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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 E9056C33CB1 for ; Fri, 17 Jan 2020 16:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BF9FD21582 for ; Fri, 17 Jan 2020 16:44:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aPONDv90" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727766AbgAQQn5 (ORCPT ); Fri, 17 Jan 2020 11:43:57 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:23025 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726901AbgAQQn4 (ORCPT ); Fri, 17 Jan 2020 11:43:56 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579279435; 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=7ywZah/acU88OdI0elxdfP2wlFAEGYbYZ2X9Wl0Y+ps=; b=aPONDv90XNmbxI3XjQCdAGwZTtIDrtRA9Q0T72fYp+mdaEnn8imbL7tTgheeHPMfkJt2OT s77r75OsSZkYkLphG+JFZ9Az5m3JWc/KcMMVMyxyJjYy8hriYMTh8802fxzF64aZ/u/dpS aCfw7gMeKiYcC7nNmoJZoneHrxc/d3c= 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-363-LeC-d3cZMfmN1hLN6_W0bg-1; Fri, 17 Jan 2020 11:43:49 -0500 X-MC-Unique: LeC-d3cZMfmN1hLN6_W0bg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5DDF66125B; Fri, 17 Jan 2020 16:43:42 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-49.rdu2.redhat.com [10.10.120.49]) by smtp.corp.redhat.com (Postfix) with ESMTP id BDA115C54A; Fri, 17 Jan 2020 16:43:39 +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: <20200116101344.GA16435@lst.de> References: <20200116101344.GA16435@lst.de> <20200115144839.GA30301@lst.de> <20200115133101.GA28583@lst.de> <4467.1579020509@warthog.procyon.org.uk> <00fc7691-77d5-5947-5493-5c97f262da81@gmx.com> <27181AE2-C63F-4932-A022-8B0563C72539@dilger.ca> <26093.1579098922@warthog.procyon.org.uk> <28755.1579100378@warthog.procyon.org.uk> To: Christoph Hellwig Cc: dhowells@redhat.com, Qu Wenruo , Andreas Dilger , linux-fsdevel , Al Viro , "Theodore Y. Ts'o" , "Darrick J. Wong" , Chris Mason , Josef Bacik , David Sterba , linux-ext4 , linux-xfs , linux-btrfs , Linux Kernel Mailing List Subject: Re: Problems with determining data presence by examining extents? MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <469987.1579279418.1@warthog.procyon.org.uk> Date: Fri, 17 Jan 2020 16:43:38 +0000 Message-ID: <469988.1579279418@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Christoph Hellwig wrote: > File systems usually pad zeroes where they have to, typically for > sub-blocksize writes. Disabling this would break data integrity. I understand that. I can, however, round up the netfs I/O granule size and alignment to a multiple of the cachefile I/O block size. Also, I'm doing DIO, so I have to use block size multiples. But if the filesystem can avoid bridging large, appropriately sized and aligned blocks, then I can use it. David