From: "J. Bruce Fields" <bfields@fieldses.org>
To: "Myklebust, Trond" <Trond.Myklebust@netapp.com>
Cc: Jeff Layton <jlayton@redhat.com>,
"linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH v10 3/8] sunrpc: create nfsd dir in rpc_pipefs
Date: Fri, 23 Mar 2012 12:00:04 -0400 [thread overview]
Message-ID: <20120323160003.GA5675@fieldses.org> (raw)
In-Reply-To: <1332516863.3087.10.camel@lade.trondhjem.org>
On Fri, Mar 23, 2012 at 03:34:21PM +0000, Myklebust, Trond wrote:
> On Fri, 2012-03-23 at 11:22 -0400, J. Bruce Fields wrote:
> > On Fri, Mar 23, 2012 at 03:20:21PM +0000, Myklebust, Trond wrote:
> > > On Fri, 2012-03-23 at 09:31 -0400, J. Bruce Fields wrote:
> > > > On Fri, Mar 23, 2012 at 08:12:08AM -0400, J. Bruce Fields wrote:
> > > > > On Wed, Mar 21, 2012 at 09:52:04AM -0400, Jeff Layton wrote:
> > > > > > Add a new top-level dir in rpc_pipefs to hold the pipe for the clientid
> > > > > > upcall.
> > > > >
> > > > > After applying this patch, my tests consistently hang. The hang happens
> > > > > in excltest (of the special connectaton tests), over nfs4.1 and krb5.
> > > > > Looking at the wire traffic, I'm seeing DELAY returned from a setattr
> > > > > for mode on a newly-created (with EXCLUSIVE4_1) file. That open got a
> > > > > delegation, so presumably that's what's causing the DELAY, though I'm
> > > > > not seeing the server send a recall. That could be a krb5 bug.
> > > > >
> > > > > Whatever bug there is here, it's hard to tell why this patch in
> > > > > particular would make it more likely.
> > > > >
> > > > > So, still investigating!
> > > >
> > > > Reproduceable by:
> > > >
> > > > mount -osec=krb5,minorversion=1 server:/export/ /mnt/
> > > > cp cthon04/special/excltest /mnt/
> > > > cd /mnt
> > > > ./excltest
> > >
> > > Umm... When would you ever get a DELAY in the above scenario? I can see
> > > getting an NFS4ERR_OPENMODE, but not DELAY.
> >
> > There's a setattr for mode right after the open. Is that unexpected?
>
> Well yes, it is. The NFSv4.1 exclusive open should always be sending a
> full set of attributes as part of the OPEN operation. The session replay
> cache is now supposed to guarantee the only-once semantics that the
> verifier used to provide.
Looking at the trace.... The client is passing a zero attribute set on
the EXCLUSIVE4_1 open.
Hm, I wonder if our support for suppattr_exclreat has a bug. On a quick
check, the code looks like it should do the right thing.
> > The server doesn't really have to recall the delegation in that case (it
> > only needs to recall *other* clients' delegations) but I don't think
> > it's wrong to.
>
> Then why isn't it allowing the operation? Any sane client would normally
> interpret NFS4ERR_DELAY to mean that the server is doing something to
> fix whatever situation is preventing the operation from completing
> (presumably by recalling delegations in this case). Just replying DELAY
> and doing nothing is not helpful...
Yes, there's a backchannel bug of some kind.
Actually I doubt the server's 4.1 krb5 implementation handles the
backchannel correctly at all.
--b.
next prev parent reply other threads:[~2012-03-23 16:00 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-21 13:52 [PATCH v10 0/8] nfsd: overhaul the client name tracking code Jeff Layton
2012-03-21 13:52 ` [PATCH v10 1/8] nfsd: convert nfs4_client->cl_cb_flags to a generic flags field Jeff Layton
2012-03-21 20:41 ` J. Bruce Fields
2012-03-21 20:52 ` Jeff Layton
2012-03-21 21:05 ` J. Bruce Fields
2012-03-21 13:52 ` [PATCH v10 2/8] nfsd: add nfsd4_client_tracking_ops struct and a way to set it Jeff Layton
2012-03-21 20:42 ` [PATCH v11 " Jeff Layton
2012-03-21 23:59 ` [PATCH v10 " Jeff Layton
2012-03-21 13:52 ` [PATCH v10 3/8] sunrpc: create nfsd dir in rpc_pipefs Jeff Layton
2012-03-23 12:12 ` J. Bruce Fields
2012-03-23 13:31 ` J. Bruce Fields
2012-03-23 15:20 ` Myklebust, Trond
2012-03-23 15:22 ` J. Bruce Fields
2012-03-23 15:34 ` Myklebust, Trond
2012-03-23 15:53 ` Jeff Layton
2012-03-23 16:12 ` Jeff Layton
2012-03-23 17:04 ` J. Bruce Fields
2012-03-28 23:09 ` [PATCH] nfsd4: use auth_unix unconditionally on backchannel J. Bruce Fields
2012-03-28 23:16 ` Myklebust, Trond
2012-03-28 23:46 ` J. Bruce Fields
2012-03-29 14:29 ` Matt W. Benjamin
2012-03-29 14:29 ` Matt W. Benjamin
2012-03-29 14:48 ` J. Bruce Fields
2012-03-23 16:00 ` J. Bruce Fields [this message]
2012-03-21 13:52 ` [PATCH v10 4/8] nfsd: add a per-net-namespace struct for nfsd Jeff Layton
2012-03-21 13:52 ` [PATCH v10 5/8] nfsd: add a header describing upcall to nfsdcld Jeff Layton
2012-03-21 13:52 ` [PATCH v10 6/8] nfsd: add the infrastructure to handle the cld upcall Jeff Layton
2012-03-21 13:52 ` [PATCH v10 7/8] nfsd: add notifier to handle mount/unmount of rpc_pipefs sb Jeff Layton
2012-03-21 13:52 ` [PATCH v10 8/8] nfsd: don't allow legacy client tracker init for anything but init_net Jeff Layton
2012-03-23 17:06 ` [PATCH v10 0/8] nfsd: overhaul the client name tracking code J. Bruce Fields
2012-03-23 17:26 ` Jeff Layton
2012-03-26 20:02 ` J. Bruce Fields
2012-03-27 15:06 ` J. Bruce Fields
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