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Date: Sun, 15 Apr 2007 23:05:11 -0400
From: Theodore Tso <tytso@mit.edu>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>, Neil Brown <neilb@suse.de>,
       =?iso-8859-1?Q?J=F6rn?= Engel <joern@lazybastard.org>,
       Christoph Hellwig <hch@infradead.org>,
       Ulrich Drepper <drepper@gmail.com>,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: If not readdir() then what?
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On Thu, Apr 12, 2007 at 10:35:49AM -0700, H. Peter Anvin wrote:
> J. Bruce Fields wrote:
> >On Thu, Apr 12, 2007 at 08:21:16AM -0400, Theodore Tso wrote:
> >>Again, compared to a directory fd cache, what you're proposing a huge
> >>hit to the filesystem, and at the moment, given that telldir/seekdir
> >>is rarely used by everyone else, it's mainly NFS which is the main bad
> >>actor here by insisting on the use of a small 31/63-bit cookie as a
> >>condition of protocol correctness.
> >
> >If we want to get bigger cookies into the protocol, then the sooner we
> >start working on that the better....  How big is big enough?  And is a
> >larger cookie sufficient on its own?
> >
> 
> Any fixed size is too small.  It should be a dynamic size.

Idally it should be dynamic, but my guess is that if the cookie were a
fixed 256 bits, it would be sufficient for pretty much all filesystems.  

						- Ted