From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754243AbZFAXVA (ORCPT ); Mon, 1 Jun 2009 19:21:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753052AbZFAXUw (ORCPT ); Mon, 1 Jun 2009 19:20:52 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:43569 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752391AbZFAXUv (ORCPT ); Mon, 1 Jun 2009 19:20:51 -0400 Date: Mon, 1 Jun 2009 16:20:10 -0700 From: Andrew Morton To: Gerard Lledo Cc: kernel-janitors@vger.kernel.org, dwmw2@infradead.org, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, gerard.lledo@gmail.com Subject: Re: [PATCH] [JFFS2] Move jffs2_gcd_mtd threads to the new kthread API Message-Id: <20090601162010.ed69436f.akpm@linux-foundation.org> In-Reply-To: <1243585181-2997-1-git-send-email-gerard.lledo@gmail.com> References: <1243585181-2997-1-git-send-email-gerard.lledo@gmail.com> X-Mailer: Sylpheed version 2.2.4 (GTK+ 2.8.20; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 29 May 2009 11:19:41 +0300 Gerard Lledo wrote: > kernel_thread() is being depracated. This patch moves the jffs2 garbage > collecting thread to the new kthread API with the minimal impact. > > Signed-off-by: Gerard Lledo > --- > fs/jffs2/background.c | 22 ++++++++++++++-------- > 1 files changed, 14 insertions(+), 8 deletions(-) > > diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c > index e958010..077fa65 100644 > --- a/fs/jffs2/background.c > +++ b/fs/jffs2/background.c > @@ -15,6 +15,7 @@ > #include > #include > #include > +#include > #include "nodelist.h" > > > @@ -31,7 +32,7 @@ void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) > /* This must only ever be called when no GC thread is currently running */ > int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > { > - pid_t pid; > + struct task_struct *tsk; > int ret = 0; > > BUG_ON(c->gc_task); > @@ -39,15 +40,16 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) > init_completion(&c->gc_thread_start); > init_completion(&c->gc_thread_exit); > > - pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES); > - if (pid < 0) { > - printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid); > + tsk = kthread_create(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index); > + if (IS_ERR(tsk)) { > + printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk)); > complete(&c->gc_thread_exit); > - ret = pid; > + ret = PTR_ERR(tsk); > } else { > - /* Wait for it... */ > - D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid)); > + D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid)); > + wake_up_process(tsk); > wait_for_completion(&c->gc_thread_start); > + ret = tsk->pid; > } A simple kthread_run() would be preferable here. The code presently sort-of open-codes it. > return ret; Also, manipulating kernel threads via their pids is atypical and inefficient. In-kernel it is better to refer to threads via their task_struct*. Fortunately all callers of this function ignore its return value so I expect we can simply change it to be void-returning. But that's a cleanup which would best be done in a spearate patch. > @@ -71,7 +73,6 @@ static int jffs2_garbage_collect_thread(void *_c) > { > struct jffs2_sb_info *c = _c; > > - daemonize("jffs2_gcd_mtd%d", c->mtd->index); > allow_signal(SIGKILL); > allow_signal(SIGSTOP); > allow_signal(SIGCONT); > @@ -107,6 +108,11 @@ static int jffs2_garbage_collect_thread(void *_c) > * the GC thread get there first. */ > schedule_timeout_interruptible(msecs_to_jiffies(50)); > > + if (kthread_should_stop()) { > + D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): kthread_stop() called.\n")); > + goto die; > + } > + > /* Put_super will send a SIGKILL and then wait on the sem. > */ > while (signal_pending(current) || freezing(current)) {