From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,T_DKIMWL_WL_HIGH,UNPARSEABLE_RELAY,USER_AGENT_MUTT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D5F2C468C2 for ; Mon, 10 Jun 2019 04:41:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5728F206C3 for ; Mon, 10 Jun 2019 04:41:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="DdQQTu+/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387452AbfFJElw (ORCPT ); Mon, 10 Jun 2019 00:41:52 -0400 Received: from userp2130.oracle.com ([156.151.31.86]:50236 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725320AbfFJElv (ORCPT ); Mon, 10 Jun 2019 00:41:51 -0400 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5A4djbq014902; Mon, 10 Jun 2019 04:41:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : references : mime-version : content-type : in-reply-to; s=corp-2018-07-02; bh=1rlW4CBK4tGHrpGFthm0IXowDU3XrX/m9jqFgg1EvJs=; b=DdQQTu+/oZ8BF78Vl3tSsb9U84OK1y8XCqxtjn2i+ZxuHFIycqvptntC3PB3NuSjZ7tQ QKmjw7cLnnSLS55U/ubPkdBlIc5x+/YSrW0qZh5QMmB56/r1MWZ5KQXRl0QeVPuYri5+ b8xUGpNJqaYNFoP8RM//vtQyCZBGgR0d2Z9NXKJp7dR9DBm8mX2EQ2sonm6F0yVTHxWd cL3ROZ6dfNfUUnA0SIOR+IO8zjh7UvQvrjV9SpTbsHGg/5gzVOr879aAAOa+1TNbjIZx DLlT37EHBXjkErOWeO8NXIvDjq5iKIJ8nShcQcyxc6zsh4mYgLzzqu28s6IQ9mMDnUfe 1w== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2t04etcn0c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 10 Jun 2019 04:41:48 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x5A4en2r188090; Mon, 10 Jun 2019 04:41:47 GMT Received: from aserv0121.oracle.com (aserv0121.oracle.com [141.146.126.235]) by aserp3030.oracle.com with ESMTP id 2t04hxkmcf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 10 Jun 2019 04:41:47 +0000 Received: from abhmp0022.oracle.com (abhmp0022.oracle.com [141.146.116.28]) by aserv0121.oracle.com (8.14.4/8.13.8) with ESMTP id x5A4fk0T009554; Mon, 10 Jun 2019 04:41:46 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Sun, 09 Jun 2019 21:41:45 -0700 Date: Sun, 9 Jun 2019 21:41:44 -0700 From: "Darrick J. Wong" To: "Theodore Ts'o" Cc: linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 1/8] mm/fs: don't allow writes to immutable files Message-ID: <20190610044144.GA1872750@magnolia> References: <155552786671.20411.6442426840435740050.stgit@magnolia> <155552787330.20411.11893581890744963309.stgit@magnolia> <20190610015145.GB3266@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190610015145.GB3266@mit.edu> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9283 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=748 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906100031 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9283 signatures=668687 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=793 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1906100032 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Sun, Jun 09, 2019 at 09:51:45PM -0400, Theodore Ts'o wrote: > On Wed, Apr 17, 2019 at 12:04:33PM -0700, Darrick J. Wong wrote: > > diff --git a/mm/memory.c b/mm/memory.c > > index ab650c21bccd..dfd5eba278d6 100644 > > --- a/mm/memory.c > > +++ b/mm/memory.c > > @@ -2149,6 +2149,9 @@ static vm_fault_t do_page_mkwrite(struct vm_fault *vmf) > > > > vmf->flags = FAULT_FLAG_WRITE|FAULT_FLAG_MKWRITE; > > > > + if (vmf->vma->vm_file && IS_IMMUTABLE(file_inode(vmf->vma->vm_file))) > > + return VM_FAULT_SIGBUS; > > + > > ret = vmf->vma->vm_ops->page_mkwrite(vmf); > > /* Restore original flags so that caller is not surprised */ > > vmf->flags = old_flags; > > Shouldn't this check be moved before the modification of vmf->flags? > It looks like do_page_mkwrite() isn't supposed to be returning with > vmf->flags modified, lest "the caller gets surprised". Yeah, I think that was a merge error during a rebase... :( Er ... if you're still planning to take this patch through your tree, can you move it to above the "vmf->flags = FAULT_FLAG_WRITE..." ? --D > - Ted