From: akpm@linux-foundation.org Subject: [patch 008/123] ext2: tighten restrictions on inode flags Date: Wed, 07 Jan 2009 18:07:21 -0800 Message-ID: <200901080207.n0827MJt011603@imap1.linux-foundation.org> Cc: akpm@linux-foundation.org, duaneg@dghda.com, adilger@sun.com, linux-ext4@vger.kernel.org To: torvalds@linux-foundation.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:60987 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751527AbZAHCPI (ORCPT ); Wed, 7 Jan 2009 21:15:08 -0500 Sender: linux-ext4-owner@vger.kernel.org List-ID: From: "Duane Griffin" 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 only NODUMP and NOATIME to be set on non-regular file, non-directories. Introduces 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 Acked-by: Andreas Dilger Cc: Signed-off-by: Andrew Morton --- fs/ext2/ialloc.c | 8 ++------ fs/ext2/ioctl.c | 3 +-- include/linux/ext2_fs.h | 17 +++++++++++++++++ 3 files changed, 20 insertions(+), 8 deletions(-) diff -puN fs/ext2/ialloc.c~ext2-tighten-restrictions-on-inode-flags fs/ext2/ialloc.c --- a/fs/ext2/ialloc.c~ext2-tighten-restrictions-on-inode-flags +++ a/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 -puN fs/ext2/ioctl.c~ext2-tighten-restrictions-on-inode-flags fs/ext2/ioctl.c --- a/fs/ext2/ioctl.c~ext2-tighten-restrictions-on-inode-flags +++ a/fs/ext2/ioctl.c @@ -50,8 +50,7 @@ long ext2_ioctl(struct file *filp, unsig 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 -puN include/linux/ext2_fs.h~ext2-tighten-restrictions-on-inode-flags include/linux/ext2_fs.h --- a/include/linux/ext2_fs.h~ext2-tighten-restrictions-on-inode-flags +++ a/include/linux/ext2_fs.h @@ -201,6 +201,23 @@ struct ext2_group_desc EXT2_NOCOMP_FL | EXT2_JOURNAL_DATA_FL |\ EXT2_NOTAIL_FL | EXT2_DIRSYNC_FL) +/* Flags that are appropriate for regular files (all but dir-specific ones). */ +#define EXT2_REG_FLMASK (~(EXT2_DIRSYNC_FL | EXT2_TOPDIR_FL)) + +/* Flags that are appropriate for non-directories/regular files. */ +#define EXT2_OTHER_FLMASK (EXT2_NODUMP_FL | EXT2_NOATIME_FL) + +/* Mask out flags that are inappropriate for the given type of inode. */ +static inline __u32 ext2_mask_flags(umode_t mode, __u32 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 */ _