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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 14A4AC43331 for ; Mon, 11 Nov 2019 08:45:05 +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 CEECA20656 for ; Mon, 11 Nov 2019 08:45:04 +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="RRRO3Ksw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CEECA20656 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]:50046 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iU5Jn-0002jR-Uv for qemu-devel@archiver.kernel.org; Mon, 11 Nov 2019 03:45:03 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:35336) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iU5Ir-0002Ay-0B for qemu-devel@nongnu.org; Mon, 11 Nov 2019 03:44:06 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iU5Io-0004Dg-Lq for qemu-devel@nongnu.org; Mon, 11 Nov 2019 03:44:03 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:45881 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iU5Io-0004DC-Dx for qemu-devel@nongnu.org; Mon, 11 Nov 2019 03:44:02 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1573461841; 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:autocrypt:autocrypt; bh=Pbfi4Suks0YP5m1BsLmgV7Au9PO7ZphT3IKGe15hhJ0=; b=RRRO3KswbBvfOov+74QTS+uqAea1zCRgJByuefpbrBPYZSJmBFkAkvRjA6RaLjEXWVZjf5 xFXf8+pZ2GLs3kCSsO9fGO1ly4Lca31b388A5tFXUzhzvbBO2TaJ5euoww8MMaEpr71uXe f4e36GHP0qvdypiUaKXef3USl08Au1w= 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-440-Qblj-b2fMvSYTX-1WFFnaw-1; Mon, 11 Nov 2019 03:42:50 -0500 X-MC-Unique: Qblj-b2fMvSYTX-1WFFnaw-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BEA5E801E5F; Mon, 11 Nov 2019 08:42:47 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-117-116.ams2.redhat.com [10.36.117.116]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E359C60192; Mon, 11 Nov 2019 08:42:43 +0000 (UTC) Subject: Re: [RFC PATCH v2 14/26] qcow2: Add subcluster support to qcow2_get_cluster_offset() To: Alberto Garcia , qemu-devel@nongnu.org References: <6932c2ddfe19a564cad7c54246290e166525fc46.1572125022.git.berto@igalia.com> <673d72da-bf8c-3ffb-a324-79e93f88a140@redhat.com> From: Max Reitz Autocrypt: addr=mreitz@redhat.com; prefer-encrypt=mutual; keydata= mQENBFXOJlcBCADEyyhOTsoa/2ujoTRAJj4MKA21dkxxELVj3cuILpLTmtachWj7QW+TVG8U /PsMCFbpwsQR7oEy8eHHZwuGQsNpEtNC2G/L8Yka0BIBzv7dEgrPzIu+W3anZXQW4702+uES U29G8TP/NGfXRRHGlbBIH9KNUnOSUD2vRtpOLXkWsV5CN6vQFYgQfFvmp5ZpPeUe6xNplu8V mcTw8OSEDW/ZnxJc8TekCKZSpdzYoxfzjm7xGmZqB18VFwgJZlIibt1HE0EB4w5GsD7x5ekh awIe3RwoZgZDLQMdOitJ1tUc8aqaxvgA4tz6J6st8D8pS//m1gAoYJWGwwIVj1DjTYLtABEB AAG0HU1heCBSZWl0eiA8bXJlaXR6QHJlZGhhdC5jb20+iQFTBBMBCAA9AhsDBQkSzAMABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheABQJVzie5FRhoa3A6Ly9rZXlzLmdudXBnLm5ldAAKCRD0 B9sAYdXPQDcIB/9uNkbYEex1rHKz3mr12uxYMwLOOFY9fstP5aoVJQ1nWQVB6m2cfKGdcRe1 2/nFaHSNAzT0NnKz2MjhZVmcrpyd2Gp2QyISCfb1FbT82GMtXFj1wiHmPb3CixYmWGQUUh+I AvUqsevLA+WihgBUyaJq/vuDVM1/K9Un+w+Tz5vpeMidlIsTYhcsMhn0L9wlCjoucljvbDy/ 8C9L2DUdgi3XTa0ORKeflUhdL4gucWoAMrKX2nmPjBMKLgU7WLBc8AtV+84b9OWFML6NEyo4 4cP7cM/07VlJK53pqNg5cHtnWwjHcbpGkQvx6RUx6F1My3y52vM24rNUA3+ligVEgPYBuQEN BFXOJlcBCADAmcVUNTWT6yLWQHvxZ0o47KCP8OcLqD+67T0RCe6d0LP8GsWtrJdeDIQk+T+F xO7DolQPS6iQ6Ak2/lJaPX8L0BkEAiMuLCKFU6Bn3lFOkrQeKp3u05wCSV1iKnhg0UPji9V2 W5eNfy8F4ZQHpeGUGy+liGXlxqkeRVhLyevUqfU0WgNqAJpfhHSGpBgihUupmyUg7lfUPeRM