qcow2: Open images with refcount order != 4

No longer refuse to open images with a different refcount entry width
than 16 bits; only reject images with a refcount width larger than 64
bits (which is prohibited by the specification).

Signed-off-by: Max Reitz <[email protected]>
Reviewed-by: Eric Blake <[email protected]>
Reviewed-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>

diff --git a/block/qcow2.c b/block/qcow2.c
index 5c92803fff29da2e3e05c2ab9e424e6d6f954634..52731ab67bb91c6fb2d2749f30731c3a39338a9b 100644 (file)
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -677,10 +677,10 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
     }
 
     /* Check support for various header values */
-    if (header.refcount_order != 4) {
-        report_unsupported(bs, errp, "%d bit reference counts",
-                           1 << header.refcount_order);
-        ret = -ENOTSUP;
+    if (header.refcount_order > 6) {
+        error_setg(errp, "Reference count entry width too large; may not "
+                   "exceed 64 bits");
+        ret = -EINVAL;
         goto fail;
     }
     s->refcount_order = header.refcount_order;