From patchwork Thu Oct 18 13:17:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 10647201 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1466B13B0 for ; Thu, 18 Oct 2018 13:17:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 07D6028435 for ; Thu, 18 Oct 2018 13:17:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EF59428438; Thu, 18 Oct 2018 13:17:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 80A06288E1 for ; Thu, 18 Oct 2018 13:17:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728165AbeJRVST (ORCPT ); Thu, 18 Oct 2018 17:18:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:59850 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728141AbeJRVST (ORCPT ); Thu, 18 Oct 2018 17:18:19 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A9039AEDC; Thu, 18 Oct 2018 13:17:17 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 596801E088D; Thu, 18 Oct 2018 15:17:16 +0200 (CEST) From: Jan Kara To: Al Viro Cc: Ted Tso , , , , Jan Kara Subject: [PATCH 0/2] vfs: Fix crashes when reading /proc/mounts Date: Thu, 18 Oct 2018 15:17:07 +0200 Message-Id: <20181018131709.11976-1-jack@suse.cz> X-Mailer: git-send-email 2.16.4 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hello, this patch series aims at fixing possible races between functions formatting output for /proc/mounts and friends and remount. Especially ->show_options functions of filesystems are not counting with the fact that options can change under them and thus races can result in bogus output or outright crashes (like was the case with ext4 handling of quota mount option, or udf could crash when printing charset name, or xfs when printing log device name etc.). Admittedly the patch 2/2 is somewhat ugly because namespace_sem ranks below sb->s_umount semaphore but I think it is bearable. Al, what do you think? Honza