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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB40AC76196 for ; Fri, 7 Apr 2023 02:07:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1C8826B0071; Thu, 6 Apr 2023 22:07:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 176926B0074; Thu, 6 Apr 2023 22:07:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0179B6B0075; Thu, 6 Apr 2023 22:07:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id E34536B0071 for ; Thu, 6 Apr 2023 22:07:26 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id AF274C0488 for ; Fri, 7 Apr 2023 02:07:26 +0000 (UTC) X-FDA: 80652958092.08.5CAC941 Received: from mail1.bemta32.messagelabs.com (mail1.bemta32.messagelabs.com [195.245.230.2]) by imf22.hostedemail.com (Postfix) with ESMTP id CD864C0003 for ; Fri, 7 Apr 2023 02:07:23 +0000 (UTC) Authentication-Results: imf22.hostedemail.com; dkim=pass header.d=fujitsu.com header.s=170520fj header.b=UmbZmDsu; spf=pass (imf22.hostedemail.com: domain of ruansy.fnst@fujitsu.com designates 195.245.230.2 as permitted sender) smtp.mailfrom=ruansy.fnst@fujitsu.com; dmarc=pass (policy=none) header.from=fujitsu.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1680833244; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=mnDRDKfqGGN9UTjKSbf8I2ivZVg7oIU2f1nu3l4WfwU=; b=XJKHE4pd8pwlciMm5Ajb08zuka2+ObcTHFjUOSLKCxLPmLPx/Q27rLLz7NjPexdHlVNsJM fO0svXN8hkHoytZL28e/Z8DoyJbkOHcU+VqCdAkNeCiiDJrWZduVM+O5HGsRtw+MD0/Gd0 PsjJipKDA75CnXh0s5cpryi/2LI0dM8= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=pass header.d=fujitsu.com header.s=170520fj header.b=UmbZmDsu; spf=pass (imf22.hostedemail.com: domain of ruansy.fnst@fujitsu.com designates 195.245.230.2 as permitted sender) smtp.mailfrom=ruansy.fnst@fujitsu.com; dmarc=pass (policy=none) header.from=fujitsu.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1680833244; a=rsa-sha256; cv=none; b=HykmQj1+7EmXF9lTLsdpLAHZe69HuUBXfB3bTjd0ZusAz+/anbzpf0+YeZQAVNJx8+Js4V pDGZIMfrz9krTmd+E3xV7fqEK+Nj7z094YDrwS1CSSlZMs2RheNO9btQuQ6LBgLs9HSq2d /jiKrmexEorXxoNjTQfKb7psYtcNVic= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fujitsu.com; s=170520fj; t=1680833242; i=@fujitsu.com; bh=mnDRDKfqGGN9UTjKSbf8I2ivZVg7oIU2f1nu3l4WfwU=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type:Content-Transfer-Encoding; b=UmbZmDsu9Q0xSd5H35QSPysE2hxexR8thmW7uEdjWTYSnf+CctW7Lpcof6OZqntN9 RTKqcuZ2wAW9TotwMoQeI8Vu9IzHfsm3pxf8OCq1OY//6a9yHHYjQeBcbL1I/Y77Kk WCkOhYnfuEeXQ6xt2yLnCn+SuNL4FnLX76ZVS6IDkX7btnesb839H4JUn6ZUowVkLY SaJrwbCE1uOScc7KzrP24/rz8W6U4NMhRdXvi0AB0Nof3WTZAN9ElBwbxmwxV6CtOt P/BMU0pAmgLlKDyZJOJ7mK+FBhULvsBtYpgkuqDNJO3s1Q4UAw6CGN9suKqjEO0D9d gfejHBLWHKdjA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMKsWRWlGSWpSXmKPExsViZ8ORqHu9Sj/ FoGeVgMWc9WvYLKZPvcBocfkJn8Xs6c1MFnv2nmSxuLfmP6vFrj872C1W/vjDavH7xxw2B06P zSu0PBbvecnksWlVJ5vHpk+T2D1OzPjN4vFi80xGjzMLjrB7fN4kF8ARxZqZl5RfkcCacenie 