nfs41: Backchannel callback service helper routines

Executes the backchannel task on the RPC state machine using
the existing open connection previously established by the client.

Signed-off-by: Ricardo Labiaga <ricardo.labiaga@netapp.com>

nfs41: Add bc_svc.o to sunrpc Makefile.

[nfs41: bc_send() does not need to be exported outside RPC module]
[nfs41: xprt_free_bc_request() need not be exported outside RPC module]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
[Update copyright]
Signed-off-by: Ricardo Labiaga <Ricardo.Labiaga@netapp.com>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
diff --git a/include/linux/sunrpc/bc_xprt.h b/include/linux/sunrpc/bc_xprt.h
index 5965ae4..6508f0d 100644
--- a/include/linux/sunrpc/bc_xprt.h
+++ b/include/linux/sunrpc/bc_xprt.h
@@ -29,12 +29,15 @@
 
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/xprt.h>
+#include <linux/sunrpc/sched.h>
 
 #ifdef CONFIG_NFS_V4_1
 struct rpc_rqst *xprt_alloc_bc_request(struct rpc_xprt *xprt);
 void xprt_free_bc_request(struct rpc_rqst *req);
 int xprt_setup_backchannel(struct rpc_xprt *, unsigned int min_reqs);
 void xprt_destroy_backchannel(struct rpc_xprt *, int max_reqs);
+void bc_release_request(struct rpc_task *);
+int bc_send(struct rpc_rqst *req);
 #else /* CONFIG_NFS_V4_1 */
 static inline int xprt_setup_backchannel(struct rpc_xprt *xprt,
 					 unsigned int min_reqs)