diff -r 5de62ca9a5aa -r d8fabd347a8e src/dbfs/op_base.h
--- a/src/dbfs/op_base.h	Thu Oct 16 22:04:53 2008 +0300
+++ b/src/dbfs/op_base.h	Thu Oct 16 22:56:29 2008 +0300
@@ -73,6 +73,8 @@
  * Lookup the op for the given fi, validate params, and assign the new req.
  *
  * In case the op failed previously, this will error the req and return NULL, indicating that the req has been handled.
+ *
+ * Repeat, if this returns NULL, consider req invalid.
  */
 struct dbfs_op *dbfs_op_req (struct fuse_req *req, fuse_ino_t ino, struct fuse_file_info *fi);