From 80c6eed49d5da3ba97cff4dc316ff051486cd1fc Mon Sep 17 00:00:00 2001 From: Philipp Reisner Date: Wed, 1 Aug 2012 14:53:39 +0200 Subject: [PATCH] drbd: More random to the connect logic Since the listening socket is open all the time, it was possible to get into stable "initial packet S crossed" loops. * when both sides realize in the drbd_socket_okay() call at the end of the loop that the other side closed the main socket you had the chance to get into a stable loop with repeated "packet S crossed" messages. * when both sides do not realize with the drbd_socket_okay() call at the end of the loop that the other side closed the main socket you had the chance to get into a stable loop with alternating "packet S crossed" "packet M crossed" messages. In order to break out these stable loops randomize the behaviour if such a crossing of P_INITIAL_DATA or P_INITIAL_META packets is detected. Signed-off-by: Philipp Reisner Signed-off-by: Lars Ellenberg --- drivers/block/drbd/drbd_receiver.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c index 1567e9b..26c30fd 100644 --- a/drivers/block/drbd/drbd_receiver.c +++ b/drivers/block/drbd/drbd_receiver.c @@ -949,20 +949,25 @@ retry: if (sock.socket) { conn_warn(tconn, "initial packet S crossed\n"); sock_release(sock.socket); + sock.socket = s; + goto randomize; } sock.socket = s; break; case P_INITIAL_META: + set_bit(DISCARD_CONCURRENT, &tconn->flags); if (msock.socket) { conn_warn(tconn, "initial packet M crossed\n"); sock_release(msock.socket); + msock.socket = s; + goto randomize; } msock.socket = s; - set_bit(DISCARD_CONCURRENT, &tconn->flags); break; default: conn_warn(tconn, "Error receiving initial packet\n"); sock_release(s); +randomize: if (random32() & 1) goto retry; } -- 2.7.4