390c684367
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>
44 lines
869 B
C
44 lines
869 B
C
#ifndef _NAMESPACE_H_
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#define _NAMESPACE_H_
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#ifdef __KERNEL__
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#include <linux/mount.h>
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#include <linux/sched.h>
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struct namespace {
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atomic_t count;
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struct vfsmount * root;
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struct list_head list;
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wait_queue_head_t poll;
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int event;
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};
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extern int copy_namespace(int, struct task_struct *);
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extern void __put_namespace(struct namespace *namespace);
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static inline void put_namespace(struct namespace *namespace)
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{
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if (atomic_dec_and_lock(&namespace->count, &vfsmount_lock))
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/* releases vfsmount_lock */
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__put_namespace(namespace);
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}
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static inline void exit_namespace(struct task_struct *p)
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{
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struct namespace *namespace = p->namespace;
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if (namespace) {
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task_lock(p);
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p->namespace = NULL;
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task_unlock(p);
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put_namespace(namespace);
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}
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}
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static inline void get_namespace(struct namespace *namespace)
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{
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atomic_inc(&namespace->count);
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}
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#endif
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#endif
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