[PATCH 3.16 091/132] NFS4: Fix v4.0 client state corruption when mount

[Ben Hutchings]

3.16.74-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: ZhangXiaoxu <zhangxiaoxu5@xxxxxxxxxx>

commit f02f3755dbd14fb935d24b14650fff9ba92243b8 upstream.

stat command with soft mount never return after server is stopped.

When alloc a new client, the state of the client will be set to
NFS4CLNT_LEASE_EXPIRED.

When the server is stopped, the state manager will work, and accord
the state to recover. But the state is NFS4CLNT_LEASE_EXPIRED, it
will drain the slot table and lead other task to wait queue, until
the client recovered. Then the stat command is hung.

When discover server trunking, the client will renew the lease,
but check the client state, it lead the client state corruption.

So, we need to call state manager to recover it when detect server
ip trunking.

Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@xxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 fs/nfs/nfs4state.c | 4 ++++
 1 file changed, 4 insertions(+)

--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -140,6 +140,10 @@ int nfs40_discover_server_trunking(struc
 		/* Sustain the lease, even if it's empty.  If the clientid4
 		 * goes stale it's of no use for trunking discovery. */
 		nfs4_schedule_state_renewal(*result);
+
+		/* If the client state need to recover, do it. */
+		if (clp->cl_state)
+			nfs4_schedule_state_manager(clp);
 	}
 out:
 	return status;