Re: xprt_adjust_timeout followed by lockd: server not responding / server OK

[Trond Myklebust <trond.myklebust@primarydata.com>]

On Fri, 2015-01-02 at 18:52 +0100, Lutz Vieweg wrote:
> On 11/25/2014 02:06 AM, andrew bezella wrote:
> > [ 3809.070778] xprt_adjust_timeout: rq_timeout = 0!
> > [ 3809.070784] lockd: server nfs-home not responding, still trying
> > [ 3809.332988] lockd: server nfs-home OK
> 
> I'm seeing the very same annoying symptom every few minutes on a
> CentOS 7 client with kernel 3.17.1 (server also running CentOS 7
> with the same kernel).
> 
> Both servers are connected to the same 10GBit/s switch and don't
> currently have much load...

Does the following patch help?

Cheers
  Trond

8<-------------------------------------------------------------
>From aff134222d6b17cdedad319f131f8e6e533e1256 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Fri, 2 Jan 2015 15:05:25 -0500
Subject: [PATCH] LOCKD: Fix a race when initialising nlmsvc_timeout

This commit fixes a race whereby nlmclnt_init() first starts the lockd
daemon, and then calls nlm_bind_host() with the expectation that
nlmsvc_timeout has already been initialised. Unfortunately, there is no
no synchronisation between lockd() and lockd_up() to guarantee that this
is the case.

Fix is to move the initialisation of nlmsvc_timeout into lockd_create_svc

Fixes: 9a1b6bf818e74 ("LOCKD: Don't call utsname()->nodename...")
Cc: Bruce Fields <bfields@fieldses.org>
Cc: stable@vger.kernel.org # 3.10.x
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
---
 fs/lockd/svc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index e94c887da2d7..55505cbe11af 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -138,10 +138,6 @@ lockd(void *vrqstp)
 
 	dprintk("NFS locking service started (ver " LOCKD_VERSION ").\n");
 
-	if (!nlm_timeout)
-		nlm_timeout = LOCKD_DFLT_TIMEO;
-	nlmsvc_timeout = nlm_timeout * HZ;
-
 	/*
 	 * The main request loop. We don't terminate until the last
 	 * NFS mount or NFS daemon has gone away.
@@ -350,6 +346,10 @@ static struct svc_serv *lockd_create_svc(void)
 		printk(KERN_WARNING
 			"lockd_up: no pid, %d users??\n", nlmsvc_users);
 
+	if (!nlm_timeout)
+		nlm_timeout = LOCKD_DFLT_TIMEO;
+	nlmsvc_timeout = nlm_timeout * HZ;
+
 	serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, svc_rpcb_cleanup);
 	if (!serv) {
 		printk(KERN_WARNING "lockd_up: create service failed\n");
-- 
2.1.0


-- 
Trond Myklebust
Linux NFS client maintainer, PrimaryData
trond.myklebust@primarydata.com