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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F1DDC433EF for ; Sat, 28 May 2022 06:12:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234184AbiE1GMa (ORCPT ); Sat, 28 May 2022 02:12:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229936AbiE1GM3 (ORCPT ); Sat, 28 May 2022 02:12:29 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 82F632DD5D for ; Fri, 27 May 2022 23:12:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=XRCyrfsOL2PXgIyjGTvYC1oF+7LmRBgFYCVBlEy3SLM=; b=JCJwFEd4qJ37PkLpdR/dcR6Hyi U/gUarqXwImt2//XtGeUXO5SC78Z4QRBmgIb5HCbIB4fXOhV4b3Cjz01ZjPqxqNSCTAdiX4x1dsip VtwhHFCiSQme/BZKiP5sJ0HwAUzW3LNqhHprG4nafN8t1RTJPpwwhxlHfdjz36PCDTN2NBLh1NPp2 xBVKYnMrb27Yn+B/Mo597bALnMCN0Q8JgfSXE5HFzCnl9pVR3dBAFslSC6qPCPEKMF4dpaxwZwrkz 5hYqYJjPUyvywBTL+IqzxD5xhjZlbDDEbtPmzNZPaZCa644NPPp65nuVU4dwDQyD3vNO+gf4c+Fq5 Y+A2L+xA==; Received: from hch by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1nupgZ-001XvQ-Qt; Sat, 28 May 2022 06:12:27 +0000 Date: Fri, 27 May 2022 23:12:27 -0700 From: Christoph Hellwig To: "Matthew Wilcox (Oracle)" Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 00/24] Begin removing PageError Message-ID: References: <20220527155036.524743-1-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220527155036.524743-1-willy@infradead.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, May 27, 2022 at 04:50:12PM +0100, Matthew Wilcox (Oracle) wrote: > After this series, there are some places which still use it. Lots of > the converted places are trivial -- they should have been checking the > uptodate flag. The trickiest are the ones which have multiple steps > and signal "hey, something went wrong with one step in the read of this > page/folio" by setting the error flag. How many of those do we have left, and how many of those can't be changed to just return them through errors or other on-stack means? > I'm thinking about (ab)using PageChecked == PG_owner_priv_1 for this > purpose. It'd be nice to be able to use page->private for this, but > that's not always available. I know some filesystems already ascribe > a meaning to PG_owner_priv_1, but those can be distinguished by whether > the uptodate flag is set. I suspect what to do will be very ad-hoc depending on the actual user. The first priority is probably to isolate PageError so that it is only used for that kind of communication insid a single file system so that all the generic uses can go away.