uts namespace : remove CONFIG_UTS_NS

CONFIG_UTS_NS has very little value as it only deactivates the unshare of the uts namespace and does not improve performance.

Signed-off-by Cedric Le Goater <[email protected]>

---
 include/linux/utsname.h |   19 -------------------
 init/Kconfig            |    8 --------
 kernel/Makefile         |    3 +--
 kernel/sysctl.c         |    3 +--
 4 files changed, 2 insertions(+), 31 deletions(-)

Index: 2.6.20-rc4-mm1/include/linux/utsname.h
===================================================================

include/linux/utsname.h +0 -19

@@ -48,7 +48,6 @@ static inline void get_uts_ns(struct uts
 	kref_get(&ns->kref);
 }
 
-#ifdef CONFIG_UTS_NS
 extern int unshare_utsname(unsigned long unshare_flags,
 				struct uts_namespace **new_uts);
 extern int copy_utsname(int flags, struct task_struct *tsk);

@@ -58,24 +57,6 @@ static inline void put_uts_ns(struct uts
 {
 	kref_put(&ns->kref, free_uts_ns);
 }
-#else
-static inline int unshare_utsname(unsigned long unshare_flags,
-			struct uts_namespace **new_uts)
-{
-	if (unshare_flags & CLONE_NEWUTS)
-		return -EINVAL;
-
-	return 0;
-}
-
-static inline int copy_utsname(int flags, struct task_struct *tsk)
-{
-	return 0;
-}
-static inline void put_uts_ns(struct uts_namespace *ns)
-{
-}
-#endif
 
 static inline struct new_utsname *utsname(void)
 {

Index: 2.6.20-rc4-mm1/init/Kconfig
===================================================================

init/Kconfig +0 -8

@@ -205,14 +205,6 @@ config TASK_DELAY_ACCT
 
 	  Say N if unsure.
 
-config UTS_NS
-	bool "UTS Namespaces"
-	default n
-	help
-	  Support uts namespaces.  This allows containers, i.e.
-	  vservers, to use uts namespaces to provide different
-	  uts info for different servers.  If unsure, say N.
-
 config AUDIT
 	bool "Auditing support"
 	depends on NET

Index: 2.6.20-rc4-mm1/kernel/Makefile
===================================================================

kernel/Makefile +1 -2

@@ -8,7 +8,7 @@ obj-y     = sched.o fork.o exec_domain.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 \
-	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o
+	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o utsname.o
 
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-y += time/

@@ -48,7 +48,6 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
 obj-$(CONFIG_RELAY) += relay.o
-obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
 

Index: 2.6.20-rc4-mm1/kernel/sysctl.c
===================================================================

kernel/sysctl.c +1 -2

@@ -187,10 +187,9 @@ int sysctl_legacy_va_layout;
 static void *get_uts(ctl_table *table, int write)
 {
 	char *which = table->data;
-#ifdef CONFIG_UTS_NS
 	struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
 	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
-#endif
+
 	if (!write)
 		down_read(&uts_sem);
 	else

Quoted 4 lines · Cedric Le Goater

CONFIG_UTS_NS has very little value as it only deactivates the unshare of the uts namespace and does not improve performance.

Signed-off-by Cedric Le Goater <[email protected]>

It really is worthless complication, with the sole effect being to complicate testing...

Acked-by Serge Hallyn <[email protected]>

Quoted 90 lines

---
 include/linux/utsname.h |   19 -------------------
 init/Kconfig            |    8 --------
 kernel/Makefile         |    3 +--
 kernel/sysctl.c         |    3 +--
 4 files changed, 2 insertions(+), 31 deletions(-)

Index: 2.6.20-rc4-mm1/include/linux/utsname.h
===================================================================

include/linux/utsname.h +0 -19

@@ -48,7 +48,6 @@ static inline void get_uts_ns(struct uts
 	kref_get(&ns->kref);
 }
 
-#ifdef CONFIG_UTS_NS
 extern int unshare_utsname(unsigned long unshare_flags,
 				struct uts_namespace **new_uts);
 extern int copy_utsname(int flags, struct task_struct *tsk);

@@ -58,24 +57,6 @@ static inline void put_uts_ns(struct uts
 {
 	kref_put(&ns->kref, free_uts_ns);
 }
-#else
-static inline int unshare_utsname(unsigned long unshare_flags,
-			struct uts_namespace **new_uts)
-{
-	if (unshare_flags & CLONE_NEWUTS)
-		return -EINVAL;
-
-	return 0;
-}
-
-static inline int copy_utsname(int flags, struct task_struct *tsk)
-{
-	return 0;
-}
-static inline void put_uts_ns(struct uts_namespace *ns)
-{
-}
-#endif
 
 static inline struct new_utsname *utsname(void)
 {

Index: 2.6.20-rc4-mm1/init/Kconfig
===================================================================

init/Kconfig +0 -8

@@ -205,14 +205,6 @@ config TASK_DELAY_ACCT
 
 	  Say N if unsure.
 
-config UTS_NS
-	bool "UTS Namespaces"
-	default n
-	help
-	  Support uts namespaces.  This allows containers, i.e.
-	  vservers, to use uts namespaces to provide different
-	  uts info for different servers.  If unsure, say N.
-
 config AUDIT
 	bool "Auditing support"
 	depends on NET

Index: 2.6.20-rc4-mm1/kernel/Makefile
===================================================================

kernel/Makefile +1 -2

@@ -8,7 +8,7 @@ obj-y     = sched.o fork.o exec_domain.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 \
-	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o
+	    hrtimer.o rwsem.o latency.o nsproxy.o srcu.o utsname.o
 
 obj-$(CONFIG_STACKTRACE) += stacktrace.o
 obj-y += time/

@@ -48,7 +48,6 @@ obj-$(CONFIG_SECCOMP) += seccomp.o
 obj-$(CONFIG_RCU_TORTURE_TEST) += rcutorture.o
 obj-$(CONFIG_DEBUG_SYNCHRO_TEST) += synchro-test.o
 obj-$(CONFIG_RELAY) += relay.o
-obj-$(CONFIG_UTS_NS) += utsname.o
 obj-$(CONFIG_TASK_DELAY_ACCT) += delayacct.o
 obj-$(CONFIG_TASKSTATS) += taskstats.o tsacct.o
 

Index: 2.6.20-rc4-mm1/kernel/sysctl.c
===================================================================

kernel/sysctl.c +0 -0

@@ -187,10 +187,9 @@ int sysctl_legacy_va_layout;
 static void *get_uts(ctl_table *table, int write)

kernel/sysctl.c int sysctl_legacy_va_layout; · line 195

Quoted 10 lines

kernel/sysctl.c +1 -2

 {
 	char *which = table->data;
-#ifdef CONFIG_UTS_NS
 	struct uts_namespace *uts_ns = current->nsproxy->uts_ns;
 	which = (which - (char *)&init_uts_ns) + (char *)uts_ns;
-#endif
+
 	if (!write)
 		down_read(&uts_sem);
 	else

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