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[Qemu-devel] [PATCH 0/4] block: Mirror discarded sectors
From: |
Fam Zheng |
Subject: |
[Qemu-devel] [PATCH 0/4] block: Mirror discarded sectors |
Date: |
Tue, 5 May 2015 20:46:45 +0800 |
This fixes the mirror assert failure reported by wangxiaolong:
https://lists.gnu.org/archive/html/qemu-devel/2015-04/msg04458.html
The direct cause is that hbitmap code couldn't handle unset of bits *after*
iterator's current position. We could fix that, but the bdrv_reset_dirty() call
is more questionable:
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.
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, we may
miss both operations and leave stale data on dest image.
Fam Zheng (4):
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
block.c | 12 --------
block/io.c | 4 +--
include/block/block_int.h | 2 --
tests/qemu-iotests/041 | 66 ++++++++++---------------------------------
tests/qemu-iotests/131 | 59 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/131.out | 5 ++++
tests/qemu-iotests/group | 1 +
tests/qemu-iotests/iotests.py | 28 ++++++++++++++++++
8 files changed, 110 insertions(+), 67 deletions(-)
create mode 100644 tests/qemu-iotests/131
create mode 100644 tests/qemu-iotests/131.out
--
1.9.3
- [Qemu-devel] [PATCH 0/4] block: Mirror discarded sectors,
Fam Zheng <=
- [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Fam Zheng, 2015/05/05
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Paolo Bonzini, 2015/05/05
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Fam Zheng, 2015/05/05
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Paolo Bonzini, 2015/05/06
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Fam Zheng, 2015/05/06
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Paolo Bonzini, 2015/05/06
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Fam Zheng, 2015/05/11
- Re: [Qemu-devel] [PATCH 1/4] block: Fix dirty bitmap in bdrv_co_discard, Paolo Bonzini, 2015/05/11
[Qemu-devel] [PATCH 2/4] block: Remove bdrv_reset_dirty, Fam Zheng, 2015/05/05