qcow2: Allow different cluster sizes

Add an option to specify the cluster size of a newly created qcow2 image.
Default is 4k which is the same value that was hard-coded before.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/block_int.h b/block_int.h
index 782de6c62d..0820ed1d5c 100644
--- a/block_int.h
+++ b/block_int.h
@@ -36,6 +36,7 @@
 #define BLOCK_OPT_COMPAT6       "compat6"
 #define BLOCK_OPT_BACKING_FILE  "backing_file"
 #define BLOCK_OPT_BACKING_FMT   "backing_fmt"
+#define BLOCK_OPT_CLUSTER_SIZE  "cluster_size"
 
 typedef struct AIOPool {
     void (*cancel)(BlockDriverAIOCB *acb);