Date: Thu, 9 Jun 2011 09:58:46 -0400
From: Jim Rees <rees@umich.edu>
To: Benny Halevy <bhalevy@panasas.com>
Cc: Peng Tao <bergwolf@gmail.com>, linux-nfs@vger.kernel.org,
        peter honeyman <honey@citi.umich.edu>
Subject: Re: [PATCH 87/88] Add configurable prefetch size for layoutget
Message-ID: <20110609135846.GA32565@merit.edu>
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Benny Halevy wrote:

  > My understanding is that layoutget specifies a min and max, and the server
  
  There's a min.  What do you consider the max?
  Whatever gets into csa_fore_chan_attrs.ca_maxresponsesize?

The spec doesn't say max, it says "desired."  I guess I assumed the server
wouldn't normally return more than desired.

18.43.3.  DESCRIPTION
...

   The LAYOUTGET operation returns layout information for the specified
   byte-range: a layout.  The client actually specifies two ranges, both
   starting at the offset in the loga_offset field.  The first range is
   between loga_offset and loga_offset + loga_length - 1 inclusive.
   This range indicates the desired range the client wants the layout to
   cover.  The second range is between loga_offset and loga_offset +
   loga_minlength - 1 inclusive.  This range indicates the required
   range the client needs the layout to cover.  Thus, loga_minlength
   MUST be less than or equal to loga_length.