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=-11.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 4B5C2C388F9 for ; Wed, 21 Oct 2020 14:34:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EE5522249 for ; Wed, 21 Oct 2020 14:34:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fieldses.org header.i=@fieldses.org header.b="qCH/JwZk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2443542AbgJUOeQ (ORCPT ); Wed, 21 Oct 2020 10:34:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2443539AbgJUOeQ (ORCPT ); Wed, 21 Oct 2020 10:34:16 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9CC20C0613CE for ; Wed, 21 Oct 2020 07:34:16 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id F1CE51C81; Wed, 21 Oct 2020 10:34:15 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org F1CE51C81 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1603290856; bh=vYsuBQdMbxYyWVXhHeP/ieHFJkCaobM4EKgUs9xY+eI=; h=Date:To:Cc:Subject:From:From; b=qCH/JwZk9fP7vdBqts73EMBddwqvic0XwoFWs+TyP2ArwCbSJxSyd200Rt4ezL7ib MygJdV9gXjOSABGNIV2YRzD3EsVuKA+BBl/efftce0+6Z7E79cP8YibTFhDZAIS8Z7 69Gx8CM8Wd5wm1kxmPrSh7KY+zzB+wl8cKf+ayRE= Date: Wed, 21 Oct 2020 10:34:15 -0400 To: Trond Myklebust , Anna Schumaker Cc: linux-nfs@vger.kernel.org Subject: [PATCH] NFSv4.2: fix failure to unregister shrinker Message-ID: <20201021143415.GA27122@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) From: bfields@fieldses.org (J. Bruce Fields) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org From: "J. Bruce Fields" We forgot to unregister the nfs4_xattr_large_entry_shrinker. That leaves the global list of shrinkers corrupted after unload of the nfs module, after which possibly unrelated code that calls register_shrinker() or unregister_shrinker() gets a BUG() with "supervisor write access in kernel mode". And similarly for the nfs4_xattr_large_entry_lru. Reported-by: Kris Karas Tested-By: Kris Karas Signed-off-by: J. Bruce Fields --- fs/nfs/nfs42xattr.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c index 86777996cfec..55b44a42d625 100644 --- a/fs/nfs/nfs42xattr.c +++ b/fs/nfs/nfs42xattr.c @@ -1048,8 +1048,10 @@ int __init nfs4_xattr_cache_init(void) void nfs4_xattr_cache_exit(void) { + unregister_shrinker(&nfs4_xattr_large_entry_shrinker); unregister_shrinker(&nfs4_xattr_entry_shrinker); unregister_shrinker(&nfs4_xattr_cache_shrinker); + list_lru_destroy(&nfs4_xattr_large_entry_lru); list_lru_destroy(&nfs4_xattr_entry_lru); list_lru_destroy(&nfs4_xattr_cache_lru); kmem_cache_destroy(nfs4_xattr_cache_cachep); -- 2.26.2