The size of a refblock entry is (in theory) variable; calculate therefore the number of entries per refblock and the according bit shift (1 << x == entry count) when opening an image.
Signed-off-by: Max Reitz <mre...@redhat.com> --- block/qcow2.c | 2 ++ block/qcow2.h | 2 ++ 2 files changed, 4 insertions(+) diff --git a/block/qcow2.c b/block/qcow2.c index f9e045f..172ad00 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -689,6 +689,8 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags, s->l2_bits = s->cluster_bits - 3; /* L2 is always one cluster */ s->l2_size = 1 << s->l2_bits; + s->refcount_block_bits = s->cluster_bits - (s->refcount_order - 3); + s->refcount_block_size = 1 << s->refcount_block_bits; bs->total_sectors = header.size / 512; s->csize_shift = (62 - (s->cluster_bits - 8)); s->csize_mask = (1 << (s->cluster_bits - 8)) - 1; diff --git a/block/qcow2.h b/block/qcow2.h index 6aeb7ea..7c01fb7 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -222,6 +222,8 @@ typedef struct BDRVQcowState { int l2_size; int l1_size; int l1_vm_state_index; + int refcount_block_bits; + int refcount_block_size; int csize_shift; int csize_mask; uint64_t cluster_offset_mask; -- 2.1.0