7aCrZEVfS2KDYzrPboYuTiEBLYwSly4sp69i5ETyFnOJLF2jwtEYiujxP8FPUwgCV4BO4l/Pz azgdgsAioSK7q/sEHEBSVOznzCAmKLCiRLHNvUBhYXFvCTePHkEViviICmxJFv15hAhjILXGa UuDVzHRPEhjYmiQ2PT4JVsQnoSFxY8JcVxOYUMJNYsP4g2CRmAQuJxW8OskPY8hLNW2czg9gS AkoSF7/eYYWwKyQapx9igrDVJK6e28Q8gVFoFpIDZyEZNQvJqAWMzKsYzYpTi8pSi3QNDfSSi jLTM0pyEzNz9BKrdBP1Ukt1y1OLS3QN9RLLi/VSi4v1iitzk3NS9PJSSzYxAuMvpZgxeQfj1b 6/eocYJTmYlER534nqpwjxJeWnVGYkFmfEF5XmpBYfYpTh4FCS4PUoBcoJFqWmp1akZeYAUwF MWoKDR0mE1yoPKM1bXJCYW5yZDpE6xajLsbbhwF5mIZa8/LxUKXFepQqgIgGQoozSPLgRsLR0 iVFWSpiXkYGBQYinILUoN7MEVf4VozgHo5IwbxvIJTyZeSVwm14BHcEEdIStvw7IESWJCCmpB qaZutvj7nPGH/M1PLbtNdfyxZ+/yN/Y5KnY0KsxoeLMX1WmBD72a4bvfA0VW5Inz7mmZRzQtj xJu9Hwe5Zj8uX8cvaWCEmh8KSdl28ppkkwlYpOsevI/vTqj+mvxffvu81zX8vQ5HR809sW+/k HHNQ51XYdC+yxll39IDn3xKSNojsm+xv0aX7yadZ/Mmv7jaJAlWSvuHSTH3+TzNpfJH0NrIqf 4vtqm7un05kZqVrtjm2sxxctP6snvFZhW3rLs/9Lbdh4NjzOlu5nmHNcb4Hb7IerD6y5k1dz0 ZIl3E3PserVgtnr7cSXrt8/i+PaNdfjlxcIL8gJFVwx72Pe83sFnW+LrV7vnXBhnuj0mFVKLM UZiYZazEXFiQB9e8tHxgMAAA== X-Env-Sender: ruansy.fnst@fujitsu.com X-Msg-Ref: server-16.tower-587.messagelabs.com!1680833238!205075!1 X-Originating-IP: [62.60.8.97] X-SYMC-ESS-Client-Auth: outbound-route-from=pass X-StarScan-Received: X-StarScan-Version: 9.104.1; banners=-,-,- X-VirusChecked: Checked Received: (qmail 2723 invoked from network); 7 Apr 2023 02:07:19 -0000 Received: from unknown (HELO n03ukasimr01.n03.fujitsu.local) (62.60.8.97) by server-16.tower-587.messagelabs.com with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 7 Apr 2023 02:07:19 -0000 Received: from n03ukasimr01.n03.fujitsu.local (localhost [127.0.0.1]) by n03ukasimr01.n03.fujitsu.local (Postfix) with ESMTP id C8A1A10019C; Fri, 7 Apr 2023 03:07:18 +0100 (BST) Received: from R01UKEXCASM121.r01.fujitsu.local (R01UKEXCASM121 [10.183.43.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by n03ukasimr01.n03.fujitsu.local (Postfix) with ESMTPS id BC23C10019A; Fri, 7 Apr 2023 03:07:18 +0100 (BST) Received: from [192.168.50.5] (10.167.234.230) by R01UKEXCASM121.r01.fujitsu.local (10.183.43.173) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Fri, 7 Apr 2023 03:07:14 +0100 Message-ID: <4972d2db-dd61-4073-897d-0ac045984dcf@fujitsu.com> Date: Fri, 7 Apr 2023 10:07:08 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH v11 2/2] mm, pmem, xfs: Introduce MF_MEM_REMOVE for unbind To: "Darrick J. Wong" CC: , , , , , , , References: <1679996506-2-1-git-send-email-ruansy.fnst@fujitsu.com> <1679996506-2-3-git-send-email-ruansy.fnst@fujitsu.com> <20230404174517.GF109974@frogsfrogsfrogs> <58328778-6fdb-db03-6156-6c6f6b203ef1@fujitsu.com> <20230406145457.GA360881@frogsfrogsfrogs> From: Shiyang Ruan In-Reply-To: <20230406145457.GA360881@frogsfrogsfrogs> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.167.234.230] X-ClientProxiedBy: G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.80) To R01UKEXCASM121.r01.fujitsu.local (10.183.43.173) X-Virus-Scanned: ClamAV using ClamSMTP X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: CD864C0003 X-Stat-Signature: 74xuduxuzxso4e1p5y15xh13n53nkg89 X-HE-Tag: 1680833243-588990 X-HE-Meta: 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 TG5crYZq gGibUGva/6nOnKwPiCpfL/xXpx/8+f7OCazT/z854CQHHYrLzBUrtWo6xVxB+Ve5nuoLqT6pIsF0LVBfT/osNtTBrRZ8UU075gzFLlutL4KLc/4pe2MGe7o8QRGLHIY0ubOQ9RIgFgmnvPNPIjiy+6Ok+XaNv51O0S1Qr+RSc8i9Yo8FOd4lr0TPASha4JKfkcB5sysHW5r2CWGIVToE4s7OoQv+gYUYPttKlLLJfqZkZACILj2opc14/Zs4tHRnjvCHhfpilnmA8OkOEQfnR75IBbdD0Tdq+t1FTP8BMkDfFlAowv86pUI5VMwR460Q3dnzwuKbgRy7uL2qVa1+L4z3ksCWtuSdKGCnyFScOCgjmQOoqXhwo3FKTEZCA4IrdMSiBsVwkSFrIW8XogfaPiR2FLRcpbBoTFipQPnSGLcGCg4nze1dsLNV6oa1LJALGYl+JtRYlZHqmvopHTq23cGdd2g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 在 2023/4/6 22:54, Darrick J. Wong 写道: > On Thu, Apr 06, 2023 at 06:50:22PM +0800, Shiyang Ruan wrote: >> >> >> 在 2023/4/5 1:45, Darrick J. Wong 写道: >>> On Tue, Mar 28, 2023 at 09:41:46AM +0000, Shiyang Ruan wrote: >>>> This patch is inspired by Dan's "mm, dax, pmem: Introduce >>>> dev_pagemap_failure()"[1]. With the help of dax_holder and >>>> ->notify_failure() mechanism, the pmem driver is able to ask filesystem >>>> (or mapped device) on it to unmap all files in use and notify processes >>>> who are using those files. >>>> >>>> Call trace: >>>> trigger unbind >>>> -> unbind_store() >>>> -> ... (skip) >>>> -> devres_release_all() >>>> -> kill_dax() >>>> -> dax_holder_notify_failure(dax_dev, 0, U64_MAX, MF_MEM_PRE_REMOVE) >>>> -> xfs_dax_notify_failure() >>>> `-> freeze_super() >>>> `-> do xfs rmap >>>> ` -> mf_dax_kill_procs() >>>> ` -> collect_procs_fsdax() // all associated >>>> ` -> unmap_and_kill() >>>> ` -> invalidate_inode_pages2() // drop file's cache >>>> `-> thaw_super() >>>> >>>> Introduce MF_MEM_PRE_REMOVE to let filesystem know this is a remove >>>> event. Freeze the filesystem to prevent new dax mapping being created. >>>> And do not shutdown filesystem directly if something not supported, or >>>> if failure range includes metadata area. Make sure all files and >>>> processes are handled correctly. Also drop the cache of associated >>>> files before pmem is removed. >>>> >>>> [1]: https://lore.kernel.org/linux-mm/161604050314.1463742.14151665140035795571.stgit@dwillia2-desk3.amr.corp.intel.com/ >>>> >>>> Signed-off-by: Shiyang Ruan >>>> --- >>>> drivers/dax/super.c | 3 +- >>>> fs/xfs/xfs_notify_failure.c | 56 +++++++++++++++++++++++++++++++++---- >>>> include/linux/mm.h | 1 + >>>> mm/memory-failure.c | 17 ++++++++--- >>>> 4 files changed, 67 insertions(+), 10 deletions(-) >>>> >>>> diff --git a/drivers/dax/super.c b/drivers/dax/super.c >>>> index c4c4728a36e4..2e1a35e82fce 100644 >>>> --- a/drivers/dax/super.c >>>> +++ b/drivers/dax/super.c >>>> @@ -323,7 +323,8 @@ void kill_dax(struct dax_device *dax_dev) >>>> return; >>>> if (dax_dev->holder_data != NULL) >>>> - dax_holder_notify_failure(dax_dev, 0, U64_MAX, 0); >>>> + dax_holder_notify_failure(dax_dev, 0, U64_MAX, >>>> + MF_MEM_PRE_REMOVE); >>>> clear_bit(DAXDEV_ALIVE, &dax_dev->flags); >>>> synchronize_srcu(&dax_srcu); >>>> diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c >>>> index 1e2eddb8f90f..1b4eff43f9b5 100644 >>>> --- a/fs/xfs/xfs_notify_failure.c >>>> +++ b/fs/xfs/xfs_notify_failure.c >>>> @@ -22,6 +22,7 @@ >>>> #include >>>> #include >>>> +#include >>>> struct xfs_failure_info { >>>> xfs_agblock_t startblock; >>>> @@ -73,10 +74,16 @@ xfs_dax_failure_fn( >>>> struct xfs_mount *mp = cur->bc_mp; >>>> struct xfs_inode *ip; >>>> struct xfs_failure_info *notify = data; >>>> + struct address_space *mapping; >>>> + pgoff_t pgoff; >>>> + unsigned long pgcnt; >>>> int error = 0; >>>> if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) || >>>> (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) { >>>> + /* The device is about to be removed. Not a really failure. */ >>>> + if (notify->mf_flags & MF_MEM_PRE_REMOVE) >>>> + return 0; >>>> notify->want_shutdown = true; >>>> return 0; >>>> } >>>> @@ -92,10 +99,18 @@ xfs_dax_failure_fn( >>>> return 0; >>>> } >>>> - error = mf_dax_kill_procs(VFS_I(ip)->i_mapping, >>>> - xfs_failure_pgoff(mp, rec, notify), >>>> - xfs_failure_pgcnt(mp, rec, notify), >>>> - notify->mf_flags); >>>> + mapping = VFS_I(ip)->i_mapping; >>>> + pgoff = xfs_failure_pgoff(mp, rec, notify); >>>> + pgcnt = xfs_failure_pgcnt(mp, rec, notify); >>>> + >>>> + /* Continue the rmap query if the inode isn't a dax file. */ >>>> + if (dax_mapping(mapping)) >>>> + error = mf_dax_kill_procs(mapping, pgoff, pgcnt, >>>> + notify->mf_flags); >>>> + >>>> + /* Invalidate the cache anyway. */ >>>> + invalidate_inode_pages2_range(mapping, pgoff, pgoff + pgcnt - 1); >>>> + >>>> xfs_irele(ip); >>>> return error; >>>> } >>>> @@ -164,11 +179,25 @@ xfs_dax_notify_ddev_failure( >>>> } >>>> xfs_trans_cancel(tp); >>>> + >>>> + /* Unfreeze filesystem anyway if it is freezed before. */ >>>> + if (mf_flags & MF_MEM_PRE_REMOVE) { >>>> + error = thaw_super(mp->m_super); >>>> + if (error) >>>> + return error; >>> >>> If someone *else* wanders in and thaws the fs, you'll get EINVAL here. >>> >>> I guess that's useful for knowing if someone's screwed up the freeze >>> state on us, but ... really, don't you want to make sure you've gotten >>> the freeze and nobody else can take it away? >> >> Ok, I know it now. >>> >>> I think you want the kernel-initiated freeze proposed by Luis here: >>> https://lore.kernel.org/linux-fsdevel/20230114003409.1168311-4-mcgrof@kernel.org/ >> >> This patch gives userspace higher priority to do freeze/thaw then >> kernelspace. Userspace can thaw it even when kernelspace needs the freeze >> state. But I think it can't happen in this case. Kernelspace(in this case) >> should