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Wed, 28 Aug 2019 17:52:28 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-204-32.brq.redhat.com [10.40.204.32]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CFDD51001B00; Wed, 28 Aug 2019 17:52:16 +0000 (UTC) To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org References: <20190826161312.489398-1-vsementsov@virtuozzo.com> <20190826161312.489398-13-vsementsov@virtuozzo.com> From: Max Reitz Openpgp: preference=signencrypt 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: <5ce15418-4320-49bf-f6eb-f6dface5c61d@redhat.com> Date: Wed, 28 Aug 2019 19:52:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20190826161312.489398-13-vsementsov@virtuozzo.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="TQLVhvG0ehtfnarhq6oJNX0OVFwjJTYdI" X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Wed, 28 Aug 2019 17:52:28 +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 v9 12/13] block: introduce backup-top filter driver 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: fam@euphon.net, kwolf@redhat.com, wencongyang2@huawei.com, xiechanglong.d@gmail.com, qemu-devel@nongnu.org, armbru@redhat.com, jsnow@redhat.com, stefanha@redhat.com, den@openvz.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) --TQLVhvG0ehtfnarhq6oJNX0OVFwjJTYdI Content-Type: multipart/mixed; boundary="SeHr5Z3q0AunMdAl3KynjP3vdtBvhJnxg"; protected-headers="v1" From: Max Reitz To: Vladimir Sementsov-Ogievskiy , qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, eblake@redhat.com, armbru@redhat.com, xiechanglong.d@gmail.com, wencongyang2@huawei.com, fam@euphon.net, stefanha@redhat.com, jsnow@redhat.com, kwolf@redhat.com, den@openvz.org Message-ID: <5ce15418-4320-49bf-f6eb-f6dface5c61d@redhat.com> Subject: Re: [PATCH v9 12/13] block: introduce backup-top filter driver References: <20190826161312.489398-1-vsementsov@virtuozzo.com> <20190826161312.489398-13-vsementsov@virtuozzo.com> In-Reply-To: <20190826161312.489398-13-vsementsov@virtuozzo.com> --SeHr5Z3q0AunMdAl3KynjP3vdtBvhJnxg Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 26.08.19 18:13, Vladimir Sementsov-Ogievskiy wrote: > Backup-top filter caches write operations and does copy-before-write > operations. >=20 > The driver will be used in backup instead of write-notifiers. >=20 > Signed-off-by: Vladimir Sementsov-Ogievskiy > --- > block/backup-top.h | 37 +++++++ > block/backup-top.c | 245 ++++++++++++++++++++++++++++++++++++++++++++= > block/Makefile.objs | 2 + > 3 files changed, 284 insertions(+) > create mode 100644 block/backup-top.h > create mode 100644 block/backup-top.c [...] > +static void backup_top_refresh_filename(BlockDriverState *bs) > +{ > + if (bs->backing =3D=3D NULL) { > + /* > + * we can be here after failed bdrv_attach_child in > + * bdrv_set_backing_hd > + */ > + return; > + } > + bdrv_refresh_filename(bs->backing->bs); bdrv_refresh_filename() should have done this already. > + pstrcpy(bs->exact_filename, sizeof(bs->exact_filename), > + bs->backing->bs->filename); > +} [...] > +BlockDriverState *bdrv_backup_top_append(BlockDriverState *source, > + const char *filter_node_name,= > + Error **errp) > +{ [...] > + assert(!(top->backing->shared_perm & BLK_PERM_WRITE)); Not wrong, but why? > + > + return top; > +} > + > +void bdrv_backup_top_set_bcs(BlockDriverState *bs, BlockCopyState *cop= y_state) > +{ > + BDRVBackupTopState *s =3D bs->opaque; > + > + assert(blk_bs(copy_state->source) =3D=3D bs->backing->bs); > + s->bcs =3D copy_state; > +} > + > +void bdrv_backup_top_drop(BlockDriverState *bs) > +{ > + AioContext *aio_context =3D bdrv_get_aio_context(bs); > + > + aio_context_acquire(aio_context); > + > + bdrv_drained_begin(bs); > + > + bdrv_child_try_set_perm(bs->backing, 0, BLK_PERM_ALL, &error_abort= ); I would prefer a state->active =3D false and bdrv_child_refresh_perms(). Max --SeHr5Z3q0AunMdAl3KynjP3vdtBvhJnxg-- --TQLVhvG0ehtfnarhq6oJNX0OVFwjJTYdI Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEkb62CjDbPohX0Rgp9AfbAGHVz0AFAl1mv04ACgkQ9AfbAGHV z0AUmwf+JyVvnz97tihfzKtvJCjg9NmuCxwFSa5piEN/G221wUJCWzc6cU/SG2q7 iuqxwvvEF20LuA9/xRHuhirJ47x7KTc0lmDxw9VC8XIcScbfILqrFh+m5K2RcB6L jq2A/Vwi//PR/j/puxILYa8i5igzaOuKgdzRI5zHtAVU/t8cbStjH7aqKS7C3fQk VC74ubmpMxeftboFzuaAzXHYlMC/3kvcmNJkRIowlaOtYuwXqpCIQxsHAXiQJwRJ ef75Zf270wyL8sKM6Pw+XxqD0nmMXBtdQpoX8XI8qxe2Cr7G3WtCu5ZUuDaDWy0T BjPuo3ReZOahlbZiWzrIgvZ6Kba6/A== =DbKF -----END PGP SIGNATURE----- --TQLVhvG0ehtfnarhq6oJNX0OVFwjJTYdI--