cifs: define server-level cache index objects and register them

Define server-level cache index objects (as managed by TCP_ServerInfo structs)
and register then with FS-Cache. Each server object is created in the CIFS
top-level index object and is itself an index into which superblock-level
objects are inserted.

The server objects are now keyed by {IPaddress,family,port} tuple.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/connect.c

@@ -48,6 +48,7 @@
 #include "nterr.h"
 #include "rfc1002pdu.h"
 #include "cn_cifs.h"
+#include "fscache.h"
 
 #define CIFS_PORT 445
 #define RFC1001_PORT 139
@@ -1460,6 +1461,8 @@ cifs_put_tcp_session(struct TCP_Server_Info *server)
 	server->tcpStatus = CifsExiting;
 	spin_unlock(&GlobalMid_Lock);
 
+	cifs_fscache_release_client_cookie(server);
+
 	task = xchg(&server->tsk, NULL);
 	if (task)
 		force_sig(SIGKILL, task);
@@ -1577,6 +1580,8 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
 	list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
 	write_unlock(&cifs_tcp_ses_lock);
 
+	cifs_fscache_get_client_cookie(tcp_ses);
+
 	return tcp_ses;
 
 out_err: