libceph: initialize ack_stamp to avoid unnecessary connection reset

Commit 4cf9d544631c recorded when an outgoing ceph message was ACKed,
in order to avoid unnecessary connection resets when an OSD is busy.

However, ack_stamp is uninitialized, so there is a window between
when the message is sent and when it is ACKed in which handle_timeout()
interprets the unitialized value as an expired timeout, and resets
the connection unnecessarily.

Close the window by initializing ack_stamp.

Signed-off-by: Jim Schutt <jaschut@sandia.gov>
Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index c340e2e0765b4bdf72efc9f2bd484bc7f7f36de5..9918e9eb276e783ac2e359821209d076484c85c0 100644 (file)
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2307,6 +2307,7 @@ struct ceph_msg *ceph_msg_new(int type, int front_len, gfp_t flags)
        m->front_max = front_len;
        m->front_is_vmalloc = false;
        m->more_to_follow = false;
+       m->ack_stamp = 0;
        m->pool = NULL;
 
        /* middle */