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=-8.2 required=3.0 tests=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 4BD94C433FF for ; Mon, 29 Jul 2019 13:36:18 +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 253F9206E0 for ; Mon, 29 Jul 2019 13:36:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 253F9206E0 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]:52250 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs5p3-0002TI-FG for qemu-devel@archiver.kernel.org; Mon, 29 Jul 2019 09:36:17 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44655) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hs5ob-0001vH-4y for qemu-devel@nongnu.org; Mon, 29 Jul 2019 09:35:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hs5oZ-0006DU-Rb for qemu-devel@nongnu.org; Mon, 29 Jul 2019 09:35:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59052) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hs5oX-0006AU-6T; Mon, 29 Jul 2019 09:35:45 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 853A93082141; Mon, 29 Jul 2019 13:35:43 +0000 (UTC) Received: from [10.3.116.93] (ovpn-116-93.phx2.redhat.com [10.3.116.93]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CBF1C5D70D; Mon, 29 Jul 2019 13:35:39 +0000 (UTC) To: Kevin Wolf , qemu-block@nongnu.org References: <20190729105343.19250-1-kwolf@redhat.com> From: Eric Blake Openpgp: preference=signencrypt Autocrypt: addr=eblake@redhat.com; keydata= xsBNBEvHyWwBCACw7DwsQIh0kAbUXyqhfiKAKOTVu6OiMGffw2w90Ggrp4bdVKmCaEXlrVLU xphBM8mb+wsFkU+pq9YR621WXo9REYVIl0FxKeQo9dyQBZ/XvmUMka4NOmHtFg74nvkpJFCD TUNzmqfcjdKhfFV0d7P/ixKQeZr2WP1xMcjmAQY5YvQ2lUoHP43m8TtpB1LkjyYBCodd+LkV GmCx2Bop1LSblbvbrOm2bKpZdBPjncRNob73eTpIXEutvEaHH72LzpzksfcKM+M18cyRH+nP sAd98xIbVjm3Jm4k4d5oQyE2HwOur+trk2EcxTgdp17QapuWPwMfhaNq3runaX7x34zhABEB AAHNHkVyaWMgQmxha2UgPGVibGFrZUByZWRoYXQuY29tPsLAegQTAQgAJAIbAwULCQgHAwUV CgkICwUWAgMBAAIeAQIXgAUCS8fL9QIZAQAKCRCnoWtKJSdDahBHCACbl/5FGkUqJ89GAjeX RjpAeJtdKhujir0iS4CMSIng7fCiGZ0fNJCpL5RpViSo03Q7l37ss+No+dJI8KtAp6ID+PMz wTJe5Egtv/KGUKSDvOLYJ9WIIbftEObekP+GBpWP2+KbpADsc7EsNd70sYxExD3liwVJYqLc Rw7so1PEIFp+Ni9A1DrBR5NaJBnno2PHzHPTS9nmZVYm/4I32qkLXOcdX0XElO8VPDoVobG6 gELf4v/vIImdmxLh/w5WctUpBhWWIfQDvSOW2VZDOihm7pzhQodr3QP/GDLfpK6wI7exeu3P pfPtqwa06s1pae3ad13mZGzkBdNKs1HEm8x6zsBNBEvHyWwBCADGkMFzFjmmyqAEn5D+Mt4P zPdO8NatsDw8Qit3Rmzu+kUygxyYbz52ZO40WUu7EgQ5kDTOeRPnTOd7awWDQcl1gGBXgrkR pAlQ0l0ReO57Q0eglFydLMi5bkwYhfY+TwDPMh3aOP5qBXkm4qIYSsxb8A+i00P72AqFb9Q7 3weG/flxSPApLYQE5qWGSXjOkXJv42NGS6o6gd4RmD6Ap5e8ACo1lSMPfTpGzXlt4aRkBfvb NCfNsQikLZzFYDLbQgKBA33BDeV6vNJ9Cj0SgEGOkYyed4I6AbU0kIy1hHAm1r6+sAnEdIKj cHi3xWH/UPrZW5flM8Kqo14OTDkI9EtlABEBAAHCwF8EGAEIAAkFAkvHyWwCGwwACgkQp6Fr SiUnQ2q03wgAmRFGDeXzc58NX0NrDijUu0zx3Lns/qZ9VrkSWbNZBFjpWKaeL1fdVeE4TDGm I5mRRIsStjQzc2R9b+2VBUhlAqY1nAiBDv0Qnt+9cLiuEICeUwlyl42YdwpmY0ELcy5+u6wz mK/jxrYOpzXKDwLq5k4X+hmGuSNWWAN3gHiJqmJZPkhFPUIozZUCeEc76pS/IUN72NfprZmF Dp6/QDjDFtfS39bHSWXKVZUbqaMPqlj/z6Ugk027/3GUjHHr8WkeL1ezWepYDY7WSoXwfoAL 2UXYsMAr/uUncSKlfjvArhsej0S4zbqim2ZY6S8aRWw94J3bSvJR+Nwbs34GPTD4Pg== Organization: Red Hat, Inc. Message-ID: <816934c1-419d-10c0-4b13-c6304e832cbb@redhat.com> Date: Mon, 29 Jul 2019 08:35:38 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <20190729105343.19250-1-kwolf@redhat.