[PATCH 1/3] uidns: improve name of tsk_mnt_same_uid

[Serge E. Hallyn]

From: Serge E. Hallyn <serue at us.ibm.com>
Subject: [PATCH 1/3] uidns: improve name of tsk_mnt_same_uid

The helper compares uidns, not uid, so change the name to
tsk_mnt_same_uidns.

Also comment the behavior above the helper.

Signed-off-by: Serge E. Hallyn <serue at us.ibm.com>
---
 fs/namei.c            |    4 ++--
 include/linux/sched.h |    9 ++++++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index ab59efe..6c207f1 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -246,7 +246,7 @@ int permission(struct inode *inode, int 
 			return -EACCES;
 	}
 
-	if (nd && !task_mnt_same_uid(current, nd->mnt))
+	if (nd && !task_mnt_same_uidns(current, nd->mnt))
 		return -EACCES;
 
 	/*
@@ -435,7 +435,7 @@ static int exec_permission_lite(struct i
 {
 	umode_t	mode = inode->i_mode;
 
-	if (!task_mnt_same_uid(current, nd->mnt))
+	if (!task_mnt_same_uidns(current, nd->mnt))
 		return -EACCES;
 	if (inode->i_op && inode->i_op->permission)
 		return -EAGAIN;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index cd31763..a4b5c77 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1591,7 +1591,14 @@ extern int cond_resched(void);
 extern int cond_resched_lock(spinlock_t * lock);
 extern int cond_resched_softirq(void);
 
-static inline int task_mnt_same_uid(struct task_struct *tsk,
+/*
+ * Check whether a task and a vfsmnt belong to the same uidns.
+ * Since the initial namespace is exempt from these checks,
+ * return 1 if so.  Also return 1 if the vfsmnt is exempt from
+ * such checking.  Otherwise, if the uid namespaces are different,
+ * return 0.
+ */ 
+static inline int task_mnt_same_uidns(struct task_struct *tsk,
 					struct vfsmount *mnt)
 {
 	if (tsk->nsproxy == init_task.nsproxy)
-- 
1.4.1