nfs41: nfs4_setup_sequence

Perform the nfs4_setup_sequence in the rpc_call_prepare state.

If a session slot is not available, we will rpc_sleep_on the
slot wait queue leaving the tk_action as rpc_call_prepare.

Once we have a session slot, hang on to it even through rpc_restart_calls.
Ensure the nfs41_sequence_res sr_slot pointer is NULL before rpc_run_task is
called as nfs41_setup_sequence will only find a new slot if it is NULL.

A future patch will call free slot after any rpc_restart_calls, and handle the
rpc restart that result from a sequence operation error.

Signed-off-by: Rahul Iyer <iyer@netapp.com>
[nfs41: sequence res use slotid]
Signed-off-by: Andy <Adamson&lt;andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: simplify nfs4_call_sync]
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: nfs4_call_sync]
[nfs41: check for session not minorversion]
[nfs41: remove rpc_message from nfs41_call_sync_args]
[moved NFS4_MAX_SLOT_TABLE logic into nfs41_setup_sequence]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: nfs41_call_sync_data use nfs_client not nfs_server]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: expose nfs4_call_sync_session for lease renewal]
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[nfs41: remove unnecessary return check]
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>