commit c4a4d603796c727b9555867571f89483be9c565e
author Eric W. Biederman <ebiederm@xmission.com> Wed Nov 16 23:15:31 2011 -0800
committer Eric W. Biederman <ebiederm@xmission.com> Sat Apr 07 16:55:51 2012 -0700
tree ae3b47a7b8b35c866df53cb4b4a051d49a28904a
parent 7e6bd8fadd1216f50468f965d0308f45e5109ced

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>

kernel/ptrace.c

diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index ee8d49b..24e0a5a 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -198,7 +198,7 @@
 		return 0;
 	rcu_read_lock();
 	tcred = __task_cred(task);
-	if (cred->user->user_ns == tcred->user->user_ns &&
+	if (cred->user_ns == tcred->user_ns &&
 	    (cred->uid == tcred->euid &&
 	     cred->uid == tcred->suid &&
 	     cred->uid == tcred->uid  &&
@@ -206,7 +206,7 @@
 	     cred->gid == tcred->sgid &&
 	     cred->gid == tcred->gid))
 		goto ok;
-	if (ptrace_has_cap(tcred->user->user_ns, mode))
+	if (ptrace_has_cap(tcred->user_ns, mode))
 		goto ok;
 	rcu_read_unlock();
 	return -EPERM;

kernel/sched/core.c

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 4603b9d..96bff85 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4042,7 +4042,7 @@
 
 	rcu_read_lock();
 	pcred = __task_cred(p);
-	if (cred->user->user_ns == pcred->user->user_ns)
+	if (cred->user_ns == pcred->user_ns)
 		match = (cred->euid == pcred->euid ||
 			 cred->euid == pcred->uid);
 	else

kernel/signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index 17afcaf..e2c5d84 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -767,14 +767,14 @@
 	const struct cred *cred = current_cred();
 	const struct cred *tcred = __task_cred(t);
 
-	if (cred->user->user_ns == tcred->user->user_ns &&
+	if (cred->user_ns == tcred->user_ns &&
 	    (cred->euid == tcred->suid ||
 	     cred->euid == tcred->uid ||
 	     cred->uid  == tcred->suid ||
 	     cred->uid  == tcred->uid))
 		return 1;
 
-	if (ns_capable(tcred->user->user_ns, CAP_KILL))
+	if (ns_capable(tcred->user_ns, CAP_KILL))
 		return 1;
 
 	return 0;

kernel/sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index f7a4351..82d8714 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -133,11 +133,11 @@
 {
 	const struct cred *cred = current_cred(), *pcred = __task_cred(p);
 
-	if (pcred->user->user_ns == cred->user->user_ns &&
+	if (pcred->user_ns == cred->user_ns &&
 	    (pcred->uid  == cred->euid ||
 	     pcred->euid == cred->euid))
 		return true;
-	if (ns_capable(pcred->user->user_ns, CAP_SYS_NICE))
+	if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
 		return true;
 	return false;
 }
@@ -1498,7 +1498,7 @@
 		return 0;
 
 	tcred = __task_cred(task);
-	if (cred->user->user_ns == tcred->user->user_ns &&
+	if (cred->user_ns == tcred->user_ns &&
 	    (cred->uid == tcred->euid &&
 	     cred->uid == tcred->suid &&
 	     cred->uid == tcred->uid  &&
@@ -1506,7 +1506,7 @@
 	     cred->gid == tcred->sgid &&
 	     cred->gid == tcred->gid))
 		return 0;
-	if (ns_capable(tcred->user->user_ns, CAP_SYS_RESOURCE))
+	if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
 		return 0;
 
 	return -EPERM;

kernel/user_namespace.c

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 3b906e9..f084083 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -90,7 +90,7 @@
 {
 	struct user_namespace *tmp;
 
-	if (likely(to == cred->user->user_ns))
+	if (likely(to == cred->user_ns))
 		return uid;
 
 
@@ -112,7 +112,7 @@
 {
 	struct user_namespace *tmp;
 
-	if (likely(to == cred->user->user_ns))
+	if (likely(to == cred->user_ns))
 		return gid;
 
 	/* Is cred->user the creator of the target user_ns

kernel/utsname.c

diff --git a/kernel/utsname.c b/kernel/utsname.c
index 405caf9..679d97a 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -43,7 +43,7 @@
 
 	down_read(&uts_sem);
 	memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
-	ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns);
+	ns->user_ns = get_user_ns(task_cred_xxx(tsk, user_ns));
 	up_read(&uts_sem);
 	return ns;
 }