From 59617f6fe70b3040b7633db22bf1d63361d072cb Mon Sep 17 00:00:00 2001
From: David Howells <dhowells@redhat.com>
Date: Mon, 25 Jun 2012 12:55:28 +0100
Subject: [PATCH] --- yaml --- r: 312939 b: refs/heads/master c:
 f015f1267b23d3530d3f874243fb83cb5f443005 h: refs/heads/master i:   312937:
 3154bc2a3a84c7e0e19e670044279d6cfe04359e   312935:
 399df603db5fe7dd5c408ec7b492b6792a3c63a3 v: v3

---
 [refs]               |  2 +-
 trunk/fs/namei.c     | 10 ++++++++++
 trunk/fs/namespace.c | 16 ++++++++++++++--
 3 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 163281cd36a2..b3ef95e67e5a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: be34d1a3bc4b6f357a49acb55ae870c81337e4f0
+refs/heads/master: f015f1267b23d3530d3f874243fb83cb5f443005
diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
index 0e1b9c3eb36d..c6dcb4c8f86c 100644
--- a/trunk/fs/namei.c
+++ b/trunk/fs/namei.c
@@ -672,6 +672,16 @@ static int follow_up_rcu(struct path *path)
 	return 1;
 }
 
+/*
+ * follow_up - Find the mountpoint of path's vfsmount
+ *
+ * Given a path, find the mountpoint of its source file system.
+ * Replace @path with the path of the mountpoint in the parent mount.
+ * Up is towards /.
+ *
+ * Return 1 if we went up a level and 0 if we were already at the
+ * root.
+ */
 int follow_up(struct path *path)
 {
 	struct mount *mnt = real_mount(path->mnt);
diff --git a/trunk/fs/namespace.c b/trunk/fs/namespace.c
index be1b07a774f1..c53d3381b0d0 100644
--- a/trunk/fs/namespace.c
+++ b/trunk/fs/namespace.c
@@ -515,8 +515,20 @@ struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry,
 }
 
 /*
- * lookup_mnt increments the ref count before returning
- * the vfsmount struct.
+ * lookup_mnt - Return the first child mount mounted at path
+ *
+ * "First" means first mounted chronologically.  If you create the
+ * following mounts:
+ *
+ * mount /dev/sda1 /mnt
+ * mount /dev/sda2 /mnt
+ * mount /dev/sda3 /mnt
+ *
+ * Then lookup_mnt() on the base /mnt dentry in the root mount will
+ * return successively the root dentry and vfsmount of /dev/sda1, then
+ * /dev/sda2, then /dev/sda3, then NULL.
+ *
+ * lookup_mnt takes a reference to the found vfsmount.
  */
 struct vfsmount *lookup_mnt(struct path *path)
 {