qcow2: Add subcluster support to qcow2_measure()

Extended L2 entries are bigger than normal L2 entries so this has an
impact on the amount of metadata needed for a qcow2 file.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <7efae2efd5e36b42d2570743a12576d68ce53685.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Alberto Garcia 2020-07-10 18:13:11 +02:00 committed by Max Reitz
parent a6841a2de6
commit 0dd07b298f

View file

@ -3232,28 +3232,31 @@ int64_t qcow2_refcount_metadata_size(int64_t clusters, size_t cluster_size,
* @total_size: virtual disk size in bytes
* @cluster_size: cluster size in bytes
* @refcount_order: refcount bits power-of-2 exponent
* @extended_l2: true if the image has extended L2 entries
*
* Returns: Total number of bytes required for the fully allocated image
* (including metadata).
*/
static int64_t qcow2_calc_prealloc_size(int64_t total_size,
size_t cluster_size,
int refcount_order)
int refcount_order,
bool extended_l2)
{
int64_t meta_size = 0;
uint64_t nl1e, nl2e;
int64_t aligned_total_size = ROUND_UP(total_size, cluster_size);
size_t l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
/* header: 1 cluster */
meta_size += cluster_size;
/* total size of L2 tables */
nl2e = aligned_total_size / cluster_size;
nl2e = ROUND_UP(nl2e, cluster_size / sizeof(uint64_t));
meta_size += nl2e * sizeof(uint64_t);
nl2e = ROUND_UP(nl2e, cluster_size / l2e_size);
meta_size += nl2e * l2e_size;
/* total size of L1 tables */
nl1e = nl2e * sizeof(uint64_t) / cluster_size;
nl1e = nl2e * l2e_size / cluster_size;
nl1e = ROUND_UP(nl1e, cluster_size / sizeof(uint64_t));
meta_size += nl1e * sizeof(uint64_t);
@ -4838,6 +4841,8 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
PreallocMode prealloc;
bool has_backing_file;
bool has_luks;
bool extended_l2 = false; /* Set to false until the option is added */
size_t l2e_size;
/* Parse image creation options */
cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
@ -4896,8 +4901,9 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
virtual_size = ROUND_UP(virtual_size, cluster_size);
/* Check that virtual disk size is valid */
l2e_size = extended_l2 ? L2E_SIZE_EXTENDED : L2E_SIZE_NORMAL;
l2_tables = DIV_ROUND_UP(virtual_size / cluster_size,
cluster_size / sizeof(uint64_t));
cluster_size / l2e_size);
if (l2_tables * sizeof(uint64_t) > QCOW_MAX_L1_SIZE) {
error_setg(&local_err, "The image size is too large "
"(try using a larger cluster size)");
@ -4960,9 +4966,9 @@ static BlockMeasureInfo *qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
}
info = g_new0(BlockMeasureInfo, 1);
info->fully_allocated =
info->fully_allocated = luks_payload_size +
qcow2_calc_prealloc_size(virtual_size, cluster_size,
ctz32(refcount_bits)) + luks_payload_size;
ctz32(refcount_bits), extended_l2);
/*
* Remove data clusters that are not required. This overestimates the