From b9061bb9cb20fcb3aada156c29b47a420ff0b64c Mon Sep 17 00:00:00 2001
From: Yingxin <yingxin.cheng@intel.com>
Date: Thu, 30 Aug 2018 18:22:49 +0800
Subject: [PATCH] crimson/net: only do zero-copy writes to out_stream

seastar doesn't support mixed buffered writes and zero-copy writes.

Signed-off-by: Yingxin <yingxin.cheng@intel.com>
---
 src/crimson/net/SocketConnection.cc | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/crimson/net/SocketConnection.cc b/src/crimson/net/SocketConnection.cc
index c163273f8bd9d..a3d459ca15a47 100644
--- a/src/crimson/net/SocketConnection.cc
+++ b/src/crimson/net/SocketConnection.cc
@@ -29,6 +29,11 @@
 
 using namespace ceph::net;
 
+template <typename T>
+seastar::net::packet make_static_packet(const T& value) {
+    return { reinterpret_cast<const char*>(&value), sizeof(value) };
+}
+
 SocketConnection::SocketConnection(Messenger *messenger,
                                    const entity_addr_t& my_addr,
                                    const entity_addr_t& peer_addr,
@@ -318,9 +323,7 @@ seastar::future<> SocketConnection::keepalive()
   seastar::shared_future<> f = send_ready.then([this] {
       k.req.stamp = ceph::coarse_real_clock::to_ceph_timespec(
         ceph::coarse_real_clock::now());
-      seastar::net::packet msg{reinterpret_cast<const char*>(&k.req),
-                               sizeof(k.req)};
-      return out.write(std::move(msg));
+      return out.write(make_static_packet(k.req));
     }).then([this] {
       return out.flush();
     });
@@ -514,7 +517,7 @@ SocketConnection::send_connect_reply(msgr_tag_t tag,
 					    policy.features_supported) |
 					   policy.features_required);
   h.reply.authorizer_len = authorizer_reply.length();
-  return out.write(reinterpret_cast<const char*>(&h.reply), sizeof(h.reply))
+  return out.write(make_static_packet(h.reply))
     .then([this, reply=std::move(authorizer_reply)]() mutable {
       return out.write(std::move(reply));
     }).then([this] {
@@ -536,7 +539,7 @@ SocketConnection::send_connect_reply_ready(msgr_tag_t tag,
     h.reply.flags = h.reply.flags | CEPH_MSG_CONNECT_LOSSY;
   }
   h.reply.authorizer_len = authorizer_reply.length();
-  return out.write(reinterpret_cast<const char*>(&h.reply), sizeof(h.reply))
+  return out.write(make_static_packet(h.reply))
     .then([this, reply=std::move(authorizer_reply)]() mutable {
       if (reply.length()) {
         return out.write(std::move(reply));
@@ -545,9 +548,9 @@ SocketConnection::send_connect_reply_ready(msgr_tag_t tag,
       }
     }).then([this] {
       if (h.reply.tag == CEPH_MSGR_TAG_SEQ) {
-	return out.write(reinterpret_cast<const char*>(&in_seq),
-                         sizeof(in_seq)).then([this] {
-	    return out.flush();
+        return out.write(make_static_packet(in_seq))
+          .then([this] {
+            return out.flush();
           }).then([this] {
             return in.read_exactly(sizeof(seq_num_t));
           }).then([this] (auto buf) {
@@ -569,9 +572,7 @@ SocketConnection::handle_keepalive2()
     .then([this] (auto buf) {
       k.ack.stamp = *reinterpret_cast<const ceph_timespec*>(buf.get());
       std::cout << "keepalive2 " << k.ack.stamp.tv_sec << std::endl;
-      seastar::net::packet msg{reinterpret_cast<const char*>(&k.ack),
-                               sizeof(k.ack)};
-      return out.write(std::move(msg));
+      return out.write(make_static_packet(k.ack));
     }).then([this] {
       return out.flush();
     });
@@ -697,8 +698,7 @@ seastar::future<> SocketConnection::handle_connect_reply(msgr_tag_t tag)
       .then([this] (auto buf) {
         auto acked_seq = reinterpret_cast<const seq_num_t*>(buf.get());
         discard_up_to(&out_q, *acked_seq);
-      }).then([this] {
-        return out.write(reinterpret_cast<const char*>(&in_seq), sizeof(in_seq));
+        return out.write(make_static_packet(in_seq));
       }).then([this] {
         return out.flush();
       }).then([this] {
@@ -774,8 +774,6 @@ seastar::future<> SocketConnection::connect(entity_type_t peer_type,
         h.connect.authorizer_len = 0;
         bl.append(create_static(h.connect));
       };
-      return bl;
-    }).then([this](bufferlist&& bl) {
       return out.write(std::move(bl));
     }).then([this] {
       return out.flush();
-- 
2.39.5