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=-15.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 B5FE9C48BDF for ; Thu, 24 Jun 2021 06:36:07 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 78F91613C7 for ; Thu, 24 Jun 2021 06:36:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 78F91613C7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=sU6kJlThuz2BSEaNZp8qpvSxWVVkUW1bFNGvlCnFO4E=; b=NnK0pD4ambtkcp Y9jsI8wOM/b0T5sqtW4aQ/oAHr0TE8Pbf+Q8A/0+5JgRPEAWeRVbPK6DPb39RNsuZaaSsEKUjDHLt 9UaRi3qV7/jLOjVFKtDn9WVRFmJN7Na/oSnRT+oh1ClufODCb/QQTx1iTqQLaJmGw5wuDMTgncHhq GMNoXYGBJ5jof1V5euVfedPVGrLtbmujd5Dm8sUJcPlhe09iV3QRrCg868SpCoBi+4K11AkVOj3pp HY06xN6WRT4OnsiGXKOUysW67yUq4lyiWJ+Vp1polCehY8hZmaxZWsBMI/zHhMQ/vf9atz6i7ICpA 5GUkg432KNPFl4Q8IYaQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1lwIxx-00D05c-BY; Thu, 24 Jun 2021 06:35:57 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1lwIxu-00D04z-2g for linux-nvme@lists.infradead.org; Thu, 24 Jun 2021 06:35:55 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6D49D68AFE; Thu, 24 Jun 2021 08:35:51 +0200 (CEST) Date: Thu, 24 Jun 2021 08:35:51 +0200 From: Christoph Hellwig To: Prabhakar Kushwaha Cc: linux-nvme@lists.infradead.org, sagi@grimberg.me, hch@lst.de, kbusch@kernel.org, axboe@fb.com, martin.belanger@dell.com, aelior@marvell.com, okulkarni@marvell.com, smalin@marvell.com, prabhakar.pkin@gmail.com, malin1024@gmail.com Subject: Re: [PATCH] nvme-tcp: Use __dev_get_by_name instead dev_get_by_name for OPT_HOST_IFACE Message-ID: <20210624063551.GB26612@lst.de> References: <20210618133956.10637-1-pkushwaha@marvell.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210618133956.10637-1-pkushwaha@marvell.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210623_233554_321934_73265503 X-CRM114-Status: GOOD ( 17.81 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org I've applied the slightly updated version below to make it a little more clear what is going on: --- >From 9de7d173c10b6be09fe9d5b7010ef182465897a1 Mon Sep 17 00:00:00 2001 From: Prabhakar Kushwaha Date: Fri, 18 Jun 2021 16:39:56 +0300 Subject: nvme-tcp: use __dev_get_by_name instead dev_get_by_name for OPT_HOST_IFACE dev_get_by_name() finds network device by name but it also increases the reference count. If a nvme-tcp queue is present and the network device driver is removed before nvme_tcp, we will face the following continuous log: "kernel:unregister_netdevice: waiting for to become free. Usage count = 2" And rmmod further halts. Similar case arises during reboot/shutdown with nvme-tcp queue present and both never completes. To fix this, use __dev_get_by_name() which finds network device by name without increasing any reference counter. Fixes: 3ede8f72a9a2 ("nvme-tcp: allow selecting the network interface for connections") Signed-off-by: Omkar Kulkarni Signed-off-by: Shai Malin Signed-off-by: Prabhakar Kushwaha Reviewed-by: Sagi Grimberg [hch: remove the ->ndev member entirely] Signed-off-by: Christoph Hellwig --- drivers/nvme/host/tcp.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index c7bd37103cf4..2b46c6e0226f 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -123,7 +123,6 @@ struct nvme_tcp_ctrl { struct blk_mq_tag_set admin_tag_set; struct sockaddr_storage addr; struct sockaddr_storage src_addr; - struct net_device *ndev; struct nvme_ctrl ctrl; struct work_struct err_work; @@ -2533,8 +2532,7 @@ static struct nvme_ctrl *nvme_tcp_create_ctrl(struct device *dev, } if (opts->mask & NVMF_OPT_HOST_IFACE) { - ctrl->ndev = dev_get_by_name(&init_net, opts->host_iface); - if (!ctrl->ndev) { + if (!__dev_get_by_name(&init_net, opts->host_iface)) { pr_err("invalid interface passed: %s\n", opts->host_iface); ret = -ENODEV; -- 2.30.2 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme