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From:   Olga Kornievskaia <aglo@umich.edu>
Date:   Thu, 14 Jan 2021 15:29:13 -0500
Message-ID: <CAN-5tyF=qQbmBPXY7HDAEReidYYqFsV-dFrtkqqJfRAsxtyu8A@mail.gmail.com>
Subject: Re: [RFC PATCH 0/7] SUNRPC: Create sysfs files for changing IP
To:     Chuck Lever <chuck.lever@oracle.com>
Cc:     Anna Schumaker <schumaker.anna@gmail.com>,
        Bruce Fields <bfields@fieldses.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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On Wed, Jan 13, 2021 at 9:18 PM Chuck Lever <chuck.lever@oracle.com> wrote:
>
>
> > On Jan 13, 2021, at 2:48 PM, Chuck Lever <chuck.lever@oracle.com> wrote:
> >
> >> 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.
>
> Or you could implement it with "-o remount,addr=new-address".

A change of address is currently not allowed by the NFS because
multiple mounts might be sharing a superblock and change of one
mount's option would not be correct. The way things work from this new
mechanism is system wide and all mounts are affected.


>
>
> --
> Chuck Lever
>
>
>