From owner-svn-src-all@freebsd.org Thu Jan 21 14:35:13 2016 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5F1BCA8CEE9; Thu, 21 Jan 2016 14:35:13 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from smtp-out-so.shaw.ca (smtp-out-so.shaw.ca [64.59.136.138]) by mx1.freebsd.org (Postfix) with ESMTP id 0BDB91731; Thu, 21 Jan 2016 14:35:12 +0000 (UTC) (envelope-from cy.schubert@komquats.com) Received: from spqr.komquats.com ([96.50.22.10]) by shaw.ca with SMTP id MGKFaL8sypK8XMGKGavseg; Thu, 21 Jan 2016 07:35:06 -0700 X-Authority-Analysis: v=2.1 cv=IaYnITea c=1 sm=1 tr=0 a=jvE2nwUzI0ECrNeyr98KWA==:117 a=jvE2nwUzI0ECrNeyr98KWA==:17 a=BWvPGDcYAAAA:8 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=VxmjJ2MpAAAA:8 a=kj9zAlcOel0A:10 a=7aQ_Q-yQQ-AA:10 a=KawIFhhbAAAA:8 a=6I5d2MoRAAAA:8 a=YxBL1-UpAAAA:8 a=t9HMtdtuVjHgw6VY3PMA:9 a=CjuIK1q_8ugA:10 Received: from slippy.cwsent.com (slippy [10.1.1.91]) by spqr.komquats.com (Postfix) with ESMTP id D54F913780; Thu, 21 Jan 2016 06:35:02 -0800 (PST) Received: from slippy (localhost [127.0.0.1]) by slippy.cwsent.com (8.15.2/8.15.2) with ESMTP id u0LEZ2Ns046079; Thu, 21 Jan 2016 06:35:02 -0800 (PST) (envelope-from Cy.Schubert@komquats.com) Message-Id: <201601211435.u0LEZ2Ns046079@slippy.cwsent.com> X-Mailer: exmh version 2.8.0 04/21/2012 with nmh-1.6 Reply-to: Cy Schubert From: Cy Schubert X-os: FreeBSD X-Sender: cy@cwsent.com X-URL: http://www.komquats.com/ To: Slawa Olhovchenkov cc: Andriy Gapon , "svn-src-head@freebsd.org" , "svn-src-all@freebsd.org" , "src-committers@freebsd.org" , Alan Somers Subject: Re: svn commit: r294329 - in head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys In-Reply-To: Message from Slawa Olhovchenkov of "Thu, 21 Jan 2016 14:38:14 +0300." <20160121113813.GG37895@zxy.spb.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 21 Jan 2016 06:35:02 -0800 X-CMAE-Envelope: MS4wfIDbrE1K440TybGjynLjM6JwWoYE4ZRgzdlPUpBKox8Jpcd6R8RuCwu22mZoEcoaPqjNfD6IJ7uoj3T5OfWEKsK4dgnoBJ1IjDaHvl+3GxYRw50GXl1S jgduwlNziZsXVXTsAsAtE7LlYG9basi67JoyNcoZRzvi1Rhpd8Zfb48Ed16cgd3vldAWie7N15HQYO3iJ450QlEXHFQNWplQjtE/Swj0A3QYH1NvwQ7VaJUA u/1Eosp1c7vBC0I8agm0ue9ogis20g1Uc7qn5L/ITWB2hvbn07lI58leCbG5OC8OLdrFJyFsN7VmLMyBXonrpnD1LPpEa0BT94keHHH0V4w= X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.20 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, 21 Jan 2016 14:35:13 -0000 In message <20160121113813.GG37895@zxy.spb.ru>, Slawa Olhovchenkov writes: > On Thu, Jan 21, 2016 at 01:34:57AM +0200, Andriy Gapon wrote: > > > On 20/01/2016 22:03, Alan Somers wrote: > > > On Wed, Jan 20, 2016 at 2:20 AM, Andriy Gapon wrote: > > >> On 19/01/2016 19:20, Alan Somers wrote: > > >>> The thing is, it never really worked in the first place. Panics and > > >>> deadlocks are so frequent that I don't think the feature was usable > > >>> for anybody. > > >> > > >> The feature is perfectly usable for me. I have never run into the probl > ems that > > >> you describe. Why not fix the real bugs that you've run into? > > > > > > Spectra Logic and iXSystems both experienced many problems with this. > > > The worst is a deadlock that can be triggered simply by pulling a > > > drive from a redundant pool when there exists a zvol anywhere in the > > > system (see https://reviews.freebsd.org/D4998 for a quick way to > > > reproduce). Fixing it correctly would likely require far more time > > > than I have available. I just want the bugs to go away. See that > > > same code review for a change to make the feature optional. > > > > I think that we all want all the bugs to go way. One way to remove bugs is > to > > remove (disable) code that contains bugs. That way the perfect bug-free > > software is clearly achievable :-) Unfortunately, that technique is not al > ways > > welcomed. > > > > P.S. > > I think that the real problem here is that a method of a geom must never dr > op > > topology_lock. In other words, the GEOM management code (like g_xxx() stuf > f in > > geom_subr.c) expects that a topology can not change underneath it. But > > zvol_geom_access() clearly breaks that contract. > > May be same cause problem with swap on zvol (don't test on latest > -stable)? Not related but should be disabled by default through sysctl is vdev on USB. OK for a laptop but not a server. 100% hang on shutdown/reboot. -- Cheers, Cy Schubert or FreeBSD UNIX: Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.