From owner-svn-src-all@freebsd.org Thu Jun 6 18:21:48 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9892815BC130 for ; Thu, 6 Jun 2019 18:21:48 +0000 (UTC) (envelope-from ian@freebsd.org) Received: from outbound2m.ore.mailhop.org (outbound2m.ore.mailhop.org [54.149.155.156]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id F128A814B7 for ; Thu, 6 Jun 2019 18:21:47 +0000 (UTC) (envelope-from ian@freebsd.org) ARC-Seal: i=1; a=rsa-sha256; t=1559845306; cv=none; d=outbound.mailhop.org; s=arc-outbound20181012; b=RvB37OqSZMMNCc+LlfzQSMsaeYxp70wALpq7/kKgft3IRyio6fpXGCXzdHPPT1AF+1YyzwD6qXZHc TYdi8/QoHIeLxSNAonEIP2m+US6Zlu6q/cSzv8HjrHbqvdKeNUoqEUAFWVGpe65mFu3O7X0XacKj9j VXzp5mrxKUnr8igPTYh5EUZ2VVBIM5jy4zdBYr3/Bj8wqJMFgYcT0PMHQ19LABxXsyBOFx8KXOFBkk Nm3e6W8dk0v237YYxAN8sX/vxYgUj7rdqkhSl6Qd8tilADGYkFwJA+Mrq2JO7w4wUwA9RbtOXMnu2B MCCjHxwkD6EHKSd46CTJkWHTFEOeqHg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=arc-outbound20181012; h=content-transfer-encoding:mime-version:content-type:references:in-reply-to: date:cc:to:from:subject:message-id:dkim-signature:from; bh=OcaJKj5YqoPvpIHLBwxSp6aC4vT1CsuZDKZ1kcWWEEY=; b=m5yrD43URR5CbJeUWN8qfUWtguP6lXLtlVjM3PvndpG/GjMxHCycmSAa5jQqm+s1JdSQLYPNAFlYM viy8Rvm6i2kxFVTtRrsgihF/KWDhFN1cmjNkSf1Ca6g0Ty5f+F1mvv6IuuzZEvokU0ywKXUC4jAjes y18+jN8RxM0n0mAiVjJav+7B0h8AZfCQcnF6/GW9ZHX6/3oWnA8oflm/OplB3/aAGjb+h1cMn9V5wR rK2HARTnttirrZ0EWK2Hhzvx1NHLEkTj1LyOy2CxXq4o6RI6tCRQZJZETywnme+WJyW0/KkFkblYXi 8eaP794vR6Tl+kBhEpnkKLlsUI1rFFw== ARC-Authentication-Results: i=1; outbound4.ore.mailhop.org; spf=softfail smtp.mailfrom=freebsd.org smtp.remote-ip=67.177.211.60; dmarc=none header.from=freebsd.org; arc=none header.oldest-pass=0; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=outbound.mailhop.org; s=dkim-high; h=content-transfer-encoding:mime-version:content-type:references:in-reply-to: date:cc:to:from:subject:message-id:from; bh=OcaJKj5YqoPvpIHLBwxSp6aC4vT1CsuZDKZ1kcWWEEY=; b=TKKwWh/gLVXgHVmsIWlly6YLm7WYOxuMj41t/71q53R116cEnTDa3kuqQqqyRfoJrRvXhi5UD5Fvb Uba+5Cz94N+Iyd79QmezwqNUphLTK/UZqMEzdTPkZM6FCVS65urazswSxRw/N8c2KCFW0GNCrXU3+X a//M8HEyf02/upTjN+u/kcVNxMvIsff+Db1kMWZC59LvHGZ9zJ0jPobnby8m9Znb/tqrUBtyBcFfNi grRqsfpzsWl4Nber70EdgjA6fJmLrcJtW2Z3XnHx77m46KdUQXz1euDIfWV81FlqleJrhO8ZJdZIFN o7JEkk0v7k1E/Ofs4hhbFmR8Nx8xAbA== X-MHO-RoutePath: aGlwcGll X-MHO-User: efe39edc-8887-11e9-b39a-9d2c53d3dedb X-Report-Abuse-To: https://support.duocircle.com/support/solutions/articles/5000540958-duocircle-standard-smtp-abuse-information X-Originating-IP: 67.177.211.60 X-Mail-Handler: DuoCircle Outbound SMTP Received: from ilsoft.org (unknown [67.177.211.60]) by outbound4.ore.mailhop.org (Halon) with ESMTPSA id efe39edc-8887-11e9-b39a-9d2c53d3dedb; Thu, 06 Jun 2019 18:21:44 +0000 (UTC) Received: from rev (rev [172.22.42.240]) by ilsoft.org (8.15.2/8.15.2) with ESMTP id x56ILhPl068985; Thu, 6 Jun 2019 12:21:43 -0600 (MDT) (envelope-from ian@freebsd.org) Message-ID: <62763406801d603b0dda6ff4754bf7e9b714a8e0.camel@freebsd.org> Subject: Re: svn commit: r348737 - head/sys/kern From: Ian Lepore To: Alan Somers , John Baldwin Cc: "Rodney W. Grimes" , src-committers , svn-src-all , svn-src-head Date: Thu, 06 Jun 2019 12:21:43 -0600 In-Reply-To: References: <201906061504.x56F4odw034764@repo.freebsd.org> <201906061735.x56HZGIJ058845@gndrsh.dnsmgr.