libceph: fix messenger retry

In ancient times, the messenger could both initiate and accept connections.
An artifact if that was data structures to store/process an incoming
ceph_msg_connect request and send an outgoing ceph_msg_connect_reply.
Sadly, the negotiation code was referencing those structures and ignoring
important information (like the peer's connect_seq) from the correct ones.

Among other things, this fixes tight reconnect loops where the server sends
RETRY_SESSION and we (the client) retries with the same connect_seq as last
time.  This bug pretty easily triggered by injecting socket failures on the
MDS and running some fs workload like workunits/direct_io/test_sync_io.

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

1 files changed, 6 insertions, 6 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index b332c3d76059..10255e81be79 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1423,7 +1423,7 @@ static int process_connect(struct ceph_connection *con)
                  * dropped messages.
                  */
                 dout("process_connect got RESET peer seq %u\n",
-                     le32_to_cpu(con->in_connect.connect_seq));
+                     le32_to_cpu(con->in_reply.connect_seq));
                 pr_err("%s%lld %s connection reset\n",
                        ENTITY_NAME(con->peer_name),
                        ceph_pr_addr(&con->peer_addr.in_addr));
@@ -1450,10 +1450,10 @@ static int process_connect(struct ceph_connection *con)
                  * If we sent a smaller connect_seq than the peer has, try
                  * again with a larger value.
                  */
-                dout("process_connect got RETRY my seq = %u, peer_seq = %u\n",
+                dout("process_connect got RETRY_SESSION my seq %u, peer %u\n",
                      le32_to_cpu(con->out_connect.connect_seq),
-                     le32_to_cpu(con->in_connect.connect_seq));
-                con->connect_seq = le32_to_cpu(con->in_connect.connect_seq);
+                     le32_to_cpu(con->in_reply.connect_seq));
+                con->connect_seq = le32_to_cpu(con->in_reply.connect_seq);
                 ceph_con_out_kvec_reset(con);
                 ret = prepare_write_connect(con);
                 if (ret < 0)
@@ -1468,9 +1468,9 @@ static int process_connect(struct ceph_connection *con)
                  */
                 dout("process_connect got RETRY_GLOBAL my %u peer_gseq %u\n",
                      con->peer_global_seq,
-                     le32_to_cpu(con->in_connect.global_seq));
+                     le32_to_cpu(con->in_reply.global_seq));
                 get_global_seq(con->msgr,
-                               le32_to_cpu(con->in_connect.global_seq));
+                               le32_to_cpu(con->in_reply.global_seq));
                 ceph_con_out_kvec_reset(con);
                 ret = prepare_write_connect(con);
                 if (ret < 0)