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Date: Thu, 21 Dec 2006 09:19:19 -0800 (PST)
From: Linus Torvalds <torvalds@osdl.org>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
cc: Andrew Morton <akpm@osdl.org>, Martin Michlmayr <tbm@cyrius.com>,
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Subject: Re: [PATCH] mm: fix page_mkclean_one (was: 2.6.19 file content
 corruption on ext3)
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On Wed, 20 Dec 2006, Trond Myklebust wrote:
> 
> I can't see that it is the business of invalidate_inode_pages2() to
> resolve races between ->direct_IO() and pages that are redirtied by
> mmap(). All it needs to ensure is that pages that clean are discarded,
> since those are neither consistent with data that the ->directIO() call
> wrote to the disk nor are they scheduled to be written to disk.

Sure, we could happily just remove the -EIO. Alternatively, we could still 
do all the invalidates over the whole range, and return -EIO at the end of 
any of the pages weren't invalidated because they had to be written back. 

I don't personally care whether we should just return success or something 
to indicate that there were busy pages, but somebody who _uses_ direct-IO 
might want to know that the thing didn't throw away everything. If you 
know such users, can you ask them?

(Maybe "-EAGAIN" is better than "-EIO", since it's not really even a fatal 
error).

		Linus