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=-8.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 7DBE4C282DD for ; Fri, 10 Jan 2020 15:47:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50CE520721 for ; Fri, 10 Jan 2020 15:47:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=joelfernandes.org header.i=@joelfernandes.org header.b="LcxSVzG5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728384AbgAJPrZ (ORCPT ); Fri, 10 Jan 2020 10:47:25 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:40311 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728137AbgAJPrY (ORCPT ); Fri, 10 Jan 2020 10:47:24 -0500 Received: by mail-pf1-f194.google.com with SMTP id q8so1319093pfh.7 for ; Fri, 10 Jan 2020 07:47:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=joelfernandes.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=z4ABlzGfi6l9NY75xhWGkqHQ22z62lYF4lGV0Z/l5RI=; b=LcxSVzG5beLFAGBipNshQyqz86YJ4TvGiOt8WALynXqSjPkkq7quMQSkFPFePo5f1q kJd0E4o7b+dPaAwBlXzfg5j5FKpHhUCAp057Fb328BFbzN8FK/VNHdiDhDR1bzkAooFs EzOxEsiGw18GT7yVSM8MCsgBXWLwE304YYV4c= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=z4ABlzGfi6l9NY75xhWGkqHQ22z62lYF4lGV0Z/l5RI=; b=oWeqlmpN9SU350nJaPc6pg/AKzoZ3OVKyLNpLLxbxOi/YuofFT8Q9S8C0fORdzyGGJ 3VY3+IDvdiMMFUdNAcX39utDW69EZXjsxwq8BQT5nriUEoyhSb4Yp1QeJ46r5ZbzIr/z iudRQU/GP+QhaPT4ktd2DRaBTAqNL7CW4aS1GaKfYp3H9Q9NwUE0oNOhXMVa+fJSpJup A31PfFgHskQozayKxRCE6As0Ka2ynnwvE6GUj5WMIyJBuzaBZBx6Hto1sNgSSE05RukF XzEk35P+EAxCHhs9iA1lVIRZEquZPOOfrXRsWikBlO7Bagmpur1aQ0+G7ZcUgzHLTJPp disg== X-Gm-Message-State: APjAAAUmFyh/mlJmsAdQbRGWXL7Kfh9qQORGFPyr1bCW0kHIfb8Z2gcq G7Qch5Wvc8lXhPIbEE4/J9ARoA== X-Google-Smtp-Source: APXvYqwJtzElrbQ8rKden7GP/HTNQxSyjLQOYjfY8yPFbp0XjIM+yXed9Z3lzn1NH9U0cYSbLjiIow== X-Received: by 2002:a62:c583:: with SMTP id j125mr5021922pfg.27.1578671244168; Fri, 10 Jan 2020 07:47:24 -0800 (PST) Received: from localhost ([2620:15c:6:12:9c46:e0da:efbf:69cc]) by smtp.gmail.com with ESMTPSA id z26sm3137300pgu.80.2020.01.10.07.47.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jan 2020 07:47:23 -0800 (PST) Date: Fri, 10 Jan 2020 10:47:22 -0500 From: Joel Fernandes To: Amol Grover Cc: Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, Madhuparna Bhowmik , "Paul E . McKenney" Subject: Re: [PATCH] drivers: nvme: target: core: Pass lockdep expression to RCU lists Message-ID: <20200110154722.GA128013@google.com> References: <20200110132356.27110-1-frextrite@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200110132356.27110-1-frextrite@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 10, 2020 at 06:53:58PM +0530, Amol Grover wrote: > ctrl->subsys->namespaces and subsys->namespaces are traversed with > hlist_for_each_entry_rcu outside an RCU read-side critical section > but under the protection of subsys->lock. > > Hence, add the corresponding lockdep expression to the list traversal > primitive to silence false-positive lockdep warnings, and > harden RCU lists. > > Add macro for the corresponding lockdep expression to make the code > clean and concise. Amol, thanks. Could you fix this checkpatch warnings? hint: Use --fix-inplace CHECK: Alignment should match open parenthesis #50: FILE: drivers/nvme/target/core.c:562: + list_for_each_entry_rcu(old, &subsys->namespaces, dev_link, + subsys_lock_held()) { CHECK: Alignment should match open parenthesis #60: FILE: drivers/nvme/target/core.c:1180: + list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link, + subsys_lock_held()) Otherwise, Reviewed-by: Joel Fernandes (Google) thanks, - Joel > > Signed-off-by: Amol Grover > --- > drivers/nvme/target/core.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c > index 28438b833c1b..7caab4ba6a04 100644 > --- a/drivers/nvme/target/core.c > +++ b/drivers/nvme/target/core.c > @@ -15,6 +15,9 @@ > > #include "nvmet.h" > > +#define subsys_lock_held() \ > + lockdep_is_held(&subsys->lock) > + > struct workqueue_struct *buffered_io_wq; > static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX]; > static DEFINE_IDA(cntlid_ida); > @@ -555,7 +558,8 @@ int nvmet_ns_enable(struct nvmet_ns *ns) > } else { > struct nvmet_ns *old; > > - list_for_each_entry_rcu(old, &subsys->namespaces, dev_link) { > + list_for_each_entry_rcu(old, &subsys->namespaces, dev_link, > + subsys_lock_held()) { > BUG_ON(ns->nsid == old->nsid); > if (ns->nsid < old->nsid) > break; > @@ -1172,7 +1176,8 @@ static void nvmet_setup_p2p_ns_map(struct nvmet_ctrl *ctrl, > > ctrl->p2p_client = get_device(req->p2p_client); > > - list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) > + list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link, > + subsys_lock_held()) > nvmet_p2pmem_ns_add_p2p(ctrl, ns); > } > > -- > 2.24.1 >