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=-8.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 A74A1C4363D for ; Wed, 23 Sep 2020 14:57:20 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1C71E206D9 for ; Wed, 23 Sep 2020 14:57:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g94TaxJO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1C71E206D9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:33502 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kL6Cs-0003k8-Kw for qemu-devel@archiver.kernel.org; Wed, 23 Sep 2020 10:57:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57536) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kL69r-00014J-4D for qemu-devel@nongnu.org; Wed, 23 Sep 2020 10:54:15 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:27722 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kL69m-00081E-7a for qemu-devel@nongnu.org; Wed, 23 Sep 2020 10:54:10 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600872844; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ro5t1jCGdDB36UmHSm5D5f/N7RXFA4qSkHw3W7QM1Q4=; b=g94TaxJOEbsNR+fDnwadfrCyHgRZ+xUZYwSmRFS+xA51nhJxzatt8zGNvwdq7ZaUcr5kJk 9ze88mn0Pjq9VhRpWSgEZCX7tNWQRnVs9FrRYzHEVEgBUzoS8HKyZcRk1+rhyMRuVnuCIt xIP3z9S/Cs915fN1ClH7LDQTJfprfuY= 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-437-lZAW9pQDP8SmEuZO0Dlm8w-1; Wed, 23 Sep 2020 10:54:03 -0400 X-MC-Unique: lZAW9pQDP8SmEuZO0Dlm8w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 610D510BBEC8; Wed, 23 Sep 2020 14:54:01 +0000 (UTC) Received: from [10.10.119.140] (ovpn-119-140.rdu2.redhat.com [10.10.119.140]) by smtp.corp.redhat.com (Postfix) with ESMTP id 20DE07368B; Wed, 23 Sep 2020 14:53:59 +0000 (UTC) Subject: Re: [PATCH 3/7] hw/ide/core: Replace magic '512' value by BDRV_SECTOR_SIZE To: Kevin Wolf , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= References: <20200814082841.27000-1-f4bug@amsat.org> <20200814082841.27000-4-f4bug@amsat.org> <20200817111745.GG11402@linux.fritz.box> From: John Snow Message-ID: <2347d8f7-5632-f7a4-6b81-bee179241da4@redhat.com> Date: Wed, 23 Sep 2020 10:53:59 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200817111745.GG11402@linux.fritz.box> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jsnow@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Received-SPF: pass client-ip=207.211.31.81; envelope-from=jsnow@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/23 08:52:41 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -32 X-Spam_score: -3.3 X-Spam_bar: --- X-Spam_report: (-3.3 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.228, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Fam Zheng , qemu-block@nongnu.org, qemu-trivial@nongnu.org, Michael Tokarev , qemu-devel@nongnu.org, Laurent Vivier , Paolo Bonzini , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 8/17/20 7:17 AM, Kevin Wolf wrote: > Am 14.08.2020 um 10:28 hat Philippe Mathieu-Daudé geschrieben: >> Use self-explicit definitions instead of magic '512' value. >> >> Signed-off-by: Philippe Mathieu-Daudé > > BDRV_SECTOR_SIZE is the arbitrary unit in which some block layer > functions and variables work (such as bs->total_sectors). It happens to > be 512. > > IDE disks have a sector size, too. Actually, two of them, a physical and > a logical one. The more important one is the logical one. We happen to > emulate only IDE devices for which the logical block size is 512 bytes > (ide_dev_initfn() errors out otherwise). > > But just because two constants both happen to be 512 in practice, they > are not the same thing. > > So if we want to replace all magic 512 values, we should probably > introduce a new IDE_SECTOR_SIZE and then decide case by case whether > IDE_SECTOR_SIZE or BDRV_SECTOR_SIZE is meant. I think most (if not all) > of the places you converted in this patch need to be IDE_SECTOR_SIZE. > > Kevin > I didn't audit the other patches, but be mindful of the distinction that Kevin is pointing out. Luckily, I think we're low risk for deciding to change the BDRV_SECTOR_SIZE default any time soon, so it probably won't matter in the near future ... --js