), 8 deletions(-) diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index a51d4ca..1559b8e 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -565,12 +565,8 @@ got: inode->i_blocks = 0; inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC; memset(ei->i_data, 0, sizeof(ei->i_data)); - ei->i_flags = EXT2_I(dir)->i_flags & EXT2_FL_INHERITED; - if (S_ISLNK(mode)) - ei->i_flags &= ~(EXT2_IMMUTABLE_FL|EXT2_APPEND_FL); - /* dirsync is only applied to directories */ - if (!S_ISDIR(mode)) - ei->i_flags &= ~EXT2_DIRSYNC_FL; + ei->i_flags = + ext2_mask_flags(mode, EXT2_I(dir)->i_flags & EXT2_FL_INHERITED); ei->i_faddr = 0; ei->i_frag_no = 0; ei->i_frag_size = 0; diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c index de876fa..7cb4bad 100644 --- a/fs/ext2/ioctl.c +++ b/fs/ext2/ioctl.c @@ -50,8 +50,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) goto setflags_out; } - if (!S_ISDIR(inode->i_mode)) - flags &= ~EXT2_DIRSYNC_FL; + flags = ext2_mask_flags(inode->i_mode, flags); mutex_lock(&inode->i_mutex); /* Is it quota file? Do not allow user to mess with it */ diff --git a/include/linux/ext2_fs.h b/include/linux/ext2_fs.h index 7ead7eb..48a6cc1 100644 --- a/include/linux/ext2_fs.h +++ b/include/linux/ext2_fs.h @@ -201,6 +201,28 @@ struct ext2_group_desc EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\ EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL) +/* Flags that are inappropriate for regular files. */ +#define EXT2_REG_FLMASK (EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL) + +/* Flags that are inappropriate for non-directories/regular files. */ +#define EXT2_OTHER_FLMASK (EXT2_SECRM_FL | EXT2_UNRM_FL | EXT2_COMPR_FL |\ + EXT2_SYNC_FL | EXT2_IMMUTABLE_FL | EXT2_APPEND_FL |\ + EXT2_DIRTY_FL | EXT2_COMPRBLK_FL | EXT2_NOCOMP_FL |\ + EXT2_ECOMPR_FL | EXT2_INDEX_FL |\ + EXT2_JOURNAL_DATA_FL | EXT2_NOTAIL_FL |\ + EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL) + +/* Mask out flags that are inappropriate for the given type of inode. */ +static inline __le32 ext2_mask_flags(__le16 mode, __le32 flags) +{ + if (S_ISDIR(mode)) + return flags; + else if (S_ISREG(mode)) + return flags & ~EXT2_REG_FLMASK; + else + return flags & ~EXT2_OTHER_FLMASK; +} + /* * ioctl commands */ -- 1.5.3.7