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Message-ID: <40A43152.4090400@yahoo.com.au>
Date: Fri, 14 May 2004 12:39:14 +1000
From: Nick Piggin <nickpiggin@yahoo.com.au>
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To: Andrew Morton <akpm@osdl.org>
CC: hugh@veritas.com, viro@parcelfarce.linux.theplanet.co.uk,
       torvalds@osdl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH][RFC] truncate vs add_to_page_cache race
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Andrew Morton wrote:
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:

>> OK, I made a debug patch to printk and schedule_timeout in this
>> race window so I can easily truncate the file. When this happens,
>> it turns out that the readpage thinks it is reading a hole and
>> fills the page with zeros -> invalid result?
> 
> 
> A zero-filled pagecache page outside i_size is OK.
> 

Yes. But in this case the zero filled page actually gets
read by read(2).

In any case, I think my patch won't close the race completely.