From patchwork Tue Apr 5 07:23:39 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557512 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8584EC47088 for ; Tue, 5 Apr 2022 09:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242503AbiDEJhQ (ORCPT ); Tue, 5 Apr 2022 05:37:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235654AbiDEJCY (ORCPT ); Tue, 5 Apr 2022 05:02:24 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FD6C27FEA; Tue, 5 Apr 2022 01:54:21 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 93BCE61476; Tue, 5 Apr 2022 08:54:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A60B5C385A0; Tue, 5 Apr 2022 08:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649148860; bh=S2KuJRjgEpRjx8Areu8U+GZvYUTs9/nOiG/mM/dEr5Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=enAZeVgWP8ZWnJRSKK6hS2E+bQhTlZp2+bHmno6chf/9DWmOm7erYSUpHg222P0iX Sjbb5Kx842H50DbbfR4k9PE/ldq01ogY/lDSJOfe5/wPU1GYdWI9WioORH9Rk7ie/I JLn7eKl6sD5ZwXjrOXf6UEs6GT/h3qURYYI07k5c= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tong Zhang , Ira Weiny , Christoph Hellwig , Dan Williams , Sasha Levin Subject: [PATCH 5.16 0506/1017] dax: make sure inodes are flushed before destroy cache Date: Tue, 5 Apr 2022 09:23:39 +0200 Message-Id: <20220405070409.319682532@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tong Zhang [ Upstream commit a7e8de822e0b1979f08767c751f6c8a9c1d4ad86 ] A bug can be triggered by following command $ modprobe nd_pmem && modprobe -r nd_pmem [ 10.060014] BUG dax_cache (Not tainted): Objects remaining in dax_cache on __kmem_cache_shutdown() [ 10.060938] Slab 0x0000000085b729ac objects=9 used=1 fp=0x000000004f5ae469 flags=0x200000000010200(slab|head|node) [ 10.062433] Call Trace: [ 10.062673] dump_stack_lvl+0x34/0x44 [ 10.062865] slab_err+0x90/0xd0 [ 10.063619] __kmem_cache_shutdown+0x13b/0x2f0 [ 10.063848] kmem_cache_destroy+0x4a/0x110 [ 10.064058] __x64_sys_delete_module+0x265/0x300 This is caused by dax_fs_exit() not flushing inodes before destroy cache. To fix this issue, call rcu_barrier() before destroy cache. Signed-off-by: Tong Zhang Reviewed-by: Ira Weiny Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220212071111.148575-1-ztong0001@gmail.com Fixes: 7b6be8444e0f ("dax: refactor dax-fs into a generic provider of 'struct dax_device' instances") Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- drivers/dax/super.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index e20d0cef10a1..0e55dde937d2 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -612,6 +612,7 @@ static int dax_fs_init(void) static void dax_fs_exit(void) { kern_unmount(dax_mnt); + rcu_barrier(); kmem_cache_destroy(dax_cache); }