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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 02BD5C76191 for ; Mon, 15 Jul 2019 14:56:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CF30C2067C for ; Mon, 15 Jul 2019 14:56:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563202578; bh=uNbRFgTFVlfLBX/aYNoEramw/MRSETRomrDvkiKnYgE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YxaVJV1oYIagY2usiYQknZxz+Due0K0oUbzV896gjVzh08bzRRF1n0jdO0cYbAVV8 GSdExIIpvE4zG2rsOF2cY0cfPB52kDo/eMQBK2wi0v6bRY4g4nsMfljt8XnT7YkuLw ArkdEhF7ZvHgNc6oUS2cEI+ucamFzAxUIXPaFDvw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390710AbfGOOXK (ORCPT ); Mon, 15 Jul 2019 10:23:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:53716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730883AbfGOOXK (ORCPT ); Mon, 15 Jul 2019 10:23:10 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 374CF2184E; Mon, 15 Jul 2019 14:23:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200589; bh=uNbRFgTFVlfLBX/aYNoEramw/MRSETRomrDvkiKnYgE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mIr7TgFeOmG/Q5x23EBPYvH/DOugIC4B0wNGyq9p+P6OjaPzcxda4jM7UJIKLQkzS 0Nw7WprjT4sjPn3NIVvKHhSrcPJ6jphp1loAPYSbFr+D5tTnq0WI8LUiGkIXGU+Kxi B4kZs+HYl5r9sBb3Bt/FDH0ddaRKRsYi3KYLdoMQ= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Anton Eidelman , Sagi Grimberg , Christoph Hellwig , Sasha Levin , linux-nvme@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 085/158] nvme: fix possible io failures when removing multipathed ns Date: Mon, 15 Jul 2019 10:16:56 -0400 Message-Id: <20190715141809.8445-85-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715141809.8445-1-sashal@kernel.org> References: <20190715141809.8445-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Anton Eidelman [ 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 d8869d978c34..e26d1191c5ad 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3168,6 +3168,14 @@ 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) { sysfs_remove_group(&disk_to_dev(ns->disk)->kobj, &nvme_ns_id_attr_group); @@ -3179,16 +3187,10 @@ 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