svn commit: r192463 - head/sys/fs/nfsserver

[Rick Macklem]

On Fri, 22 May 2009, Dag-Erling Smørgrav wrote:

> Rick Macklem <rmacklem at FreeBSD.org> writes:
>> Log:
>>   Although it should never happen, all the nfsv4 server can do
>>   when it runs out of clientids is reboot. I had replaced cpu_reboot()
>>   with printf(), since cpu_reboot() doesn't exist for sparc64.
>>   This change replaces the printf() with panic(), so the reboot
>>   would occur for this highly unlikely occurrence.
>
> Regardless of how improbable this is, wouldn't it be better (and
> simpler) to just log an error message and deny further mount requests?
>
Well, it this really is an issue I can just take the check for the
wraparound out and let it continue on.

Why?

Because the likelyhood of a clientid issued 4billion time ago (many
many years aka centuries, in practice) being for a client that still
exists and hasn't rebooted or re-acquired a more recent clientid is
essentialy 0 as well.

In case you haven't done the calculation, 4billion seconds is 136 years.
Since I cannot image a server seeing anything close to 1 new clientid/sec
over an extended period (there could be a burst just after booting), the
wraparound will take centuries to happen (maybe highly unlikely wasn't a
strong enough term).

Just don't worry about it, rick