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="xbXoJAgpa9inZuxHGvlaKP0a2s1u570VO" X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Mon, 29 Jul 2019 13:35:43 +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 for-4.1] block/copy-on-read: Fix permissions for inactive node 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: qemu-devel@nongnu.org, mreitz@redhat.com 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) --xbXoJAgpa9inZuxHGvlaKP0a2s1u570VO Content-Type: multipart/mixed; boundary="Rtgieef7EMHoe5cFD0WzctcmFul8vv4uD"; protected-headers="v1" From: Eric Blake To: Kevin Wolf , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, mreitz@redhat.com Message-ID: <816934c1-419d-10c0-4b13-c6304e832cbb@redhat.com> Subject: Re: [Qemu-devel] [PATCH for-4.1] block/copy-on-read: Fix permissions for inactive node References: <20190729105343.19250-1-kwolf@redhat.com> In-Reply-To: <20190729105343.19250-1-kwolf@redhat.com> --Rtgieef7EMHoe5cFD0WzctcmFul8vv4uD Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 7/29/19 5:53 AM, Kevin Wolf wrote: > The copy-on-read drive must not request the WRITE_UNCHANGED permission > for its child if the node is inactive, otherwise starting a migration > destination with -incoming will fail because the child cannot provide > write access yet: >=20 > qemu-system-x86_64: -blockdev copy-on-read,file=3Dimg,node-name=3Dcor= : Block node is read-only >=20 > Earlier QEMU versions additionally ran into an abort() on the migration= > source side: bdrv_inactivate_recurse() failed to update permissions. > This is silently ignored today because it was only supposed to loosen > restrictions. This is the symptom that was originally reported here: >=20 > https://bugzilla.redhat.com/show_bug.cgi?id=3D1733022 >=20 > Signed-off-by: Kevin Wolf > --- > block/copy-on-read.c | 16 +++++++--------- > 1 file changed, 7 insertions(+), 9 deletions(-) Do any of the iotests cover this? Should they, especially if you are trying to get this in for -rc3 tomorrow? >=20 > diff --git a/block/copy-on-read.c b/block/copy-on-read.c > index 22f24fd0db..6631f30205 100644 > --- a/block/copy-on-read.c > +++ b/block/copy-on-read.c > @@ -56,16 +56,14 @@ static void cor_child_perm(BlockDriverState *bs, Bd= rvChild *c, > uint64_t perm, uint64_t shared, > uint64_t *nperm, uint64_t *nshared) > { > - if (c =3D=3D NULL) { > - *nperm =3D (perm & PERM_PASSTHROUGH) | BLK_PERM_WRITE_UNCHANGE= D; > - *nshared =3D (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED; > - return; > - } > + *nperm =3D perm & PERM_PASSTHROUGH; > + *nshared =3D (shared & PERM_PASSTHROUGH) | PERM_UNCHANGED; > =20 > - *nperm =3D (perm & PERM_PASSTHROUGH) | > - (c->perm & PERM_UNCHANGED); > - *nshared =3D (shared & PERM_PASSTHROUGH) | > - (c->shared_perm & PERM_UNCHANGED); The old code unconditionally returned one set of permissions when c =3D=3D= NULL, or made a choice based on c's existing permissions on whether to pass in those two bits. > + /* We must not request write permissions for an inactive node, the= child > + * cannot provide it. */ > + if (!(bs->open_flags & BDRV_O_INACTIVE)) { > + *nperm |=3D BLK_PERM_WRITE_UNCHANGED; > + } The new code changes the condition for or'ing in WRITE_UNCHANGED to *nperm (it is no longer dependent on whether c =3D=3D NULL, but whether t= he drive is inactive), which matches your commit message. But the new code also changes to always pass in the PERM_UNCHANGED to *nshared; that used to be skipped if c was non-NULL and did not already have the permission. I don't follow that change from the commit message, am I missing something? --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org --Rtgieef7EMHoe5cFD0WzctcmFul8vv4uD-- --xbXoJAgpa9inZuxHGvlaKP0a2s1u570VO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAl0+9ioACgkQp6FrSiUn Q2rptAgAnBECWiJ/VeCE7wWPDbcBdoCItz73oBkBfhvHQ/fncfGJhDaBmq2vND9o ECduT3qW/F9sXmAg2CM4i/KzNpgKu1vbuOQF1Ls4/AW4eWjG4S2Jq30pZoQbHRHN 7VdOyBuJPaBRK/ALFV/JhsnKBMgugYxk0Q/vDIUtPs/kJujZNeRUtYMs5jkjKqYx IdtxQfFytt5f6l57oozE3l0qaibKpAKYayvR4CeJLcFyzJmcr7fFCWU0K8Ybc9yQ KABA3pcQs3f2m5wvT5/kAVugLZDCFn4EMJ9i7XDGL4QaGcwqJsre+c9eU4UsDcc9 JmQSEcsUSfmejig1u8V+zirnulLasg== =yLbk -----END PGP SIGNATURE----- --xbXoJAgpa9inZuxHGvlaKP0a2s1u570VO--