SUNRPC: subscribe RPC clients to pipefs notifications

This patch subscribes RPC clients to RPC pipefs notifications. RPC clients
notifier block is registering with pipefs initialization during SUNRPC module
init.
This notifier callback is responsible for RPC client PipeFS directory and GSS
pipes creation. For pipes creation and destruction two additional callbacks
were added to struct rpc_authops.
Note that no locking required in notifier callback because PipeFS superblock
pointer is passed as an argument from it's creation or destruction routine and
thus we can be sure about it's validity.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 7874a8a56638..492a36d72829 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -99,6 +99,8 @@ struct rpc_authops {
 
         struct rpc_cred *       (*lookup_cred)(struct rpc_auth *, struct auth_cred *, int);
         struct rpc_cred *       (*crcreate)(struct rpc_auth*, struct auth_cred *, int);
+        int                     (*pipes_create)(struct rpc_auth *);
+        void                    (*pipes_destroy)(struct rpc_auth *);
 };
 
 struct rpc_credops {