NFSD: Forget state for a specific client

Write the client's ip address to any state file and all appropriate
state for that client will be forgotten.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 4017f35..d1c229f 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -502,6 +502,7 @@
 int nfsd_fault_inject_init(void);
 void nfsd_fault_inject_cleanup(void);
 u64 nfsd_for_n_state(u64, u64 (*)(struct nfs4_client *, u64));
+struct nfs4_client *nfsd_find_client(struct sockaddr_storage *, size_t);
 
 u64 nfsd_forget_client(struct nfs4_client *, u64);
 u64 nfsd_forget_client_locks(struct nfs4_client*, u64);