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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED, 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 CA678C10F0F for ; Fri, 5 Apr 2019 00:29:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DF6A217D4 for ; Fri, 5 Apr 2019 00:29:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="E9bhYQx3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729608AbfDEA3j (ORCPT ); Thu, 4 Apr 2019 20:29:39 -0400 Received: from userp2120.oracle.com ([156.151.31.85]:47688 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727053AbfDEA3j (ORCPT ); Thu, 4 Apr 2019 20:29:39 -0400 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x350ScJf100391; Fri, 5 Apr 2019 00:29:35 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=uaeA4mehYWLm3W6213n3D3TB8vOpPLTkH5cNKfq8CC8=; b=E9bhYQx3BITlLJG+TdN55WXHsQSdWBFPdOuB23O4nt+PPWnZ7HONQh27pPn0ThxSFsnt 2AfY5E4a7x96xtGcneoMC6Ong87Efa4l4rVB3Amauztmq6AR+qNH4qDZhX5BcCBrtwT5 ocX10QfITWTI3p73dJdQ4jYW3Gk6fMGey8eixbeQ/GAOhZ2/GhBGbAVRLhsXcAcZc+Hd 9xAgRnXHTI2zsbql6YdmLyZrDWg1x7VTRGdr6F3osHFyE0xjnwp2zdnsm+ILsb/TTaWK EgVDDvYDqXDbZfqvGTvrx/u/zNLRj2CTLF1jlh6VE0+WT5eUwe/NxoNQpMrxVbbe7UhW jw== Received: from userp3030.oracle.com (userp3030.oracle.com [156.151.31.80]) by userp2120.oracle.com with ESMTP id 2rj13qj2wm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 05 Apr 2019 00:29:35 +0000 Received: from pps.filterd (userp3030.oracle.com [127.0.0.1]) by userp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x350SHXW059204; Fri, 5 Apr 2019 00:29:35 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3030.oracle.com with ESMTP id 2rm8f5yhxs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 05 Apr 2019 00:29:35 +0000 Received: from abhmp0010.oracle.com (abhmp0010.oracle.com [141.146.116.16]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x350TXji008924; Fri, 5 Apr 2019 00:29:34 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Thu, 04 Apr 2019 17:29:33 -0700 Date: Thu, 4 Apr 2019 17:29:29 -0700 From: "Darrick J. Wong" To: Dave Chinner 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 2/3] xfs: reset page mappings after setting immutable Message-ID: <20190405002929.GD1177@magnolia> References: <155379543409.24796.5783716624820175068.stgit@magnolia> <155379544747.24796.1807309281507099911.stgit@magnolia> <20190328212147.GK23020@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190328212147.GK23020@dastard> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9217 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904050002 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9217 signatures=668685 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=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1904050002 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Fri, Mar 29, 2019 at 08:21:47AM +1100, Dave Chinner wrote: > On Thu, Mar 28, 2019 at 10:50:47AM -0700, Darrick J. Wong wrote: > > From: Darrick J. Wong > > > > The chattr manpage has this to say about immutable files: > > > > "A file with the 'i' attribute cannot be modified: it cannot be deleted > > or renamed, no link can be created to this file, most of the file's > > metadata can not be modified, and the file can not be opened in write > > mode." > > > > This means that we need to flush the page cache when setting the > > nit: flush and invalidate the page cache. > > > immutable flag so that programs cannot continue to write to writable > > mappings. > > Do we even need to invalidate the page cache for this? i.e. we've > cleaned the pages so that any new write to them will fault, > that will see the immutable flag via ->page_mkwrite and then the > app should segv, right? Yeah, we only need to flush the pages. No need to invalidate. > > Signed-off-by: Darrick J. Wong > > --- > > fs/xfs/xfs_ioctl.c | 63 +++++++++++++++++++++++++++++++++++----------------- > > 1 file changed, 43 insertions(+), 20 deletions(-) > > > > > > diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c > > index 6ecdbb3af7de..2bd1c5ab5008 100644 > > --- a/fs/xfs/xfs_ioctl.c > > +++ b/fs/xfs/xfs_ioctl.c > > @@ -998,6 +998,37 @@ xfs_diflags_to_linux( > > #endif > > } > > > > +static int > > +xfs_ioctl_setattr_flush( > > + struct xfs_inode *ip, > > + int *join_flags) > > +{ > > + struct inode *inode = VFS_I(ip); > > + int error; > > + > > + if (S_ISDIR(inode->i_mode)) > > + return 0; > > + if ((*join_flags) & (XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL)) > > + return 0; > > + > > + /* lock, flush and invalidate mapping in preparation for flag change */ > > + xfs_ilock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL); > > + error = filemap_write_and_wait(inode->i_mapping); > > + if (error) > > + goto out_unlock; > > + error = invalidate_inode_pages2(inode->i_mapping); > > + if (error) > > + goto out_unlock; > > + > > + *join_flags = XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL; > > + return 0; > > + > > +out_unlock: > > + xfs_iunlock(ip, XFS_MMAPLOCK_EXCL | XFS_IOLOCK_EXCL); > > + return error; > > + > > +} > > Doesn't wait for direct IO to drain. Wouldn't it be better to do > this? > > lock() > xfs_flush_unmap_range(ip, 0, XFS_SIZE(ip)); > unlock() But if we only need to filemap_write_and_wait, then calling flush_unmap (which also calls truncate_pagecache_range) is too much work. --D > > Otherwise looks ok. > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com