Re: [RFC PATCH 0/7] SUNRPC: Create sysfs files for changing IP

[Chuck Lever <chuck.lever@oracle.com>]

> On Jan 13, 2021, at 2:23 PM, Anna Schumaker <schumaker.anna@gmail.com> wrote:
> 
> On Tue, Jan 12, 2021 at 11:59 AM J. Bruce Fields <bfields@fieldses.org> wrote:
>> 
>> On Tue, Jan 12, 2021 at 08:09:09AM -0500, Chuck Lever wrote:
>>> Hi Anna-
>>> 
>>>> On Jan 11, 2021, at 4:41 PM, schumaker.anna@gmail.com wrote:
>>>> 
>>>> From: Anna Schumaker <Anna.Schumaker@Netapp.com>
>>>> 
>>>> It's possible for an NFS server to go down but come back up with a
>>>> different IP address. These patches provide a way for administrators to
>>>> handle this issue by providing a new IP address for xprt sockets to
>>>> connect to.
>>>> 
>>>> This is a first draft of the code, so any thoughts or suggestions would
>>>> be greatly appreciated!
>>> 
>>> One implementation question, one future question.
>>> 
>>> Would /sys/kernel/net be a little better? or /sys/kernel/sunrpc ?
> 
> Possibly! I was trying to match /sys/fs/nfs, but I can definitely
> change this if another location is better.

Ah... since this is a supplement to the mount() interface, maybe
placing this new API under /sys/fs/nfs/ might make some sense.


>>> Do you have a plan to integrate support for fs_locations to probe
>>> servers for alternate IP addresses? Would that be a userspace
>>> utility that would plug values into this new /sys API?
> 
> Yeah, I would expect there to be a new utility to help with assigning
> new values. I haven't given any thought to using fs_locations yet, but
> it could probably work.

I could see a tool that performs an fs_locations from user space
and plugs that information into the kernel NFS client as needed.
Future work!


--
Chuck Lever