From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69C3C1427A for ; Tue, 8 Aug 2023 18:41:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05EC0C433C7; Tue, 8 Aug 2023 18:41:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691520087; bh=Lc7JVkNFcw65RIJUGUc7Ey8+fVjd9Ixy2Gj31K040wA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=IQYu/FVKgUAdSrDKuV0MH2RIjnSFK7i83eSY6On0P6crpWYl7Mo9uARai5o5vRgyD dionhFqRqEafk/TxbbDk6Y7dwqmGUguFR12+zgjlbXWJiTxcliWUNLhOfumdSFTQEc EhOkx/aati3Pv62QLBWauYMGKwYQm/unl15rnEXbAvW6E9FRsKc7iqcQ1nuSozi+QB lyp4dQ4K6U0iD6WMyLEPdA4nTPI3WOa3S2I0bTuGNXnIzoKifGoYFoqfb3pk5o42Kz 0xWVikaBSA/mP0h8d1kWVNi8aQYiP56E+uWRn1hVBLNYL8QIa68k2SmocFhpA2DpaB erW8A3s/9tE0w== Date: Tue, 8 Aug 2023 21:41:16 +0300 From: Leon Romanovsky To: Jijie Shao Cc: yisen.zhuang@huawei.com, salil.mehta@huawei.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, shenjian15@huawei.com, wangjie125@huawei.com, liuyonglong@huawei.com, wangpeiyang1@huawei.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 net 4/4] net: hns3: fix deadlock issue when externel_lb and reset are executed together Message-ID: <20230808184116.GF94631@unreal> References: <20230807113452.474224-1-shaojijie@huawei.com> <20230807113452.474224-5-shaojijie@huawei.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230807113452.474224-5-shaojijie@huawei.com> On Mon, Aug 07, 2023 at 07:34:52PM +0800, Jijie Shao wrote: > From: Yonglong Liu > > When externel_lb and reset are executed together, a deadlock may > occur: > [ 3147.217009] INFO: task kworker/u321:0:7 blocked for more than 120 seconds. > [ 3147.230483] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. > [ 3147.238999] task:kworker/u321:0 state:D stack: 0 pid: 7 ppid: 2 flags:0x00000008 > [ 3147.248045] Workqueue: hclge hclge_service_task [hclge] > [ 3147.253957] Call trace: > [ 3147.257093] __switch_to+0x7c/0xbc > [ 3147.261183] __schedule+0x338/0x6f0 > [ 3147.265357] schedule+0x50/0xe0 > [ 3147.269185] schedule_preempt_disabled+0x18/0x24 > [ 3147.274488] __mutex_lock.constprop.0+0x1d4/0x5dc > [ 3147.279880] __mutex_lock_slowpath+0x1c/0x30 > [ 3147.284839] mutex_lock+0x50/0x60 > [ 3147.288841] rtnl_lock+0x20/0x2c > [ 3147.292759] hclge_reset_prepare+0x68/0x90 [hclge] > [ 3147.298239] hclge_reset_subtask+0x88/0xe0 [hclge] > [ 3147.303718] hclge_reset_service_task+0x84/0x120 [hclge] > [ 3147.309718] hclge_service_task+0x2c/0x70 [hclge] > [ 3147.315109] process_one_work+0x1d0/0x490 > [ 3147.319805] worker_thread+0x158/0x3d0 > [ 3147.324240] kthread+0x108/0x13c > [ 3147.328154] ret_from_fork+0x10/0x18 > > In externel_lb process, the hns3 driver call napi_disable() > first, then the reset happen, then the restore process of the > externel_lb will fail, and will not call napi_enable(). When > doing externel_lb again, napi_disable() will be double call, > cause a deadlock of rtnl_lock(). > > This patch use the HNS3_NIC_STATE_DOWN state to protect the > calling of napi_disable() and napi_enable() in externel_lb > process, just as the usage in ndo_stop() and ndo_start(). > > Fixes: 04b6ba143521 ("net: hns3: add support for external loopback test") > Signed-off-by: Yonglong Liu > Signed-off-by: Jijie Shao > --- > drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 14 +++++++++++++- > 1 file changed, 13 insertions(+), 1 deletion(-) > Thanks, Reviewed-by: Leon Romanovsky