[PATCH][smb3 client] log less confusing message on multichannel mounts to Samba when no interfaces returned

[Steve French]

message updated as suggested

    multichannel not available
    empty network interface returned by server localhost

See attached

On Tue, Oct 11, 2022 at 2:40 PM Tom Talpey <tom at talpey.com> wrote:
>
> In the patch:
>
> > +     /*
> > +      * Samba server e.g. can return an empty interface list in some cases,
> > +      * which would only be a problem if we were requesting multichannel
> > +      */
> > +     if (bytes_left == 0) {
> > +             /* avoid spamming logs every 10 minutes, so log only in mount */
> > +             if ((ses->chan_max > 1) && in_mount)
> > +                     cifs_dbg(VFS,
> > +                              "empty network interface list returned by server %s\n",
> > +                              ses->server->hostname);
> > +             rc = -EINVAL;
> > +             goto out;
> > +     }
>
>
>
> This logs the server name, but it might be confusing to the
> admin since the mount does not actually fail. Perhaps add some
> words to the effect of "multichannel not available"?
>
> Acked-by: Tom Talpey <tom at talpey.com>
>
> On 10/3/2022 6:36 PM, Steve French wrote:
> > attached wrong patch - resending
> >
> >
> > On Mon, Oct 3, 2022 at 5:32 PM Steve French <smfrench at gmail.com> wrote:
> >>
> >> updated patch to:
> >> 1) log the server name for this message
> >> 2) only log on mount (not every ten minutes)
> >>
> >> See attached
> >>
> >> On Mon, Oct 3, 2022 at 9:21 AM Tom Talpey <tom at talpey.com> wrote:
> >>>
> >>> On 10/3/2022 12:38 AM, Steve French wrote:
> >>>> On Sat, Oct 1, 2022 at 6:22 PM Tom Talpey <tom at talpey.com> wrote:
> >>>>>
> >>>>> On 10/1/2022 12:54 PM, Steve French wrote:
> >>>>>> Some servers can return an empty network interface list so, unless
> >>>>>> multichannel is requested, no need to log an error for this, and
> >>>>>> when multichannel is requested on mount but no interfaces, log
> >>>>>> something less confusing.  For this case change
> >>>>>>       parse_server_interfaces: malformed interface info
> >>>>>> to
> >>>>>>       empty network interface list returned by server
> >>>>>
> >>>>> Will this spam the log if it happens on every MC refresh (10 mins)?
> >>>>> It might be helpful to identify the servername, too.
> >>>>
> >>>> Yes - I just noticed that in this case (multichannel mount to Samba
> >>>> where no valid interfaces) we log it every ten minutes.
> >>>> Maybe best way to fix this is to change it to a log once error (with
> >>>> server name is fine with me) since it is probably legal to return an
> >>>> empty list (so not serious enough to be worth logging every ten
> >>>> minutes) and in theory server could fix its interfaces later.
> >>>
> >>> Ten minutes is the default recommended polling interval in the doc.
> >>>
> >>> While it's odd, it's not prevented by the protocol. I could guess
> >>> that a server running in a namespace might return strange things
> >>> as devices came and went, for example.
> >>>
> >>> It's not an error, so the message is purely informational. It is
> >>> useful though. Is it possible to suppress the logging if the
> >>> message *doesn't* change, but otherwise emit new ones? That might
> >>> require some per-server fiddling to avoid multiple servers flipping
> >>> the message.
> >>>
> >>> A boolean or bit in the server struct? A little ugly for the purpose,
> >>> but surfacing multichannel events - especially ones that prevent it
> >>> from happening - seems worthwhile.
> >>>
> >>> Tom.
> >>>
> >>>
> >>> Tom.
> >>>
> >>>
> >>>>>> Cc: <stable at vger.kernel.org>
> >>>>>> Signed-off-by: Steve French <stfrench at microsoft.com>
> >>>>>>
> >>>>>> See attached patch
> >>>>>>
> >>>>
> >>>>
> >>>>
> >>
> >>
> >>
> >> --
> >> Thanks,
> >>
> >> Steve
> >
> >
> >



-- 
Thanks,

Steve
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