[Qemu-devel] [PATCH v6 3/6] qcow2: Reduce REFT_OFFSET_MASK

[Eric Blake <eblake@redhat.com>]

Match our code to the spec change in the previous patch - there's
no reason for the refcount table to allow larger offsets than the
L1/L2 tables. In practice, no image has more than 64PB of
allocated clusters anyways, as anything beyond that can't be
expressed via L2 mappings to host offsets.

Suggested-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>

---
v4: new patch
---
 block/qcow2.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/qcow2.h b/block/qcow2.h
index adf5c3950fd..1df15a18aa1 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -443,7 +443,7 @@ typedef enum QCow2MetadataOverlap {
 #define L2E_OFFSET_MASK 0x00fffffffffffe00ULL
 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL

-#define REFT_OFFSET_MASK 0xfffffffffffffe00ULL
+#define REFT_OFFSET_MASK 0x00fffffffffffe00ULL

 static inline int64_t start_of_cluster(BDRVQcow2State *s, int64_t offset)
 {
-- 
2.14.3