From nobody Mon Jun 29 08:55:55 2026 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 AE05EC433EF for ; Sat, 12 Feb 2022 07:13:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232361AbiBLHLr (ORCPT ); Sat, 12 Feb 2022 02:11:47 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbiBLHLp (ORCPT ); Sat, 12 Feb 2022 02:11:45 -0500 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D80572716D for ; Fri, 11 Feb 2022 23:11:35 -0800 (PST) Received: by mail-pj1-x102b.google.com with SMTP id a11-20020a17090a740b00b001b8b506c42fso14057278pjg.0 for ; Fri, 11 Feb 2022 23:11:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xJWv4+1FQbvdMw4wXNISW5YNlFR3GL+Z3R6+p6cC0cc=; b=lBgkmU2opob3nAv4YJBAi7Ijhve5HmiVL/lIxW0/7P6OzFU0/Mh7ex2JlOG8luGs9H vpjykZkjt7W94Ni7KqUspWHtN0L5VfYJUQ6phxdGKl9TOmkLonCs/8g3SxsKgxnXkgg/ 98AuFJIy06P4vmrsYPVECQD6zZr2m0qsGsckeq7Gm07FVolyL+RUyS+S7sZO//Mogi0I c7NLtPpNMxJPNtdtESHGMhmKK1WUwjRkY+w+bo3Muco4+Uqmh5sgxfbAqEVlDOKbhPHq un2XdxIQXPyIezyPpk0phRyLImFAy8rDceBn5Mzvr3Hk1YuuCGpDpNYxuxOi5/HeyHDR vpfg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=xJWv4+1FQbvdMw4wXNISW5YNlFR3GL+Z3R6+p6cC0cc=; b=Fk67viQ2vSaorYImRLXEhu9e/JgtPU78xtgqMTWsu2J6CkkdP4EWPuAtrZEneHK7Fm Pv6KAKPyfzu7Ri2KTrX7sgbN2Hx2JUwz6gwg4xgOJxos7/athv7rXsU8Xy0TQd2Te6gb qpPdp9Bo3DJRYZTHJHiw1PqevSK8rnTpbZeWfkwsKQ32kpod7j5MlE8caqz1zfdQI31y /azlOMK9U27ACq/l6k0nf8lpU5uuhY0pS26h6T8plHZgOwQUs/B5dlTzDs4WkwPwD2XP nJmeMfqnLj1Zfa5Ys34slq9pMMqRJ3C+GEcBLg/WZ03Yd2CFmIUI/CXdF9HXmILsv7Z9 ucMg== X-Gm-Message-State: AOAM533O2AfYO5S7QX60hVgMDabcw+pxHPSwLX7CGPPpIGJD+zsrpC/I C7PSmYjWp0ixbWt0L1tqAXE= X-Google-Smtp-Source: ABdhPJwTA48YczQpfo6bhiUx1wcqZqvTgPvQut2lcZVm/LMuAOj6LdjJVrgHXf106G9P5rpFlGKCZQ== X-Received: by 2002:a17:90b:4c06:: with SMTP id na6mr4015192pjb.62.1644649895097; Fri, 11 Feb 2022 23:11:35 -0800 (PST) Received: from tong-desktop.local (99-105-211-126.lightspeed.sntcca.sbcglobal.net. [99.105.211.126]) by smtp.googlemail.com with ESMTPSA id l14sm7773309pjf.1.2022.02.11.23.11.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 11 Feb 2022 23:11:34 -0800 (PST) From: Tong Zhang To: Dan Williams , Vishal Verma , Dave Jiang , nvdimm@lists.linux.dev, linux-kernel@vger.kernel.org Cc: Tong Zhang Subject: [PATCH] dax: make sure inodes are flushed before destroy cache Date: Fri, 11 Feb 2022 23:11:11 -0800 Message-Id: <20220212071111.148575-1-ztong0001@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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=3D9 used=3D1 fp=3D0x00000000= 4f5ae469 flags=3D0x200000000010200(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: Christoph Hellwig Reviewed-by: Ira Weiny --- drivers/dax/super.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index e3029389d809..6bd565fe2e63 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -476,6 +476,7 @@ static int dax_fs_init(void) static void dax_fs_exit(void) { kern_unmount(dax_mnt); + rcu_barrier(); kmem_cache_destroy(dax_cache); } =20 --=20 2.25.1