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Date: Thu, 28 Dec 2000 13:18:34 -0500
From: Chris Mason <mason@suse.com>
To: Rik van Riel <riel@conectiva.com.br>
cc: Daniel Phillips <phillips@innominate.de>,
        Linus Torvalds <torvalds@transmeta.com>, linux-kernel@vger.kernel.org
Subject: Re: innd mmap bug in 2.4.0-test12
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On Thursday, December 28, 2000 15:51:24 -0200 Rik van Riel
<riel@conectiva.com.br> wrote:

> On Thu, 28 Dec 2000, Chris Mason wrote:
> 
>> I think a dirty page without a writepage func seems a bit
>> broken.  How about we give ramfs a writepage func that just
>> returns 1.  That way nobody does any special if
>> (ramfs_page(page)) kinds of tests...
> 
> This will lead to the ramfs pages staying on the inactive_dirty
> list forever, deadlocking the system.
> 


This wouldn't be the first time this week I've read this part of
page_launder wrong, but I don't see a difference between a NULL writepage
func, and a writepage func that returns 1.  I read the code like this:

if(PageDirty(page)) {
...
	if (!writepage)
		goto page_active ;
...
	result = writepage(page)
	if (result != 1)
		continue ;
	SetPageDirty(page);
	goto page_active ;
}

-chris
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