From owner-svn-src-head@freebsd.org Sun Jan 24 14:35:22 2016 Return-Path: Delivered-To: svn-src-head@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 D32287537; Sun, 24 Jan 2016 14:35:22 +0000 (UTC) (envelope-from cschuber@gmail.com) Received: from mail-pf0-x232.google.com (mail-pf0-x232.google.com [IPv6:2607:f8b0:400e:c00::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A32641B3; Sun, 24 Jan 2016 14:35:22 +0000 (UTC) (envelope-from cschuber@gmail.com) Received: by mail-pf0-x232.google.com with SMTP id e65so68302853pfe.0; Sun, 24 Jan 2016 06:35:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:mime-version:from:subject:date:to:cc:content-type; bh=kRB229AmBlHEx8ARzNEdP21zQtL1MEXdgo7LTrlh2/s=; b=yaYIkAPqrt8+F/Bt3z9euy3oS7hzdDQw1S4BesGIJtKxfjGfxDFWhdP2WIaeFHyCUX Qop18RjFiEPapV6Rccvzv0l66ZnrgQnOlkXCbXR/lj7p5zVyiDENQOfR9Q/dVErNODHc RZonRSE0/lmy6n3iyhtPmqOt3rSFARVqs9ANpv61q0P6eaQCd1MokxJ0UUUJGYAUEvWI KLIBVZvinttNTDbQNtLbQ5P+SoMvBp20XMH74oQKEeqdbZ2X952bjnYst1E0+Px7ORqG yQvqn2msa9IpqyY7FfWkXiVvVKASYZjOJHfPRHqVJ1blMHASfas2kwD7cO8kU7NQslt3 P6Xw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:mime-version:from:subject:date:to:cc :content-type; bh=kRB229AmBlHEx8ARzNEdP21zQtL1MEXdgo7LTrlh2/s=; b=QnViE9q+TyWubcLFalNoZEzqitUSDl5KArQeIYMbsGtYtxTLOrwzD+CWMSMWpffmPb mDAkP53LqEmmuDepgFbsv0TWH472U2hCFePjSWjfHhy6nmGomJOuoDLbSbfT42A9t540 3UHEjH0LI4Aj5H4T4r0yUmLh8Nt29qUj5vsGnST+Cf7+yy2EEmev+b7QE6FDOuMut+59 LG/zRXt6X7/7oy1FFLGX+QjtwE1ZKNKgMFnSa+6of6PGM6416DwqR2ElD6qoSR9j1i7R PXx0i3S9+0321xVe45Fe86MIbW4xrnj42ENtdVDDT9sDrFXTrfE3Sh/13Jfkt0WoRPMQ mldg== X-Gm-Message-State: AG10YOS6aESrxDG7mi5g9V7RwbZdXfWlZC7wPUnt1ooaEATSMGdn21KEtckz+8vWFo0xcA== X-Received: by 10.98.70.17 with SMTP id t17mr18765725pfa.107.1453646122230; Sun, 24 Jan 2016 06:35:22 -0800 (PST) Received: from [10.168.3.103] (S0106d4ca6d8943b0.gv.shawcable.net. [24.68.134.59]) by smtp.gmail.com with ESMTPSA id qz9sm22135447pab.39.2016.01.24.06.35.21 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 24 Jan 2016 06:35:21 -0800 (PST) Message-ID: <56a4e129.a98b420a.ebf8f.ffffe225@mx.google.com> MIME-Version: 1.0 From: Cy Schubert Subject: RE: svn commit: r294329 - inhead/sys/cddl/contrib/opensolaris/uts/common/fs/zfs: . sys Date: Sun, 24 Jan 2016 06:35:22 -0800 To: Julian Elischer , Shawn Webb , Alan Somers CC: "src-committers@freebsd.org" , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" , Xin LI , "cy.schubert@cschubert.com" Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.20 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: Sun, 24 Jan 2016 14:35:23 -0000 A previous email in this thread said that a sysctl will be committed before= MFC. I personally have never encountered this particular problem. Sent from my cellphone, ~Cy -----Original Message----- From: Julian Elischer Sent: 24/01/2016 06:20 To: Shawn Webb; Alan Somers Cc: src-committers@freebsd.org; svn-src-all@freebsd.org; svn-src-head@freeb= sd.org; Xin LI Subject: Re: svn commit: r294329 - inhead/sys/cddl/contrib/opensolaris/uts/= common/fs/zfs: . sys On 24/01/2016 10:13 PM, Shawn Webb wrote: > On Tue, Jan 19, 2016 at 05:00:25PM +0000, Alan Somers wrote: >> Author: asomers >> Date: Tue Jan 19 17:00:25 2016 >> New Revision: 294329 >> URL: https://svnweb.freebsd.org/changeset/base/294329 >> >> Log: >> Disallow zvol-backed ZFS pools >> =20 >> Using zvols as backing devices for ZFS pools is fraught with panics a= nd >> deadlocks. For example, attempting to online a missing device in the >> presence of a zvol can cause a panic when vdev_geom tastes the zvol. = Better >> to completely disable vdev_geom from ever opening a zvol. The solutio= n >> relies on setting a thread-local variable during vdev_geom_open, and >> returning EOPNOTSUPP during zvol_open if that thread-local variable i= s set. >> =20 >> Remove the check for MUTEX_HELD(&zfsdev_state_lock) in zvol_open. Its= intent >> was to prevent a recursive mutex acquisition panic. However, the new = check >> for the thread-local variable also fixes that problem. >> =20 >> Also, fix a panic in vdev_geom_taste_orphan. For an unknown reason, t= his >> function was set to panic. But it can occur that a device disappears = during >> tasting, and it causes no problems to ignore this departure. >> =20 >> Reviewed by: delphij >> MFC after: 1 week >> Relnotes: yes >> Sponsored by: Spectra Logic Corp >> Differential Revision: https://reviews.freebsd.org/D4986 > I've just been bit by this pretty hard. I have a bhyve VM that's backed > by a zvol. The VM is running root-on-zfs. I wrote some experimental code > that's now preventing the VM from booting (kernel panic due to userland > change). Since I can't import the pool, I have no way of fixing the > problem. > > I'm probably just going to go revert this commit locally on my box so I > can get some work done. I use an md device to do this in bhyve but I was considering using a zvol. Populating it in the host system and then presenting it to the VM as a=20 disk. maybe it could be enabled with a sysctl? Is the problem always present? > > Thanks, >