Re: [PATCH 2/2] nfsd: expose /proc/net/sunrpc/nfsd in net namespaces

[Jeff Layton <jlayton@kernel.org>]

On Wed, 2024-01-24 at 17:12 -0500, Josef Bacik wrote:
> On Wed, Jan 24, 2024 at 03:32:06PM -0500, Chuck Lever wrote:
> > On Wed, Jan 24, 2024 at 02:37:00PM -0500, Josef Bacik wrote:
> > > We are running nfsd servers inside of containers with their own network
> > > namespace, and we want to monitor these services using the stats found
> > > in /proc.  However these are not exposed in the proc inside of the
> > > container, so we have to bind mount the host /proc into our containers
> > > to get at this information.
> > > 
> > > Separate out the stat counters init and the proc registration, and move
> > > the proc registration into the pernet operations entry and exit points
> > > so that these stats can be exposed inside of network namespaces.
> > 
> > Maybe I missed something, but this looks like it exposes the global
> > stat counters to all net namespaces...? Is that an information leak?
> > As an administrator I might be surprised by that behavior.
> > 
> > Seems like this patch needs to make nfsdstats and nfsd_svcstats into
> > per-namespace objects as well.
> > 
> > 
> 
> I've got the patches written for this, but I've got a question.  There's a 
> 
> svc_seq_show(seq, &nfsd_svcstats);
> 
> in nfsd/stats.c.  This appears to be an empty struct, there's nothing that
> utilizes it, so this is always going to print 0 right?  There's a svc_info in
> the nfsd_net, and that stats block appears to get updated properly.  Should I
> print this out here?  I don't see anywhere we get the rpc stats out of nfsd, am
> I missing something?  I don't want to rip out stuff that I don't quite
> understand.  Thanks,
> 
> 

nfsd_svcstats ends up being the sv_stats for the nfsd service. The RPC
code has some counters in there for counting different sorts of net and
rpc events (see svc_process_common, and some of the recv and accept
handlers).  I think nfsstat(8) may fetch that info via the above
seqfile, so it's definitely not unused (and it should be printing more
than just a '0').

svc_info is a completely different thing: it's a container for the
svc_serv...so I'm not sure I understand your question?
-- 
Jeff Layton <jlayton@kernel.org>