@@ -596,7 +596,7 @@ static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
refcount = be16_to_cpu(refcount_block[block_index]);
refcount += addend;
- if (refcount < 0 || refcount > 0xffff) {
+ if (refcount < 0 || refcount > s->refcount_max) {
ret = -EINVAL;
goto fail;
}
@@ -787,7 +787,7 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
return refcount;
}
- if (refcount == 0xffff) {
+ if (refcount == s->refcount_max) {
offset = 0;
}
}
@@ -684,6 +684,9 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
s->refcount_order = header.refcount_order;
+ s->refcount_bits = 1 << s->refcount_order;
+ s->refcount_max = UINT64_C(1) << (s->refcount_bits - 1);
+ s->refcount_max += s->refcount_max - 1;
if (header.crypt_method > QCOW_CRYPT_AES) {
error_setg(errp, "Unsupported encryption method: %" PRIu32,
@@ -258,6 +258,8 @@ typedef struct BDRVQcowState {
int qcow_version;
bool use_lazy_refcounts;
int refcount_order;
+ int refcount_bits;
+ uint64_t refcount_max;
bool discard_passthrough[QCOW2_DISCARD_MAX];
Add two new fields regarding refcount information (the bit width of every entry and the maximum refcount value) to the BDRVQcowState. Signed-off-by: Max Reitz <mreitz@redhat.com> --- block/qcow2-refcount.c | 4 ++-- block/qcow2.c | 3 +++ block/qcow2.h | 2 ++ 3 files changed, 7 insertions(+), 2 deletions(-)