From patchwork Wed May 18 12:26:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yu Kuai X-Patchwork-Id: 12853590 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3157EC4332F for ; Wed, 18 May 2022 12:13:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236285AbiERMNB (ORCPT ); Wed, 18 May 2022 08:13:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236264AbiERMMt (ORCPT ); Wed, 18 May 2022 08:12:49 -0400 Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C374714B669; Wed, 18 May 2022 05:12:39 -0700 (PDT) Received: from kwepemi100016.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4L3BZQ49YlzCsjp; Wed, 18 May 2022 20:07:42 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by kwepemi100016.china.huawei.com (7.221.188.123) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 18 May 2022 20:12:37 +0800 Received: from huawei.com (10.175.127.227) by kwepemm600009.china.huawei.com (7.193.23.164) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 18 May 2022 20:12:36 +0800 From: Yu Kuai To: , , CC: , , , , Subject: [PATCH -next v2 3/6] nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed Date: Wed, 18 May 2022 20:26:15 +0800 Message-ID: <20220518122618.1702997-4-yukuai3@huawei.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220518122618.1702997-1-yukuai3@huawei.com> References: <20220518122618.1702997-1-yukuai3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Otherwise io will hung because request will only be completed if the cmd has the flag 'NBD_CMD_INFLIGHT'. Fixes: 07175cb1baf4 ("nbd: make sure request completion won't concurrent") Signed-off-by: Yu Kuai --- drivers/block/nbd.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index 2ee1e376d5c4..a0d0910dae2a 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -403,13 +403,14 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, if (!mutex_trylock(&cmd->lock)) return BLK_EH_RESET_TIMER; - if (!__test_and_clear_bit(NBD_CMD_INFLIGHT, &cmd->flags)) { + if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) { mutex_unlock(&cmd->lock); return BLK_EH_DONE; } if (!refcount_inc_not_zero(&nbd->config_refs)) { cmd->status = BLK_STS_TIMEOUT; + __clear_bit(NBD_CMD_INFLIGHT, &cmd->flags); mutex_unlock(&cmd->lock); goto done; } @@ -478,6 +479,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req, dev_err_ratelimited(nbd_to_dev(nbd), "Connection timed out\n"); set_bit(NBD_RT_TIMEDOUT, &config->runtime_flags); cmd->status = BLK_STS_IOERR; + __clear_bit(NBD_CMD_INFLIGHT, &cmd->flags); mutex_unlock(&cmd->lock); sock_shutdown(nbd); nbd_config_put(nbd); @@ -745,7 +747,7 @@ static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index, cmd = blk_mq_rq_to_pdu(req); mutex_lock(&cmd->lock); - if (!__test_and_clear_bit(NBD_CMD_INFLIGHT, &cmd->flags)) { + if (!test_bit(NBD_CMD_INFLIGHT, &cmd->flags)) { dev_err(disk_to_dev(nbd->disk), "Suspicious reply %d (status %u flags %lu)", tag, cmd->status, cmd->flags); ret = -ENOENT; @@ -854,8 +856,16 @@ static void recv_work(struct work_struct *work) } rq = blk_mq_rq_from_pdu(cmd); - if (likely(!blk_should_fake_timeout(rq->q))) - blk_mq_complete_request(rq); + if (likely(!blk_should_fake_timeout(rq->q))) { + bool complete; + + mutex_lock(&cmd->lock); + complete = __test_and_clear_bit(NBD_CMD_INFLIGHT, + &cmd->flags); + mutex_unlock(&cmd->lock); + if (complete) + blk_mq_complete_request(rq); + } percpu_ref_put(&q->q_usage_counter); }