documentation: expand comments to unionfs_lookup_backend

Signed-off-by: Erez Zadok <ezk@cs.sunysb.edu>

diff --git a/fs/unionfs/lookup.c b/fs/unionfs/lookup.c
index ffc00446ce62b8388c5e5c56125f1a343bbcc3f5..6409387ec81647f34ba63c85da25f7f72f5d344f 100644 (file)
--- a/fs/unionfs/lookup.c
+++ b/fs/unionfs/lookup.c
@@ -70,7 +70,12 @@ out:
        return err;
 }
 
-/* main (and complex) driver function for Unionfs's lookup */
+/*
+ * Main (and complex) driver function for Unionfs's lookup
+ *
+ * Returns: NULL (ok), ERR_PTR if an error occurred, or a non-null non-error
+ * PTR if d_splice returned a different dentry.
+ */
 struct dentry *unionfs_lookup_backend(struct dentry *dentry,
                                      struct nameidata *nd, int lookupmode)
 {