Re: kernel not recovering from statd port change

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



I've been debugging the same thing on an Ubuntu 12.04 server running 3.8.0-44, and ended up in the same place you are. Did you find out anything more? I have carefully inserted rpc_force_rebind() near nlm_client_get, but I don't think it is a good fix for others.

In production servers, I am starting rpc.statd with "--port #####", which does seem to solve the problem. NLM (vs NSM) apparently doesn't suffer from it.

One thing that puzzles me is that of several hundred NFS clients only a handful have a problem getting a lock. The problem clients are running 3.2 and 2.6.26. The not-problem clients are 3.8 mostly. NFSv3.

On 08/21/2014 04:34 PM, J. Bruce Fields wrote:
While testing server restart somebody noticed that knfsd can't recover
from statd restarting with a new port.

 From only a very quick skim of the code it looked like creating the nsm
client with RPC_CLNT_CREATE_AUTOBIND should cause us to call rpcbind
again on connection failures, but that doesn't seem to be working.

Any ideas?  I'll keep looking....

--b.

commit 2c9fb5570fe2
Author: J. Bruce Fields <bfields@xxxxxxxxxx>
Date:   Wed Aug 20 17:21:32 2014 -0400

     lockd: allow rebinding to statd

     During normal operation statd isn't restarted, but it may be if, for
     example, the server is shut down and restarted to simulate a shutdown or
     perform some kind of failover.  In that case the kernel may need to
     query rpcbind again to get statd's new port number.

     Symptoms were locking failures after a manual server restart (without
     rebooting the machine), and loopback network traces showing the new
     kernel nfsd attempting to contact statd at its old port number.

     This was probably introduced by cb7323fffa85, which first allowed
     reusing the statd rpc client, but it looks like a reference count may
     typically have prevented any symptoms until e498daa81295 "LOCKD: Clear
     ln->nsm_clnt only when ln->nsm_users is zero".

     Fixes: cb7323fffa85 "lockd: create and use per-net NSM RPC clients on MON/UNMON requests"
     Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 1812f026960c..3bce1d318435 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -80,7 +80,8 @@ static struct rpc_clnt *nsm_create(struct net *net)
  		.program		= &nsm_program,
  		.version		= NSM_VERSION,
  		.authflavor		= RPC_AUTH_NULL,
-		.flags			= RPC_CLNT_CREATE_NOPING,
+		.flags			= RPC_CLNT_CREATE_NOPING|
+			                  RPC_CLNT_CREATE_AUTOBIND,
  	};

  	return rpc_create(&args);
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux