From owner-freebsd-stable@freebsd.org Wed Jul 20 21:33:11 2016 Return-Path: Delivered-To: freebsd-stable@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 3E6E3B9FE82 for ; Wed, 20 Jul 2016 21:33:11 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citapm.icyb.net.ua (citapm.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id 93B5D13A8 for ; Wed, 20 Jul 2016 21:33:10 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citapm.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id AAA24611; Thu, 21 Jul 2016 00:33:02 +0300 (EEST) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1bPz70-0004eF-Gs; Thu, 21 Jul 2016 00:33:02 +0300 Subject: Re: Panic on BETA1 in the ZFS subsystem To: Karl Denninger , freebsd-stable@FreeBSD.org References: <8f44bc09-1237-44d0-fe7a-7eb9cf4fe85b@denninger.net> From: Andriy Gapon Message-ID: <54e5974c-312e-c33c-ab83-9e1148618ddc@FreeBSD.org> Date: Thu, 21 Jul 2016 00:32:05 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <8f44bc09-1237-44d0-fe7a-7eb9cf4fe85b@denninger.net> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 20 Jul 2016 21:33:11 -0000 On 20/07/2016 17:26, Karl Denninger wrote: > #185 0xffffffff8222955d in zio_vdev_io_start (zio=0xfffff80108754770) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:2870 > #186 0xffffffff82225d96 in zio_execute (zio=) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:1556 > #187 0xffffffff8220c72d in vdev_queue_io_done (zio=) > at > /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_queue.c:887 > #188 0xffffffff82229719 in zio_vdev_io_done (zio=0xfffff804cfdf7770) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:2895 > #189 0xffffffff82225d96 in zio_execute (zio=) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:1556 > #190 0xffffffff8222955d in zio_vdev_io_start (zio=0xfffff804cfdf7770) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:2870 > #191 0xffffffff82225d96 in zio_execute (zio=) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:1556 > #192 0xffffffff8220c72d in vdev_queue_io_done (zio=) > at > /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_queue.c:887 > #193 0xffffffff82229719 in zio_vdev_io_done (zio=0xfffff801469a13b8) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:2895 > #194 0xffffffff82225d96 in zio_execute (zio=) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:1556 > #195 0xffffffff8222955d in zio_vdev_io_start (zio=0xfffff801469a13b8) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:2870 > #196 0xffffffff82225d96 in zio_execute (zio=) > at /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zio.c:1556 > #197 0xffffffff8220c72d in vdev_queue_io_done (zio=) > at > /usr/src/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/vdev_queue.c:887 > #198 0xffffffff82229719 in zio_vdev_io_done (zio=0xfffff805dcd9d3b8) I see how this pseudo-recursion can happen in theory, but not why it has happened. It would interesting to see 3 or 4 of zio-s printed, including the top-most one at 0xfffff805dcd9d3b8. Something like: set print pretty p *zio p *zio->io_vd p *zio->io_vd->vdev_ops in several frames. -- Andriy Gapon