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From: Daniel Phillips <phillips@bonn-fries.net>
To: Andrew Morton <andrewm@uow.edu.au>
Subject: Re: [patch] truncate_inode_pages
Date: Sun, 10 Jun 2001 18:40:23 +0200
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On Sunday 10 June 2001 03:31, Andrew Morton wrote:
> Daniel Phillips wrote:
> > This is easy, just set the list head to the page about to be truncated.
>
> Works for me.

It looks good, but it's black magic - it could use a comment along the lines 
of:

/*
 * Ensure at least one pass through all three lists with lock held
 */

There is some fuzz on the original code that could use a scrubbing.  "start" 
should not be the 1st full page needing truncating, it should be the first 
page needing truncating at all, full or partial.

The truncation condition becomes:

-		if ((offset >= start) || (*partial && (offset + 1) == start)) {
+		if (offset >= start) {
[...]
-			if (*partial && (offset + 1) == start)
+			if (*partial && offset == start)

Then the conditions are so easy to test it's not worth passing the &partial, 
just pass lstart... and... oh bother, it's not broke, why fix it ;-)

--
Daniel