From patchwork Tue Aug 24 14:12:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12455133 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 7535BC4338F for ; Tue, 24 Aug 2021 14:02:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CF3D61212 for ; Tue, 24 Aug 2021 14:02:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237451AbhHXODA (ORCPT ); Tue, 24 Aug 2021 10:03:00 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:15209 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237545AbhHXOC7 (ORCPT ); Tue, 24 Aug 2021 10:02:59 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4Gv9l529BRz1DD7t; Tue, 24 Aug 2021 22:01:37 +0800 (CST) Received: from dggema762-chm.china.huawei.com (10.1.198.204) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Tue, 24 Aug 2021 22:02:09 +0800 Received: from huawei.com (10.175.127.227) by dggema762-chm.china.huawei.com (10.1.198.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Tue, 24 Aug 2021 22:02:08 +0800 From: Yu Kuai To: , , , CC: , , , , Subject: [PATCH v3 3/5] nbd: don't handle response without a corresponding request message Date: Tue, 24 Aug 2021 22:12:25 +0800 Message-ID: <20210824141227.808340-4-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210824141227.808340-1-yukuai3@huawei.com> References: <20210824141227.808340-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggema762-chm.china.huawei.com (10.1.198.204) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org While handling a response message from server, nbd_read_stat() will try to get request by tag, and then complete the request. However, this is problematic if nbd haven't sent a corresponding request message: t1 t2 submit_bio nbd_queue_rq blk_mq_start_request recv_work nbd_read_stat blk_mq_get_rq_by_tag blk_mq_complete_request nbd_send_cmd Thus add a new cmd flag 'NBD_CMD_INFLIGHT', it will be set in nbd_send_cmd() and checked in nbd_read_stat(). Signed-off-by: Yu Kuai --- drivers/block/nbd.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index ca54a0736090..7b9e19675224 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -127,6 +127,11 @@ struct nbd_device { }; #define NBD_CMD_REQUEUED 1 +/* + * This flag will be set if nbd_send_cmd() succeed, and will be checked in + * normal completion. + */ +#define NBD_CMD_INFLIGHT 2 struct nbd_cmd { struct nbd_device *nbd; @@ -743,6 +748,12 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index) cmd = blk_mq_rq_to_pdu(req); mutex_lock(&cmd->lock); + if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) { + dev_err(disk_to_dev(nbd->disk), "NBD_CMD_INFLIGHT is not set %d\n", + tag); + ret = -ENOENT; + goto out; + } if (cmd->cmd_cookie != nbd_handle_to_cookie(handle)) { dev_err(disk_to_dev(nbd->disk), "Double reply on req %p, cmd_cookie %u, handle cookie %u\n", req, cmd->cmd_cookie, nbd_handle_to_cookie(handle)); @@ -980,6 +991,8 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index) * returns EAGAIN can be retried on a different socket. */ ret = nbd_send_cmd(nbd, cmd, index); + if (!ret) + set_bit(NBD_CMD_INFLIGHT, &cmd->flags); if (ret == -EAGAIN) { dev_err_ratelimited(disk_to_dev(nbd->disk), "Request send failed, requeueing\n");