From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754205AbdLGSAr (ORCPT ); Thu, 7 Dec 2017 13:00:47 -0500 Received: from fldsmtpe03.verizon.com ([140.108.26.142]:60661 "EHLO fldsmtpe03.verizon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755866AbdLGPsk (ORCPT ); Thu, 7 Dec 2017 10:48:40 -0500 From: alexander.levin@verizon.com Cc: Christoph Hellwig , alexander.levin@verizon.com X-Host: mariner.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.14 075/135] nvme: use kref_get_unless_zero in nvme_find_get_ns Thread-Topic: [PATCH AUTOSEL for 4.14 075/135] nvme: use kref_get_unless_zero in nvme_find_get_ns Thread-Index: AQHTb3J0h/hbmbNrp0iWwxWZOOOZqQ== Date: Thu, 7 Dec 2017 15:45:48 +0000 Message-ID: <20171207154513.4154-75-alexander.levin@verizon.com> References: <20171207154513.4154-1-alexander.levin@verizon.com> In-Reply-To: <20171207154513.4154-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vB7I1lLM011666 From: Christoph Hellwig [ Upstream commit 2dd4122854f697afc777582d18548dded03ce5dd ] For kref_get_unless_zero to protect against lookup vs free races we need to use it in all places where we aren't guaranteed to already hold a reference. There is no such guarantee in nvme_find_get_ns, so switch to kref_get_unless_zero in this function. Signed-off-by: Christoph Hellwig Reviewed-by: Sagi Grimberg Reviewed-by: Hannes Reinecke Reviewed-by: Johannes Thumshirn Signed-off-by: Sasha Levin --- drivers/nvme/host/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 37f9039bb9ca..0655f45643d9 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -2299,7 +2299,8 @@ static struct nvme_ns *nvme_find_get_ns(struct nvme_ctrl *ctrl, unsigned nsid) mutex_lock(&ctrl->namespaces_mutex); list_for_each_entry(ns, &ctrl->namespaces, list) { if (ns->ns_id == nsid) { - kref_get(&ns->kref); + if (!kref_get_unless_zero(&ns->kref)) + continue; ret = ns; break; } -- 2.11.0