hold the freeze state and, IOW, has higher priority than userspace. >> I think we could change the @usercall to @priority. >> >> -int freeze_super(struct super_block *sb) >> +int freeze_super(struct super_block *sb, int priority) >> >> And priority definitions like: >> #define FREEZE_PRO_AUTO 0 // for auto freeze > > What is an auto-freeze, and who would be calling it? It was a concept Luis introduced in his patchset. > I suspect we > could get by with "exclusive" and "non-exclusive". Non-exclusive is the > free-for-all we have now where any userspace can thaw, and exclusive is > for kernel users (like PRE_REMOVE) who want to block everyone else from > thawing. Yes, I think this is better (after I reading that patchset and its comments carefully). > >> #define FREEZE_PRO_USERCALL 1 // for user call >> #define FREEZE_PRO_KERNELCALL 2 // for kernel call > > "Linux 6.5, now with FREEZE PRO!!!!" ;) What I was going to say here was priority, which is abbreviated PRIO. My mistake here. > > THAW_PROT_* since we're really protecting who gets to thaw the fs; and > "PROT" is a more customary mnemonic for 'protection. OK. This looks more appropriate. Thanks! -- Ruan. > > --D > >> >> >> -- >> Thanks, >> Ruan. >> >>> >>> Also: Is Fujitsu still pursuing pmem products? Even though Optane is >>> dead? I'm no longer sure of what the roadmap is for all this fsdax code >>> and whatnot. >>> >>> --D >>> >>>> + } >>>> + >>>> + /* >>>> + * Determine how to shutdown the filesystem according to the >>>> + * error code and flags. >>>> + */ >>>> if (error || notify.want_shutdown) { >>>> xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); >>>> if (!error) >>>> error = -EFSCORRUPTED; >>>> - } >>>> + } else if (mf_flags & MF_MEM_PRE_REMOVE) >>>> + xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT); >>>> + >>>> return error; >>>> } >>>> @@ -182,6 +211,7 @@ xfs_dax_notify_failure( >>>> struct xfs_mount *mp = dax_holder(dax_dev); >>>> u64 ddev_start; >>>> u64 ddev_end; >>>> + int error; >>>> if (!(mp->m_super->s_flags & SB_BORN)) { >>>> xfs_warn(mp, "filesystem is not ready for notify_failure()!"); >>>> @@ -196,6 +226,8 @@ xfs_dax_notify_failure( >>>> if (mp->m_logdev_targp && mp->m_logdev_targp->bt_daxdev == dax_dev && >>>> mp->m_logdev_targp != mp->m_ddev_targp) { >>>> + if (mf_flags & MF_MEM_PRE_REMOVE) >>>> + return 0; >>>> xfs_err(mp, "ondisk log corrupt, shutting down fs!"); >>>> xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_ONDISK); >>>> return -EFSCORRUPTED; >>>> @@ -209,6 +241,12 @@ xfs_dax_notify_failure( >>>> ddev_start = mp->m_ddev_targp->bt_dax_part_off; >>>> ddev_end = ddev_start + bdev_nr_bytes(mp->m_ddev_targp->bt_bdev) - 1; >>>> + /* Notify failure on the whole device. */ >>>> + if (offset == 0 && len == U64_MAX) { >>>> + offset = ddev_start; >>>> + len = bdev_nr_bytes(mp->m_ddev_targp->bt_bdev); >>>> + } >>>> + >>>> /* Ignore