Return-Path: From: Lars Ellenberg To: Jens Axboe , linux-kernel@vger.kernel.org, linux-block@vger.kernel.org Date: Thu, 20 Dec 2018 17:23:38 +0100 Message-Id: <20181220162344.8430-12-lars.ellenberg@linbit.com> In-Reply-To: <20181220162344.8430-1-lars.ellenberg@linbit.com> References: <20181220162344.8430-1-lars.ellenberg@linbit.com> Cc: drbd-dev@lists.linbit.com Subject: [Drbd-dev] [PATCH 11/17] drbd: avoid spurious self-outdating with concurrent disconnect / down List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 --- 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 @@ int drbd_adm_connect(struct sk_buff *skb, struct genl_info *info) 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= C_WF_CONNECTION) + goto repeat; /* The peer probably wants to see us outdated.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); -- 2.17.1