include/linux/pid_namespace.h

   1 #ifndef _LINUX_PID_NS_H
   2 #define _LINUX_PID_NS_H
   3
   4 #include <linux/sched.h>
   5 #include <linux/mm.h>
   6 #include <linux/threads.h>
   7 #include <linux/nsproxy.h>
   8 #include <linux/kref.h>
   9
  10 struct pidmap {
  11        atomic_t nr_free;
  12        void *page;
  13 };
  14
  15 #define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
  16
  17 struct pid_namespace {
  18         struct kref kref;
  19         struct pidmap pidmap[PIDMAP_ENTRIES];
  20         int last_pid;
  21         struct task_struct *child_reaper;
  22         struct kmem_cache *pid_cachep;
  23         int level;
  24         struct pid_namespace *parent;
  25 #ifdef CONFIG_PROC_FS
  26         struct vfsmount *proc_mnt;
  27 #endif
  28 };
  29
  30 extern struct pid_namespace init_pid_ns;
  31
  32 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  33 {
  34         if (ns != &init_pid_ns)
  35                 kref_get(&ns->kref);
  36         return ns;
  37 }
  38
  39 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
  40 extern void free_pid_ns(struct kref *kref);
  41
  42 static inline void put_pid_ns(struct pid_namespace *ns)
  43 {
  44         if (ns != &init_pid_ns)
  45                 kref_put(&ns->kref, free_pid_ns);
  46 }
  47
  48 static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
  49 {
  50         return tsk->nsproxy->pid_ns;
  51 }
  52
  53 static inline struct task_struct *task_child_reaper(struct task_struct *tsk)
  54 {
  55         BUG_ON(tsk != current);
  56         return tsk->nsproxy->pid_ns->child_reaper;
  57 }
  58
  59 #endif /* _LINUX_PID_NS_H */