msg/Pipe: associate sending msgs to con inside lock

Associate a sending message with the connection inside the pipe_lock.
This way if a racing thread tries to steal these messages it will
be sure to reset the con point *after* we do such that it the con
pointer is valid in encode_payload() (and later).

This may be part of #3678.

Signed-off-by: Sage Weil <sage@inktank.com>

diff --git a/src/msg/Pipe.cc b/src/msg/Pipe.cc
index bf8c4566d69455fbb0166b722c96f2d53c22422a..aacc0109496c0dd6b2c170616a9f1fb15dc1c1bb 100644 (file)
--- a/src/msg/Pipe.cc
+++ b/src/msg/Pipe.cc
@@ -1466,13 +1466,14 @@ void Pipe::writer()
          sent.push_back(m); 
          m->get();
        }
-       pipe_lock.Unlock();
-
-        ldout(msgr->cct,20) << "writer encoding " << m->get_seq() << " " << m << " " << *m << dendl;
 
        // associate message with Connection (for benefit of encode_payload)
        m->set_connection(connection_state->get());
 
+       pipe_lock.Unlock();
+
+        ldout(msgr->cct,20) << "writer encoding " << m->get_seq() << " " << m << " " << *m << dendl;
+
        // encode and copy out of *m
        m->encode(connection_state->get_features(), !msgr->cct->_conf->ms_nocrc);