diff options
Diffstat (limited to 'block/qcow2.h')
| -rw-r--r-- | block/qcow2.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/block/qcow2.h b/block/qcow2.h index 29c98d87a0..8662b68575 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -42,6 +42,12 @@ #define QCOW_MAX_CRYPT_CLUSTERS 32 #define QCOW_MAX_SNAPSHOTS 65536 +/* Field widths in qcow2 mean normal cluster offsets cannot reach + * 64PB; depending on cluster size, compressed clusters can have a + * smaller limit (64PB for up to 16k clusters, then ramps down to + * 512TB for 2M clusters). */ +#define QCOW_MAX_CLUSTER_OFFSET ((1ULL << 56) - 1) + /* 8 MB refcount table is enough for 2 PB images at 64k cluster size * (128 GB for 512 byte clusters, 2 EB for 2 MB clusters) */ #define QCOW_MAX_REFTABLE_SIZE S_8MiB |