From be80ff88356ab6f5529daf24d3052a4e3cc727ec Mon Sep 17 00:00:00 2001 From: Lars Ellenberg Date: Thu, 20 Dec 2018 17:23:38 +0100 Subject: [PATCH] drbd: avoid spurious self-outdating with concurrent disconnect / down If peers are "simultaneously" told to disconnect from each other, either explicitly, or implicitly by taking down the resource, with bad timing, one side may see its disconnect "fail" with a result of "state change failed by peer", and interpret this as "please oudate yourself". Try to catch this by checking for current connection status, and possibly retry as local-only state change instead. Signed-off-by: Lars Ellenberg Signed-off-by: Jens Axboe --- drivers/block/drbd/drbd_nl.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index 1958eb33b643..82915880c5e9 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -2711,8 +2711,10 @@ out: static enum drbd_state_rv conn_try_disconnect(struct drbd_connection *connection, bool force) { + enum drbd_conns cstate; enum drbd_state_rv rv; +repeat: rv = conn_request_state(connection, NS(conn, C_DISCONNECTING), force ? CS_HARD : 0); @@ -2730,6 +2732,11 @@ static enum drbd_state_rv conn_try_disconnect(struct drbd_connection *connection break; case SS_CW_FAILED_BY_PEER: + spin_lock_irq(&connection->resource->req_lock); + cstate = connection->cstate; + spin_unlock_irq(&connection->resource->req_lock); + if (cstate <= C_WF_CONNECTION) + goto repeat; /* The peer probably wants to see us outdated. */ rv = conn_request_state(connection, NS2(conn, C_DISCONNECTING, disk, D_OUTDATED), 0);