kernel-ark/include/linux/namespace.h
Ram Pai 390c684367 [PATCH] making namespace_sem global
This removes the per-namespace semaphore in favor of a global semaphore.
This can have an effect on namespace scalability.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-11-07 18:18:10 -08:00

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C

#ifndef _NAMESPACE_H_
#define _NAMESPACE_H_
#ifdef __KERNEL__
#include <linux/mount.h>
#include <linux/sched.h>
struct namespace {
atomic_t count;
struct vfsmount * root;
struct list_head list;
wait_queue_head_t poll;
int event;
};
extern int copy_namespace(int, struct task_struct *);
extern void __put_namespace(struct namespace *namespace);
static inline void put_namespace(struct namespace *namespace)
{
if (atomic_dec_and_lock(&namespace->count, &vfsmount_lock))
/* releases vfsmount_lock */
__put_namespace(namespace);
}
static inline void exit_namespace(struct task_struct *p)
{
struct namespace *namespace = p->namespace;
if (namespace) {
task_lock(p);
p->namespace = NULL;
task_unlock(p);
put_namespace(namespace);
}
}
static inline void get_namespace(struct namespace *namespace)
{
atomic_inc(&namespace->count);
}
#endif
#endif