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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 A5763C07E99 for ; Mon, 12 Jul 2021 13:24:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 89B9861106 for ; Mon, 12 Jul 2021 13:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233822AbhGLN0x (ORCPT ); Mon, 12 Jul 2021 09:26:53 -0400 Received: from szxga01-in.huawei.com ([45.249.212.187]:6805 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233578AbhGLN0w (ORCPT ); Mon, 12 Jul 2021 09:26:52 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4GNkq55C33zXs7H; Mon, 12 Jul 2021 21:18:25 +0800 (CST) Received: from dggema761-chm.china.huawei.com (10.1.198.203) 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; Mon, 12 Jul 2021 21:24:01 +0800 Received: from [10.174.178.46] (10.174.178.46) by dggema761-chm.china.huawei.com (10.1.198.203) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 12 Jul 2021 21:24:00 +0800 Subject: Re: [PATCH] nvme-pci: Don't WARN_ON in nvme_reset_work if ctrl.state is not RESETTING To: , , , , CC: , , References: <20210705133829.349660-1-chengzhihao1@huawei.com> From: Zhihao Cheng Message-ID: <2563e82f-6e0a-4c54-9ca8-afd7b7754246@huawei.com> Date: Mon, 12 Jul 2021 21:24:00 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20210705133829.349660-1-chengzhihao1@huawei.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.178.46] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggema761-chm.china.huawei.com (10.1.198.203) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ÔÚ 2021/7/5 21:38, Zhihao Cheng дµÀ: > Followling process: > nvme_probe > nvme_reset_ctrl > nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING) > queue_work(nvme_reset_wq, &ctrl->reset_work) > > --------------> nvme_remove > nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING) > worker_thread > process_one_work > nvme_reset_work > WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING) > > , which will trigger WARN_ON in nvme_reset_work(): > [ 127.534298] WARNING: CPU: 0 PID: 139 at drivers/nvme/host/pci.c:2594 > [ 127.536161] CPU: 0 PID: 139 Comm: kworker/u8:7 Not tainted 5.13.0 > [ 127.552518] Call Trace: > [ 127.552840] ? kvm_sched_clock_read+0x25/0x40 > [ 127.553936] ? native_send_call_func_single_ipi+0x1c/0x30 > [ 127.555117] ? send_call_function_single_ipi+0x9b/0x130 > [ 127.556263] ? __smp_call_single_queue+0x48/0x60 > [ 127.557278] ? ttwu_queue_wakelist+0xfa/0x1c0 > [ 127.558231] ? try_to_wake_up+0x265/0x9d0 > [ 127.559120] ? ext4_end_io_rsv_work+0x160/0x290 > [ 127.560118] process_one_work+0x28c/0x640 > [ 127.561002] worker_thread+0x39a/0x700 > [ 127.561833] ? rescuer_thread+0x580/0x580 > [ 127.562714] kthread+0x18c/0x1e0 > [ 127.563444] ? set_kthread_struct+0x70/0x70 > [ 127.564347] ret_from_fork+0x1f/0x30 > > The preceding problem can be easily reproduced by executing following > script (based on blktests suite): > test() { > pdev="$(_get_pci_dev_from_blkdev)" > sysfs="/sys/bus/pci/devices/${pdev}" > for ((i = 0; i < 10; i++)); do > echo 1 > "$sysfs/remove" > echo 1 > /sys/bus/pci/rescan > done > } > > Since the device ctrl could be updated as an non-RESETTING state by > repeating probe/remove in userspace (which is a normal situation), we > can replace stack dumping WARN_ON with a warnning message. > > Fixes: 82b057caefaff ("nvme-pci: fix multiple ctrl removal schedulin") > Signed-off-by: Zhihao Cheng > --- > drivers/nvme/host/pci.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index a29b170701fc..966a4c84e699 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -2591,7 +2591,9 @@ static void nvme_reset_work(struct work_struct *work) > bool was_suspend = !!(dev->ctrl.ctrl_config & NVME_CC_SHN_NORMAL); > int result; > > - if (WARN_ON(dev->ctrl.state != NVME_CTRL_RESETTING)) { > + if (dev->ctrl.state != NVME_CTRL_RESETTING) { > + dev_warn(dev->ctrl.device, "ctrl state %d is not RESETTING\n", > + dev->ctrl.state); > result = -ENODEV; > goto out; > } friendly ping