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=-6.8 required=3.0 tests=BAYES_00, 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 2DC82C4363D for ; Sat, 3 Oct 2020 05:24:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E902C206C3 for ; Sat, 3 Oct 2020 05:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725764AbgJCFYH (ORCPT ); Sat, 3 Oct 2020 01:24:07 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:60179 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725730AbgJCFYH (ORCPT ); Sat, 3 Oct 2020 01:24:07 -0400 Received: from callcc.thunk.org (pool-72-74-133-215.bstnma.fios.verizon.net [72.74.133.215]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 0935NxQZ002033 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 3 Oct 2020 01:24:00 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 95E7442003C; Sat, 3 Oct 2020 01:23:59 -0400 (EDT) Date: Sat, 3 Oct 2020 01:23:59 -0400 From: "Theodore Y. Ts'o" To: "Darrick J. Wong" Cc: linux-ext4 Subject: Re: [PATCH] ext4: limit entries returned when counting fsmap records Message-ID: <20201003052359.GO23474@mit.edu> References: <20201001222148.GA49520@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201001222148.GA49520@magnolia> Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu, Oct 01, 2020 at 03:21:48PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong > > If userspace asked fsmap to try to count the number of entries, we cannot > return more than UINT_MAX entries because fmh_entries is u32. > Therefore, stop counting if we hit this limit or else we will waste time > to return truncated results. > > Fixes: 0c9ec4beecac ("ext4: support GETFSMAP ioctls") > Signed-off-by: Darrick J. Wong Applied, thanks. - Ted