namespaces: cleanup the code managed with the USER_NS option

Make the user_namespace.o compilation depend on this option and move the
init_user_ns into user.c file to make the kernel compile and work without the
namespaces support.  This make the user namespace code be organized similar to
other namespaces'.

Also mask the USER_NS option as "depend on NAMESPACES".

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/init/Kconfig b/init/Kconfig
index 47879a874966bc8e29e916b976c1e5b37bb8e367..2a6499d6f28306ff28146c47fb5cf46ee54a1cf1 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -214,15 +214,6 @@ config TASK_IO_ACCOUNTING
 
          Say N if unsure.
 
-config USER_NS
-       bool "User Namespaces (EXPERIMENTAL)"
-       default n
-       depends on EXPERIMENTAL
-       help
-         Support user namespaces.  This allows containers, i.e.
-         vservers, to use user namespaces to provide different
-         user info for different servers.  If unsure, say N.
-
 config PID_NS
        bool "PID Namespaces (EXPERIMENTAL)"
        default n
@@ -443,6 +434,14 @@ config IPC_NS
          In this namespace tasks work with IPC ids which correspond to
          different IPC objects in different namespaces
 
+config USER_NS
+       bool "User namespace (EXPERIMENTAL)"
+       depends on NAMESPACES && EXPERIMENTAL
+       help
+         This allows containers, i.e. vservers, to use user namespaces
+         to provide different user info for different servers.
+         If unsure, say N.
+
 config BLK_DEV_INITRD
        bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
        depends on BROKEN || !FRV

diff --git a/kernel/Makefile b/kernel/Makefile
index 0f15bd409367ba1adf91bf3ead50b354970cfb34..30a957a35c911fd3a5bf58c5631ff0b1f1eb2527 100644 (file)
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -4,7 +4,7 @@
 
 obj-y     = sched.o fork.o exec_domain.o panic.o printk.o profile.o \
            exit.o itimer.o time.o softirq.o resource.o \
-           sysctl.o capability.o ptrace.o timer.o user.o user_namespace.o \
+           sysctl.o capability.o ptrace.o timer.o user.o \
            signal.o sys.o kmod.o workqueue.o pid.o \
            rcupdate.o extable.o params.o posix-timers.o \
            kthread.o wait.o kfifo.o sys_ni.o posix-cpu-timers.o mutex.o \
@@ -33,7 +33,6 @@ obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
 obj-$(CONFIG_UID16) += uid16.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
-obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_PM) += power/
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_KEXEC) += kexec.o
@@ -43,6 +42,8 @@ obj-$(CONFIG_CGROUPS) += cgroup.o
 obj-$(CONFIG_CGROUP_DEBUG) += cgroup_debug.o
 obj-$(CONFIG_CPUSETS) += cpuset.o
 obj-$(CONFIG_CGROUP_NS) += ns_cgroup.o
+obj-$(CONFIG_UTS_NS) += utsname.o
+obj-$(CONFIG_USER_NS) += user_namespace.o
 obj-$(CONFIG_IKCONFIG) += configs.o
 obj-$(CONFIG_RESOURCE_COUNTERS) += res_counter.o
 obj-$(CONFIG_STOP_MACHINE) += stop_machine.o

diff --git a/kernel/user.c b/kernel/user.c
index bc1c48d35cb32726623b37b47a09d4325aaf4074..7d7900c5a1fd29262028470af3e45deb71682db9 100644 (file)
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -17,6 +17,14 @@
 #include <linux/module.h>
 #include <linux/user_namespace.h>
 
+struct user_namespace init_user_ns = {
+       .kref = {
+               .refcount       = ATOMIC_INIT(2),
+       },
+       .root_user = &root_user,
+};
+EXPORT_SYMBOL_GPL(init_user_ns);
+
 /*
  * UID task count cache, to get fast user lookup in "alloc_uid"
  * when changing user ID's (ie setuid() and friends).
@@ -427,6 +435,7 @@ void switch_uid(struct user_struct *new_user)
        suid_keys(current);
 }
 
+#ifdef CONFIG_USER_NS
 void release_uids(struct user_namespace *ns)
 {
        int i;
@@ -451,6 +460,7 @@ void release_uids(struct user_namespace *ns)
 
        free_uid(ns->root_user);
 }
+#endif
 
 static int __init uid_cache_init(void)
 {

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 7af90fc4f0fd3d870c1f5dbb3b0771fc16bbc5a4..4c9006275df7fef80ae61944d39cdeea78246bb0 100644 (file)
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -10,17 +10,6 @@
 #include <linux/nsproxy.h>
 #include <linux/user_namespace.h>
 
-struct user_namespace init_user_ns = {
-       .kref = {
-               .refcount       = ATOMIC_INIT(2),
-       },
-       .root_user = &root_user,
-};
-
-EXPORT_SYMBOL_GPL(init_user_ns);
-
-#ifdef CONFIG_USER_NS
-
 /*
  * Clone a new ns copying an original user ns, setting refcount to 1
  * @old_ns: namespace to clone
@@ -84,5 +73,3 @@ void free_user_ns(struct kref *kref)
        release_uids(ns);
        kfree(ns);
 }
-
-#endif /* CONFIG_USER_NS */