Re: [PATCH 1/2] Freezer: Fix s2disk resume from initrd (rev. 2)

[Pavel Machek <pavel@ucw.cz>]

Hi!

> Add appropriate freezer annotations to handle_initrd(), so that it's possible
> to resume from disk from an initrd.
> 
> This patch fixes Bug #9345: http://bugzilla.kernel.org/show_bug.cgi?id=9345


Unfortunately, bugzilla does not help me in understanding this.

> Index: linux-2.6/init/do_mounts_initrd.c
> ===================================================================
> --- linux-2.6.orig/init/do_mounts_initrd.c
> +++ linux-2.6/init/do_mounts_initrd.c
> @@ -55,12 +55,18 @@ static void __init handle_initrd(void)
>  	sys_mount(".", "/", NULL, MS_MOVE, NULL);
>  	sys_chroot(".");
>  
> +	/*
> +	 * In case that a resume from disk is carried out by linuxrc or one of
> +	 * its children, we need to tell the freezer not to wait for us.
> +	 */
> +	current->flags |= PF_FREEZER_SKIP;
> +
>  	pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
>  	if (pid > 0)
> -		while (pid != sys_wait4(-1, NULL, 0, NULL)) {
> -			try_to_freeze();
> +		while (pid != sys_wait4(-1, NULL, 0, NULL))
>  			yield();
> -		}
> +
> +	current->flags &= ~PF_FREEZER_SKIP;

New code should work (but it is uglier than the old one). What was
wrong with the old one? Refrigerator should make sys_wait4() return,
and that it turn should put handle_initrd() into refrigerator...

								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html