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=-8.0 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 1E5F1C38A30 for ; Thu, 9 Apr 2020 10:14:19 +0000 (UTC) Received: from lists.gnu.org (unknown [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 E38B12145D for ; Thu, 9 Apr 2020 10:06:31 +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="YSsJ3NGM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E38B12145D 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]:47346 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jMU4l-0005IT-1n for qemu-devel@archiver.kernel.org; Thu, 09 Apr 2020 06:06:23 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:35976) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jMU3o-0004Yy-VG for qemu-devel@nongnu.org; Thu, 09 Apr 2020 06:05:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jMU3m-0007Kj-H1 for qemu-devel@nongnu.org; Thu, 09 Apr 2020 06:05:24 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:43405 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jMU3m-0007Js-7B for qemu-devel@nongnu.org; Thu, 09 Apr 2020 06:05:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586426721; 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=jn60Za3/XpDDD8+cNEv53D7ebaM3vr0CnRKiFBLie2w=; b=YSsJ3NGMfwd/XcAWbmA5WipychrgWT9Ic3FhxgXbzuafbzXKEs6kez7UEf+9yke+WqdtMq YDCWCtwJCZ6/VGGN4c8PPxAfD8ZIPdf2VjDPs7FTyHhI/obsHJMzddY4VUXGwsgdJ7fn0u a6oOWwuM1agRzZEIEQiaUTcsFEP6EyY= 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-96-3hobxj7bNUmpPPO0GPceOA-1; Thu, 09 Apr 2020 06:05:19 -0400 X-MC-Unique: 3hobxj7bNUmpPPO0GPceOA-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 951CD107ACC4; Thu, 9 Apr 2020 10:05:17 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-114-98.ams2.redhat.com [10.36.114.98]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BC6CC5C28F; Thu, 9 Apr 2020 10:05:14 +0000 (UTC) Subject: Re: [PATCH v4 20/30] qcow2: Add subcluster support to discard_in_l2_slice() To: Alberto Garcia , qemu-devel@nongnu.org References: <99b45e3beb4a38b17eb50fcde1e09cdefdb99724.1584468723.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: <4b3b1ef4-2f8b-b16f-3c48-2ba6137763e4@redhat.com> Date: Thu, 9 Apr 2020 12:05:12 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <99b45e3beb4a38b17eb50fcde1e09cdefdb99724.1584468723.git.berto@igalia.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="18MRABuRMVEtO1epiS9mjotXxubvEjGDC" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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) --18MRABuRMVEtO1epiS9mjotXxubvEjGDC Content-Type: multipart/mixed; boundary="lhhq8TBTbE2ofq49tAPgLpaGbvGqohq1F" --lhhq8TBTbE2ofq49tAPgLpaGbvGqohq1F Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 17.03.20 19:16, Alberto Garcia wrote: > Two changes are needed in this function: >=20 > 1) A full discard deallocates a cluster so we can skip the operation if > it is already unallocated. With extended L2 entries however if any > of the subclusters has the 'all zeroes' bit set then we have to > clear it. >=20 > 2) Setting the QCOW_OFLAG_ZERO bit of the L2 entry is forbidden if an > image has extended L2 entries. Instead, the individual 'all zeroes' > bits must be used. >=20 > Signed-off-by: Alberto Garcia > --- > block/qcow2-cluster.c | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) >=20 > diff --git a/block/qcow2-cluster.c b/block/qcow2-cluster.c > index 746006a117..824c710760 100644 > --- a/block/qcow2-cluster.c > +++ b/block/qcow2-cluster.c > @@ -1790,12 +1790,20 @@ static int discard_in_l2_slice(BlockDriverState *= bs, uint64_t offset, > * TODO We might want to use bdrv_block_status(bs) here, but we'= re > * holding s->lock, so that doesn't work today. > * > - * If full_discard is true, the sector should not read back as z= eroes, > + * If full_discard is true, the cluster should not read back as = zeroes, > * but rather fall through to the backing file. > */ > switch (qcow2_get_cluster_type(bs, old_l2_entry)) { > case QCOW2_CLUSTER_UNALLOCATED: > - if (full_discard || !bs->backing) { > + if (full_discard) { > + /* If the image has extended L2 entries we can only > + * skip this operation if the L2 bitmap is zero. */ > + uint64_t bitmap =3D has_subclusters(s) ? > + get_l2_bitmap(s, l2_slice, l2_index + i) : 0; Isn=E2=80=99t this bitmap only valid for standard clusters? In this case, = the whole cluster is unallocated, so the bitmap shouldn=E2=80=99t be relevant, = AFAIU. Max > + if (bitmap =3D=3D 0) { > + continue; > + } > + } else if (!bs->backing) { > continue; > } > break; --lhhq8TBTbE2ofq49tAPgLpaGbvGqohq1F-- --18MRABuRMVEtO1epiS9mjotXxubvEjGDC Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl6O81gACgkQ9AfbAGHV z0BuzggArTrhkf4lesEcyHiN8y+j7HS0FEDQyYNtFm3DCf197kT2hDaJZ9N2cpvl 0OVtHwkb02UVPLL2lMx0O0IuVsn99knIeg++oxVVA/NMvXfwdbocLYBZTz27+tva 9oSPaGAtPw9g0MSSrw2bRW2KC+Wp/rMO/T5JqOvDKeUMjAqfi+jevhfvyE3hNdQq vujWLAIUtMFgl0/3JFpcOxYiFAxxxSFDU2UqhM7Llvh7SJ14iII2UeNDjoc5ftaW KUZRWTsL5opTzjILWHRHQEIPyb6a4VwtrKa38rVJpBDI3zOU/934axEjIOseeTV9 V5uiMCBAPnc3XcPk+KpjoLET7XtZpw== =CWSt -----END PGP SIGNATURE----- --18MRABuRMVEtO1epiS9mjotXxubvEjGDC--