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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 76C9EC2B9F4 for ; Mon, 14 Jun 2021 15:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6240A61185 for ; Mon, 14 Jun 2021 15:38:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233966AbhFNPkj (ORCPT ); Mon, 14 Jun 2021 11:40:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:39565 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233910AbhFNPkd (ORCPT ); Mon, 14 Jun 2021 11:40:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623685110; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=qKSz/LRN00+0nJv4NZOhjKiU+MuuvkiLXHI2jFvDWTo=; b=cyMp5Rykvxo818HDegBz1uUFprdy7qBaujMADKgU0NscvK7QryAAGEIh52P8rAmINnYSiV AhWii7QmJmE1aZhCJUSb3gItD/pSVTOSvmO+nWyeJdfL8Tc5ce/r2tiD13E4/GUYBU9V3f pFDy2AogffPb/JexZ80DpnvOXIcHcHM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-428-7bpBxVSNPlCeR3mvDSJyDA-1; Mon, 14 Jun 2021 11:38:26 -0400 X-MC-Unique: 7bpBxVSNPlCeR3mvDSJyDA-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0652619253C6; Mon, 14 Jun 2021 15:38:24 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-118-65.rdu2.redhat.com [10.10.118.65]) by smtp.corp.redhat.com (Postfix) with ESMTP id B766219C46; Mon, 14 Jun 2021 15:38:22 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <162367681795.460125.11729955608839747375.stgit@warthog.procyon.org.uk> <162367682522.460125.5652091227576721609.stgit@warthog.procyon.org.uk> To: Matthew Wilcox Cc: dhowells@redhat.com, jlayton@kernel.org, linux-afs@lists.infradead.org, ceph-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/3] afs: Fix afs_write_end() to handle short writes MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <475130.1623685101.1@warthog.procyon.org.uk> Date: Mon, 14 Jun 2021 16:38:21 +0100 Message-ID: <475131.1623685101@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Matthew Wilcox wrote: > > - ASSERT(PageUptodate(page)); > > - > > if (PagePrivate(page)) { > > priv = page_private(page); > > f = afs_page_dirty_from(page, priv); > > Why are you removing this assertion? Does AFS now support dirty, > partially-uptodate pages? If so, a subsequent read() to that > page is going to need to be careful to only read the parts of the page > from the server that haven't been written ... Because the previous hunk in the patch: + if (!PageUptodate(page)) { + if (copied < len) { + copied = 0; + goto out; + } + + SetPageUptodate(page); + } means you can't get there unless PageUptodate() is true by that point. David