From 7661a886a17ccf3aff398b124baad9dd95f64bed Mon Sep 17 00:00:00 2001 From: Stefan Reiter Date: Mon, 10 Aug 2020 11:55:22 +0200 Subject: [PATCH 1/2] block/block-copy: always align copied region to cluster size Since commit 42ac214406e0 (block/block-copy: refactor task creation) block_copy_task_create calculates the area to be copied via bdrv_dirty_bitmap_next_dirty_area, but that can return an unaligned byte count if the image's last cluster end is not aligned to the bitmap's granularity. Always ALIGN_UP the resulting bytes value to satisfy block_copy_do_copy, which requires the 'bytes' parameter to be aligned to cluster size. Reviewed-by: Vladimir Sementsov-Ogievskiy Signed-off-by: Stefan Reiter Message-Id: <20200810095523.15071-1-s.reiter@proxmox.com> Signed-off-by: Max Reitz --- block/block-copy.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/block-copy.c b/block/block-copy.c index f7428a7c08..a30b9097ef 100644 --- a/block/block-copy.c +++ b/block/block-copy.c @@ -142,6 +142,9 @@ static BlockCopyTask *block_copy_task_create(BlockCopyState *s, return NULL; } + assert(QEMU_IS_ALIGNED(offset, s->cluster_size)); + bytes = QEMU_ALIGN_UP(bytes, s->cluster_size); + /* region is dirty, so no existent tasks possible in it */ assert(!find_conflicting_task(s, offset, bytes)); From 1f3765b652930a3b485f1a67542c2410c3774abe Mon Sep 17 00:00:00 2001 From: Stefan Reiter Date: Mon, 10 Aug 2020 11:55:23 +0200 Subject: [PATCH 2/2] iotests: add test for unaligned granularity bitmap backup Start a VM with a 4097 byte image attached, add a 4096 byte granularity dirty bitmap, mark it dirty, and then do a backup. This used to run into an assert and fail, check that it works as expected and also check the created image to ensure that misaligned backups in general work correctly. Signed-off-by: Stefan Reiter Message-Id: <20200810095523.15071-2-s.reiter@proxmox.com> [mreitz: Drop bitmap, and do not write past the image's end] Signed-off-by: Max Reitz --- tests/qemu-iotests/304 | 60 ++++++++++++++++++++++++++++++++++++++ tests/qemu-iotests/304.out | 2 ++ tests/qemu-iotests/group | 1 + 3 files changed, 63 insertions(+) create mode 100755 tests/qemu-iotests/304 create mode 100644 tests/qemu-iotests/304.out diff --git a/tests/qemu-iotests/304 b/tests/qemu-iotests/304 new file mode 100755 index 0000000000..aaf9e14617 --- /dev/null +++ b/tests/qemu-iotests/304 @@ -0,0 +1,60 @@ +#!/usr/bin/env python3 +# +# Tests dirty-bitmap backup with unaligned bitmap granularity +# +# Copyright (c) 2020 Proxmox Server Solutions +# +# This program is free software; you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 2 of the License, or +# (at your option) any later version. +# +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . +# +# owner=s.reiter@proxmox.com + +import iotests +from iotests import qemu_img_create, qemu_img_log, file_path + +iotests.script_initialize(supported_fmts=['qcow2'], + supported_protocols=['file']) + +test_img = file_path('test.qcow2') +target_img = file_path('target.qcow2') + +# unaligned by one byte +image_len = 4097 +bitmap_granularity = 4096 + +qemu_img_create('-f', iotests.imgfmt, test_img, str(image_len)) + +# create VM +vm = iotests.VM().add_drive(test_img) +vm.launch() + +# write to the entire image +vm.hmp_qemu_io('drive0', 'write -P0x16 0 4096'); +vm.hmp_qemu_io('drive0', 'write -P0x17 4096 1'); + +# do backup and wait for completion +vm.qmp('drive-backup', **{ + 'device': 'drive0', + 'sync': 'full', + 'target': target_img +}) + +event = vm.event_wait(name='BLOCK_JOB_COMPLETED', + match={'data': {'device': 'drive0'}}, + timeout=5.0) + +# shutdown to sync images +vm.shutdown() + +# backup succeeded, check if image is correct +qemu_img_log('compare', test_img, target_img) diff --git a/tests/qemu-iotests/304.out b/tests/qemu-iotests/304.out new file mode 100644 index 0000000000..381cc056f7 --- /dev/null +++ b/tests/qemu-iotests/304.out @@ -0,0 +1,2 @@ +Images are identical. + diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group index 025ed5238d..7f76066640 100644 --- a/tests/qemu-iotests/group +++ b/tests/qemu-iotests/group @@ -309,3 +309,4 @@ 299 auto quick 301 backing quick 302 quick +304 rw quick