the range out of filesystem area */ >>>> if (offset + len - 1 < ddev_start) >>>> return -ENXIO; >>>> @@ -225,6 +263,14 @@ xfs_dax_notify_failure( >>>> if (offset + len - 1 > ddev_end) >>>> len = ddev_end - offset + 1; >>>> + if (mf_flags & MF_MEM_PRE_REMOVE) { >>>> + xfs_info(mp, "device is about to be removed!"); >>>> + /* Freeze the filesystem to prevent new mappings created. */ >>>> + error = freeze_super(mp->m_super); >>>> + if (error) >>>> + return error; >>>> + } >>>> + >>>> return xfs_dax_notify_ddev_failure(mp, BTOBB(offset), BTOBB(len), >>>> mf_flags); >>>> } >>>> diff --git a/include/linux/mm.h b/include/linux/mm.h >>>> index 1f79667824eb..ac3f22c20e1d 100644 >>>> --- a/include/linux/mm.h >>>> +++ b/include/linux/mm.h >>>> @@ -3436,6 +3436,7 @@ enum mf_flags { >>>> MF_UNPOISON = 1 << 4, >>>> MF_SW_SIMULATED = 1 << 5, >>>> MF_NO_RETRY = 1 << 6, >>>> + MF_MEM_PRE_REMOVE = 1 << 7, >>>> }; >>>> int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, >>>> unsigned long count, int mf_flags); >>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>>> index fae9baf3be16..6e6acec45568 100644 >>>> --- a/mm/memory-failure.c >>>> +++ b/mm/memory-failure.c >>>> @@ -623,7 +623,7 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill, >>>> */ >>>> static void collect_procs_fsdax(struct page *page, >>>> struct address_space *mapping, pgoff_t pgoff, >>>> - struct list_head *to_kill) >>>> + struct list_head *to_kill, bool pre_remove) >>>> { >>>> struct vm_area_struct *vma; >>>> struct task_struct *tsk; >>>> @@ -631,8 +631,15 @@ static void collect_procs_fsdax(struct page *page, >>>> i_mmap_lock_read(mapping); >>>> read_lock(&tasklist_lock); >>>> for_each_process(tsk) { >>>> - struct task_struct *t = task_early_kill(tsk, true); >>>> + struct task_struct *t = tsk; >>>> + /* >>>> + * Search for all tasks while MF_MEM_PRE_REMOVE, because the >>>> + * current may not be the one accessing the fsdax page. >>>> + * Otherwise, search for the current task. >>>> + */ >>>> + if (!pre_remove) >>>> + t = task_early_kill(tsk, true); >>>> if (!t) >>>> continue; >>>> vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) { >>>> @@ -1732,6 +1739,7 @@ int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, >>>> dax_entry_t cookie; >>>> struct page *page; >>>> size_t end = index + count; >>>> + bool pre_remove = mf_flags & MF_MEM_PRE_REMOVE; >>>> mf_flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; >>>> @@ -1743,9 +1751,10 @@ int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index, >>>> if (!page) >>>> goto unlock; >>>> - SetPageHWPoison(page); >>>> + if (!pre_remove) >>>> + SetPageHWPoison(page); >>>> - collect_procs_fsdax(page, mapping, index, &to_kill); >>>> + collect_procs_fsdax(page, mapping, index, &to_kill, pre_remove); >>>> unmap_and_kill(&to_kill, page_to_pfn(page), mapping, >>>> index, mf_flags); >>>> unlock: >>>> -- >>>> 2.39.2 >>>>