From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78220C433E2 for ; Mon, 7 Sep 2020 16:57:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 497EC207DE for ; Mon, 7 Sep 2020 16:57:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599497869; bh=6b7jyqDgzjf/XlXCPAtkiF64G1ssZErU0QXenjYYtsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VB59TuoiCXlS2hrpAXIgIcSke5dwLH1vIynlDmdcSxVwFdoYzGVvUPCKQgI83Aba6 9LbITaBRJ4EjFAeBD+zfB6d/Rb5Ka/NFRdl/ch5r3c2IWibe7sWS9AW1pTPnd15sh0 oIWHjd60Xgs7P7ZRBkJmNlwMi59wNk9yjZdTsChQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731142AbgIGQ5q (ORCPT ); Mon, 7 Sep 2020 12:57:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:48006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730737AbgIGQeG (ORCPT ); Mon, 7 Sep 2020 12:34:06 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D288421D7E; Mon, 7 Sep 2020 16:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1599496444; bh=6b7jyqDgzjf/XlXCPAtkiF64G1ssZErU0QXenjYYtsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=o+QN39vqX7/OrfKe9+NPf3BTn87eiVGUTDtZptZxUv0Inz5BWpyW2Xh1n9K1XDz/+ E5S0VMvo6GaS6zOVv2IUwEOfd6buICjvWEpWIhkKfj09lqw9tPPZgCPAAddmXEqpjK 1GU5kKoAOBCLJK6j98ukQvpTE5qJm+aIDSVl93n8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sagi Grimberg , Christoph Hellwig , James Smart , Sasha Levin , linux-nvme@lists.infradead.org Subject: [PATCH AUTOSEL 5.4 27/43] nvme-rdma: fix timeout handler Date: Mon, 7 Sep 2020 12:33:13 -0400 Message-Id: <20200907163329.1280888-27-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200907163329.1280888-1-sashal@kernel.org> References: <20200907163329.1280888-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sagi Grimberg [ Upstream commit 0475a8dcbcee92a5d22e40c9c6353829fc6294b8 ] When a request times out in a LIVE state, we simply trigger error recovery and let the error recovery handle the request cancellation, however when a request times out in a non LIVE state, we make sure to complete it immediately as it might block controller setup or teardown and prevent forward progress. However tearing down the entire set of I/O and admin queues causes freeze/unfreeze imbalance (q->mq_freeze_depth) because and is really an overkill to what we actually need, which is to just fence controller teardown that may be running, stop the queue, and cancel the request if it is not already completed. Now that we have the controller teardown_lock, we can safely serialize request cancellation. This addresses a hang caused by calling extra queue freeze on controller namespaces, causing unfreeze to not complete correctly. Reviewed-by: Christoph Hellwig Reviewed-by: James Smart Signed-off-by: Sagi Grimberg Signed-off-by: Sasha Levin --- drivers/nvme/host/rdma.c | 49 +++++++++++++++++++++++++++------------- 1 file changed, 33 insertions(+), 16 deletions(-) diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index b164c662fed30..4e73da2c45bb6 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -1101,6 +1101,7 @@ static void nvme_rdma_error_recovery(struct nvme_rdma_ctrl *ctrl) if (!nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_RESETTING)) return; + dev_warn(ctrl->ctrl.device, "starting error recovery\n"); queue_work(nvme_reset_wq, &ctrl->err_work); } @@ -1704,6 +1705,22 @@ static int nvme_rdma_cm_handler(struct rdma_cm_id *cm_id, return 0; } +static void nvme_rdma_complete_timed_out(struct request *rq) +{ + struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq); + struct nvme_rdma_queue *queue = req->queue; + struct nvme_rdma_ctrl *ctrl = queue->ctrl; + + /* fence other contexts that may complete the command */ + mutex_lock(&ctrl->teardown_lock); + nvme_rdma_stop_queue(queue); + if (!blk_mq_request_completed(rq)) { + nvme_req(rq)->status = NVME_SC_HOST_ABORTED_CMD; + blk_mq_complete_request(rq); + } + mutex_unlock(&ctrl->teardown_lock); +} + static enum blk_eh_timer_return nvme_rdma_timeout(struct request *rq, bool reserved) { @@ -1714,29 +1731,29 @@ nvme_rdma_timeout(struct request *rq, bool reserved) dev_warn(ctrl->ctrl.device, "I/O %d QID %d timeout\n", rq->tag, nvme_rdma_queue_idx(queue)); - /* - * Restart the timer if a controller reset is already scheduled. Any - * timed out commands would be handled before entering the connecting - * state. - */ - if (ctrl->ctrl.state == NVME_CTRL_RESETTING) - return BLK_EH_RESET_TIMER; - if (ctrl->ctrl.state != NVME_CTRL_LIVE) { /* - * Teardown immediately if controller times out while starting - * or we are already started error recovery. all outstanding - * requests are completed on shutdown, so we return BLK_EH_DONE. + * If we are resetting, connecting or deleting we should + * complete immediately because we may block controller + * teardown or setup sequence + * - ctrl disable/shutdown fabrics requests + * - connect requests + * - initialization admin requests + * - I/O requests that entered after unquiescing and + * the controller stopped responding + * + * All other requests should be cancelled by the error + * recovery work, so it's fine that we fail it here. */ - flush_work(&ctrl->err_work); - nvme_rdma_teardown_io_queues(ctrl, false); - nvme_rdma_teardown_admin_queue(ctrl, false); + nvme_rdma_complete_timed_out(rq); return BLK_EH_DONE; } - dev_warn(ctrl->ctrl.device, "starting error recovery\n"); + /* + * LIVE state should trigger the normal error recovery which will + * handle completing this request. + */ nvme_rdma_error_recovery(ctrl); - return BLK_EH_RESET_TIMER; } -- 2.25.1