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=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 F3B07C38A2A for ; Wed, 6 May 2020 21:42:38 +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 C15502070B for ; Wed, 6 May 2020 21:42:37 +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="HQw9iArx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C15502070B 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]:45110 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jWRoL-00060g-4J for qemu-devel@archiver.kernel.org; Wed, 06 May 2020 17:42:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52396) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jWRnj-0005W4-Po for qemu-devel@nongnu.org; Wed, 06 May 2020 17:41:59 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:37119 helo=us-smtp-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 1jWRni-0006wi-6M for qemu-devel@nongnu.org; Wed, 06 May 2020 17:41:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588801316; 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=Q/vD6iOeJiLlEAmtaYx5vn6gQh4tGwdxTD/sIAmOCP8=; b=HQw9iArxw1MN0Jim/BNYSc3XM3UZcamAeYrBGhAiTycRb6recfSzlL3ZzWm8uQBTbTdkSb Mn/aqe8osoPPRpACuKQhc1bXK+2RfV0qntR1dlAVxq8wGVjpzz20LpuxNBe3g2p4miD/7Y fb1h8wDOTGC+w0ZvmlLuVqS/W1oB/wQ= 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-377-9r3MznAzMOe8yVCTJn-h3g-1; Wed, 06 May 2020 17:41:55 -0400 X-MC-Unique: 9r3MznAzMOe8yVCTJn-h3g-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 80E64835B40; Wed, 6 May 2020 21:41:53 +0000 (UTC) Received: from [10.3.114.73] (ovpn-114-73.phx2.redhat.com [10.3.114.73]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 738E26061C; Wed, 6 May 2020 21:41:49 +0000 (UTC) Subject: Re: [PATCH 5/8] block/file-posix: drop unallocated_blocks_are_zero To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20200506092513.20904-1-vsementsov@virtuozzo.com> <20200506092513.20904-6-vsementsov@virtuozzo.com> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <432055ab-57f8-c7e2-1032-414069fe1e64@redhat.com> Date: Wed, 6 May 2020 16:41:48 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200506092513.20904-6-vsementsov@virtuozzo.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=207.211.31.120; envelope-from=eblake@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/06 16:22:47 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, 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_H2=-0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN 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@euphon.net, kwolf@redhat.com, ronniesahlberg@gmail.com, sw@weilnetz.de, pl@kamp.de, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, den@openvz.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 5/6/20 4:25 AM, Vladimir Sementsov-Ogievskiy wrote: > raw_co_block_status() in block/file-posix.c never returns 0, so > unallocated_blocks_are_zero is useless. Drop it. As in 4/8, you are correct that it had no impact on block_status, but it did affect qemu-img convert. So again, removing the clients first makes this easier to justify as a cleanup patch. That said... > > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/file-posix.c | 3 --- > 1 file changed, 3 deletions(-) > > diff --git a/block/file-posix.c b/block/file-posix.c > index 05e094be29..5c01735108 100644 > --- a/block/file-posix.c > +++ b/block/file-posix.c > @@ -2878,9 +2878,6 @@ static int coroutine_fn raw_co_pwrite_zeroes( > > static int raw_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) > { > - BDRVRawState *s = bs->opaque; > - > - bdi->unallocated_blocks_are_zero = s->discard_zeroes; > return 0; > } the function now does nothing. Hmm - why does bdrv_get_info() return -ENOTSUP if the driver does not implement this function? Wouldn't it be better if the block layer could allow us to omit .bdrv_get_info and do the same thing, without us having to write a dummy function that does nothing but return 0? As separate patches, of course, as it would require changing several existing bdrv_get_info() callers to behave sanely when getting an all-0 success return where they now deal with an -ENOTSUP return. So in the meantime, yes, we need this placeholder. Reviewed-by: Eric Blake -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org