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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35C46C433F5 for ; Thu, 7 Oct 2021 14:53:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1AB256109F for ; Thu, 7 Oct 2021 14:53:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242212AbhJGOzi (ORCPT ); Thu, 7 Oct 2021 10:55:38 -0400 Received: from sender2-pp-o92.zoho.com.cn ([163.53.93.251]:25328 "EHLO sender2-pp-o92.zoho.com.cn" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242165AbhJGOzi (ORCPT ); Thu, 7 Oct 2021 10:55:38 -0400 ARC-Seal: i=1; a=rsa-sha256; t=1633618384; cv=none; d=zoho.com.cn; s=zohoarc; b=DDDHZlDWo+5WO3B+uN7PiJMZPS3Ma7R8eSk3Xg4n+RImp0vrhVIH/lgMHgaBBXCbWfmeknC8tkvansvD/nIHZeo23Q5ZiFZhjaE3Li1G3D7WLJVT4lKy/TDANoXDPbp4cX2gW8NRbrOMyuh0y8hpkP4XOItYVyR8r4Jx6A23l/g= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com.cn; s=zohoarc; t=1633618384; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:MIME-Version:Message-ID:Reply-To:References:Subject:To; bh=ALDuNPX38fhXXa+zXpsu/pg/N+jdzTq1/9LsmnJf8oE=; b=haXNF92PhlygjHFnDrGa6rVw41FF+NYWBVcGSIOj245/euJunAMDZ0FtCi8/xZR0q5WVeZ1jqPVxFzJzGVeunxSp2s/FlueHR9QDc3Huh97+PfdRf64864HsXSURh44MShece1Q3ox7SAdug+8CYVl1YSMTdOZnCP5dOPhjMVnw= ARC-Authentication-Results: i=1; mx.zoho.com.cn; dkim=pass header.i=mykernel.net; spf=pass smtp.mailfrom=cgxu519@mykernel.net; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1633618384; s=zohomail; d=mykernel.net; i=cgxu519@mykernel.net; h=Date:From:Reply-To:To:Cc:Message-ID:In-Reply-To:References:Subject:MIME-Version:Content-Type:Content-Transfer-Encoding; bh=ALDuNPX38fhXXa+zXpsu/pg/N+jdzTq1/9LsmnJf8oE=; b=L+O1RDm1I3OpdzH0D6CTw2wyfU0dcaZteD/O29Fd2o5YjEBSNkNtABol0C1uMzkw cN6FztZZ0n4UUz0GE8ioNGnhLjZInMABhE0MeHBypVJ5MiTqps70yMIZSYETjf3+X00 aT/mbHhLtTu1QzgX834N4qvEKiHtScX14z7z+UtI= Received: from mail.baihui.com by mx.zoho.com.cn with SMTP id 1633618382638215.82362575268553; Thu, 7 Oct 2021 22:53:02 +0800 (CST) Date: Thu, 07 Oct 2021 22:53:02 +0800 From: Chengguang Xu Reply-To: cgxu519@mykernel.net To: "Jan Kara" , "Miklos Szeredi" Cc: "Amir Goldstein" , "linux-fsdevel" , "overlayfs" , "linux-kernel" Message-ID: <17c5b3e4f2b.113dc38cd26071.2800661599712778589@mykernel.net> In-Reply-To: <20211007144646.GL12712@quack2.suse.cz> References: <20210923130814.140814-1-cgxu519@mykernel.net> <20210923130814.140814-7-cgxu519@mykernel.net> <17c5aba1fef.c5c03d5825886.6577730832510234905@mykernel.net> <17c5adfe5ea.12f1be94625921.4478415437452327206@mykernel.net> <20211007144646.GL12712@quack2.suse.cz> Subject: Re: [RFC PATCH v5 06/10] ovl: implement overlayfs' ->write_inode operation MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Importance: Medium User-Agent: ZohoCN Mail X-Mailer: ZohoCN Mail Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org ---- =E5=9C=A8 =E6=98=9F=E6=9C=9F=E5=9B=9B, 2021-10-07 22:46:46 Jan Kara <= jack@suse.cz> =E6=92=B0=E5=86=99 ---- > On Thu 07-10-21 15:34:19, Miklos Szeredi wrote: > > On Thu, 7 Oct 2021 at 15:10, Chengguang Xu wrot= e: > > > > However that wasn't what I was asking about. AFAICS ->write_inod= e() > > > > won't start write back for dirty pages. Maybe I'm missing somet= hing, > > > > but there it looks as if nothing will actually trigger writeback = for > > > > dirty pages in upper inode. > > > > > > > > > > Actually, page writeback on upper inode will be triggered by overlay= fs ->writepages and > > > overlayfs' ->writepages will be called by vfs writeback function (i.= e writeback_sb_inodes). > >=20 > > Right. > >=20 > > But wouldn't it be simpler to do this from ->write_inode()? >=20 > You could but then you'd have to make sure you have I_DIRTY_SYNC always = set > when I_DIRTY_PAGES is set on the upper inode so that your ->write_inode(= ) > callback gets called. Overall I agree the logic would be probably simple= r. >=20 Hi Jan, Miklos Thnaks for your suggestions. Let me have a try in next version. Thanks, Chengguang