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         struct kmem_cache *pid_cachep;
  24         int level;
  25         struct pid_namespace *parent;
  26 };
  27
  28 extern struct pid_namespace init_pid_ns;
  29
  30 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
  31 {
  32         kref_get(&ns->kref);
  33         return ns;
  34 }
  35
  36 extern struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *ns);
  37 extern void free_pid_ns(struct kref *kref);
  38
  39 static inline void put_pid_ns(struct pid_namespace *ns)
  40 {
  41         kref_put(&ns->kref, free_pid_ns);
  42 }
  43
  44 static inline struct pid_namespace *task_active_pid_ns(struct task_struct *tsk)
  45 {
  46         return tsk->nsproxy->pid_ns;
  47 }
  48
  49 static inline struct task_struct *task_child_reaper(struct task_struct *tsk)
  50 {
  51         return init_pid_ns.child_reaper;
  52 }
  53
  54 #endif /* _LINUX_PID_NS_H */