kernfs: introduce kernfs_node_id

inode number and generation can identify a kernfs node. We are going to
export the identification by exportfs operations, so put ino and
generation into a separate structure. It's convenient when later patches
use the identification.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index 8c00d28f468a..06a0c5913e1d 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -95,6 +95,15 @@ struct kernfs_elem_attr {
         struct kernfs_node      *notify_next;   /* for kernfs_notify() */
 };
 
+/* represent a kernfs node */
+union kernfs_node_id {
+        struct {
+                u32             ino;
+                u32             generation;
+        };
+        u64                     id;
+};
+
 /*
  * kernfs_node - the building block of kernfs hierarchy.  Each and every
  * kernfs node is represented by single kernfs_node.  Most fields are
@@ -131,11 +140,10 @@ struct kernfs_node {
 
         void                    *priv;
 
+        union kernfs_node_id    id;
         unsigned short          flags;
         umode_t                 mode;
-        unsigned int            ino;
         struct kernfs_iattrs    *iattr;
-        u32                     generation;
 };
 
 /*