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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 56C59CDE008 for ; Fri, 26 Jun 2026 06:40:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Tkl1F+PeL8LjSKVfU4hFQjEK6MtNlA5RxXorsZD4Ex0=; b=yVPJEizHV/ZogWypxmrEGxsnUw PdCOV/8hjqMdRY85XK7nZO5GzYg2DkAsDtg4fl1qI/CRn6sIMAQyFYqvj0U+oiPHz4dJWGqACyGuB gGeZEqZa5Bs5Ba/NLAwKbafgDpzT5Em87N52SE93fWFFQCqqgcCzzbusW/bRGrWdhc/k/bKyo0nIN fHWLq+Qp3i4F0asLOqW9/6iWLfDDMx7/gM1MOcg6GE6DS3krX5NJFmCA/b2MUSNnqXkKWn4akhWW4 /7erLQaNv52d5LrAJtIU065RMAvvK/1+N2ZO6S9UD4YyXe32QBrC/F3ywWb/UHNBIHiReEb2BO7mn fhmg2SIQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd0FF-0000000Abui-08Jq; Fri, 26 Jun 2026 06:40:57 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wd0FC-0000000AbuG-2NsB for linux-nvme@lists.infradead.org; Fri, 26 Jun 2026 06:40:55 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id E087A68B05; Fri, 26 Jun 2026 08:40:50 +0200 (CEST) Date: Fri, 26 Jun 2026 08:40:50 +0200 From: Christoph Hellwig To: Nilay Shroff Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, kbusch@kernel.org, sagi@grimberg.me, axboe@fb.com, bvanassche@acm.org, elver@google.com, gjoyce@linux.ibm.com, "Paul E. McKenney" Subject: Re: [PATCHv2 05/17] nvme: add Clang context annotations for nvme_ns_head::current_path Message-ID: <20260626064050.GE10731@lst.de> References: <20260614131541.2017845-1-nilay@linux.ibm.com> <20260614131541.2017845-6-nilay@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260614131541.2017845-6-nilay@linux.ibm.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260625_234054_773425_0C8A0CE6 X-CRM114-Status: GOOD ( 15.22 ) 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: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Sun, Jun 14, 2026 at 06:45:20PM +0530, Nilay Shroff wrote: > +++ b/drivers/nvme/host/multipath.c > @@ -231,8 +231,16 @@ bool nvme_mpath_clear_current_path(struct nvme_ns *ns) > bool changed = false; > int node; > > + /* > + * This helper is used by namespace failover/teardown and I/O policy > + * update paths. We only compare the head->current_path[] pointer value > + * and do not dereference the referenced namespace, so suppress the > + * context analysis warning for this lockless inspection of the > + * __rcu_guarded pointer. > + */ > for_each_node(node) { > - if (ns == rcu_access_pointer(head->current_path[node])) { > + if (context_unsafe(ns == > + rcu_access_pointer(head->current_path[node]))) { I think we need a helper for this, as for a simple pointer value comparison without a dereference we don't really need either rcu_access_pointer nor locking. Maybe somthing like a rcu_compare_pointer(rcu_pointer, nonrcu_pointer) ?