A refblock entry may have a different size than 16 bits, it may even be smaller than a byte. Correct the refcount_block_entries calculation accordingly.
Signed-off-by: Max Reitz <mre...@redhat.com> --- docs/specs/qcow2.txt | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/docs/specs/qcow2.txt b/docs/specs/qcow2.txt index cfbc8b0..0a878aa 100644 --- a/docs/specs/qcow2.txt +++ b/docs/specs/qcow2.txt @@ -183,7 +183,7 @@ blocks and are exactly one cluster in size. Given a offset into the image file, the refcount of its cluster can be obtained as follows: - refcount_block_entries = (cluster_size / sizeof(uint16_t)) + refcount_block_entries = (cluster_size * 8 / refcount_bits) refcount_block_index = (offset / cluster_size) % refcount_block_entries refcount_table_index = (offset / cluster_size) / refcount_block_entries -- 2.1.0