nfs41: introduce nfs4_call_sync

Use nfs4_call_sync rather than rpc_call_sync to provide
for a nfs41 sessions-enabled interface for sessions manipulation.

The nfs41 rpc logic uses the rpc_call_prepare method to
recover and create the session, as well as selecting a free slot id
and the rpc_call_done to free the slot and update slot table
related metadata.

In the coming patches we'll add rpc prepare and done routines
for setting up the sequence op and processing the sequence result.

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_call_sync]
As per 11-14-08 review.
Squash into "nfs41: introduce nfs4_call_sync" and "nfs41: nfs4_setup_sequence"
Define two functions one for v4 and one for v41
add a pointer to struct nfs4_client to the correct one.
Signed-off-by: Andy Adamson <andros@netapp.com>
[added BUG() in _nfs4_call_sync_session if !CONFIG_NFS_V4_1]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: check for session not minorversion]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[group minorversion specific stuff together]
Signed-off-by: Alexandros Batsakis <Alexandros.Batsakis@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Andy Adamson <andros@netapp.com>
[nfs41: fixup nfs4_clear_client_minor_version]
[introduce nfs4_init_client_minor_version() in this patch]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[cleaned-up patch: got rid of nfs_call_sync_t, dprintks, cosmetics, extra server defs]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index f1506f1..a9828ba 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -194,6 +194,8 @@
 		nfs4_destroy_session(clp->cl_session);
 		clp->cl_session = NULL;
 	}
+
+	clp->cl_call_sync = _nfs4_call_sync;
 #endif /* CONFIG_NFS_V4_1 */
 }
 
@@ -1073,6 +1075,8 @@
  */
 static int nfs4_init_client_minor_version(struct nfs_client *clp)
 {
+	clp->cl_call_sync = _nfs4_call_sync;
+
 #if defined(CONFIG_NFS_V4_1)
 	if (clp->cl_minorversion) {
 		struct nfs4_session *session = NULL;
@@ -1086,6 +1090,7 @@
 			return -ENOMEM;
 
 		clp->cl_session = session;
+		clp->cl_call_sync = _nfs4_call_sync_session;
 	}
 #endif /* CONFIG_NFS_V4_1 */