From owner-svn-src-head@freebsd.org Tue May 19 15:31:42 2020 Return-Path: Delivered-To: svn-src-head@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 6D1882DC505; Tue, 19 May 2020 15:31:42 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49RKcG1w1Xz3T0v; Tue, 19 May 2020 15:31:41 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: from mail-qk1-f171.google.com (mail-qk1-f171.google.com [209.85.222.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) (Authenticated sender: kevans) by smtp.freebsd.org (Postfix) with ESMTPSA id 970E12C61E; Tue, 19 May 2020 15:31:41 +0000 (UTC) (envelope-from kevans@freebsd.org) Received: by mail-qk1-f171.google.com with SMTP id b6so15603395qkh.11; Tue, 19 May 2020 08:31:41 -0700 (PDT) X-Gm-Message-State: AOAM530mVNhlFvGbTZNtpnFrAU5jPanaHUXZSsbQhtt5Lq/tmzO2yzUe X+3a8MMRoExuKCA+7NKl/1OYq886wL2H8g6c8lc= X-Google-Smtp-Source: ABdhPJySxY22UQ2jLVIsYxGQ7gG5Mt48i6fQzRXuTExxuVvvuyOgPcPNv7AKmOlxb38jAXgyZkCRiwuRYDZDpLgm+tg= X-Received: by 2002:a37:5b47:: with SMTP id p68mr21800981qkb.120.1589902296704; Tue, 19 May 2020 08:31:36 -0700 (PDT) MIME-Version: 1.0 References: <202005191527.04JFRiMs006683@gndrsh.dnsmgr.net> In-Reply-To: <202005191527.04JFRiMs006683@gndrsh.dnsmgr.net> From: Kyle Evans Date: Tue, 19 May 2020 10:31:23 -0500 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r361238 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs To: "Rodney W. Grimes" Cc: src-committers , svn-src-all , svn-src-head Content-Type: text/plain; charset="UTF-8" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 May 2020 15:31:42 -0000 On Tue, May 19, 2020 at 10:27 AM Rodney W. Grimes wrote: > > > On Tue, May 19, 2020 at 10:23 AM Rodney W. Grimes > > wrote: > > > > > > > Author: kevans > > > > Date: Tue May 19 02:41:05 2020 > > > > New Revision: 361238 > > > > URL: https://svnweb.freebsd.org/changeset/base/361238 > > > > > > > > Log: > > > > zfs: reject read(2) of a dirfd with EISDIR > > > > > > > > This is independent of the recently-discussed global change, which is still > > > > in review/discussion stage. > > > > > > > > This is effectively a measure for consistency in the ZFS world, where > > > > FreeBSD was the only platform (as far as I could find) that allowed this. > > > > What ZFS exposes is decidedly not useful for any real purposes, to > > > > paraphrase (hopefully faithfully) jhb's findings when exploring this: > > > > > > > > The size of a directory in ZFS is the number of directory entries within. > > > > When reading a directory, you would instead get the leading part of its raw > > > > contents; the amount you get being dictated by the "size," i.e. number of > > > > directory entries. There's decidedly (luckily) no stack disclosure happening > > > > here, though the behavior is bizarre and almost certainly a historical > > > > accident. > > > > > > > > This change has already been upstreamed to OpenZFS. > > > > > > Until the grep -d skip issue is addressed I object to this change as > > > it is going to cause people who do grep with wildcards to see lots > > > of errors that before where pretty much either silent (no match occured) > > > or spit out a "binary file foo matches." > > > > > > > That seems preferable to grepping random bytes that don't particularly > > contain any strings? They'd never see "binary file foo matches" in > > this case. > > The difference is you rarely get a hit, and now your gauranteed to > get a hit on every single directory making grep * very noisy, where > it was often silent or nearly silent before. > As you noted in the review for the larger change, -d skip is a good option for the people that don't like this. It probably makes sense as a default, but then we'd be diverging from the other popular grep that defaults to -d read and spews out EISDIR more often than not. > > > > This isn't exactly divergent from the behavior they'd see with ZFS > > anywhere else. > > It is extremly divergent from 42 years of behavior. > I don't think ZFS has been implemented on FreeBSD for 42 years, and I don't find this grep argument compelling enough to restore peoples' ability to read the raw znode of a directory.