block/backup: fix backup_cow_with_offload for last cluster

We shouldn't try to copy bytes beyond EOF. Fix it.

Fixes: 9ded4a0114
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 20190920142056.12778-3-vsementsov@virtuozzo.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Vladimir Sementsov-Ogievskiy 2019-09-20 17:20:43 +03:00 committed by Max Reitz
parent 981fb5810a
commit 1048ddf0a3

View File

@ -161,7 +161,7 @@ static int coroutine_fn backup_cow_with_offload(BackupBlockJob *job,
assert(QEMU_IS_ALIGNED(job->copy_range_size, job->cluster_size));
assert(QEMU_IS_ALIGNED(start, job->cluster_size));
nbytes = MIN(job->copy_range_size, end - start);
nbytes = MIN(job->copy_range_size, MIN(end, job->len) - start);
nr_clusters = DIV_ROUND_UP(nbytes, job->cluster_size);
bdrv_reset_dirty_bitmap(job->copy_bitmap, start,
job->cluster_size * nr_clusters);