pids: kill signal_struct-> __pgrp/__session and friends

We are wasting 2 words in signal_struct without any reason to implement
task_pgrp_nr() and task_session_nr().

task_session_nr() has no callers since
2e2ba22ea4, we can remove it.

task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and
fs/coda.

This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills
__pgrp/__session and the related helpers.

The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense
anyway.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <number6@the-village.bc.nu>		[tty parts]
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2009-04-02 16:58:39 -07:00 committed by Linus Torvalds
parent 52ee2dfdd4
commit 1b0f7ffd0e
5 changed files with 12 additions and 51 deletions

View File

@ -2681,7 +2681,7 @@ void __do_SAK(struct tty_struct *tty)
/* Kill the entire session */
do_each_pid_task(session, PIDTYPE_SID, p) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): task_session_nr(p)==tty->session\n",
" (%s): task_session(p)==tty->session\n",
task_pid_nr(p), p->comm);
send_sig(SIGKILL, p, 1);
} while_each_pid_task(session, PIDTYPE_SID, p);
@ -2691,7 +2691,7 @@ void __do_SAK(struct tty_struct *tty)
do_each_thread(g, p) {
if (p->signal->tty == tty) {
printk(KERN_NOTICE "SAK: killed process %d"
" (%s): task_session_nr(p)==tty->session\n",
" (%s): task_session(p)==tty->session\n",
task_pid_nr(p), p->comm);
send_sig(SIGKILL, p, 1);
continue;

View File

@ -547,25 +547,8 @@ struct signal_struct {
struct list_head cpu_timers[3];
/* job control IDs */
/*
* pgrp and session fields are deprecated.
* use the task_session_Xnr and task_pgrp_Xnr routines below
*/
union {
pid_t pgrp __deprecated;
pid_t __pgrp;
};
struct pid *tty_old_pgrp;
union {
pid_t session __deprecated;
pid_t __session;
};
/* boolean value for session group leader */
int leader;
@ -1469,16 +1452,6 @@ static inline int rt_task(struct task_struct *p)
return rt_prio(p->prio);
}
static inline void set_task_session(struct task_struct *tsk, pid_t session)
{
tsk->signal->__session = session;
}
static inline void set_task_pgrp(struct task_struct *tsk, pid_t pgrp)
{
tsk->signal->__pgrp = pgrp;
}
static inline struct pid *task_pid(struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
@ -1552,11 +1525,6 @@ static inline pid_t task_tgid_vnr(struct task_struct *tsk)
}
static inline pid_t task_pgrp_nr(struct task_struct *tsk)
{
return tsk->signal->__pgrp;
}
static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
struct pid_namespace *ns)
{
@ -1569,11 +1537,6 @@ static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
}
static inline pid_t task_session_nr(struct task_struct *tsk)
{
return tsk->signal->__session;
}
static inline pid_t task_session_nr_ns(struct task_struct *tsk,
struct pid_namespace *ns)
{
@ -1585,6 +1548,12 @@ static inline pid_t task_session_vnr(struct task_struct *tsk)
return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
}
/* obsolete, do not use */
static inline pid_t task_pgrp_nr(struct task_struct *tsk)
{
return task_pgrp_nr_ns(tsk, &init_pid_ns);
}
/**
* pid_alive - check that a task structure is not stale
* @p: Task structure to be checked.

View File

@ -357,16 +357,12 @@ static void reparent_to_kthreadd(void)
void __set_special_pids(struct pid *pid)
{
struct task_struct *curr = current->group_leader;
pid_t nr = pid_nr(pid);
if (task_session(curr) != pid) {
if (task_session(curr) != pid)
change_pid(curr, PIDTYPE_SID, pid);
set_task_session(curr, nr);
}
if (task_pgrp(curr) != pid) {
if (task_pgrp(curr) != pid)
change_pid(curr, PIDTYPE_PGID, pid);
set_task_pgrp(curr, nr);
}
}
static void set_special_pids(struct pid *pid)

View File

@ -1265,8 +1265,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->signal->leader_pid = pid;
tty_kref_put(p->signal->tty);
p->signal->tty = tty_kref_get(current->signal->tty);
set_task_pgrp(p, task_pgrp_nr(current));
set_task_session(p, task_session_nr(current));
attach_pid(p, PIDTYPE_PGID, task_pgrp(current));
attach_pid(p, PIDTYPE_SID, task_session(current));
list_add_tail_rcu(&p->tasks, &init_task.tasks);

View File

@ -1013,10 +1013,8 @@ SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
if (err)
goto out;
if (task_pgrp(p) != pgrp) {
if (task_pgrp(p) != pgrp)
change_pid(p, PIDTYPE_PGID, pgrp);
set_task_pgrp(p, pid_nr(pgrp));
}
err = 0;
out: