[PATCH] pid: use struct pid for talking about process groups in exitc

Modify has_stopped_jobs and will_become_orphan_pgrp to use struct pid based
process groups.  This reduces the number of hash tables looks ups and paves
the way for multiple pid spaces.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 20 deletions

diff --git a/kernel/exit.c b/kernel/exit.c
index 3ac6a7a6f857..407b80aaefda 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -210,22 +210,22 @@ struct pid *session_of_pgrp(struct pid *pgrp)
  *
  * "I ask you, have you ever known what it is to be an orphan?"
  */
-static int will_become_orphaned_pgrp(int pgrp, struct task_struct *ignored_task)
+static int will_become_orphaned_pgrp(struct pid *pgrp, struct task_struct *ignored_task)
 {
         struct task_struct *p;
         int ret = 1;
 
-        do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
+        do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
                 if (p == ignored_task
                                 || p->exit_state
                                 || is_init(p->real_parent))
                         continue;
-                if (process_group(p->real_parent) != pgrp &&
-                    process_session(p->real_parent) == process_session(p)) {
+                if (task_pgrp(p->real_parent) != pgrp &&
+                    task_session(p->real_parent) == task_session(p)) {
                         ret = 0;
                         break;
                 }
-        } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
+        } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
         return ret;     /* (sighing) "Often!" */
 }
 
@@ -234,23 +234,23 @@ int is_orphaned_pgrp(int pgrp)
         int retval;
 
         read_lock(&tasklist_lock);
-        retval = will_become_orphaned_pgrp(pgrp, NULL);
+        retval = will_become_orphaned_pgrp(find_pid(pgrp), NULL);
         read_unlock(&tasklist_lock);
 
         return retval;
 }
 
-static int has_stopped_jobs(int pgrp)
+static int has_stopped_jobs(struct pid *pgrp)
 {
         int retval = 0;
         struct task_struct *p;
 
-        do_each_task_pid(pgrp, PIDTYPE_PGID, p) {
+        do_each_pid_task(pgrp, PIDTYPE_PGID, p) {
                 if (p->state != TASK_STOPPED)
                         continue;
                 retval = 1;
                 break;
-        } while_each_task_pid(pgrp, PIDTYPE_PGID, p);
+        } while_each_pid_task(pgrp, PIDTYPE_PGID, p);
         return retval;
 }
 
@@ -648,14 +648,14 @@ reparent_thread(struct task_struct *p, struct task_struct *father, int traced)
          * than we are, and it was the only connection
          * outside, so the child pgrp is now orphaned.
          */
-        if ((process_group(p) != process_group(father)) &&
-            (process_session(p) == process_session(father))) {
-                int pgrp = process_group(p);
+        if ((task_pgrp(p) != task_pgrp(father)) &&
+            (task_session(p) == task_session(father))) {
+                struct pid *pgrp = task_pgrp(p);
 
                 if (will_become_orphaned_pgrp(pgrp, NULL) &&
                     has_stopped_jobs(pgrp)) {
-                        __kill_pg_info(SIGHUP, SEND_SIG_PRIV, pgrp);
-                        __kill_pg_info(SIGCONT, SEND_SIG_PRIV, pgrp);
+                        __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+                        __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
                 }
         }
 }
@@ -735,6 +735,7 @@ static void exit_notify(struct task_struct *tsk)
         int state;
         struct task_struct *t;
         struct list_head ptrace_dead, *_p, *_n;
+        struct pid *pgrp;
 
         if (signal_pending(tsk) && !(tsk->signal->flags & SIGNAL_GROUP_EXIT)
             && !thread_group_empty(tsk)) {
@@ -787,12 +788,13 @@ static void exit_notify(struct task_struct *tsk)
          
         t = tsk->real_parent;
         
-        if ((process_group(t) != process_group(tsk)) &&
-            (process_session(t) == process_session(tsk)) &&
-            will_become_orphaned_pgrp(process_group(tsk), tsk) &&
-            has_stopped_jobs(process_group(tsk))) {
-                __kill_pg_info(SIGHUP, SEND_SIG_PRIV, process_group(tsk));
-                __kill_pg_info(SIGCONT, SEND_SIG_PRIV, process_group(tsk));
+        pgrp = task_pgrp(tsk);
+        if ((task_pgrp(t) != pgrp) &&
+            (task_session(t) != task_session(tsk)) &&
+            will_become_orphaned_pgrp(pgrp, tsk) &&
+            has_stopped_jobs(pgrp)) {
+                __kill_pgrp_info(SIGHUP, SEND_SIG_PRIV, pgrp);
+                __kill_pgrp_info(SIGCONT, SEND_SIG_PRIV, pgrp);
         }
 
         /* Let father know we died