cifs: set up recurring workqueue job to do SMB echo requests

Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 4de7375..9c728dd 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -218,6 +218,7 @@
 	bool	sec_kerberosu2u;	/* supports U2U Kerberos */
 	bool	sec_ntlmssp;		/* supports NTLMSSP */
 	bool session_estab; /* mark when very first sess is established */
+	struct delayed_work	echo; /* echo ping workqueue job */
 #ifdef CONFIG_CIFS_FSCACHE
 	struct fscache_cookie   *fscache; /* client index cache cookie */
 #endif