ksmbd: set epoch in create context v2 lease

To support v2 lease(directory lease), ksmbd set epoch in create context
v2 lease response.
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/smb/server/oplock.c

@@ -104,7 +104,7 @@ static int alloc_lease(struct oplock_info *opinfo, struct lease_ctx_info *lctx)
 	lease->duration = lctx->duration;
 	memcpy(lease->parent_lease_key, lctx->parent_lease_key, SMB2_LEASE_KEY_SIZE);
 	lease->version = lctx->version;
-	lease->epoch = 0;
+	lease->epoch = le16_to_cpu(lctx->epoch);
 	INIT_LIST_HEAD(&opinfo->lease_entry);
 	opinfo->o_lease = lease;
 
@@ -1032,6 +1032,7 @@ static void copy_lease(struct oplock_info *op1, struct oplock_info *op2)
 	       SMB2_LEASE_KEY_SIZE);
 	lease2->duration = lease1->duration;
 	lease2->flags = lease1->flags;
+	lease2->epoch = lease1->epoch++;
 }
 
 static int add_lease_global_list(struct oplock_info *opinfo)
@@ -1364,6 +1365,7 @@ void create_lease_buf(u8 *rbuf, struct lease *lease)
 		memcpy(buf->lcontext.LeaseKey, lease->lease_key,
 		       SMB2_LEASE_KEY_SIZE);
 		buf->lcontext.LeaseFlags = lease->flags;
+		buf->lcontext.Epoch = cpu_to_le16(++lease->epoch);
 		buf->lcontext.LeaseState = lease->state;
 		memcpy(buf->lcontext.ParentLeaseKey, lease->parent_lease_key,
 		       SMB2_LEASE_KEY_SIZE);
@@ -1423,6 +1425,7 @@ struct lease_ctx_info *parse_lease_state(void *open_req)
 		memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE);
 		lreq->req_state = lc->lcontext.LeaseState;
 		lreq->flags = lc->lcontext.LeaseFlags;
+		lreq->epoch = lc->lcontext.Epoch;
 		lreq->duration = lc->lcontext.LeaseDuration;
 		memcpy(lreq->parent_lease_key, lc->lcontext.ParentLeaseKey,
 				SMB2_LEASE_KEY_SIZE);

fs/smb/server/oplock.h

@@ -34,6 +34,7 @@ struct lease_ctx_info {
 	__le32			flags;
 	__le64			duration;
 	__u8			parent_lease_key[SMB2_LEASE_KEY_SIZE];
+	__le16			epoch;
 	int			version;
 };