Am 17.05.2016 um 11:15 hat Denis V. Lunev geschrieben: > We should check for (res & BDRV_BLOCK_ZERO) only. The situation when we > will have !(res & BDRV_BLOCK_DATA) and will not have BDRV_BLOCK_ZERO is > not possible.
The patch is okay, but I'm correcting this paragraph into: We should check for (res & BDRV_BLOCK_ZERO) only. The situation when we will have !(res & BDRV_BLOCK_DATA) and will not have BDRV_BLOCK_ZERO is not possible for images with bdi.unallocated_blocks_are_zero == true. For those images where it's false, however, it can happen and we must not consider the data zeroed then or we would corrupt the image. Kevin