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 FreeBSD GNOME Team Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: F128A814B7 X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-7.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-1.00)[-0.996,0]; REPLY(-4.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 06 Jun 2019 18:21:48 -0000 On Thu, 2019-06-06 at 12:04 -0600, Alan Somers wrote: > On Thu, Jun 6, 2019 at 12:01 PM John Baldwin wrote: > > > > On 6/6/19 10:39 AM, Alan Somers wrote: > > > On Thu, Jun 6, 2019 at 11:35 AM Rodney W. Grimes > > > wrote: > > > > > > > > > Author: asomers > > > > > Date: Thu Jun 6 15:04:50 2019 > > > > > New Revision: 348737 > > > > > URL: https://svnweb.freebsd.org/changeset/base/348737 > > > > > > > > > > Log: > > > > > Add a testing facility to manually reclaim a vnode > > > > > > > > > > Add the debug.try_reclaim_vnode sysctl. When a pathname is > > > > > written to it, it > > > > > will be reclaimed, as long as it isn't already or doomed. > > > > > The purpose is to > > > > > gain test coverage for vnode reclamation, which is > > > > > otherwise hard to > > > > > achieve. > > > > > > > > > > Add the debug.ftry_reclaim_vnode sysctl. It does the same > > > > > thing, except > > > > > that its argument is a file descriptor instead of a > > > > > pathname. > > > > > > > > Should not this all be wrapped in some #ifdef or other > > > > protection, > > > > is it really a good idea to have this on every single box > > > > running > > > > FreeBSD? > > > > > > I initially thought so too, but kib thought that it could be > > > useful > > > for debugging problems in the field. The potential downside is > > > limited, because only root can write to the sysctls, and the > > > worse-case damage is similar to a "umount -f". > > > > A compromise might be to stick this in a kernel module instead of > > in the > > base kernel. You could still kldload it in the field for debugging > > but > > not necessarily have it directly available out of the box. > > > > -- > > John Baldwin > > If we already had such a module, it would make sense to put these > sysctls in there. But I don't want to create an entire module for > just a few dozen LOC. Nor do I want to mediate a bike shed. So > let's > vote. kib already registered a vote for making them available all of > the time. rgrimes voted to guard them by INVARIANTS. Anybody else > who cares can reply to this thread. I'll count the votes in 24 > hours. > -Alan > If our new policy is to remove sysctls that aren't used often "because something bad might happen" (without any requirement for the complainer to elaborate on just what might happen or why it's so much worse than the damage a root user could do with any other sysctl), I think several people could be employed full time doing that removal work. Or we could all just get on with doing some real work. -- Ian