From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dan Cross <cross@math.psu.edu>
Message-Id: <200101290519.AAA28124@augusta.math.psu.edu>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] 9P to 9P2000 migration path
In-Reply-To: <20010128192407.7C8F3199EF@mail.cse.psu.edu>
Cc: 
Date: Mon, 29 Jan 2001 00:19:13 -0500
Topicbox-Message-UUID: 53d10d56-eac9-11e9-9e20-41e7f4b1d025

In article <20010128192407.7C8F3199EF@mail.cse.psu.edu> you write:
>That sort of thing.
>
>The necessary hooks for protocol versioning is provided by the
>"version" message.

I'm guessing it's easy for a file server to detect an old protocol
client (Tversion won't be the first message sent from an old 9p client,
as old 9p doesn't have Tversion.  Any connection starting out this way
won't be the new protocol).

I was reading the file server paper again today while I was on the
train, and one thing I noticed is that the disk-resident directory
entry contains the 28 byte file name in a fixed width field.  It would
seem that if the restriction on file name length is being removed from
the protocol, a similar change must be taking place in the file
server.  If this is the case, then the question becomes, ``how does one
migrate data off of disk on an old file server and onto a new one?''
Also, if the disk resident data structure is changing, is this a good
time to move the length field to a vlong?

	- Dan C.