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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 46753C11F64 for ; Thu, 1 Jul 2021 11:58:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A0DC761418 for ; Thu, 1 Jul 2021 11:58:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0DC761418 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2143A8D0005; Thu, 1 Jul 2021 07:58:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1C44D8D0001; Thu, 1 Jul 2021 07:58:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 08CBC8D0005; Thu, 1 Jul 2021 07:58:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0068.hostedemail.com [216.40.44.68]) by kanga.kvack.org (Postfix) with ESMTP id DB7BE8D0001 for ; Thu, 1 Jul 2021 07:58:42 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id A0601267DE for ; Thu, 1 Jul 2021 11:58:42 +0000 (UTC) X-FDA: 78313872084.20.A1899D6 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf29.hostedemail.com (Postfix) with ESMTP id DC85B9000334 for ; Thu, 1 Jul 2021 11:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=FYHFyPNMs7ektzXfPfpbCo/kDILWq4D/qoEUsHcHhK8=; b=Vazh2/Pg+EvfWut0RdLDhYKwhN 4ZmOqysXZLnDn9JIkKSoUFJ/63riyWnckj1EuYEZ1rA/LN6PyXQP899qDX2XVoxTo4EIlcd1hPzCu Q+j9LUD2G1S2+Vnr1jIgLbhMLwSeq2huvkEnFjC95wWMbRRU7TwcQz5Xtvdx6Vf2Ie6fe+54jsIPa Q5BIoGxGDVHGXoc5uItDuAaQy8T/TvoI4+v9lAgexdl6ife0hAS2ATHu3/QlmqeIILwhdblhos9ZC zulDMkuwTmyJThVMqguJYPNltcMIQmZjbLOpDy/Cc3c2MKZStIk++TUvomEJ9aWuK4XEepI+GU52E nI06CjbQ==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1lyvKM-006WJc-Ap; Thu, 01 Jul 2021 11:57:59 +0000 Date: Thu, 1 Jul 2021 12:57:54 +0100 From: Matthew Wilcox To: =?utf-8?B?6raM7Jik7ZuI?= Cc: "gregkh@linuxfoundation.org" , "akpm@linux-foundation.org" , "konrad.wilk@oracle.com" , "ohkwon1043@gmail.com" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] mm: cleancache: fix potential race in cleancache apis Message-ID: References: <20210630073310epcms1p2ad6803cfd9dbc8ab501c4c99f799f4da@epcms1p2> <20210701050644epcms1p5ceaf654fdabec4a126081f9edcbb3fff@epcms1p5> <20210701085650epcms1p381d6d9c0052408c2ba011777fe3e74ba@epcms1p3> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210701085650epcms1p381d6d9c0052408c2ba011777fe3e74ba@epcms1p3> Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b="Vazh2/Pg"; dmarc=none; spf=none (imf29.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-Stat-Signature: 3htqiehyxjffswrbaneq18djn36wb3wi X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DC85B9000334 X-HE-Tag: 1625140721-840413 Content-Transfer-Encoding: quoted-printable 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: On Thu, Jul 01, 2021 at 05:56:50PM +0900, =EA=B6=8C=EC=98=A4=ED=9B=88 wro= te: > On Thu, Jul 01, 2021 at 07:58:36AM +0200, gregkh@linuxfoundation.org wr= ote: > > On Thu, Jul 01, 2021 at 02:06:44PM +0900, =EA=B6=8C=EC=98=A4=ED=9B=88= wrote: > > > We are using Cleancache APIs for our proprietary feature in Samsung= . > > > As Wilcox mentioned, however, there is no cleancache backend in cur= rent kernel > > > mainline. > > > So if the race patch shall be accepted, then it seems unnecessary t= o patch=20 > > > previous stable kernels. > > >=20 > > > Meanwhile, I personally think cleancache API still has potential to= be a good > > > material when used with new arising technologies such as pmem or NV= Me. > > >=20 > > > So I suggest to postpone removing cleancache for a while. > > =20 > > If there are no in-kernel users, it needs to be removed. If you rely= on > > this, wonderful, please submit your code as soon as possible. > > =20 > > thanks, > > =20 > > greg k-h > >=20 > We will discuss internally and see if we can submit our feature. You have two months. I'll submit the removal then if no new backend has shown up.