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=-8.3 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_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY, URIBL_BLOCKED,USER_AGENT_SANE_1 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 5FE63C3F2CE for ; Wed, 4 Mar 2020 15:48:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 373D022B48 for ; Wed, 4 Mar 2020 15:48:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="LFhKRlBG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388252AbgCDPsM (ORCPT ); Wed, 4 Mar 2020 10:48:12 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:51026 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729754AbgCDPsI (ORCPT ); Wed, 4 Mar 2020 10:48:08 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 024Fd1U0136814; Wed, 4 Mar 2020 15:48:04 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-2020-01-29; bh=4pIPpk9UM2GlyA237h0AGb6LahzrQQPr44APCEOTTpQ=; b=LFhKRlBGN+2VcurWuONe3fjFrn0Trzk3NVNEMsdjo2Iy9ob04uv9sWAmzjIVLl9k/i/9 4yZcWainsZHYjc1VfuEyjFDG3nRRnyj59HfRPXZNp8QlMpIVQdHtEaEgd0HFWiblO5AI o4JSYxnqM0DTbuUidqo/DLxYlPLLFtDMyjZi4wdfSDwhcKkMTFRE/inOPw+PP2O7fPQG kl6wVkHPzZHuCqcPVrYY7EdHP8vdgz/oS6bSGT7rrsdp5hjVwKJFK2qmHITmX5rFtnaP Bj4xePR+ZvcEO8JgRIvIJkTk9Davk40Rxj5x+vlt5qpAyX2A9U8Hv45Nf5LCxTM7p4Py mw== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 2yghn3awr0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 04 Mar 2020 15:48:04 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 024Fiipj086123; Wed, 4 Mar 2020 15:48:03 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 2yg1p7s7bn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 04 Mar 2020 15:48:03 +0000 Received: from abhmp0013.oracle.com (abhmp0013.oracle.com [141.146.116.19]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 024Fm2n9006238; Wed, 4 Mar 2020 15:48:02 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 04 Mar 2020 07:48:02 -0800 Date: Wed, 4 Mar 2020 07:48:01 -0800 From: "Darrick J. Wong" To: akpm@linux-foundation.org Cc: linux-pm@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] vfs: partially revert "don't allow writes to swap files" Message-ID: <20200304154801.GE8037@magnolia> References: <20200303191023.GD8037@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200303191023.GD8037@magnolia> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9549 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 malwarescore=0 mlxlogscore=999 mlxscore=0 spamscore=0 adultscore=0 bulkscore=0 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003040115 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9549 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 malwarescore=0 phishscore=0 spamscore=0 impostorscore=0 mlxscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 priorityscore=1501 bulkscore=0 clxscore=1015 suspectscore=1 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2003040115 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Mar 03, 2020 at 11:10:23AM -0800, Darrick J. Wong wrote: > From: Darrick J. Wong > > In commit dc617f29dbe5 we tried to prevent userspace programs from > writing to active swap devices. However, it turns out that userspace > hibernation requires the ability to write the hibernation image to a > swap device, so revert the write path checks. > > Fixes: dc617f29dbe5 ("vfs: don't allow writes to swap files") > Reported-by: Domenico Andreoli > Reported-by: Marian Klein > Signed-off-by: Darrick J. Wong self-NAK, Domenico Andreoli has taken this on. Andrew, could you please drop this patch from your queue? --D > --- > fs/block_dev.c | 3 --- > mm/filemap.c | 3 --- > mm/memory.c | 4 ---- > mm/mmap.c | 8 ++------ > 4 files changed, 2 insertions(+), 16 deletions(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index 69bf2fb6f7cd..08b088dac1f0 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -2001,9 +2001,6 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) > if (bdev_read_only(I_BDEV(bd_inode))) > return -EPERM; > > - if (IS_SWAPFILE(bd_inode)) > - return -ETXTBSY; > - > if (!iov_iter_count(from)) > return 0; > > diff --git a/mm/filemap.c b/mm/filemap.c > index 1784478270e1..d1b8cd15b2bf 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -2920,9 +2920,6 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) > loff_t count; > int ret; > > - if (IS_SWAPFILE(inode)) > - return -ETXTBSY; > - > if (!iov_iter_count(from)) > return 0; > > diff --git a/mm/memory.c b/mm/memory.c > index 0bccc622e482..e908490f7034 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -2357,10 +2357,6 @@ 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_SWAPFILE(vmf->vma->vm_file->f_mapping->host)) > - 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; > diff --git a/mm/mmap.c b/mm/mmap.c > index d681a20eb4ea..77d086139e13 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1461,12 +1461,8 @@ unsigned long do_mmap(struct file *file, unsigned long addr, > case MAP_SHARED_VALIDATE: > if (flags & ~flags_mask) > return -EOPNOTSUPP; > - if (prot & PROT_WRITE) { > - if (!(file->f_mode & FMODE_WRITE)) > - return -EACCES; > - if (IS_SWAPFILE(file->f_mapping->host)) > - return -ETXTBSY; > - } > + if ((prot&PROT_WRITE) && !(file->f_mode&FMODE_WRITE)) > + return -EACCES; > > /* > * Make sure we don't allow writing to an append-only