Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755448AbXKYOoR (ORCPT ); Sun, 25 Nov 2007 09:44:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752324AbXKYOoG (ORCPT ); Sun, 25 Nov 2007 09:44:06 -0500 Received: from x346.tv-sign.ru ([89.108.83.215]:54905 "EHLO mail.screens.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752778AbXKYOoE (ORCPT ); Sun, 25 Nov 2007 09:44:04 -0500 Date: Sun, 25 Nov 2007 17:44:28 +0300 From: Oleg Nesterov To: Andrew Morton Cc: Pavel Emelyanov , linux-kernel@vger.kernel.org Subject: [PATCH] sys_setpgid: simplify pid/ns interaction Message-ID: <20071125144428.GA6304@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2402 Lines: 81 sys_setpgid() does unneeded conversions from pid_t to "struct pid" and vice versa. Use "struct pid" more consistently. Saves one find_vpid() and eliminates the explicit usage of ->nsproxy->pid_ns. Imho, cleanups the code. Also use the same_thread_group() helper. Signed-off-by: Oleg Nesterov --- PT/kernel/sys.c~ 2007-11-20 17:16:10.000000000 +0300 +++ PT/kernel/sys.c 2007-11-25 17:16:59.000000000 +0300 @@ -916,8 +916,8 @@ asmlinkage long sys_setpgid(pid_t pid, p { struct task_struct *p; struct task_struct *group_leader = current->group_leader; - int err = -EINVAL; - struct pid_namespace *ns; + struct pid *pgrp; + int err; if (!pid) pid = task_pid_vnr(group_leader); @@ -929,12 +929,10 @@ asmlinkage long sys_setpgid(pid_t pid, p /* From this point forward we keep holding onto the tasklist lock * so that our parent does not change from under us. -DaveM */ - ns = current->nsproxy->pid_ns; - write_lock_irq(&tasklist_lock); err = -ESRCH; - p = find_task_by_pid_ns(pid, ns); + p = find_task_by_vpid(pid); if (!p) goto out; @@ -942,7 +940,7 @@ asmlinkage long sys_setpgid(pid_t pid, p if (!thread_group_leader(p)) goto out; - if (p->real_parent->tgid == group_leader->tgid) { + if (same_thread_group(p->real_parent, group_leader)) { err = -EPERM; if (task_session(p) != task_session(group_leader)) goto out; @@ -959,10 +957,12 @@ asmlinkage long sys_setpgid(pid_t pid, p if (p->signal->leader) goto out; + pgrp = task_pid(p); if (pgid != pid) { struct task_struct *g; - g = find_task_by_pid_type_ns(PIDTYPE_PGID, pgid, ns); + pgrp = find_vpid(pgid); + g = pid_task(pgrp, PIDTYPE_PGID); if (!g || task_session(g) != task_session(group_leader)) goto out; } @@ -971,13 +971,10 @@ asmlinkage long sys_setpgid(pid_t pid, p if (err) goto out; - if (task_pgrp_nr_ns(p, ns) != pgid) { - struct pid *pid; - + if (task_pgrp(p) != pgrp) { detach_pid(p, PIDTYPE_PGID); - pid = find_vpid(pgid); - attach_pid(p, PIDTYPE_PGID, pid); - set_task_pgrp(p, pid_nr(pid)); + attach_pid(p, PIDTYPE_PGID, pgrp); + set_task_pgrp(p, pid_nr(pgrp)); } err = 0; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/