lookup_open(): lock the parent shared unless O_CREAT is given
Signed-off-by: Al Viro <[email protected]>
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 12c57abd..46f3bb7 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -575,3 +575,6 @@
Old method is only used if the new one is absent; eventually it will
be removed. Switch while you still can; the old one won't stay.
+--
+[mandatory]
+ ->atomic_open() calls without O_CREAT may happen in parallel.
