If we are growing the image and potentially using preallocation for the new area, we need to make sure that no write requests are made to the "preallocated" area which [@old_size, @offset), not [@offset, offset * 2 - @old_size).
Signed-off-by: Fam Zheng <f...@redhat.com> --- block/io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block/io.c b/block/io.c index d07849fa96..ed18eb0ca3 100644 --- a/block/io.c +++ b/block/io.c @@ -3070,7 +3070,8 @@ int coroutine_fn bdrv_co_truncate(BdrvChild *child, int64_t offset, } bdrv_inc_in_flight(bs); - tracked_request_begin(&req, bs, offset, new_bytes, BDRV_TRACKED_TRUNCATE); + tracked_request_begin(&req, bs, offset - new_bytes, new_bytes, + BDRV_TRACKED_TRUNCATE); /* If we are growing the image and potentially using preallocation for the * new area, we need to make sure that no write requests are made to it -- 2.17.1