userns: Use cred->user_ns instead of cred->user->user_ns

Optimize performance and prepare for the removal of the user_ns reference
from user_struct.  Remove the slow long walk through cred->user->user_ns and
instead go straight to cred->user_ns.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

3 files changed, 3 insertions, 3 deletions

diff --git a/security/keys/key.c b/security/keys/key.c
index 06783cffb3af..7e6034793af3 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -253,7 +253,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
         quotalen = desclen + type->def_datalen;
 
         /* get hold of the key tracking for this user */
-        user = key_user_lookup(uid, cred->user->user_ns);
+        user = key_user_lookup(uid, cred->user_ns);
         if (!user)
                 goto no_memory_1;
 
diff --git a/security/keys/permission.c b/security/keys/permission.c
index c35b5229e3cd..e146cbd714bd 100644
--- a/security/keys/permission.c
+++ b/security/keys/permission.c
@@ -36,7 +36,7 @@ int key_task_permission(const key_ref_t key_ref, const struct cred *cred,
 
         key = key_ref_to_ptr(key_ref);
 
-        if (key->user->user_ns != cred->user->user_ns)
+        if (key->user->user_ns != cred->user_ns)
                 goto use_other_perms;
 
         /* use the second 8-bits of permissions for keys the caller owns */
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index be7ecb2018dd..70febff06da9 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -858,7 +858,7 @@ void key_replace_session_keyring(void)
         new-> sgid      = old-> sgid;
         new->fsgid      = old->fsgid;
         new->user       = get_uid(old->user);
-        new->user_ns    = new->user->user_ns;
+        new->user_ns    = new->user_ns;
         new->group_info = get_group_info(old->group_info);
 
         new->securebits = old->securebits;