Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757866Ab1CCIrk (ORCPT ); Thu, 3 Mar 2011 03:47:40 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:45879 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab1CCIri (ORCPT ); Thu, 3 Mar 2011 03:47:38 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=Eco5Lpx+HMBTNCIWhf9yaEYPL69d+JW+PD7lQ1YhdclLzGEKQReSMcqvr2CcQtS7hN skXKSrbz99g0LoD5BjwA63X6asCjrtHz8lKs5vozTH6Gi3BI4+HY9njTkPhS1CnI2+t7 Y6s9hL6XL3M/DLwNEz2NaLHkuODXKH1ADRCPc= Message-ID: <4D6F5473.2070709@gmail.com> Date: Thu, 03 Mar 2011 09:42:27 +0100 From: Marco Stornelli User-Agent: Mozilla/5.0 (X11; U; Linux i686; it; rv:1.9.1.16) Gecko/20101125 SUSE/3.0.11 Thunderbird/3.0.11 MIME-Version: 1.0 To: Linux Kernel CC: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, cluster-devel@redhat.com, xfs@oss.sgi.com, Linux FS Devel Subject: [PATCH v2] Check for immutable flag in fallocate path References: <4D6221B8.9040303@gmail.com> In-Reply-To: <4D6221B8.9040303@gmail.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2784 Lines: 88 From: Marco Stornelli All fs must check for the immutable flag in their fallocate callback. It's possible to have a race condition in this scenario: an application open a file in read/write and it does something, meanwhile root set the immutable flag on the file, the application at that point can call fallocate with success. Only Ocfs2 check for the immutable flag at the moment. Signed-off-by: Marco Stornelli --- Patch is against 2.6.38-rc5 ChangeLog v2: Added the check for append-only file for XFS v1: First draft --- linux-2.6.38-rc5-orig/fs/ext4/extents.c 2011-02-16 04:23:45.000000000 +0100 +++ linux-2.6.38-rc5/fs/ext4/extents.c 2011-02-21 08:43:37.000000000 +0100 @@ -3670,6 +3670,12 @@ long ext4_fallocate(struct file *file, i */ credits = ext4_chunk_trans_blocks(inode, max_blocks); mutex_lock(&inode->i_mutex); + + if (IS_IMMUTABLE(inode)) { + mutex_unlock(&inode->i_mutex); + return -EPERM; + } + ret = inode_newsize_ok(inode, (len + offset)); if (ret) { mutex_unlock(&inode->i_mutex); --- linux-2.6.38-rc5-orig/fs/btrfs/file.c 2011-02-16 04:23:45.000000000 +0100 +++ linux-2.6.38-rc5/fs/btrfs/file.c 2011-02-21 08:55:58.000000000 +0100 @@ -1289,6 +1289,12 @@ static long btrfs_fallocate(struct file btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start); mutex_lock(&inode->i_mutex); + + if (IS_IMMUTABLE(inode)) { + ret = -EPERM; + goto out; + } + ret = inode_newsize_ok(inode, alloc_end); if (ret) goto out; --- linux-2.6.38-rc5-orig/fs/gfs2/file.c 2011-02-16 04:23:45.000000000 +0100 +++ linux-2.6.38-rc5/fs/gfs2/file.c 2011-02-21 09:09:17.000000000 +0100 @@ -797,6 +797,11 @@ static long gfs2_fallocate(struct file * if (unlikely(error)) goto out_uninit; + if (IS_IMMUTABLE(inode)) { + error = -EPERM; + goto out_unlock; + } + if (!gfs2_write_alloc_required(ip, offset, len)) goto out_unlock; --- ./linux-2.6.38-rc5/fs/xfs/linux-2.6/xfs_file.c 2011-02-16 04:23:45.000000000 +0100 +++ ./linux-2.6.38-rc5/fs/xfs/linux-2.6/xfs_file.c 2011-03-03 09:25:32.000000000 +0100 @@ -906,8 +906,18 @@ xfs_file_fallocate( xfs_ilock(ip, XFS_IOLOCK_EXCL); - if (mode & FALLOC_FL_PUNCH_HOLE) + if (mode & FALLOC_FL_PUNCH_HOLE) { cmd = XFS_IOC_UNRESVSP; + if (IS_APPEND(inode)) { + error = -EPERM; + goto out_unlock; + } + } + + if (IS_IMMUTABLE(inode)) { + error = -EPERM; + goto out_unlock; + } /* check the new inode size is valid before allocating */ if (!(mode & FALLOC_FL_KEEP_SIZE) && -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/