From owner-freebsd-arch@freebsd.org Thu May 14 20:17:21 2020 Return-Path: Delivered-To: freebsd-arch@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id A6A472DDBC3; Thu, 14 May 2020 20:17:21 +0000 (UTC) (envelope-from jhs@berklix.com) Received: from slim.berklix.org (slim.berklix.org [94.185.90.68]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "slim.berklix.org", Issuer "slim.berklix.org" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 49NNB73y3pz3MfK; Thu, 14 May 2020 20:17:18 +0000 (UTC) (envelope-from jhs@berklix.com) Received: from mart.js.berklix.net (p5ddb7209.dip0.t-ipconnect.de [93.219.114.9]) (authenticated bits=128) by slim.berklix.org (8.15.2/8.15.2) with ESMTPSA id 04EKHBXi052956 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 14 May 2020 22:17:15 +0200 (CEST) (envelope-from jhs@berklix.com) Received: from fire.js.berklix.net (fire.js.berklix.net [192.168.91.41]) by mart.js.berklix.net (8.14.3/8.14.3) with ESMTP id 04EKHAnD091168; Thu, 14 May 2020 22:17:11 +0200 (CEST) (envelope-from jhs@berklix.com) Received: from fire.js.berklix.net (localhost [127.0.0.1]) by fire.js.berklix.net (8.14.7/8.14.7) with ESMTP id 04EKH0aA093503; Thu, 14 May 2020 22:17:10 +0200 (CEST) (envelope-from jhs@berklix.com) Message-Id: <202005142017.04EKH0aA093503@fire.js.berklix.net> To: Kyle Evans cc: "freebsd-arch@freebsd.org" , hackers@freebsd.org Subject: Re: [HEADSUP] Disallowing read() of a directory fd From: "Julian H. Stacey" Organization: http://berklix.com/jhs http://stolenvotes.uk User-agent: EXMH on FreeBSD http://berklix.com/free/ X-From: http://www.berklix.org/~jhs/ In-reply-to: Your message "Thu, 14 May 2020 13:26:46 -0500." Date: Thu, 14 May 2020 22:17:00 +0200 X-Rspamd-Queue-Id: 49NNB73y3pz3MfK X-Spamd-Bar: / Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=none (mx1.freebsd.org: domain of jhs@berklix.com has no SPF policy when checking 94.185.90.68) smtp.mailfrom=jhs@berklix.com X-Spamd-Result: default: False [0.16 / 15.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[berklix.com]; AUTH_NA(1.00)[]; HAS_ORG_HEADER(0.00)[]; RCVD_COUNT_THREE(0.00)[4]; IP_SCORE(-0.00)[ip: (0.01), ipnet: 94.185.88.0/22(0.01), asn: 33824(-0.00), country: DE(-0.02)]; NEURAL_SPAM_LONG(0.01)[0.011,0]; RCVD_IN_DNSWL_NONE(0.00)[68.90.185.94.list.dnswl.org : 127.0.10.0]; NEURAL_HAM_MEDIUM(-0.75)[-0.750,0]; R_SPF_NA(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:33824, ipnet:94.185.88.0/22, country:DE]; RCVD_TLS_LAST(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[9.114.219.93.khpj7ygk5idzvmvt5x4ziurxhy.zen.dq.spamhaus.net : 127.0.0.10] X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 May 2020 20:17:21 -0000 Kyle Evans wrote: > Hi, > > This is a heads up, given that I'm completely flipping our historical > behavior- I intend to commit this review in a couple days' time > without substantial objection: https://reviews.freebsd.org/D24596 > > With this, FreeBSD 13 will not allow read() of a directory fd, which > could have previously returned some data from the underlying > filesystem in no particular standardized format. > > This is a still-standards-compliant switch from one > implementation-defined behavior to another that's already been adopted > in various other popular kernels, to include OpenBSD, MacOS, and > Linux. > > Worth noting is that there's not really one largely-compelling reasons > to switch this after so many years (unless you find yourself that > irate when you accidentally `cat` a directory), but there are some > benefits which are briefly discussed in the commentary around the > review along with the history of the current behavior. > > This change also simplifies filesystem implementations to some extent. > > Thanks, > > Kyle Evans There is ZERO need for a spurious change at 2 days notice after 42+ years ! "cat ." as been supported since Unix V6 1978 or earlier, no problem, even occasionaly useful. Most FreeBSD users wont have heard of https://reviews.freebsd.org/D24596 (& there's only 5 other people's opinions there, apart from proposer, & skimming through the impression is far from un-qualified approval. kevans@ issued arch@ just a couple days notice of intention to commit. arch@ is also not widely read, ( I jhs@ added CC hackers@) Many FreeBSD end users won't even be reading hackers@ (some not even announce@,) & would notice just yet another pointless change sometime after upgrade. Do not force all FreeBSD users towards gratuitous change for personal preference for Linux behaviour. Switch to Linux, Or hack a personalised shell on BSD that does what you want when you type "cat ." If it's later widely popular, use it as proof to re-propose. No Rush. A bigger issue is due notice procedure, & respect to FreeBSD stability of code & users expectations of predictability. Unwarned playing about would detract from FreeBSD's business image. Cheers -- Julian Stacey, Consultant Systems Engineer, BSD Linux http://berklix.com/jhs/ http://www.berklix.org/corona/#masks Tie 2 handkerchiefs or 1 pillow case. Jobs & economy hit by Corona to be hit again by Crash Brexit 31st Dec. 2020