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,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 881C5CA9EC5 for ; Wed, 30 Oct 2019 12:05:26 +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 5524E20663 for ; Wed, 30 Oct 2019 12:05:26 +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="WIf9XcMW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5524E20663 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]:39804 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iPmj7-0000EP-Gt for qemu-devel@archiver.kernel.org; Wed, 30 Oct 2019 08:05:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59442) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iPmi0-0007rO-Jv for qemu-devel@nongnu.org; Wed, 30 Oct 2019 08:04:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iPmhw-0000iD-04 for qemu-devel@nongnu.org; Wed, 30 Oct 2019 08:04:14 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:31399 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 1iPmhv-0000hC-RE for qemu-devel@nongnu.org; Wed, 30 Oct 2019 08:04:11 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1572437051; 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=GmU2smz0stxozhfUlOlFnroE/8XyetW2RWDOuA0QmX4=; b=WIf9XcMWdDl8CDjx6wS4rY1HeAGdFjQ9Aywlt0gGbYvS/oN1hDYxsxLkpf9yklWb0qaGZF ZBN+0ulmo+SEK6LP6NH+lmySAkacS9V7nEWSKZPtGr0DYfQLKcOfQiAxG8lzM5hUTldh3s nGbOEAr8D6MjQZUD0p4zkBCgjPYgnmU= 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-363-t0huNYUGNKOigW9NV4kg4Q-1; Wed, 30 Oct 2019 08:04:08 -0400 X-MC-Unique: t0huNYUGNKOigW9NV4kg4Q-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 9D760801E7E; Wed, 30 Oct 2019 12:04:06 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-117-147.ams2.redhat.com [10.36.117.147]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C7F1F60876; Wed, 30 Oct 2019 12:04:03 +0000 (UTC) Subject: Re: [RFC PATCH v2 01/26] qcow2: Add calculate_l2_meta() To: Alberto Garcia , qemu-devel@nongnu.org References: <22820af5867124e4fdf3d0cb74b99f31edc1b37f.1572125022.git.berto@igalia.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: <49444fb1-d0b2-4325-20ed-91159182ed37@redhat.com> Date: Wed, 30 Oct 2019 13:04:02 +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: <22820af5867124e4fdf3d0cb74b99f31edc1b37f.1572125022.git.berto@igalia.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="ntep0cE7TBUSHQ7ry37e5LWN8ftuGTcyT" 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) --ntep0cE7TBUSHQ7ry37e5LWN8ftuGTcyT Content-Type: multipart/mixed; boundary="l9a7BIHlk32BEL0I4sjzP6sGuVEhy6Y8G" --l9a7BIHlk32BEL0I4sjzP6sGuVEhy6Y8G Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 26.10.19 23:25, Alberto Garcia wrote: > handle_alloc() creates a QCowL2Meta structure in order to update the > image metadata and perform the necessary copy-on-write operations. >=20 > This patch moves that code to a separate function so it can be used > from other places. >=20 > Signed-off-by: Alberto Garcia > --- > block/qcow2-cluster.c | 76 +++++++++++++++++++++++++++++-------------- > 1 file changed, 52 insertions(+), 24 deletions(-) >=20 > diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c > index 8982b7b762..6c1dcdc781 100644 > --- a/block/qcow2-cluster.c > +++ b/block/qcow2-cluster.c > @@ -1019,6 +1019,55 @@ void qcow2_alloc_cluster_abort(BlockDriverState *b= s, QCowL2Meta *m) > QCOW2_DISCARD_NEVER); > } > =20 > +/* > + * For a given write request, create a new QCowL2Meta structure and > + * add it to @m. > + * > + * @host_offset points to the beginning of the first cluster. (I intended not to comment on such things on an RFC, but here I am...) I=E2=80=99d call it host_cluster_offset to make clear that it points to a cluster and isn=E2=80=99t the host offset for @guest_offset. And now that I=E2=80=99ve gone this far already, I might as well say that