util: storage: Move checking of the actual backing image to the worker

Move the code checking the presence of the backing file to the recursive
worker function instead of the metadata parser. The recursive worker
will later be changed to parse more than just local files and this
change will help the separation.

src/util/virstoragefile.c

@@ -803,8 +803,7 @@ virStorageFileGetMetadataInternal(const char *path,
                                   size_t len,
                                   int format,
                                   virStorageFileMetadataPtr meta,
-                                  int *backingFormat,
-                                  char **backingDirectory)
+                                  int *backingFormat)
 {
     int ret = -1;
 
@@ -871,31 +870,6 @@ virStorageFileGetMetadataInternal(const char *path,
 
         if (store == BACKING_STORE_ERROR)
             goto cleanup;
-
-        if (meta->backingStoreRaw) {
-            if (virStorageIsFile(meta->backingStoreRaw)) {
-                if (virFindBackingFile(directory,
-                                       meta->backingStoreRaw,
-                                       backingDirectory,
-                                       &meta->backingStore) < 0) {
-                    /* the backing file is (currently) unavailable, treat this
-                     * file as standalone:
-                     * backingStoreRaw is kept to mark broken image chains */
-                    *backingFormat = VIR_STORAGE_FILE_NONE;
-                    VIR_WARN("Backing file '%s' of image '%s' is missing.",
-                             meta->backingStoreRaw, path);
-
-                }
-            } else {
-                if (VIR_STRDUP(meta->backingStore, meta->backingStoreRaw) < 0)
-                    goto cleanup;
-
-                *backingFormat = VIR_STORAGE_FILE_RAW;
-            }
-        } else {
-            meta->backingStore = NULL;
-            *backingFormat = VIR_STORAGE_FILE_NONE;
-        }
     }
 
     if (fileTypeInfo[format].getFeatures != NULL &&
@@ -1016,7 +990,7 @@ virStorageFileGetMetadataFromBuf(const char *path,
 
     if (virStorageFileGetMetadataInternal(path, canonPath, ".", buf, len,
                                           format, ret,
-                                          backingFormat, NULL) < 0) {
+                                          backingFormat) < 0) {
         virStorageFileFreeMetadata(ret);
         ret = NULL;
     }
@@ -1040,8 +1014,7 @@ virStorageFileGetMetadataFromFDInternal(const char *path,
                                         int fd,
                                         int format,
                                         virStorageFileMetadataPtr meta,
-                                        int *backingFormat,
-                                        char **backingDirectory)
+                                        int *backingFormat)
 {
     char *buf = NULL;
     ssize_t len = VIR_STORAGE_MAX_HEADER;
@@ -1083,7 +1056,7 @@ virStorageFileGetMetadataFromFDInternal(const char *path,
 
     ret = virStorageFileGetMetadataInternal(path, canonPath, directory,
                                             buf, len, format, meta,
-                                            backingFormat, backingDirectory);
+                                            backingFormat);
 
     if (ret == 0) {
         if (S_ISREG(sb.st_mode))
@@ -1126,7 +1099,7 @@ virStorageFileGetMetadataFromFD(const char *path,
         goto cleanup;
     if (virStorageFileGetMetadataFromFDInternal(path, canonPath, ".",
                                                 fd, format, ret,
-                                                NULL, NULL) < 0) {
+                                                NULL) < 0) {
         virStorageFileFreeMetadata(ret);
         ret = NULL;
     }
@@ -1172,8 +1145,7 @@ virStorageFileGetMetadataRecurse(const char *path, const char *canonPath,
         ret = virStorageFileGetMetadataFromFDInternal(path, canonPath,
                                                       directory,
                                                       fd, format, meta,
-                                                      &backingFormat,
-                                                      &backingDirectory);
+                                                      &backingFormat);
 
         if (VIR_CLOSE(fd) < 0)
             VIR_WARN("could not close file %s", path);
@@ -1190,9 +1162,27 @@ virStorageFileGetMetadataRecurse(const char *path, const char *canonPath,
         ret = 0;
     }
 
-    if (ret == 0 && meta->backingStore) {
+    if (ret == 0 && meta->backingStoreRaw) {
         virStorageFileMetadataPtr backing;
 
+        if (virStorageIsFile(meta->backingStoreRaw)) {
+            if (virFindBackingFile(directory,
+                                   meta->backingStoreRaw,
+                                   &backingDirectory,
+                                   &meta->backingStore) < 0) {
+                /* the backing file is (currently) unavailable, treat this
+                 * file as standalone:
+                 * backingStoreRaw is kept to mark broken image chains */
+                VIR_WARN("Backing file '%s' of image '%s' is missing.",
+                         meta->backingStoreRaw, path);
+
+                return 0;
+            }
+        } else {
+            if (VIR_STRDUP(meta->backingStore, meta->backingStoreRaw) < 0)
+                return -1;
+        }
+
         if (backingFormat == VIR_STORAGE_FILE_AUTO && !allow_probe)
             backingFormat = VIR_STORAGE_FILE_RAW;
         else if (backingFormat == VIR_STORAGE_FILE_AUTO_SAFE)