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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]:39186 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k8hoj-0005nL-76 for qemu-devel@archiver.kernel.org; Thu, 20 Aug 2020 06:29:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48264) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k8hoB-0005II-TY for qemu-devel@nongnu.org; Thu, 20 Aug 2020 06:28:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:58780) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k8ho9-0003Nn-NP for qemu-devel@nongnu.org; Thu, 20 Aug 2020 06:28:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1597919310; 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=cM0T8rn9IHg1rp01B/PgURaEezejJhiOPhwqrtbfcm8=; b=cA9ERQkzgnDtcGBf66W+ULaI6U9xNN6KE8LMU9d7eT+ecEKjajuTb+jtsyNETUQXkJRD9U DLqLwSQvrU5wzKSoitU6UCJHFu4n5ULyVVbojsCTUuKkgW/ytgkR/u/cq2Ke6q1qFZyYQl pKciGttJbWHnyNfuj7k9/uadD91WuII= 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-289-Xe5l8NcfMjecVhqYcMznew-1; Thu, 20 Aug 2020 06:28:28 -0400 X-MC-Unique: Xe5l8NcfMjecVhqYcMznew-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 01FAC81F024; Thu, 20 Aug 2020 10:28:27 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-113-133.ams2.redhat.com [10.36.113.133]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D6EE9600DD; Thu, 20 Aug 2020 10:28:25 +0000 (UTC) Subject: Re: [PATCH v7 33/47] mirror: Deal with filters To: Kevin Wolf References: <20200625152215.941773-1-mreitz@redhat.com> <20200625152215.941773-34-mreitz@redhat.com> <20200819165036.GH10272@linux.fritz.box> 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: <7d3e38bb-53ed-031a-9955-a3c23abe119d@redhat.com> Date: Thu, 20 Aug 2020 12:28:23 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200819165036.GH10272@linux.fritz.box> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0.0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="LOLFNF76Xeol2B55D6VqO7Odk8qKkVUpc" Received-SPF: pass client-ip=216.205.24.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/20 06:28:30 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, 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_H5=-1, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no 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: 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" This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --LOLFNF76Xeol2B55D6VqO7Odk8qKkVUpc Content-Type: multipart/mixed; boundary="4nUboUfEMwZgc28dILjFhKltp0Zy5KEuv" --4nUboUfEMwZgc28dILjFhKltp0Zy5KEuv Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 19.08.20 18:50, Kevin Wolf wrote: > Am 25.06.2020 um 17:22 hat Max Reitz geschrieben: >> This includes some permission limiting (for example, we only need to >> take the RESIZE permission for active commits where the base is smaller >> than the top). >> >> Use this opportunity to rename qmp_drive_mirror()'s "source" BDS to >> "target_backing_bs", because that is what it really refers to. >> >> Signed-off-by: Max Reitz >=20 >> @@ -1682,6 +1721,7 @@ static BlockJob *mirror_start_job( >> s->zero_target =3D zero_target; >> s->copy_mode =3D copy_mode; >> s->base =3D base; >> + s->base_overlay =3D bdrv_find_overlay(bs, base); >> s->granularity =3D granularity; >> s->buf_size =3D ROUND_UP(buf_size, granularity); >> s->unmap =3D unmap; >=20 > Is this valid without freezing the links between base_overlay and base? Er... > Actually, I guess we should freeze everything between bs and base (for > base !=3D NULL) and it's a preexisting problem that just happens to affec= t > this code, too. Yes, that=E2=80=99s how it looks to me, too. I don=E2=80=99t think that ha= s anything to do with this patch. > Or maybe freezing everything is too much. We only want to make sure that > no non-filter is inserted between base and base_overlay and that base > (and now base_overlay) always stay in the backing chain of bs. But what > options apart from freezing do we have to achieve this? I don=E2=80=99t know of any, and I don=E2=80=99t know whether anyone would = actually care if we were to just freeze everything. > Why is using base_overlay even better than using base? Assuming there is > a good reason, maybe the commit message could spell it out. The problem is that querying the block status for a filter node falls through to the underlying data-carrying node. So if there=E2=80=99s a filt= er on top of @base, and we query for is_allocated_above above @base, then we=E2=80=99ll include @base, which we do not want. Max --4nUboUfEMwZgc28dILjFhKltp0Zy5KEuv-- --LOLFNF76Xeol2B55D6VqO7Odk8qKkVUpc Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl8+UEgACgkQ9AfbAGHV z0AM8gf9EPZYl1O3apy5u4GXs3N12w/rgN/MQkTs/47undbDcDIfbXCUxdWRmVw+ 6/ijEbn+zkGAV3qNJOWb2rfPuijcL7e22Wvuq5G+BUkck/Cxro3u5cboqID4MDh7 zLtBqkm62usEe0oML3L5d2cRn84PYQc4Uvj3jA8ld6d7fFIiVgGv14ALKHoFE2Q2 Kol16dxBo+62rehctfxkUYeLLpE6P/oLVJr9ni5Y13al3x5z/YzGwxBsptiN4Qtl 2vyeLNtkXXoc7m49NXqgJ+4crfj6IGU4A++diPMsV0KMOnCfrm+27FZS1vw9jgCn z04HxMQzxQwhdNR6m9TjQDAv70t2KA== =Y0HL -----END PGP SIGNATURE----- --LOLFNF76Xeol2B55D6VqO7Odk8qKkVUpc--