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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A5F8AC433EF for ; Wed, 18 May 2022 13:04:44 +0000 (UTC) Received: from localhost ([::1]:36184 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nrJM3-0007Km-H6 for qemu-devel@archiver.kernel.org; Wed, 18 May 2022 09:04:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57152) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nrJFL-0002tW-4c for qemu-devel@nongnu.org; Wed, 18 May 2022 08:57:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:55131) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nrJFI-0004sO-GV for qemu-devel@nongnu.org; Wed, 18 May 2022 08:57:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652878663; 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=r/iWT7CDvmmD4iCK2Ha+DpB0e/sEI/E5l04AHhRzZyI=; b=aARlmBd3lZ6fjQjTwPHfJZyy6ykIdDOmPPyN3vVvxzc7D1uE4WgYxqoilE/t+SbLajCN+M dog+tiX/mkNuvF6E9vTPK2dWiHgdvt4Johh+Q9fSN3UT21ftubfBbVrztf1jHRdsWwsLpk cgIPtyCu6RoCnPQnTt+zpas8UWSSsPs= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-215--6ulXlTAPpaKeRhMNS3dbA-1; Wed, 18 May 2022 08:57:40 -0400 X-MC-Unique: -6ulXlTAPpaKeRhMNS3dbA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DAF80294EDC0; Wed, 18 May 2022 12:57:38 +0000 (UTC) Received: from redhat.com (unknown [10.2.17.180]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B695B2026D6A; Wed, 18 May 2022 12:57:30 +0000 (UTC) Date: Wed, 18 May 2022 07:57:29 -0500 From: Eric Blake To: Alberto Faria Cc: qemu-devel@nongnu.org, Andrew Jeffery , Peter Maydell , qemu-block@nongnu.org, Palmer Dabbelt , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , qemu-ppc@nongnu.org, Vladimir Sementsov-Ogievskiy , Hanna Reitz , John Snow , Stefan Hajnoczi , Jeff Cody , qemu-riscv@nongnu.org, =?utf-8?Q?C=C3=A9dric?= Le Goater , Joel Stanley , Stefan Weil , Laurent Vivier , "Denis V. Lunev" , Juan Quintela , "Dr. David Alan Gilbert" , Niek Linnenbank , Greg Kurz , Daniel Henrique Barboza , Kevin Wolf , "Edgar E. Iglesias" , qemu-arm@nongnu.org, Fam Zheng , Alistair Francis , Beniamino Galvani , Bin Meng , David Gibson Subject: Re: [PATCH 01/18] block: Make blk_{pread,pwrite}() return 0 on success Message-ID: <20220518125729.jya2p4rdw2b4qrvs@redhat.com> References: <20220517113524.197910-1-afaria@redhat.com> <20220517113524.197910-2-afaria@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220517113524.197910-2-afaria@redhat.com> User-Agent: NeoMutt/20220429-71-6f7d3e X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, May 17, 2022 at 12:35:07PM +0100, Alberto Faria wrote: > They currently return the value of their 'bytes' parameter on success. > > Make them return 0 instead, for consistency with other I/O functions and > in preparation to implement them using generated_co_wrapper. This also > makes it clear that short reads/writes are not possible. > > Signed-off-by: Alberto Faria > --- > +++ b/qemu-img.c > @@ -5120,30 +5120,27 @@ static int img_dd(int argc, char **argv) > in.buf = g_new(uint8_t, in.bsz); > > for (out_pos = 0; in_pos < size; block_count++) { in_pos, out_pos, and size are int64_t... > - int in_ret, out_ret; > + int bytes, in_ret, out_ret; > > - if (in_pos + in.bsz > size) { > - in_ret = blk_pread(blk1, in_pos, in.buf, size - in_pos); > - } else { > - in_ret = blk_pread(blk1, in_pos, in.buf, in.bsz); > - } > + bytes = (in_pos + in.bsz > size) ? size - in_pos : in.bsz; ...but in.bsz is int, so declaring 'int bytes' appears safe. Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org