pid到task_struct的对应

pid_t <–> struct pid *

#include 

pid_t pid_vnr(struct pid *pid)
{
    return pid_nr_ns(pid, current->nsproxy->pid_ns);
}
EXPORT_SYMBOL_GPL(pid_vnr);

struct pid *find_pid_ns(int nr, struct pid_namespace *ns);
EXPORT_SYMBOL_GPL(find_pid_ns);

struct pid *find_vpid(int nr)
{
    return find_pid_ns(nr, current->nsproxy->pid_ns);
}
EXPORT_SYMBOL_GPL(find_vpid);

struct pid *find_get_pid(int nr)
{
    struct pid *pid;

    rcu_read_lock();
    pid = get_pid(find_vpid(nr));
    rcu_read_unlock();

    return pid;
}
EXPORT_SYMBOL_GPL(find_get_pid);

void put_pid(struct pid *pid);
EXPORT_SYMBOL_GPL(put_pid);

struct pid * –> struct task_struct *

#include 

struct pid *get_task_pid(sturct task_struct *task, enum pid_type);
EXPORT_SYMBOL_GPL(get_task_pid);

struct task_struct *pid_task(struct pid *pid, enum pid_type);
EXPORT_SYMBOL(pid_task);

struct task_struct *get_pid_task(struct pid *pid, enum pid_type)
{
    struct task_struct *result;
    rcu_read_lock();
    result = pid_task(pid, type);
    if (result)
        get_task_struct(result);
    rcu_read_unlock();
    return result;
}
EXPORT_SYMBOL(get_pid_task);

#include 
#define get_task_struct(tsk) do { atomic_inc(&(tsk)->usage); } while (0)
static inline void put_task_struct(struct task_struct *t)
{
    if (atomic_dec_and_test(&t->usage))
        __put_task_struct(t);
}

void __put_task_struct(struct task_struct *t);
EXPORT_SYMBOL_GPL(__put_task_struct);