address PR comments

endpoints/v2/blob.py

@@ -343,9 +343,11 @@ def _upload_chunk(blob_upload, start_offset, length):
   """
   # Check for invalidate arguments.
   if None in {blob_upload, start_offset, length}:
+    logger.error('None provided as argument to _upload_chunk')
     return None
 
   if start_offset > 0 and start_offset > blob_upload.byte_count:
+    logger.error('start_offset provided to _upload_chunk greater than blob.upload.byte_count')
     return None
 
   location_set = {blob_upload.location_name}
@@ -391,19 +393,17 @@ def _upload_chunk(blob_upload, start_offset, length):
       size_info, fn = calculate_size_handler()
       input_fp = wrap_with_handler(input_fp, fn)
 
-    try:
-      length_written, new_metadata, error = storage.stream_upload_chunk(
-        location_set,
-        blob_upload.uuid,
-        start_offset,
-        length,
-        input_fp,
-        blob_upload.storage_metadata,
-        content_type=BLOB_CONTENT_TYPE,
-      )
-      if error is not None:
-        return None
-    except InvalidChunkException:
+    length_written, new_metadata, error = storage.stream_upload_chunk(
+      location_set,
+      blob_upload.uuid,
+      start_offset,
+      length,
+      input_fp,
+      blob_upload.storage_metadata,
+      content_type=BLOB_CONTENT_TYPE,
+    )
+    if error is not None:
+      logger.error('storage.stream_upload_chunk returned error %s', error)
       return None
 
   # If we determined an uncompressed size and this is the first chunk, add it to the blob.