util: storage: Allow specifying format for virStorageFileGetMetadataFromBuf

To allow reusing this function in the qemu driver we need to allow
specifying the storage format. Also separate return of the backing store
path now isn't necessary.

diff --git a/src/storage/storage_backend_gluster.c b/src/storage/storage_backend_gluster.c
index 1a2b4ec5a3d2142b777f3a8a7e54ce4a903e88e0..5ecc098c7aaded805fa5f7fe8e794fea33b4817d 100644 (file)
--- a/src/storage/storage_backend_gluster.c
+++ b/src/storage/storage_backend_gluster.c
@@ -294,10 +294,13 @@ virStorageBackendGlusterRefreshVol(virStorageBackendGlusterStatePtr state,
         goto cleanup;
 
     if (!(meta = virStorageFileGetMetadataFromBuf(name, header, len,
-                                                  &vol->backingStore.path,
+                                                  VIR_STORAGE_FILE_AUTO,
                                                   &vol->backingStore.format)))
         goto cleanup;
 
+    vol->backingStore.path = meta->backingStoreRaw;
+    meta->backingStoreRaw = NULL;
+
     vol->target.format = meta->format;
     if (vol->backingStore.path &&
         vol->backingStore.format < 0)

diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c
index 01d4a7eac998b418c57bfa169671549c5e5c0fcf..0b8715d04c44ec946f745290e86a0f9518ea95d9 100644 (file)
--- a/src/util/virstoragefile.c
+++ b/src/util/virstoragefile.c
@@ -930,19 +930,20 @@ virStorageFileMetadataNew(const char *path,
  * @path: name of file, for error messages
  * @buf: header bytes from @path
  * @len: length of @buf
- * @backing: output malloc'd name of backing image, if any
+ * @format: format of the storage file
  * @backingFormat: format of @backing
  *
- * Extract metadata about the storage volume, including probing its
- * format.  Does not recurse.  Callers are advised not to trust the
- * learned format if a guest has ever used the volume when it was
- * raw, since a malicious guest can turn a raw file into any
- * other non-raw format at will.
+ * Extract metadata about the storage volume with the specified image format.
+ * If image format is VIR_STORAGE_FILE_AUTO, it will probe to automatically
+ * identify the format.  Does not recurse.
+ *
+ * Callers are advised never to use VIR_STORAGE_FILE_AUTO as a format on a file
+ * that might be raw if that file will then be passed to a guest, since a
+ * malicious guest can turn a raw file into any other non-raw format at will.
  *
- * If the returned @backingFormat is VIR_STORAGE_FILE_AUTO
- * it indicates the image didn't specify an explicit format for its
- * backing store. Callers are advised against probing for the
- * backing store format in this case.
+ * If the returned @backingFormat is VIR_STORAGE_FILE_AUTO it indicates the
+ * image didn't specify an explicit format for its backing store. Callers are
+ * advised against probing for the backing store format in this case.
  *
  * Caller MUST free the result after use via virStorageSourceFree.
  */
@@ -950,25 +951,20 @@ virStorageSourcePtr
 virStorageFileGetMetadataFromBuf(const char *path,
                                  char *buf,
                                  size_t len,
-                                 char **backing,
+                                 int format,
                                  int *backingFormat)
 {
     virStorageSourcePtr ret = NULL;
-    virStorageSourcePtr meta = NULL;
 
-    if (!(meta = virStorageFileMetadataNew(path, VIR_STORAGE_FILE_AUTO)))
+    if (!(ret = virStorageFileMetadataNew(path, format)))
         return NULL;
 
-    if (virStorageFileGetMetadataInternal(meta, buf, len,
-                                          backingFormat) < 0)
-        goto cleanup;
-    if (VIR_STRDUP(*backing, meta->backingStoreRaw) < 0)
-        goto cleanup;
+    if (virStorageFileGetMetadataInternal(ret, buf, len,
+                                          backingFormat) < 0) {
+        virStorageSourceFree(ret);
+        return NULL;
+    }
 
-    ret = meta;
-    meta = NULL;
- cleanup:
-    virStorageSourceFree(meta);
     return ret;
 }
 

diff --git a/src/util/virstoragefile.h b/src/util/virstoragefile.h
index 4f7357b229e72963b8b4f751ca1f0cc2d83b458c..89ecc1e187c6b8e9d3d58823f2658127b0a900be 100644 (file)
--- a/src/util/virstoragefile.h
+++ b/src/util/virstoragefile.h
@@ -290,7 +290,7 @@ virStorageSourcePtr virStorageFileGetMetadataFromFD(const char *path,
 virStorageSourcePtr virStorageFileGetMetadataFromBuf(const char *path,
                                                      char *buf,
                                                      size_t len,
-                                                     char **backing,
+                                                     int format,
                                                      int *backingFormat)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(4)
     ATTRIBUTE_NONNULL(5);