Mount protocol/showmount vs NFSv4

[Colin Percival]

On 11/07/16 14:12, Rick Macklem wrote:
> Colin Percival wrote:
>> On 11/06/16 12:51, Rick Macklem wrote:
>>> I have never done anything about this, since most were still using NFSv3, but it seems
>>> that maybe something should be done now?
>>> - What do people think of having a new option on mountd(8) that would be used for
>>>    NFSv4 only servers that disables servicing of Mount RPCs.
>>
>> Done in isolation, it seems that this would guarantee that unmounting an
>> nfsv4 filesystem will result in umount(8) hanging while it waits for
>> responses to the UDP packets it sends.  So I'd think that we should fix
>> the client side to stop sending those first?
> Yes, the NFSv4 client should be fixed so that it doesn't do Unmount RPCs before
> mountd gets changed. (I had thought of this, but neglected to mention it in the first
> post. Thanks for bringing this up.)

I was thinking more in terms of time line -- presumably there will be some
people running older FreeBSD clients connecting to newer FreeBSD servers.
Should we wait some time between fixing the nfsv4 client and when we turn
off RPC handling in the mountd server?  (And if yes, how long?)

-- 
Colin Percival
Security Officer Emeritus, FreeBSD | The power to serve
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid