1 files changed, 18 insertions, 1 deletions

diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index b0122dc6f96a..ca1be5c9136c 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -50,7 +50,24 @@ enum kernfs_node_flag {
 
 /* @flags for kernfs_create_root() */
 enum kernfs_root_flag {
-        KERNFS_ROOT_CREATE_DEACTIVATED = 0x0001,
+        /*
+         * kernfs_nodes are created in the deactivated state and invisible.
+         * They require explicit kernfs_activate() to become visible.  This
+         * can be used to make related nodes become visible atomically
+         * after all nodes are created successfully.
+         */
+        KERNFS_ROOT_CREATE_DEACTIVATED          = 0x0001,
+
+        /*
+         * For regular flies, if the opener has CAP_DAC_OVERRIDE, open(2)
+         * succeeds regardless of the RW permissions.  sysfs had an extra
+         * layer of enforcement where open(2) fails with -EACCES regardless
+         * of CAP_DAC_OVERRIDE if the permission doesn't have the
+         * respective read or write access at all (none of S_IRUGO or
+         * S_IWUGO) or the respective operation isn't implemented.  The
+         * following flag enables that behavior.
+         */
+        KERNFS_ROOT_EXTRA_OPEN_PERM_CHECK       = 0x0002,
 };
 
 /* type-specific structures for kernfs_node union members */