+
+/**
+ * If request has a new allocated XID (new request or EINPROGRESS resend),
+ * use this XID as matchbits of bulk, otherwise allocate a new matchbits for
+ * request to ensure previous bulk fails and avoid problems with lost replies
+ * and therefore several transfers landing into the same buffer from different
+ * sending attempts.
+ */
+void ptlrpc_set_bulk_mbits(struct ptlrpc_request *req)
+{
+ struct ptlrpc_bulk_desc *bd = req->rq_bulk;
+
+ LASSERT(bd != NULL);
+
+ if (!req->rq_resend) {
+ /* this request has a new xid, just use it as bulk matchbits */
+ req->rq_mbits = req->rq_xid;
+
+ } else { /* needs to generate a new matchbits for resend */
+ __u64 old_mbits = req->rq_mbits;
+
+ if (OCD_HAS_FLAG(&bd->bd_import->imp_connect_data, BULK_MBITS)){
+ req->rq_mbits = ptlrpc_next_xid();
+ } else {/* old version transfers rq_xid to peer as matchbits */
+ spin_lock(&req->rq_import->imp_lock);
+ list_del_init(&req->rq_unreplied_list);
+ ptlrpc_assign_next_xid_nolock(req);
+ req->rq_mbits = req->rq_xid;
+ spin_unlock(&req->rq_import->imp_lock);
+ }
+ CDEBUG(D_HA, "resend bulk old x%llu new x%llu\n",
+ old_mbits, req->rq_mbits);
+ }
+
+ /* For multi-bulk RPCs, rq_mbits is the last mbits needed for bulks so
+ * that server can infer the number of bulks that were prepared,
+ * see LU-1431 */
+ req->rq_mbits += ((bd->bd_iov_count + LNET_MAX_IOV - 1) /
+ LNET_MAX_IOV) - 1;
+
+ /* Set rq_xid as rq_mbits to indicate the final bulk for the old
+ * server which does not support OBD_CONNECT_BULK_MBITS. LU-6808 */
+ if (!OCD_HAS_FLAG(&bd->bd_import->imp_connect_data, BULK_MBITS))
+ req->rq_xid = req->rq_mbits;
+}