[PATCH 10/43] userns: Deprecate and rename the user_namespace reference in the user_struct

"Eric W. Beiderman
2012-04-08T05:21:56Z

From: Eric W. Biederman <ebiederm@xmission.com>

With a user_ns reference in struct cred the only user of the user namespace
reference in struct user_struct is to keep the uid hash table alive.

The user_namespace reference in struct user_struct will be going away soon, and
I have removed all of the references. Rename the field from user_ns to _user_ns
so that the compiler can verify nothing follows the user struct to the user
namespace anymore.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
include/linux/sched.h | 2 +-
kernel/user.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 720ce8d..6867ae9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -729,7 +729,7 @@ struct user_struct {
/* Hash table maintenance information */
struct hlist_node uidhash_node;
uid_t uid;
- struct user_namespace *user_ns;
+ struct user_namespace *_user_ns; /* Don't use will be removed soon */

#ifdef CONFIG_PERF_EVENTS
atomic_long_t locked_vm;
diff --git a/kernel/user.c b/kernel/user.c
index 71dd236..d65fec0 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -58,7 +58,7 @@ struct user_struct root_user = {
.files = ATOMIC_INIT(0),
.sigpending = ATOMIC_INIT(0),
.locked_shm = 0,
- .user_ns = &init_user_ns,
+ ._user_ns = &init_user_ns,
};

/*
@@ -72,7 +72,7 @@ static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent)
static void uid_hash_remove(struct user_struct *up)
{
hlist_del_init(&up->uidhash_node);
- put_user_ns(up->user_ns);
+ put_user_ns(up->_user_ns); /* It is safe to free the uid hash table now */
}

static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
@@ -153,7 +153,7 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
new->uid = uid;
atomic_set(&new->__count, 1);

- new->user_ns = get_user_ns(ns);
+ new->_user_ns = get_user_ns(ns);

/*
* Before adding this, check whether we raced
--
1.7.2.5