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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 17E57C433DF for ; Wed, 12 Aug 2020 21:02:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D8D3520768 for ; Wed, 12 Aug 2020 21:02:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597266120; bh=45o/6kcUWrkmqm8N+mYZAZL/jcUSdt+KCnWphd31iOU=; h=Date:From:To:Subject:Reply-To:List-ID:From; b=Xg2P3VkKcYF9xycMUW18OqE6ZHEJ+8yEmcFP0uagSzyB1HOEgEom2rOrrSPsQRoEk fC9t6fFflcCL38i2bdGshvxUdsVO+sXXTPM2X0tMK0KS0yW8RsIbpXk/d+b+cZcQhv dkeFYcnw5Fay4hjT8v3CHPtM6sEdLmzhUluWUG6k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726611AbgHLVCA (ORCPT ); Wed, 12 Aug 2020 17:02:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:48124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726526AbgHLVCA (ORCPT ); Wed, 12 Aug 2020 17:02:00 -0400 Received: from localhost.localdomain (c-71-198-47-131.hsd1.ca.comcast.net [71.198.47.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8088520774; Wed, 12 Aug 2020 21:01:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597266119; bh=45o/6kcUWrkmqm8N+mYZAZL/jcUSdt+KCnWphd31iOU=; h=Date:From:To:Subject:From; b=2ZSGZe2SMa+fqtS+ws34Zrxw/y8HUNb6kBdgI2Osr+2u4uR1p4dbv1Fw+eiA6NmUD 3Uur7EgISbnYppfYTh6PSxlSI1suk7IsHkXDGXfIPWw5LjVpdV/pjh6AL1wvl7PjH1 i444TdqSdjxGlS5ggaunJ72ObGdQR3Cl3jsdvxwg= Date: Wed, 12 Aug 2020 14:01:59 -0700 From: akpm@linux-foundation.org To: amir73il@gmail.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, mszeredi@redhat.com, viro@zeniv.linux.org.uk, walters@verbum.org, willy@infradead.org Subject: [merged] hugetlbfs-prevent-filesystem-stacking-of-hugetlbfs.patch removed from -mm tree Message-ID: <20200812210159.rzoTj8Mfw%akpm@linux-foundation.org> User-Agent: s-nail v14.8.16 Sender: mm-commits-owner@vger.kernel.org Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: hugetlbfs: prevent filesystem stacking of hugetlbfs has been removed from the -mm tree. Its filename was hugetlbfs-prevent-filesystem-stacking-of-hugetlbfs.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Mike Kravetz Subject: hugetlbfs: prevent filesystem stacking of hugetlbfs syzbot found issues with having hugetlbfs on a union/overlay as reported in [1]. Due to the limitations (no write) and special functionality of hugetlbfs, it does not work well in filesystem stacking. There are no know use cases for hugetlbfs stacking. Rather than making modifications to get hugetlbfs working in such environments, simply prevent stacking. [1] https://lore.kernel.org/linux-mm/000000000000b4684e05a2968ca6@google.com/ Link: http://lkml.kernel.org/r/80f869aa-810d-ef6c-8888-b46cee135907@oracle.com Signed-off-by: Mike Kravetz Reported-by: syzbot+d6ec23007e951dadf3de@syzkaller.appspotmail.com Suggested-by: Amir Goldstein Acked-by: Miklos Szeredi Cc: Al Viro Cc: Matthew Wilcox Cc: Colin Walters Signed-off-by: Andrew Morton --- fs/hugetlbfs/inode.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/fs/hugetlbfs/inode.c~hugetlbfs-prevent-filesystem-stacking-of-hugetlbfs +++ a/fs/hugetlbfs/inode.c @@ -1364,6 +1364,12 @@ hugetlbfs_fill_super(struct super_block sb->s_magic = HUGETLBFS_MAGIC; sb->s_op = &hugetlbfs_ops; sb->s_time_gran = 1; + + /* + * Due to the special and limited functionality of hugetlbfs, it does + * not work well as a stacking filesystem. + */ + sb->s_stack_depth = FILESYSTEM_MAX_STACK_DEPTH; sb->s_root = d_make_root(hugetlbfs_get_root(sb, ctx)); if (!sb->s_root) goto out_free; _ Patches currently in -mm which might be from mike.kravetz@oracle.com are