+static int process_req_last_xid(struct ptlrpc_request *req)
+{
+ __u64 last_xid;
+ ENTRY;
+
+ /* check request's xid is consistent with export's last_xid */
+ last_xid = lustre_msg_get_last_xid(req->rq_reqmsg);
+ if (last_xid > req->rq_export->exp_last_xid)
+ req->rq_export->exp_last_xid = last_xid;
+
+ if (req->rq_xid == 0 ||
+ (req->rq_xid <= req->rq_export->exp_last_xid)) {
+ DEBUG_REQ(D_ERROR, req, "Unexpected xid %llx vs. "
+ "last_xid %llx\n", req->rq_xid,
+ req->rq_export->exp_last_xid);
+ /* Some request is allowed to be sent during replay,
+ * such as OUT update requests, FLD requests, so it
+ * is possible that replay requests has smaller XID
+ * than the exp_last_xid.
+ *
+ * Some non-replay requests may have smaller XID as
+ * well:
+ *
+ * - Client send a no_resend RPC, like statfs;
+ * - The RPC timedout (or some other error) on client,
+ * then it's removed from the unreplied list;
+ * - Client send some other request to bump the
+ * exp_last_xid on server;
+ * - The former RPC got chance to be processed;
+ */
+ if (!(lustre_msg_get_flags(req->rq_reqmsg) & MSG_REPLAY))
+ RETURN(-EPROTO);
+ }
+
+ /* try to release in-memory reply data */
+ if (tgt_is_multimodrpcs_client(req->rq_export)) {
+ tgt_handle_received_xid(req->rq_export,
+ lustre_msg_get_last_xid(req->rq_reqmsg));
+ if (!(lustre_msg_get_flags(req->rq_reqmsg) &
+ (MSG_RESENT | MSG_REPLAY)))
+ tgt_handle_tag(req->rq_export,
+ lustre_msg_get_tag(req->rq_reqmsg));
+ }
+ RETURN(0);
+}
+