From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50802) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z8TY0-00041k-EZ for qemu-devel@nongnu.org; Fri, 26 Jun 2015 09:20:01 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z8TXz-0003Dt-8C for qemu-devel@nongnu.org; Fri, 26 Jun 2015 09:20:00 -0400 Date: Fri, 26 Jun 2015 14:19:50 +0100 From: Stefan Hajnoczi Message-ID: <20150626131950.GN15457@stefanha-thinkpad.redhat.com> References: <1433742974-20128-1-git-send-email-famz@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Vxa5joy26gVGOrvU" Content-Disposition: inline In-Reply-To: <1433742974-20128-1-git-send-email-famz@redhat.com> Subject: Re: [Qemu-devel] [PATCH v7 0/8] block: Mirror discarded sectors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: Kevin Wolf , qemu-block@nongnu.org, Jeff Cody , qemu-devel@nongnu.org, qemu-stable@nongnu.org, pbonzini@redhat.com, jsnow@redhat.com, wangxiaolong@ucloud.cn --Vxa5joy26gVGOrvU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jun 08, 2015 at 01:56:06PM +0800, Fam Zheng wrote: > v7: Fix the lost assignment of s->unmap. >=20 > v6: Fix pnum in bdrv_get_block_status_above. [Paolo] >=20 > v5: Rewrite patch 1. > Address Eric's comments on patch 3. > Add Eric's rev-by to patches 2 & 4. > Check BDRV_BLOCK_DATA in patch 3. [Paolo] >=20 > This fixes the mirror assert failure reported by wangxiaolong: >=20 > https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg04458.html >=20 > The direct cause is that hbitmap code couldn't handle unset of bits *afte= r* > iterator's current position. We could fix that, but the bdrv_reset_dirty(= ) call > is more questionable: >=20 > Before, if guest discarded some sectors during migration, it could see > different data after moving to dest side, depending on block backends of = the > src and the dest. This is IMO worse than mirroring the actual reading as = done > in this series, because we don't know what the guest is doing. >=20 > For example if a guest first issues WRITE SAME to wipe out the area then = issues > UNMAP to discard it, just to get rid of some sensitive data completely, w= e may > miss both operations and leave stale data on dest image. >=20 >=20 > Fam Zheng (8): > block: Add bdrv_get_block_status_above > qmp: Add optional bool "unmap" to drive-mirror > mirror: Do zero write on target if sectors not allocated > block: Fix dirty bitmap in bdrv_co_discard > block: Remove bdrv_reset_dirty > qemu-iotests: Make block job methods common > qemu-iotests: Add test case for mirror with unmap > iotests: Use event_wait in wait_ready >=20 > block.c | 12 -------- > block/io.c | 60 ++++++++++++++++++++++++++++++-------= -- > block/mirror.c | 28 +++++++++++++++--- > blockdev.c | 5 ++++ > hmp.c | 2 +- > include/block/block.h | 4 +++ > include/block/block_int.h | 4 +-- > qapi/block-core.json | 8 +++++- > qmp-commands.hx | 3 ++ > tests/qemu-iotests/041 | 66 ++++++++++---------------------------= ------ > tests/qemu-iotests/132 | 59 ++++++++++++++++++++++++++++++++++++++ > tests/qemu-iotests/132.out | 5 ++++ > tests/qemu-iotests/group | 1 + > tests/qemu-iotests/iotests.py | 23 +++++++++++++++ > 14 files changed, 196 insertions(+), 84 deletions(-) > create mode 100644 tests/qemu-iotests/132 > create mode 100644 tests/qemu-iotests/132.out >=20 > --=20 > 2.4.2 Thanks, applied to my block tree again now that the bool/enum question has been resolved: https://github.com/stefanha/qemu/commits/block Stefan --Vxa5joy26gVGOrvU Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJVjVF2AAoJEJykq7OBq3PIVuoH/3T7q5HlcKa8HVY+HpwOJybP m46J1cHO0wTmqzUC+9f/5158hjvfgus0LL/Dl0zAug9wshKLxnuq3vES4VWwQ0yH xObhOAUAPHaL/KwzSf49XevY40bzcufs45WWq8qJw2JZYOwMyrLS0CPp2mjpqEXw aVFQIqLLos1vWuU7kDVGImgzXKrn601KfeLYJ+0eBu7YQca2ckZyg2g3AMiuGAoO 1FJ8AdoNXBwtU+p4PjQvOfeL0s2sWLKdxB/sS5VXvKWLF3ujyQAdgylNoN8pN2KE 1wdraVUKt1LSxpeGC1ds8CJ+JLXS2xsFjYmCIM/AEZorpggyH1Rl/mRjR/giXhc= =na4z -----END PGP SIGNATURE----- --Vxa5joy26gVGOrvU--