#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
#define VMDK4_COMPRESSION_DEFLATE 1
#define VMDK4_FLAG_RGD (1 << 1)
+/* Zeroed-grain enable bit */
+#define VMDK4_FLAG_ZERO_GRAIN (1 << 2)
#define VMDK4_FLAG_COMPRESS (1 << 16)
#define VMDK4_FLAG_MARKER (1 << 17)
#define VMDK4_GD_AT_END 0xffffffffffffffffULL
+#define VMDK_GTE_ZEROED 0x1
/* VMDK internal error codes */
#define VMDK_OK 0
bool flat;
bool compressed;
bool has_marker;
+ bool has_zero_grain;
+ int version;
int64_t sectors;
int64_t end_sector;
int64_t flat_start_offset;
extent->compressed =
le16_to_cpu(header.compressAlgorithm) == VMDK4_COMPRESSION_DEFLATE;
extent->has_marker = le32_to_cpu(header.flags) & VMDK4_FLAG_MARKER;
+ extent->version = le32_to_cpu(header.version);
+ extent->has_zero_grain = le32_to_cpu(header.flags) & VMDK4_FLAG_ZERO_GRAIN;
ret = vmdk_init_tables(bs, extent);
if (ret) {
/* free extent allocated by vmdk_add_extent */
unsigned int l1_index, l2_offset, l2_index;
int min_index, i, j;
uint32_t min_count, *l2_table, tmp = 0;
+ bool zeroed = false;
if (m_data) {
m_data->valid = 0;
l2_index = ((offset >> 9) / extent->cluster_sectors) % extent->l2_size;
*cluster_offset = le32_to_cpu(l2_table[l2_index]);
- if (!*cluster_offset) {
+ if (extent->has_zero_grain && *cluster_offset == VMDK_GTE_ZEROED) {
+ zeroed = true;
+ }
+
+ if (!*cluster_offset || zeroed) {
if (!allocate) {
- return VMDK_UNALLOC;
+ return zeroed ? VMDK_ZEROED : VMDK_UNALLOC;
}
/* Avoid the L2 tables update for the images that have snapshots. */
ret = get_cluster_offset(bs, extent, NULL,
sector_num * 512, 0, &offset);
qemu_co_mutex_unlock(&s->lock);
- /* get_cluster_offset returning 0 means success */
- ret = !ret;
+
+ ret = (ret == VMDK_OK || ret == VMDK_ZEROED);
index_in_cluster = sector_num % extent->cluster_sectors;
n = extent->cluster_sectors - index_in_cluster;
if (n > nb_sectors) {
n = nb_sectors;
}
- if (ret) {
+ if (ret != VMDK_OK) {
/* if not allocated, try to read from parent image, if exist */
- if (bs->backing_hd) {
+ if (bs->backing_hd && ret != VMDK_ZEROED) {
if (!vmdk_is_cid_valid(bs)) {
return -EINVAL;
}