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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 B9F67C3A5AA for ; Thu, 5 Sep 2019 13:13:31 +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 6CF2C20692 for ; Thu, 5 Sep 2019 13:13:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6CF2C20692 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]:45890 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i5rZq-0003uX-HB for qemu-devel@archiver.kernel.org; Thu, 05 Sep 2019 09:13:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43999) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i5rY6-00021T-Ra for qemu-devel@nongnu.org; Thu, 05 Sep 2019 09:11:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i5rY2-0007jk-0b for qemu-devel@nongnu.org; Thu, 05 Sep 2019 09:11:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37008) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i5rXx-0007eG-5L; Thu, 05 Sep 2019 09:11:33 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 2569A3007C30; Thu, 5 Sep 2019 13:11:32 +0000 (UTC) Received: from localhost.localdomain (ovpn-116-80.ams2.redhat.com [10.36.116.80]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 180A01001281; Thu, 5 Sep 2019 13:11:30 +0000 (UTC) Date: Thu, 5 Sep 2019 15:11:29 +0200 From: Kevin Wolf To: Max Reitz Message-ID: <20190905131129.GB4911@localhost.localdomain> References: <20190809161407.11920-1-mreitz@redhat.com> <20190809161407.11920-12-mreitz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190809161407.11920-12-mreitz@redhat.com> User-Agent: Mutt/1.12.0 (2019-05-25) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Thu, 05 Sep 2019 13:11:32 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH v6 11/42] block: Add bdrv_supports_compressed_writes() 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: Vladimir Sementsov-Ogievskiy , qemu-devel@nongnu.org, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Am 09.08.2019 um 18:13 hat Max Reitz geschrieben: > Filters cannot compress data themselves but they have to implement > .bdrv_co_pwritev_compressed() still (or they cannot forward compressed > writes). Therefore, checking whether > bs->drv->bdrv_co_pwritev_compressed is non-NULL is not sufficient to > know whether the node can actually handle compressed writes. This > function looks down the filter chain to see whether there is a > non-filter that can actually convert the compressed writes into > compressed data (and thus normal writes). > > Signed-off-by: Max Reitz > Reviewed-by: Vladimir Sementsov-Ogievskiy Should patches 2 and 3 that add the .bdrv_co_pwritev_compressed() callback to filter drivers come only after this one? And should we also support it in the mirror filter? Kevin