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/pid.h>
   8 #include <linux/nsproxy.h>
   9 #include <linux/kref.h>
  10
  11 struct pidmap {
  12        atomic_t nr_free;
  13        void *page;
  14 };
  15
  16 #define PIDMAP_ENTRIES         ((PID_MAX_LIMIT + 8*PAGE_SIZE - 1)/PAGE_SIZE/8)
  17
  18 struct pid_namespace {
  19         struct kref kref;
  20         struct pidmap pidmap[PIDMAP_ENTRIES];
  21         int last_pid;
  22         struct task_struct *child_reaper;
  23 };
  24
  25 extern struct pid_namespace init_pid_ns;
  26
  27 static inline void get_pid_ns(struct pid_namespace *ns)
  28 {
  29         kref_get(&ns->kref);
  30 }
  31
  32 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
  33 extern void free_pid_ns(struct kref *kref);
  34
  35 static inline void put_pid_ns(struct pid_namespace *ns)
  36 {
  37         kref_put(&ns->kref, free_pid_ns);
  38 }
  39
  40 static inline struct task_struct *child_reaper(struct task_struct *tsk)
  41 {
  42         return init_pid_ns.child_reaper;
  43 }
  44
  45 #endif /* _LINUX_PID_NS_H */