qcow2: Add two new fields to BDRVQcowState

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>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Max Reitz 2015-02-10 15:28:43 -05:00 committed by Kevin Wolf
parent 0a6ed70006
commit 346a53df38
3 changed files with 7 additions and 2 deletions

View File

@ -584,7 +584,7 @@ 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;
}
@ -775,7 +775,7 @@ int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size)
return refcount;
}
if (refcount == 0xffff) {
if (refcount == s->refcount_max) {
offset = 0;
}
}

View File

@ -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,

View File

@ -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];