qcow2: Add subcluster support to qcow2_get_host_offset()

The logic of this function remains pretty much the same, except that
it uses count_contiguous_subclusters(), which combines the logic of
count_contiguous_clusters() / count_contiguous_clusters_unallocated()
and checks individual subclusters.

qcow2_cluster_to_subcluster_type() is not necessary as a separate
function anymore so it's inlined into its caller.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <d2193fd48653a350d80f0eca1c67b1d9053fb2f3.1594396418.git.berto@igalia.com>
[mreitz: Initialize expected_type to anything]
Signed-off-by: Max Reitz <mreitz@redhat.com>

1 files changed, 14 insertions, 24 deletions

diff --git a/block/qcow2.h b/block/qcow2.h
index 5df761edc3..4fad40b96b 100644
--- a/block/qcow2.h
+++ b/block/qcow2.h
@@ -711,29 +711,6 @@ static inline QCow2ClusterType qcow2_get_cluster_type(BlockDriverState *bs,
 }
 
 /*
- * For an image without extended L2 entries, return the
- * QCow2SubclusterType equivalent of a given QCow2ClusterType.
- */
-static inline
-QCow2SubclusterType qcow2_cluster_to_subcluster_type(QCow2ClusterType type)
-{
-    switch (type) {
-    case QCOW2_CLUSTER_COMPRESSED:
-        return QCOW2_SUBCLUSTER_COMPRESSED;
-    case QCOW2_CLUSTER_ZERO_PLAIN:
-        return QCOW2_SUBCLUSTER_ZERO_PLAIN;
-    case QCOW2_CLUSTER_ZERO_ALLOC:
-        return QCOW2_SUBCLUSTER_ZERO_ALLOC;
-    case QCOW2_CLUSTER_NORMAL:
-        return QCOW2_SUBCLUSTER_NORMAL;
-    case QCOW2_CLUSTER_UNALLOCATED:
-        return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
-    default:
-        g_assert_not_reached();
-    }
-}
-
-/*
  * In an image without subsclusters @l2_bitmap is ignored and
  * @sc_index must be 0.
  * Return QCOW2_SUBCLUSTER_INVALID if an invalid l2 entry is detected
@@ -776,7 +753,20 @@ QCow2SubclusterType qcow2_get_subcluster_type(BlockDriverState *bs,
             g_assert_not_reached();
         }
     } else {
-        return qcow2_cluster_to_subcluster_type(type);
+        switch (type) {
+        case QCOW2_CLUSTER_COMPRESSED:
+            return QCOW2_SUBCLUSTER_COMPRESSED;
+        case QCOW2_CLUSTER_ZERO_PLAIN:
+            return QCOW2_SUBCLUSTER_ZERO_PLAIN;
+        case QCOW2_CLUSTER_ZERO_ALLOC:
+            return QCOW2_SUBCLUSTER_ZERO_ALLOC;
+        case QCOW2_CLUSTER_NORMAL:
+            return QCOW2_SUBCLUSTER_NORMAL;
+        case QCOW2_CLUSTER_UNALLOCATED:
+            return QCOW2_SUBCLUSTER_UNALLOCATED_PLAIN;
+        default:
+            g_assert_not_reached();
+        }
     }
 }