Date: Thu, 10 Jan 2008 11:07:57 -0500
From: Rik van Riel <riel@redhat.com>
To: "Anton Salikhmetov" <salikhmetov@gmail.com>
Cc: "Jakob Oestergaard" <jakob@unthought.net>, Valdis.Kletnieks@vt.edu,
       linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH][RFC][BUG] updating the ctime and mtime time stamps in
 msync()
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On Thu, 10 Jan 2008 18:56:07 +0300
"Anton Salikhmetov" <salikhmetov@gmail.com> wrote:

> However, I don't see how they will work if there has been
> something like a sync(2) done after the mmap'd region is
> modified and the msync call.  When the inode is written out
> as part of the sync process, I_DIRTY_PAGES will be cleared,
> thus causing a miss in this code.
> 
> The I_DIRTY_PAGES check here is good, but I think that there
> needs to be some code elsewhere too, to catch the case where
> I_DIRTY_PAGES is being cleared, but the time fields still need
> to be updated.

Agreed. The mtime and ctime should probably also be updated
when I_DIRTY_PAGES is cleared.

The alternative would be to remember that the inode had been
dirty in the past, and have the mtime and ctime updated on
msync or close - which would be more complex.

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