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 5E9A3ECE58C for ; Wed, 9 Oct 2019 17:31:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 350CD2190F for ; Wed, 9 Oct 2019 17:31:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570642276; bh=HqvXM5KNaKG/zgmqzl+/ZTz93tY+4j8tnfWyNVjau/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=GSxbLn2mEsZxaw/WoWNkY+0aVzkLHE+Iu1cxw/3DwujCf2xKio6e4Y9Om9hDyYwYW KvaXcwJeLh5NY42Um1P7RsnXU7i+yXaGTRsSCTaxUgHUS7i0fbbLp1OCORSIxK/MDk qvhfLtohfJhCSdL2C8LSmjmyAD1i4t4c3hbXu+C4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732839AbfJIRbP (ORCPT ); Wed, 9 Oct 2019 13:31:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:48510 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732096AbfJIRYE (ORCPT ); Wed, 9 Oct 2019 13:24:04 -0400 Received: from sasha-vm.mshome.net (unknown [167.220.2.234]) (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 C89FA21929; Wed, 9 Oct 2019 17:24:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570641843; bh=HqvXM5KNaKG/zgmqzl+/ZTz93tY+4j8tnfWyNVjau/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rB5L71OlaJzeuc1a/F/Pbtv9Vc7iaYO+SZdYz6wCuOFoix7ep6I7vNivjCxCBBS71 HdVP5OkKi6AYGku9I9EE/dqhh5sMKEaD8G+AEAANn7sT1GQcdVdFG+K79m7gudPJUw bSyb7VCEwXH/D6iaKfeZ3OWFbLbxwKr+NXYijJP8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Balbir Singh , Keith Busch , Sagi Grimberg , Sasha Levin , linux-nvme@lists.infradead.org Subject: [PATCH AUTOSEL 4.19 02/26] nvme-pci: Fix a race in controller removal Date: Wed, 9 Oct 2019 13:05:34 -0400 Message-Id: <20191009170558.32517-2-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191009170558.32517-1-sashal@kernel.org> References: <20191009170558.32517-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Balbir Singh [ Upstream commit b224726de5e496dbf78147a66755c3d81e28bdd2 ] User space programs like udevd may try to read to partitions at the same time the driver detects a namespace is unusable, and may deadlock if revalidate_disk() is called while such a process is waiting to enter the frozen queue. On detecting a dead namespace, move the disk revalidate after unblocking dispatchers that may be holding bd_butex. changelog Suggested-by: Keith Busch Signed-off-by: Balbir Singh Reviewed-by: Keith Busch Signed-off-by: Sagi Grimberg Signed-off-by: Sasha Levin --- drivers/nvme/host/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index ae0b01059fc6d..5d0f99bcc987f 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -111,10 +111,13 @@ static void nvme_set_queue_dying(struct nvme_ns *ns) */ if (!ns->disk || test_and_set_bit(NVME_NS_DEAD, &ns->flags)) return; - revalidate_disk(ns->disk); blk_set_queue_dying(ns->queue); /* Forcibly unquiesce queues to avoid blocking dispatch */ blk_mq_unquiesce_queue(ns->queue); + /* + * Revalidate after unblocking dispatchers that may be holding bd_butex + */ + revalidate_disk(ns->disk); } static void nvme_queue_scan(struct nvme_ctrl *ctrl) -- 2.20.1