I= =E2=80=99d like if it the comment noted that this function not only creates the L2Meta structure but also adds it to the cluster_allocs list. > + * @guest_offset and @bytes indicate the offset and length of the > + * request. > + * > + * If @keep_old is true it means that the clusters were already > + * allocated and will be overwritten. If false then the clusters are > + * new and we have to decrease the reference count of the old ones. > + */ > +static void calculate_l2_meta(BlockDriverState *bs, uint64_t host_offset= , > + uint64_t guest_offset, uint64_t bytes, And now I=E2=80=99m so deep into non-RFC-level review territory, I might as= well say I=E2=80=99d prefer @bytes to be an unsigned (or maybe even a plain int)= , because anything more wouldn=E2=80=99t work. (Not least because cow_end_to= is an unsigned). Sorry... Max > + QCowL2Meta **m, bool keep_old) > +{ > + BDRVQcow2State *s =3D bs->opaque; > + unsigned cow_start_from =3D 0; > + unsigned cow_start_to =3D offset_into_cluster(s, guest_offset); > + unsigned cow_end_from =3D cow_start_to + bytes; > + unsigned cow_end_to =3D ROUND_UP(cow_end_from, s->cluster_size); > + unsigned nb_clusters =3D size_to_clusters(s, cow_end_from); > + QCowL2Meta *old_m =3D *m; > + > + *m =3D g_malloc0(sizeof(**m)); > + **m =3D (QCowL2Meta) { > + .next =3D old_m, > + > + .alloc_offset =3D host_offset, > + .offset =3D start_of_cluster(s, guest_offset), > + .nb_clusters =3D nb_clusters, > + > + .keep_old_clusters =3D keep_old, > + > + .cow_start =3D { > + .offset =3D cow_start_from, > + .nb_bytes =3D cow_start_to - cow_start_from, > + }, > + .cow_end =3D { > + .offset =3D cow_end_from, > + .nb_bytes =3D cow_end_to - cow_end_from, > + }, > + }; > + > + qemu_co_queue_init(&(*m)->dependent_requests); > + QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); > +} > + > /* > * Returns the number of contiguous clusters that can be used for an all= ocating > * write, but require COW to be performed (this includes yet unallocated= space, > @@ -1417,35 +1466,14 @@ static int handle_alloc(BlockDriverState *bs, uin= t64_t guest_offset, > uint64_t requested_bytes =3D *bytes + offset_into_cluster(s, guest_o= ffset); > int avail_bytes =3D nb_clusters << s->cluster_bits; > int nb_bytes =3D MIN(requested_bytes, avail_bytes); > - QCowL2Meta *old_m =3D *m; > - > - *m =3D g_malloc0(sizeof(**m)); > - > - **m =3D (QCowL2Meta) { > - .next =3D old_m, > - > - .alloc_offset =3D alloc_cluster_offset, > - .offset =3D start_of_cluster(s, guest_offset), > - .nb_clusters =3D nb_clusters, > - > - .keep_old_clusters =3D keep_old_clusters, > - > - .cow_start =3D { > - .offset =3D 0, > - .nb_bytes =3D offset_into_cluster(s, guest_offset), > - }, > - .cow_end =3D { > - .offset =3D nb_bytes, > - .nb_bytes =3D avail_bytes - nb_bytes, > - }, > - }; > - qemu_co_queue_init(&(*m)->dependent_requests); > - QLIST_INSERT_HEAD(&s->cluster_allocs, *m, next_in_flight); > =20 > *host_offset =3D alloc_cluster_offset + offset_into_cluster(s, guest= _offset); > *bytes =3D MIN(*bytes, nb_bytes - offset_into_cluster(s, guest_offse= t)); > assert(*bytes !=3D 0); > =20 > + calculate_l2_meta(bs, alloc_cluster_offset, guest_offset, *bytes, > + m, keep_old_clusters); > + > return 1; > =20 > fail: >=20 --l9a7BIHlk32BEL0I4sjzP6sGuVEhy6Y8G-- --ntep0cE7TBUSHQ7ry37e5LWN8ftuGTcyT Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl25fDIACgkQ9AfbAGHV z0DLwwf/fg7y8+YnJRX13HMzCh6Ie/HP/3Ti9gxPFilWYL8QcEhhNmCu/j4jO2ls fchTiJrGW9YGSrKiz1QF78AAeFxuyXYbpdZJx2sijezMcEqBU58N7NdyAa2yMgTV 8sSPlMUTkTj5HWzlHg8RpXUmUi1EeV96/4LT2jhPJqZz9P7HHKCAYXL5V5AoXot1 Fczlmy56ITqtgPC9/Th7roQ2fv+OWE54CmjlhGhNtny1poOVypKD03dDReyemw4y TZE4nex+O7UI0JcRuo2mYSk8zR5Q8QKDJYPkPEhpmjwste0oH0EaO5FpadXNNkvj 6OApmaMMrO0CNkL9AGd0JeaFMewCPA== =eO1k -----END PGP SIGNATURE----- --ntep0cE7TBUSHQ7ry37e5LWN8ftuGTcyT--