From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33034) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Z1q2t-0007tM-Py for qemu-devel@nongnu.org; Mon, 08 Jun 2015 01:56:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Z1q2s-0008Uy-Df for qemu-devel@nongnu.org; Mon, 08 Jun 2015 01:56:27 -0400 From: Fam Zheng Date: Mon, 8 Jun 2015 13:56:06 +0800 Message-Id: <1433742974-20128-1-git-send-email-famz@redhat.com> Subject: [Qemu-devel] [PATCH v7 0/8] block: Mirror discarded sectors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , qemu-block@nongnu.org, Jeff Cody , qemu-stable@nongnu.org, Stefan Hajnoczi , pbonzini@redhat.com, jsnow@redhat.com, wangxiaolong@ucloud.cn v7: Fix the lost assignment of s->unmap. v6: Fix pnum in bdrv_get_block_status_above. [Paolo] 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] 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 (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 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 -- 2.4.2