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=-12.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 7B486C433E5 for ; Mon, 27 Jul 2020 14:05:31 +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 444D92073E for ; Mon, 27 Jul 2020 14:05:31 +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="NEdIeyR1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 444D92073E 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]:38882 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k03kw-00072w-J2 for qemu-devel@archiver.kernel.org; Mon, 27 Jul 2020 10:05:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k03kB-0006N7-4R for qemu-devel@nongnu.org; Mon, 27 Jul 2020 10:04:43 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:29586 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 1k03k9-0005Wt-DF for qemu-devel@nongnu.org; Mon, 27 Jul 2020 10:04:42 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595858679; 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=zq+6NFALOXmOuaSqQvXYPWBoHbCcCk+cahNZb/Y0w0I=; b=NEdIeyR1pPC6K0JyjXbIN/aiy1WiHHpx0iiT8kqdhY3KILxFDyvBBTJThYLzhuQGoSicuY EFQn1Q2HpVBqDGColuz88KhO/pT3rDBLpUk1JSfnSVq7uxBSUo+AmpI9/q9LN+yPCwAtMH /+NVMndD9hPo3ZVuUc5t/Ggz6OqO5OI= 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-251-0G9s6fukNceC-ZBbwa73KA-1; Mon, 27 Jul 2020 10:04:18 -0400 X-MC-Unique: 0G9s6fukNceC-ZBbwa73KA-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 1110D186A820; Mon, 27 Jul 2020 14:04:17 +0000 (UTC) Received: from [10.3.113.26] (ovpn-113-26.phx2.redhat.com [10.3.113.26]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 92AF069327; Mon, 27 Jul 2020 14:04:16 +0000 (UTC) Subject: Re: [PATCH 1/2] block: nbd: Fix convert qcow2 compressed to nbd To: Nir Soffer , qemu-block@nongnu.org, qemu-devel@nongnu.org References: <20200726152532.256261-1-nsoffer@redhat.com> <20200726152532.256261-2-nsoffer@redhat.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <1737bdc4-6192-1adb-7027-faf09bdbd92c@redhat.com> Date: Mon, 27 Jul 2020 09:04:15 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200726152532.256261-2-nsoffer@redhat.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.81; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/27 03:37:14 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Kevin Wolf , Nir Soffer , Max Reitz Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/26/20 10:25 AM, Nir Soffer wrote: > When converting to qcow2 compressed format, the last step is a special > zero length compressed write, ending in call to bdrv_co_truncate(). This > call always fail for the nbd driver since it does not implement fails > bdrv_co_truncate(). Arguably, qemu-img should be taught to ignore the failure, since it is not unique to the nbd driver. But I can live with your approach here. > > For block devices, which have the same limits, the call succeeds since > file driver implements bdrv_co_truncate(). If the caller asked to > truncate to the same or smaller size with exact=false, the truncate > succeeds. Implement the same logic for nbd. > > Example failing without this change: > > > Fixes: https://bugzilla.redhat.com/1860627 > Signed-off-by: Nir Soffer > --- > block/nbd.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/block/nbd.c b/block/nbd.c > index 65a4f56924..2154113af3 100644 > --- a/block/nbd.c > +++ b/block/nbd.c > @@ -1966,6 +1966,30 @@ static void nbd_close(BlockDriverState *bs) > nbd_clear_bdrvstate(s); > } > > +/* > + * NBD cannot truncate, but if the caller ask to truncate to the same size, or asks > + * to a smaller size with extact=false, there is not reason to fail the exact, no > + * operation. > + */ > +static int coroutine_fn nbd_co_truncate(BlockDriverState *bs, int64_t offset, > + bool exact, PreallocMode prealloc, > + BdrvRequestFlags flags, Error **errp) > +{ > + BDRVNBDState *s = bs->opaque; > + > + if (offset != s->info.size && exact) { > + error_setg(errp, "Cannot resize NBD nodes"); > + return -ENOTSUP; > + } > + > + if (offset > s->info.size) { > + error_setg(errp, "Cannot grow NBD nodes"); > + return -EINVAL; > + } > + > + return 0; Looks reasonable. As Max said, I wonder if we want to reject particular preallocation modes (looking at block/file-posix.c:raw_co_truncate), in the case where the image was resized down and then back up (since s->info.size is constant, but the BDS size is not if inexact resize succeeds). As you have a bugzilla entry, I think this is safe for -rc2; I'll be touching up the typos and queuing it through my NBD tree later today. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org