From mboxrd@z Thu Jan  1 00:00:00 1970
From: Oleg Nesterov <oleg@redhat.com>
Subject: Re: [PATCH v3 1/3] init / kthread: add module_long_probe_init() and
	module_long_probe_exit()
Date: Mon, 18 Aug 2014 14:22:17 +0200
Message-ID: <20140818122217.GA12707@redhat.com>
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Cc: "Luis R. Rodriguez" <mcgrof@suse.com>,
	"Luis R. Rodriguez" <mcgrof@do-not-panic.com>,
	gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
	Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
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	Andrew Morton <akpm@linux-foundation.org>,
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	Abhijit Mahajan <abhijit.mahajan@avagotech.com>,
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	Santosh Rastapur <santosh@chelsio.com>,
	MPT-FusionLinux.pdl@avagotech.com, linux-scsi@vger.kernel.org,
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To: Takashi Iwai <tiwai@suse.de>
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On 08/18, Takashi Iwai wrote:
>
> #define module_long_probe_init(initfn)				\
> 	static int _long_probe_##initfn(void *arg)		\
> 	{							\
> 		module_put_and_exit(initfn());			\
> 		return 0;					\
> 	}							\
> 	static int __init __long_probe_##initfn(void)		\
> 	{							\
> 		struct task_struct *__init_thread =		\
> 			kthread_create(_long_probe_##initfn,	\
> 				       NULL, #initfn);		\
> 		if (IS_ERR(__init_thread))			\
> 			return PTR_ERR(__init_thread);		\
> 		__module_get(THIS_MODULE);			\
> 		wake_up_process(__init_thread);			\
> 		return 0;					\
> 	}							\
> 	module_init(__long_probe_##initfn)
>
> ... and module_exit() remains identical as the normal version.

Aaaah. This is not true, module_exit() should not call exitfn() if initfn()
fails... So _long_probe_##initfn() needs to save the error code which should
be checked by module_exit().

> But, it's really a small difference, and I don't mind much which way
> to take, too.

Agreed.

Oleg.