DzAN1pIqoFuxnN+BRHdAecpsLcbR8sQddXmDg9BpSKozO/JyBmaS1RlquI8HERQoe6EynJhd 64aICHDfj61rp+/0jTIcevxIIAzW70IadoS/y3DVIkuhncgDBvGbF3aBtjrJVP+5ABEBAAGJ ASUEGAEIAA8FAlXOJlcCGwwFCRLMAwAACgkQ9AfbAGHVz0CbFwf9F/PXxQR9i4N0iipISYjU sxVdjJOM2TMut+ZZcQ6NSMvhZ0ogQxJ+iEQ5OjnIputKvPVd5U7WRh+4lF1lB/NQGrGZQ1ic alkj6ocscQyFwfib+xIe9w8TG1CVGkII7+TbS5pXHRxZH1niaRpoi/hYtgzkuOPp35jJyqT/ /ELbqQTDAWcqtJhzxKLE/ugcOMK520dJDeb6x2xVES+S5LXby0D4juZlvUj+1fwZu+7Io5+B bkhSVPb/QdOVTpnz7zWNyNw+OONo1aBUKkhq2UIByYXgORPFnbfMY7QWHcjpBVw9MgC4tGeF R4bv+1nAMMxKmb5VvQCExr0eFhJUAHAhVg== Message-ID: Date: Mon, 11 Nov 2019 09:42:41 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Mimecast-Spam-Score: 0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="FbCymjLmEURSjMRkyp8tkEEvcY6bQpAgt" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 207.211.31.81 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 , Anton Nefedov , qemu-block@nongnu.org, Vladimir Sementsov-Ogievskiy , "Denis V . Lunev" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --FbCymjLmEURSjMRkyp8tkEEvcY6bQpAgt Content-Type: multipart/mixed; boundary="fh3pW6BmduHJZsWAby7WxUBi74RQokH1J" --fh3pW6BmduHJZsWAby7WxUBi74RQokH1J Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 08.11.19 16:42, Alberto Garcia wrote: > On Mon 04 Nov 2019 03:58:57 PM CET, Max Reitz wrote: [...] >>> @@ -514,8 +499,8 @@ int qcow2_get_cluster_offset(BlockDriverState *bs, = uint64_t offset, >> >> I suppose this is get_subcluster_offset now. >=20 > Hmmm no, this returns the actual host cluster offset, then the caller > uses offset_into_cluster() to get the final value (which doesn't need to > be subcluster-aligned anyway). It still returns the subcluster type, though. Which makes the whole thing kind of a weird chimera... Maybe it would work better if the subcluster type would be stored in a pointer parameter, so it=E2=80=99d be = clear? But does it have actually have any advantages to on one hand return a cluster-aligned host offset and on the other return a bytes count that starts at the mid-cluster offset? That=E2=80=99s weird already. Maybe the offset that=E2=80=99s returned should just not be cluster-aligned and the w= hole function be called qcow2_get_host_offset(). I suppose one reason (maybe the only one?) to return aligned offsets is for compressed clusters. It would be another kind of magic to return aligned offsets only for them. But maybe it=E2=80=99s worth it? (Judging = from a quick glance, it doesn=E2=80=99t look too difficult to me to modify the callers to accept a mid-cluster host offset.) (Another thing I just noticed is that the comment above qcow2_get_cluster_offset() needs some fixing, because it still refers to whole clusters.) Max --fh3pW6BmduHJZsWAby7WxUBi74RQokH1J-- --FbCymjLmEURSjMRkyp8tkEEvcY6bQpAgt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl3JHwEACgkQ9AfbAGHV z0AVegf+JA0gnScPG16YBiGp1Ny/BuWZ6Ey2ZI0vwe59TzSQkyqzDop5BzTrkMFL xnkfdI6D3ek200sb9j0OrbLBj/ZlsSNvLjiHKsFuQQr0ocCQk44BaCdzYCearHzv 1KP9y2isEivvln9TsL71OFVTVKlzVKqvARO/GK+Dsm/DoVJHvg8EqRNe8q+KBq2V vaa58ZPStzCyvp8a4zmb+R3YU9sVJdAPkfzNF/1SS6YHhTrEJbfY22aLh61RqkTV iuj5kVudr2FLJwF0gI4T3utl06iCUAKlIwRKWNdoRcmyIIyOk6lbEBqDRfNanxH/ 9oeJ7B38H5z52fozq1Nnj0u55oOAdA== =qtLg -----END PGP SIGNATURE----- --FbCymjLmEURSjMRkyp8tkEEvcY6bQpAgt--