qcow2: Fix types in qcow2_alloc_clusters and alloc_clusters_noref

In order to avoid integer overflows.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
(cherry picked from commit bb572ae)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

block/qcow2-refcount.c

@@ -28,7 +28,7 @@
 #include "qemu/range.h"
 #include "qapi/qmp/types.h"
 
-static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size);
+static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size);
 static int QEMU_WARN_UNUSED_RESULT update_refcount(BlockDriverState *bs,
                             int64_t offset, int64_t length,
                             int addend, enum qcow2_discard_type type);
@@ -634,15 +634,16 @@ int qcow2_update_cluster_refcount(BlockDriverState *bs,
 
 
 /* return < 0 if error */
-static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
+static int64_t alloc_clusters_noref(BlockDriverState *bs, uint64_t size)
 {
     BDRVQcowState *s = bs->opaque;
-    int i, nb_clusters, refcount;
+    uint64_t i, nb_clusters;
+    int refcount;
 
     nb_clusters = size_to_clusters(s, size);
 retry:
     for(i = 0; i < nb_clusters; i++) {
-        int64_t next_cluster_index = s->free_cluster_index++;
+        uint64_t next_cluster_index = s->free_cluster_index++;
         refcount = get_refcount(bs, next_cluster_index);
 
         if (refcount < 0) {
@@ -659,7 +660,7 @@ static int64_t alloc_clusters_noref(BlockDriverState *bs, int64_t size)
     return (s->free_cluster_index - nb_clusters) << s->cluster_bits;
 }
 
-int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size)
+int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size)
 {
     int64_t offset;
     int ret;

block/qcow2.h

@@ -222,8 +222,8 @@ typedef struct BDRVQcowState {
     uint64_t *refcount_table;
     uint64_t refcount_table_offset;
     uint32_t refcount_table_size;
-    int64_t free_cluster_index;
-    int64_t free_byte_offset;
+    uint64_t free_cluster_index;
+    uint64_t free_byte_offset;
 
     CoMutex lock;
 
@@ -467,7 +467,7 @@ void qcow2_refcount_close(BlockDriverState *bs);
 int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
                                   int addend, enum qcow2_discard_type type);
 
-int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
+int64_t qcow2_alloc_clusters(BlockDriverState *bs, uint64_t size);
 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
     int nb_clusters);
 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);