util: qcow2GetExtensions: Remove support for 'data file' extension

The implementation was never finished in libvirt. Remove it.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/util/virstoragefile.c

@@ -199,7 +199,6 @@ qedGetBackingStore(char **, int *, const char *, size_t);
 
 #define QCOW2_HDR_EXTENSION_END 0
 #define QCOW2_HDR_EXTENSION_BACKING_FORMAT 0xE2792ACA
-#define QCOW2_HDR_EXTENSION_DATA_FILE 0x44415441
 
 #define QCOW2v3_HDR_FEATURES_INCOMPATIBLE (QCOW2_HDR_TOTAL_SIZE)
 #define QCOW2v3_HDR_FEATURES_COMPATIBLE (QCOW2v3_HDR_FEATURES_INCOMPATIBLE+8)
@@ -426,8 +425,7 @@ cowGetBackingStore(char **res,
 static int
 qcow2GetExtensions(const char *buf,
                    size_t buf_size,
-                   int *backingFormat,
-                   char **externalDataStoreRaw)
+                   int *backingFormat)
 {
     size_t offset;
     size_t extension_start;
@@ -517,19 +515,6 @@ qcow2GetExtensions(const char *buf,
             break;
         }
 
-        case QCOW2_HDR_EXTENSION_DATA_FILE: {
-            if (!externalDataStoreRaw)
-                break;
-
-            if (VIR_ALLOC_N(*externalDataStoreRaw, len + 1) < 0)
-                return -1;
-            memcpy(*externalDataStoreRaw, buf + offset, len);
-            (*externalDataStoreRaw)[len] = '\0';
-            VIR_DEBUG("parsed externalDataStoreRaw='%s'",
-                      *externalDataStoreRaw);
-            break;
-        }
-
         case QCOW2_HDR_EXTENSION_END:
             return 0;
         }
@@ -579,7 +564,7 @@ qcowXGetBackingStore(char **res,
     memcpy(*res, buf + offset, size);
     (*res)[size] = '\0';
 
-    if (qcow2GetExtensions(buf, buf_size, format, NULL) < 0)
+    if (qcow2GetExtensions(buf, buf_size, format) < 0)
         return BACKING_STORE_INVALID;
 
     return BACKING_STORE_OK;