teach set_special_pids() to use struct pid

Change set_special_pids() to work with struct pid, not pid_t from global name
space. This again speedups and imho cleanups the code, also a preparation for
the next patch.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 18 insertions, 18 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 8a4812c1c038..d1c9b7f1d51e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1632,7 +1632,7 @@ extern struct task_struct *find_task_by_vpid(pid_t nr);
 extern struct task_struct *find_task_by_pid_ns(pid_t nr,
                 struct pid_namespace *ns);
 
-extern void __set_special_pids(pid_t session, pid_t pgrp);
+extern void __set_special_pids(struct pid *pid);
 
 /* per-UID process charging. */
 extern struct user_struct * alloc_uid(struct user_namespace *, uid_t);
diff --git a/init/main.c b/init/main.c
index 2a78932f6c07..9a5b18c0a63d 100644
--- a/init/main.c
+++ b/init/main.c
@@ -833,7 +833,7 @@ static int __init kernel_init(void * unused)
          */
         init_pid_ns.child_reaper = current;
 
-        __set_special_pids(1, 1);
+        __set_special_pids(task_pid(current));
         cad_pid = task_pid(current);
 
         smp_prepare_cpus(setup_max_cpus);
diff --git a/kernel/exit.c b/kernel/exit.c
index 42a8713b2050..96716fd22373 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -293,26 +293,27 @@ static void reparent_to_kthreadd(void)
         switch_uid(INIT_USER);
 }
 
-void __set_special_pids(pid_t session, pid_t pgrp)
+void __set_special_pids(struct pid *pid)
 {
         struct task_struct *curr = current->group_leader;
+        pid_t nr = pid_nr(pid);
 
-        if (task_session_nr(curr) != session) {
+        if (task_session(curr) != pid) {
                 detach_pid(curr, PIDTYPE_SID);
-                set_task_session(curr, session);
-                attach_pid(curr, PIDTYPE_SID, find_pid(session));
+                attach_pid(curr, PIDTYPE_SID, pid);
+                set_task_session(curr, nr);
         }
-        if (task_pgrp_nr(curr) != pgrp) {
+        if (task_pgrp(curr) != pid) {
                 detach_pid(curr, PIDTYPE_PGID);
-                set_task_pgrp(curr, pgrp);
-                attach_pid(curr, PIDTYPE_PGID, find_pid(pgrp));
+                attach_pid(curr, PIDTYPE_PGID, pid);
+                set_task_pgrp(curr, nr);
         }
 }
 
-static void set_special_pids(pid_t session, pid_t pgrp)
+static void set_special_pids(struct pid *pid)
 {
         write_lock_irq(&tasklist_lock);
-        __set_special_pids(session, pgrp);
+        __set_special_pids(pid);
         write_unlock_irq(&tasklist_lock);
 }
 
@@ -383,7 +384,11 @@ void daemonize(const char *name, ...)
          */
         current->flags |= PF_NOFREEZE;
 
-        set_special_pids(1, 1);
+        if (current->nsproxy != &init_nsproxy) {
+                get_nsproxy(&init_nsproxy);
+                switch_task_namespaces(current, &init_nsproxy);
+        }
+        set_special_pids(find_pid(1));
         proc_clear_tty(current);
 
         /* Block and flush all signals */
@@ -398,11 +403,6 @@ void daemonize(const char *name, ...)
         current->fs = fs;
         atomic_inc(&fs->count);
 
-        if (current->nsproxy != init_task.nsproxy) {
-                get_nsproxy(init_task.nsproxy);
-                switch_task_namespaces(current, init_task.nsproxy);
-        }
-
         exit_files(current);
         current->files = init_task.files;
         atomic_inc(&current->files->count);
diff --git a/kernel/sys.c b/kernel/sys.c
index e13bc518b444..c326d6dceee3 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1065,7 +1065,7 @@ asmlinkage long sys_setsid(void)
                 goto out;
 
         group_leader->signal->leader = 1;
-        __set_special_pids(pid_nr(sid), pid_nr(sid));
+        __set_special_pids(sid);
 
         spin_lock(&group_leader->sighand->siglock);
         group_leader->signal->tty = NULL;