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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 AEC05C76186 for ; Wed, 24 Jul 2019 19:50:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FBDC22ADA for ; Wed, 24 Jul 2019 19:50:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997807; bh=Fv1GO9PlmjTooBqbuFhXyMTElMJv3FrPLNhYlG03CHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Cftjs/aU+hKJQ9QoJog9zqFDOeGWBd58kp5KtlA3qqVq5ZF+pH6lOET5R600k/EAv xlHAx/XJloLxp0Rop+xAtEpJPYXAaNZ/ZKhndosMojAON/qT6VLa6JsTCsjGTyeS1H Tm8pIvUJNti0S2C05ysLI+MEr+7Dm9p0D/4WC70o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728767AbfGXTuG (ORCPT ); Wed, 24 Jul 2019 15:50:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:58432 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403826AbfGXTt6 (ORCPT ); Wed, 24 Jul 2019 15:49:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B964E22ADA; Wed, 24 Jul 2019 19:49:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563997798; bh=Fv1GO9PlmjTooBqbuFhXyMTElMJv3FrPLNhYlG03CHM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TJ19pM9mvNx/P+WGvoBsoro4X6VPmo31BZV2RP9F8LrZsBL1r6TNibqSvUxmTexc0 /ASSjGPhjOiVONsCNEizduQYmm56GQG5dEByxJoHLXZNB29A3zTUFDLN+0rfnoSa6T ugRrFhyFdS73q8ogadFbgEWUApOULalXDxQOWS58= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anton Eidelman , Sagi Grimberg , Christoph Hellwig , Sasha Levin Subject: [PATCH 5.1 120/371] nvme: fix possible io failures when removing multipathed ns Date: Wed, 24 Jul 2019 21:17:52 +0200 Message-Id: <20190724191733.868806918@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191724.382593077@linuxfoundation.org> References: <20190724191724.382593077@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 2181e455612a8db2761eabbf126640552a451e96 ] When a shared namespace is removed, we call blk_cleanup_queue() when the device can still be accessed as the current path and this can result in submission to a dying queue. Hence, direct_make_request() called by our mpath device may fail (propagating the failure to userspace). Instead, we want to failover this I/O to a different path if one exists. Thus, before we cleanup the request queue, we make sure that the device is cleared from the current path nor it can be selected again as such. Fix this by: - clear the ns from the head->list and synchronize rcu to make sure there is no concurrent path search that restores it as the current path - clear the mpath current path in order to trigger a subsequent path search and sync srcu to wait for any ongoing request submissions - safely continue to namespace removal and blk_cleanup_queue Signed-off-by: Anton Eidelman Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- drivers/nvme/host/core.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 3a390b2c7540..cbbdd3dae5a1 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3341,6 +3341,14 @@ static void nvme_ns_remove(struct nvme_ns *ns) return; nvme_fault_inject_fini(ns); + + mutex_lock(&ns->ctrl->subsys->lock); + list_del_rcu(&ns->siblings); + mutex_unlock(&ns->ctrl->subsys->lock); + synchronize_rcu(); /* guarantee not available in head->list */ + nvme_mpath_clear_current_path(ns); + synchronize_srcu(&ns->head->srcu); /* wait for concurrent submissions */ + if (ns->disk && ns->disk->flags & GENHD_FL_UP) { del_gendisk(ns->disk); blk_cleanup_queue(ns->queue); @@ -3348,16 +3356,10 @@ static void nvme_ns_remove(struct nvme_ns *ns) blk_integrity_unregister(ns->disk); } - mutex_lock(&ns->ctrl->subsys->lock); - list_del_rcu(&ns->siblings); - nvme_mpath_clear_current_path(ns); - mutex_unlock(&ns->ctrl->subsys->lock); - down_write(&ns->ctrl->namespaces_rwsem); list_del_init(&ns->list); up_write(&ns->ctrl->namespaces_rwsem); - synchronize_srcu(&ns->head->srcu); nvme_mpath_check_last_path(ns); nvme_put_ns(ns); } -- 2.20.1