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 66F1DC4CECD for ; Wed, 18 Sep 2019 00:27:44 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 34710206C2 for ; Wed, 18 Sep 2019 00:27:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="TF+sDs0K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34710206C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=amzn.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:To :From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ISa47YBbQXw6HwLXvQRAbtzXxZOWfGQiAc8HIhHhJvU=; b=TF+sDs0KJXbeYp /iXP2aoieIeivU086jhxmZwMv2UgCZIXT9+VPY8TTINnz8gLDfEPH38pkcakC4AikehERomhpJLaZ RTI3WD5A1CiXzFpielLBV7saVwVE/K98AjuB6pphMTAn8u04Ztmzs3mvCwb4H+jqdGxGFVXG2Std0 PUqm9QPec0WhOrzOV6WR+U939P/+k4JtW26IGLRlNZbKVijiKOcGrlZdhGrJSLbUrrfykE9cCXklG aIL7JBKcl4Q7H0dkDbUk80JMND2ISNA6RFq3BUWzYZNlEc85Z+P4zyz1GxAxI56G+OOWh932M6q49 NQ48nEO8JGAyKS2+t4CQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.2 #3 (Red Hat Linux)) id 1iANop-0007c8-Lm; Wed, 18 Sep 2019 00:27:39 +0000 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iANom-0007bb-40 for linux-nvme@lists.infradead.org; Wed, 18 Sep 2019 00:27:37 +0000 X-IronPort-AV: E=Sophos;i="5.64,518,1559520000"; d="scan'208";a="833569971" Received: from sea3-co-svc-lb6-vlan2.sea.amazon.com (HELO email-inbound-relay-2c-397e131e.us-west-2.amazon.com) ([10.47.22.34]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 18 Sep 2019 00:27:23 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2c-397e131e.us-west-2.amazon.com (Postfix) with ESMTPS id 9E9AEA2226; Wed, 18 Sep 2019 00:27:23 +0000 (UTC) Received: from EX13D23UWC001.ant.amazon.com (10.43.162.196) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 18 Sep 2019 00:27:23 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D23UWC001.ant.amazon.com (10.43.162.196) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 18 Sep 2019 00:27:22 +0000 Received: from localhost (172.23.204.141) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 18 Sep 2019 00:27:22 +0000 From: Balbir Singh To: Subject: [PATCH v4] nvme/host/pci: Fix a race in controller removal Date: Wed, 18 Sep 2019 00:27:20 +0000 Message-ID: <20190918002720.18330-1-sblbir@amzn.com> X-Mailer: git-send-email 2.16.5 MIME-Version: 1.0 Precedence: Bulk X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190917_172736_204035_464A8D16 X-CRM114-Status: GOOD ( 10.13 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kbusch@kernel.org, axboe@fb.com, Balbir Singh , hch@lst.de, sagi@grimberg.me Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org 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 --- Changelov v4 - Simplify the changelog Changelog v3 - Simplify the comment about moving revalidate_disk Changelog v2 - Rely on blk_set_queue_dying to do the wake_all() 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 b45f82d58be8..6ad1f1df9e44 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -103,10 +103,13 @@ 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) -- 2.16.5 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme