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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_SANE_1 autolearn=ham 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 3C73FC34022 for ; Wed, 19 Feb 2020 05:03:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 08AC024658 for ; Wed, 19 Feb 2020 05:03:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="rtZ6DjLt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725904AbgBSFD1 (ORCPT ); Wed, 19 Feb 2020 00:03:27 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:47768 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725306AbgBSFD1 (ORCPT ); Wed, 19 Feb 2020 00:03:27 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 01J53Ccr008615; Wed, 19 Feb 2020 05:03:23 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : subject : message-id : references : mime-version : content-type : content-transfer-encoding : in-reply-to; s=corp-2020-01-29; bh=4wb1PXrowO/bZ2zmYBNcI9KLy084JjW31QmqVq7Tmpk=; b=rtZ6DjLtAePl3u5vyRF4ewe6M6oT4TAPArEUztpLW2ghHOlQYqis+52Y0+rentyxiSM6 mF84WCtOQNGIQt+QEscqC6w5woVZzhIB7vFPGdwSX13QVejcwA4DkvBq0TVShuYrAeX0 ipIbyK10O+jFx1pbCmR2qLJZDvE8fUpKHaN6VKQgC8RlbA3NKYK5rnuosQuTw2hRmF9C +BNHwpPRQ30qs/fPK1AovGhVbwwZJF18m8U4FgvIURgQ/+j4LmhHn21CvKtv8KDr0Z66 t4mbjWGCUcdoBkOHnUXv25FnHsjJlSeIbLFHrLi4gZGB6v5ykKRMI3avPX2ES1g28OWq 4A== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by aserp2120.oracle.com with ESMTP id 2y8udk8j4y-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Feb 2020 05:03:22 +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 01J51mph078154; Wed, 19 Feb 2020 05:03:22 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 2y8ud08knm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 19 Feb 2020 05:03:22 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 01J53F1m020548; Wed, 19 Feb 2020 05:03:16 GMT Received: from localhost (/67.169.218.210) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 18 Feb 2020 21:03:15 -0800 Date: Tue, 18 Feb 2020 21:03:14 -0800 From: "Darrick J. Wong" To: Christoph Hellwig , Linus Torvalds , Linux Kernel Mailing List , linux-pm@vger.kernel.org Subject: Re: Regression: hibernation is broken since e6bc9de714972cac34daa1dc1567ee48a47a9342 Message-ID: <20200219050314.GA9504@magnolia> References: <20200213172351.GA6747@dumbo> <20200213175753.GS6874@magnolia> <20200213183515.GA8798@dumbo> <20200213193410.GB6868@magnolia> <20200213194135.GF6870@magnolia> <20200214211523.GA32637@dumbo> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200214211523.GA32637@dumbo> User-Agent: Mutt/1.9.4 (2018-02-28) X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9535 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 malwarescore=0 mlxlogscore=999 suspectscore=0 adultscore=0 spamscore=0 mlxscore=0 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002190033 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9535 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 suspectscore=0 spamscore=0 priorityscore=1501 adultscore=0 mlxscore=0 clxscore=1011 malwarescore=0 mlxlogscore=999 phishscore=0 impostorscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2001150001 definitions=main-2002190033 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Fri, Feb 14, 2020 at 10:15:24PM +0100, Domenico Andreoli wrote: > [ added linux-pm ] > > On Thu, Feb 13, 2020 at 11:41:35AM -0800, Darrick J. Wong wrote: > > On Thu, Feb 13, 2020 at 11:34:10AM -0800, Darrick J. Wong wrote: > > > > > > Well ... you could try the in-kernel hibernate (which I think is what > > > 'systemctl hibernate' does), though you'd lose the nifty features of > > > µswsusp. > > Indeed 'systemctl hibernate' works perfectly with v5.6-rc1 in my setup. As I suspected, the in-kernel hibernate can write the memory image to the swap file just fine... > > > In the end, though, I'll probably have to revert all those IS_SWAPFILE > > > checks (at least if CONFIG_HIBERNATION=y) since it's not fair to force > > > you to totally reconfigure your hibernation setup. > > > > Also, does the following partial revert fix uswsusp for you? It'll > > allow the direct writes that uswsusp wants to do, while leaving the rest > > (mmap writes) in place. > > > > --D > > > > diff --git a/fs/block_dev.c b/fs/block_dev.c > > index 69bf2fb6f7cd..077d9fa6b87d 100644 > > --- a/fs/block_dev.c > > +++ b/fs/block_dev.c > > @@ -2001,8 +2001,10 @@ ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) > > if (bdev_read_only(I_BDEV(bd_inode))) > > return -EPERM; > > > > +#ifndef CONFIG_HIBERNATION > > if (IS_SWAPFILE(bd_inode)) > > return -ETXTBSY; > > +#endif > > This alone is enough to make uswsusp work again. > > I propose this alternative: > > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -2001,7 +2001,8 @@ 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)) > + /* Hibernation might happen via uswsusp, let it write to the swap */ > + if (IS_SWAPFILE(bd_inode) && !IS_ENABLED(CONFIG_HIBERNATION)) ...but maybe we could do something a little more targeted? > return -ETXTBSY; > > if (!iov_iter_count(from)) > > I looked for a more selective way to enable writes to swap at runtime, > so I tried with system_entering_hibernation() but it's not yet armed > at the point in which uswsusp wants to write to the swap and therefore > it does not work. Hmm. I was poking around in the uswsusp code and I /think/ it prepares the kernel for the userspace-driven hibernation by calling the ioctl SNAPSHOT_SET_SWAP_FILE on the device that it's going to use. If that's true, we could have it clear S_SWAPFILE on the chosen device, though I'd have to do some more digging to figure out how to restore the flag after resuming from hibernation. --D > > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -34,6 +34,7 @@ > #include > #include > #include > +#include > #include "internal.h" > > struct bdev_inode { > @@ -2001,7 +2002,8 @@ 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)) > + /* Hibernation might happen via uswsusp, let it write to the swap */ > + if (IS_SWAPFILE(bd_inode) && !system_entering_hibernation()) > return -ETXTBSY; > > if (!iov_iter_count(from)) > > > if (!iov_iter_count(from)) > > return 0; > > diff --git a/mm/filemap.c b/mm/filemap.c > > index 1784478270e1..3df3211abe25 100644 > > --- a/mm/filemap.c > > +++ b/mm/filemap.c > > @@ -2920,8 +2920,10 @@ inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from) > > loff_t count; > > int ret; > > > > +#ifndef CONFIG_HIBERNATION > > if (IS_SWAPFILE(inode)) > > return -ETXTBSY; > > +#endif > > > > if (!iov_iter_count(from)) > > return 0; > > The above is not needed in my case but I'm not sure it would not be > needed in some other configuration of uswsusp. > > Dom > > -- > rsa4096: 3B10 0CA1 8674 ACBA B4FE FCD2 CE5B CF17 9960 DE13 > ed25519: FFB4 0CC3 7F2E 091D F7DA 356E CC79 2832 ED38 CB05