nfsd: make NFSv4 recovery client tracking options per net

Pointer to client tracking operations - client_tracking_ops - have to be
containerized, because different environment can support different trackers
(for example, legacy tracker currently is not suported in container).

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/netns.h b/fs/nfsd/netns.h
index 964b554..fac4123c 100644
--- a/fs/nfsd/netns.h
+++ b/fs/nfsd/netns.h
@@ -35,6 +35,7 @@
 #define SESSION_HASH_SIZE	512
 
 struct cld_net;
+struct nfsd4_client_tracking_ops;
 
 struct nfsd_net {
 	struct cld_net *cld_net;
@@ -87,6 +88,7 @@
 
 	struct file *rec_file;
 	bool in_grace;
+	struct nfsd4_client_tracking_ops *client_tracking_ops;
 
 	time_t nfsd4_lease;
 	time_t nfsd4_grace;