releases/3.7.6/nfsv4.1-handle-nfs4err_delay-when-resetting-the-nfsv4.1-session.patch

From c489ee290bdbbace6bb63ebe6ebd4dd605819495 Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust@netapp.com>
Date: Wed, 30 Jan 2013 13:04:10 -0500
Subject: NFSv4.1: Handle NFS4ERR_DELAY when resetting the NFSv4.1 session

From: Trond Myklebust <Trond.Myklebust@netapp.com>

commit c489ee290bdbbace6bb63ebe6ebd4dd605819495 upstream.

NFS4ERR_DELAY is a legal reply when we call DESTROY_SESSION. It
usually means that the server is busy handling an unfinished RPC
request. Just sleep for a second and then retry.
We also need to be able to handle the NFS4ERR_BACK_CHAN_BUSY return
value. If the NFS server has outstanding callbacks, we just want to
similarly sleep & retry.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/nfs/nfs4state.c |   14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1997,8 +1997,18 @@ static int nfs4_reset_session(struct nfs
 	nfs4_begin_drain_session(clp);
 	cred = nfs4_get_exchange_id_cred(clp);
 	status = nfs4_proc_destroy_session(clp->cl_session, cred);
-	if (status && status != -NFS4ERR_BADSESSION &&
-	    status != -NFS4ERR_DEADSESSION) {
+	switch (status) {
+	case 0:
+	case -NFS4ERR_BADSESSION:
+	case -NFS4ERR_DEADSESSION:
+		break;
+	case -NFS4ERR_BACK_CHAN_BUSY:
+	case -NFS4ERR_DELAY:
+		set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
+		status = 0;
+		ssleep(1);
+		goto out;
+	default:
 		status = nfs4_recovery_handle_error(clp, status);
 		goto out;
 	}