From nobody Mon Feb 9 00:30:12 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1491417181009526.71923335403; Wed, 5 Apr 2017 11:33:01 -0700 (PDT) Received: from localhost ([::1]:41836 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cvpjn-00011z-P7 for importer@patchew.org; Wed, 05 Apr 2017 14:32:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34135) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cvpgC-0006g6-17 for qemu-devel@nongnu.org; Wed, 05 Apr 2017 14:29:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cvpgA-00029c-OG for qemu-devel@nongnu.org; Wed, 05 Apr 2017 14:29:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53898) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cvpg3-00027w-Pe; Wed, 05 Apr 2017 14:29:07 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id CA21D6AAD3; Wed, 5 Apr 2017 18:29:06 +0000 (UTC) Received: from localhost (ovpn-116-76.phx2.redhat.com [10.3.116.76]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 703FF7D57D; Wed, 5 Apr 2017 18:29:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CA21D6AAD3 Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx02.extmail.prod.ext.phx2.redhat.com; spf=pass smtp.mailfrom=jcody@redhat.com DKIM-Filter: OpenDKIM Filter v2.11.0 mx1.redhat.com CA21D6AAD3 From: Jeff Cody To: qemu-devel@nongnu.org Date: Wed, 5 Apr 2017 14:28:44 -0400 Message-Id: In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 05 Apr 2017 18:29:06 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH for-2.10 2/9] block: do not set BDS read_only if copy_on_read enabled X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, jsnow@redhat.com, stefanha@redhat.com, qemu-block@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" A few block drivers will set the BDS read_only flag from their .bdrv_open() function. This means the bs->read_only flag could be set after we enable copy_on_read, as the BDRV_O_COPY_ON_READ flag check occurs prior to the call to bdrv->bdrv_open(). This adds an error return to bdrv_set_read_only(), and an error will be return if we try to set the BDS to read_only while copy_on_read is enabled. Signed-off-by: Jeff Cody Reviewed-by: Stefan Hajnoczi --- block.c | 10 +++++++++- block/bochs.c | 5 ++++- block/cloop.c | 5 ++++- block/dmg.c | 6 +++++- block/rbd.c | 6 +++++- block/vvfat.c | 15 ++++++++++++--- include/block/block.h | 2 +- 7 files changed, 40 insertions(+), 9 deletions(-) diff --git a/block.c b/block.c index 7b4c7ef..f60d5ea 100644 --- a/block.c +++ b/block.c @@ -192,9 +192,17 @@ void path_combine(char *dest, int dest_size, } } =20 -void bdrv_set_read_only(BlockDriverState *bs, bool read_only) +int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp) { + /* Do not set read_only if copy_on_read is enabled */ + if (bs->copy_on_read && read_only) { + error_setg(errp, "Cannot set node '%s' to r/o while COW enabled", + bdrv_get_device_or_node_name(bs)); + return -EINVAL; + } + bs->read_only =3D read_only; + return 0; } =20 void bdrv_get_full_backing_filename_from_filename(const char *backed, diff --git a/block/bochs.c b/block/bochs.c index bdc2831..a759b6e 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -110,7 +110,10 @@ static int bochs_open(BlockDriverState *bs, QDict *opt= ions, int flags, return -EINVAL; } =20 - bdrv_set_read_only(bs, true); /* no write support yet */ + ret =3D bdrv_set_read_only(bs, true, errp); /* no write support yet */ + if (ret < 0) { + return ret; + } =20 ret =3D bdrv_pread(bs->file, 0, &bochs, sizeof(bochs)); if (ret < 0) { diff --git a/block/cloop.c b/block/cloop.c index 11f17c8..d6597fc 100644 --- a/block/cloop.c +++ b/block/cloop.c @@ -72,7 +72,10 @@ static int cloop_open(BlockDriverState *bs, QDict *optio= ns, int flags, return -EINVAL; } =20 - bdrv_set_read_only(bs, true); + ret =3D bdrv_set_read_only(bs, true, errp); + if (ret < 0) { + return ret; + } =20 /* read header */ ret =3D bdrv_pread(bs->file, 128, &s->block_size, 4); diff --git a/block/dmg.c b/block/dmg.c index 27ce4a6..900ae5a 100644 --- a/block/dmg.c +++ b/block/dmg.c @@ -419,8 +419,12 @@ static int dmg_open(BlockDriverState *bs, QDict *optio= ns, int flags, return -EINVAL; } =20 + ret =3D bdrv_set_read_only(bs, true, errp); + if (ret < 0) { + return ret; + } + block_module_load_one("dmg-bz2"); - bdrv_set_read_only(bs, true); =20 s->n_chunks =3D 0; s->offsets =3D s->lengths =3D s->sectors =3D s->sectorcounts =3D NULL; diff --git a/block/rbd.c b/block/rbd.c index 6ad2904..328e4a9 100644 --- a/block/rbd.c +++ b/block/rbd.c @@ -641,7 +641,11 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict *= options, int flags, goto failed_open; } =20 - bdrv_set_read_only(bs, (s->snap !=3D NULL)); + r =3D bdrv_set_read_only(bs, (s->snap !=3D NULL), &local_err); + if (r < 0) { + error_propagate(errp, local_err); + goto failed_open; + } =20 qemu_opts_del(opts); return 0; diff --git a/block/vvfat.c b/block/vvfat.c index d4ce6d7..34a2854 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -1156,8 +1156,6 @@ static int vvfat_open(BlockDriverState *bs, QDict *op= tions, int flags, =20 s->current_cluster=3D0xffffffff; =20 - /* read only is the default for safety */ - bdrv_set_read_only(bs, true); s->qcow =3D NULL; s->qcow_filename =3D NULL; s->fat2 =3D NULL; @@ -1173,7 +1171,18 @@ static int vvfat_open(BlockDriverState *bs, QDict *o= ptions, int flags, if (ret < 0) { goto fail; } - bdrv_set_read_only(bs, false); + ret =3D bdrv_set_read_only(bs, false, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + goto fail; + } + } else { + /* read only is the default for safety */ + ret =3D bdrv_set_read_only(bs, true, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + goto fail; + } } =20 bs->total_sectors =3D cyls * heads * secs; diff --git a/include/block/block.h b/include/block/block.h index 06c9032..beb563a 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -426,7 +426,7 @@ int bdrv_is_allocated_above(BlockDriverState *top, Bloc= kDriverState *base, int64_t sector_num, int nb_sectors, int *pnum); =20 bool bdrv_is_read_only(BlockDriverState *bs); -void bdrv_set_read_only(BlockDriverState *bs, bool read_only); +int bdrv_set_read_only(BlockDriverState *bs, bool read_only, Error **errp); bool bdrv_is_sg(BlockDriverState *bs); bool bdrv_is_inserted(BlockDriverState *bs); int bdrv_media_changed(BlockDriverState *bs); --=20 2.9.3