Bug#648155: Patch to make nfs4 return EKEYEXPIRED to user code

[John Hughes <john@Calva.COM>]

This patch (for 3.1-rc10, probably works for all versions that have this 
problem) makes nfs4 return the EKEYEXPIRED to user level, which works 
well with nfs4 mounted home directories on user systems.

The normal case will be that the workstation screen will be locked when 
the ticket expires, the user will enter her password and a new ticket 
will be granted.   Any processes that try to access the home directory 
while the ticket is expired will get EKEYEXPIRED and probably give up.

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 4700fae..dc28a78 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -302,7 +302,6 @@ static int nfs4_handle_exception(struct nfs_server *server, int errorcode, struc
 			}
 		case -NFS4ERR_GRACE:
 		case -NFS4ERR_DELAY:
-		case -EKEYEXPIRED:
 			ret = nfs4_delay(server->client, &exception->timeout);
 			if (ret != 0)
 				break;
@@ -3732,7 +3731,6 @@ nfs4_async_handle_error(struct rpc_task *task, const struct nfs_server *server,
 		case -NFS4ERR_DELAY:
 			nfs_inc_server_stats(server, NFSIOS_DELAY);
 		case -NFS4ERR_GRACE:
-		case -EKEYEXPIRED:
 			rpc_delay(task, NFS4_POLL_RETRY_MAX);
 			task->tk_status = 0;
 			return -EAGAIN;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 39914be..2bee41e 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1377,8 +1377,9 @@ static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
 			/* Zero session reset errors */
 			return 0;
 		case -EKEYEXPIRED:
-			/* Nothing we can do */
-			nfs4_warn_keyexpired(clp->cl_hostname);
+			/* Nothing we can do, so do nothing.  Don't even
+			   print a warning message, this is not a kernel
+			   problem */
 			return 0;
 	}
 	return error;