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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19F97C43334 for ; Fri, 10 Jun 2022 06:07:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346402AbiFJGHu (ORCPT ); Fri, 10 Jun 2022 02:07:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52564 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235636AbiFJGHt (ORCPT ); Fri, 10 Jun 2022 02:07:49 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 20F362044E3; Thu, 9 Jun 2022 23:07:46 -0700 (PDT) Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4LK9Qj3k6szRhWb; Fri, 10 Jun 2022 14:04:29 +0800 (CST) Received: from kwepemm600009.china.huawei.com (7.193.23.164) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 10 Jun 2022 14:07:43 +0800 Received: from [10.174.176.73] (10.174.176.73) 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; Fri, 10 Jun 2022 14:07:42 +0800 Subject: Re: [PATCH -next v4 3/6] nbd: don't clear 'NBD_CMD_INFLIGHT' flag if request is not completed To: , , CC: , , , References: <20220528021235.2120995-1-yukuai3@huawei.com> <20220528021235.2120995-4-yukuai3@huawei.com> From: Yu Kuai Message-ID: <43a7b24c-6fd1-d6bd-4466-284d3a0962ac@huawei.com> Date: Fri, 10 Jun 2022 14:07:41 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20220528021235.2120995-4-yukuai3@huawei.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.73] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600009.china.huawei.com (7.193.23.164) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2022/05/28 10:12, Yu Kuai дµÀ: > 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 | 13 +++++++++---- > 1 file changed, 9 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index 2ee1e376d5c4..a673a97b9b6b 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; > @@ -813,6 +815,10 @@ static struct nbd_cmd *nbd_handle_reply(struct nbd_device *nbd, int index, > } > out: > trace_nbd_payload_received(req, handle); > + if (!ret && likely(!blk_should_fake_timeout(req->q))) > + __clear_bit(NBD_CMD_INFLIGHT, &cmd->flags); > + else if (!ret) > + ret = -ENOENT; Hi, Josef Do you prefer to move blk_should_fake_time() into nbd_handle_reply() like this ? Code is a litter simplier. Thanks, Kuai > mutex_unlock(&cmd->lock); > return ret ? ERR_PTR(ret) : cmd; > } > @@ -854,8 +860,7 @@ 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); > + blk_mq_complete_request(rq); > percpu_ref_put(&q->q_usage_counter); > } > >