cifs: add a timestamp to track when the lease of the cached dir was taken

and clear the timestamp when we receive a lease break.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/cifsglob.h

@@ -988,6 +988,7 @@ struct cached_fid {
 	bool is_valid:1;	/* Do we have a useable root fid */
 	bool file_all_info_is_valid:1;
 	bool has_lease:1;
+	unsigned long time; /* jiffies of when lease was taken */
 	struct kref refcount;
 	struct cifs_fid *fid;
 	struct mutex fid_mutex;

fs/cifs/smb2misc.c

@@ -667,6 +667,7 @@ smb2_is_valid_lease_break(char *buffer)
 				    !memcmp(rsp->LeaseKey,
 					    tcon->crfid.fid->lease_key,
 					    SMB2_LEASE_KEY_SIZE)) {
+					tcon->crfid.time = 0;
 					INIT_WORK(&tcon->crfid.lease_break,
 						  smb2_cached_lease_break);
 					queue_work(cifsiod_wq,

fs/cifs/smb2ops.c

@@ -912,6 +912,8 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
 				&rsp_iov[1], sizeof(struct smb2_file_all_info),
 				(char *)&tcon->crfid.file_all_info))
 		tcon->crfid.file_all_info_is_valid = true;
+	tcon->crfid.time = jiffies;
+
 
 oshr_exit:
 	mutex_unlock(&tcon->crfid.fid_mutex);