Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp1824914pxk; Fri, 2 Oct 2020 22:28:10 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxlOj2eayRMEtiszUVPo9HjwD4PbHDoYc+7/RqEdaHgQQHwzCho+fnDFNLqbx+4tuQZLCfn X-Received: by 2002:a50:fa81:: with SMTP id w1mr6287758edr.122.1601702890341; Fri, 02 Oct 2020 22:28:10 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1601702890; cv=none; d=google.com; s=arc-20160816; b=oVsaRBupuCK9vyWx6XYnjT9Gwg0h7VJRfc1u9rvNwkJ3SN13XZ5+dIgo4jYhLZG2F6 luMUNUEnWcqeJab2Ydabo+QzwJkYr4ZR1N4l6TmQFfc295ZAfQe1l7LwCiWjTNQKNKCK Aq7XIxzKvyCqXHxc9J5X5Hj+IFdviSNU1lk69MVfrsXZASIvSp6ZVBeVGlp+2NeIlHKK x2WZEyj7mQOcfRo0b4bjpnWcGaC8QmsmBBcpX3HxZ68lreTGKfGfBkP0MkOiQSHO5NVU +Jvu4CtiPjA4Gf3fut6TIJvloqJUjU71A6slWvWShoJ1yE0N4PCiMvWkJ3u9VbLPerx5 ynFg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:in-reply-to:content-disposition:mime-version :references:message-id:subject:cc:to:from:date; bh=kFvUK46xDTp/QQAhN8XTpp1emIxgM73ZQCelRp8dhqQ=; b=sHpv+Bpb2FRlire8S3v/nhhf2RiGSglLURk7LmVkvVV/PEwMoMsLSd5ISi0LQVHxpr LnksDI2D5S2gIKjAV4kYOl4jq7kCq8i08BJaqzx4TLomk0X+p9puYe5+h5np6CtUVY50 RtdqjZOzOR+rt86dmpFSCe/S0dzs45CIIGuOsfTPBofS1bQbTCJ/TEVl68Gelmol0YTk ojTZeYSxf4kvb+QImG+ce7n9JacBorJlGwAOnkyz3YnFyucjbXuTI7iItLtB6C004lHL 63Z1RZIF8UacwsbcY5sBx7ngU4+At9OajtgKnkU21hn2sXr/XwwQdzwiiVzo19NYQHQk YrrQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id h22si2570580ejd.367.2020.10.02.22.27.45; Fri, 02 Oct 2020 22:28:10 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-ext4-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-ext4-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725763AbgJCFYH (ORCPT + 99 others); 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