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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT 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 1D0B4C433FF for ; Wed, 31 Jul 2019 23:35:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECD0120449 for ; Wed, 31 Jul 2019 23:35:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730802AbfGaXfl (ORCPT ); Wed, 31 Jul 2019 19:35:41 -0400 Received: from ale.deltatee.com ([207.54.116.67]:39844 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728171AbfGaXfl (ORCPT ); Wed, 31 Jul 2019 19:35:41 -0400 Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hsy8B-0003W5-Ki; Wed, 31 Jul 2019 17:35:40 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.89) (envelope-from ) id 1hsy89-0001Gw-Ok; Wed, 31 Jul 2019 17:35:37 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Cc: Christoph Hellwig , Keith Busch , Jens Axboe , Sagi Grimberg , Chaitanya Kulkarni , Max Gurtovoy , Logan Gunthorpe Date: Wed, 31 Jul 2019 17:35:32 -0600 Message-Id: <20190731233534.4841-3-logang@deltatee.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190731233534.4841-1-logang@deltatee.com> References: <20190731233534.4841-1-logang@deltatee.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, hch@lst.de, kbusch@kernel.org, axboe@fb.com, sagi@grimberg.me, chaitanya.kulkarni@wdc.com, maxg@mellanox.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v3 2/4] nvmet-loop: Flush nvme_delete_wq when removing the port X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org After calling nvme_loop_delete_ctrl(), the controllers will not yet be deleted because nvme_delete_ctrl() only schedules work to do the delete. This means a race can occur if a port is removed but there are still active controllers trying to access that memory. To fix this, flush the nvme_delete_wq before returning from nvme_loop_remove_port() so that any controllers that might be in the process of being deleted won't access a freed port. Signed-off-by: Logan Gunthorpe Reviewed-by: Sagi Grimberg Reviewed-by: Max Gurtovoy --- drivers/nvme/target/loop.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index b16dc3981c69..0940c5024a34 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -654,6 +654,14 @@ static void nvme_loop_remove_port(struct nvmet_port *port) mutex_lock(&nvme_loop_ports_mutex); list_del_init(&port->entry); mutex_unlock(&nvme_loop_ports_mutex); + + /* + * Ensure any ctrls that are in the process of being + * deleted are in fact deleted before we return + * and free the port. This is to prevent active + * ctrls from using a port after it's freed. + */ + flush_workqueue(nvme_delete_wq); } static const struct nvmet_fabrics_ops nvme_loop_ops = { -- 2.20.1