From owner-svn-src-stable@freebsd.org Thu Aug 11 23:13:19 2016 Return-Path: Delivered-To: svn-src-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 F10DDBB6273; Thu, 11 Aug 2016 23:13:18 +0000 (UTC) (envelope-from gjb@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) by mx1.freebsd.org (Postfix) with ESMTP id D6F3F15F6; Thu, 11 Aug 2016 23:13:18 +0000 (UTC) (envelope-from gjb@FreeBSD.org) Received: from FreeBSD.org (freefall.freebsd.org [IPv6:2001:1900:2254:206c::16:87]) by freefall.freebsd.org (Postfix) with ESMTP id 6F4381304; Thu, 11 Aug 2016 23:13:18 +0000 (UTC) (envelope-from gjb@FreeBSD.org) Date: Thu, 11 Aug 2016 23:13:17 +0000 From: Glen Barber To: Slawa Olhovchenkov Cc: Andriy Gapon , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: Re: svn commit: r303970 - in stable/11/sys/cddl: compat/opensolaris/sys contrib/opensolaris/uts/common/fs/zfs contrib/opensolaris/uts/common/fs/zfs/sys Message-ID: <20160811231317.GH51184@FreeBSD.org> References: <201608112048.u7BKm4OH076291@repo.freebsd.org> <20160811223331.GF22212@zxy.spb.ru> <20160811223637.GE51184@FreeBSD.org> <20160811225202.GI8192@zxy.spb.ru> <20160811225723.GG51184@FreeBSD.org> <20160811230747.GJ8192@zxy.spb.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="e5bfZ/T2xnjpUIbw" Content-Disposition: inline In-Reply-To: <20160811230747.GJ8192@zxy.spb.ru> X-Operating-System: FreeBSD 11.0-CURRENT amd64 X-SCUD-Definition: Sudden Completely Unexpected Dataloss X-SULE-Definition: Sudden Unexpected Learning Event X-PEKBAC-Definition: Problem Exists, Keyboard Between Admin/Computer User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 11 Aug 2016 23:13:19 -0000 --e5bfZ/T2xnjpUIbw Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Aug 12, 2016 at 02:07:47AM +0300, Slawa Olhovchenkov wrote: > On Thu, Aug 11, 2016 at 10:57:23PM +0000, Glen Barber wrote: >=20 > > On Fri, Aug 12, 2016 at 01:52:02AM +0300, Slawa Olhovchenkov wrote: > > > On Thu, Aug 11, 2016 at 10:36:37PM +0000, Glen Barber wrote: > > >=20 > > > > On Fri, Aug 12, 2016 at 01:33:31AM +0300, Slawa Olhovchenkov wrote: > > > > > On Thu, Aug 11, 2016 at 08:48:04PM +0000, Andriy Gapon wrote: > > > > >=20 > > > > > > Author: avg > > > > > > Date: Thu Aug 11 20:48:03 2016 > > > > > > New Revision: 303970 > > > > > > URL: https://svnweb.freebsd.org/changeset/base/303970 > > > > > >=20 > > > > > > Log: > > > > > > MFC r303763,303791,303869: zfs: honour and make use of vfs vn= ode locking protocol > > > > > > =20 > > > > > > ZFS POSIX Layer is originally written for Solaris VFS which i= s very > > > > > > different from FreeBSD VFS. Most importantly many things tha= t FreeBSD VFS > > > > > > manages on behalf of all filesystems are implemented in ZPL i= n a different > > > > > > way. > > > > > > Thus, ZPL contains code that is redundant on FreeBSD or dupli= cates VFS > > > > > > functionality or, in the worst cases, badly interacts / inter= feres > > > > > > with VFS. > > > > > > =20 > > > > > > The most prominent problem is a deadlock caused by the lock o= rder reversal > > > > > > of vnode locks that may happen with concurrent zfs_rename() a= nd lookup(). > > > > > > The deadlock is a result of zfs_rename() not observing the vn= ode locking > > > > > > contract expected by VFS. > > > > > > =20 > > > > > > This commit removes all ZPL internal locking that protects pa= rent-child > > > > > > relationships of filesystem nodes. These relationships are p= rotected > > > > > > by vnode locks and the code is changed to take advantage of t= hat fact > > > > > > and to properly interact with VFS. > > > > > > =20 > > > > > > Removal of the internal locking allowed all ZPL dmu_tx_assign= calls to > > > > > > use TXG_WAIT mode. > > > > > > =20 > > > > > > Another victim, disputable perhaps, is ZFS support for filesy= stems with > > > > > > mixed case sensitivity. That support is not provided by the = OS anyway, > > > > > > so in ZFS it was a buch of dead code. > > > > > > =20 > > > > > > To do: > > > > > > - replace ZFS_ENTER mechanism with VFS managed / visible mech= anism > > > > > > - replace zfs_zget with zfs_vget[f] as much as possible > > > > > > - get rid of not really useful now zfs_freebsd_* adapters > > > > > > - more cleanups of unneeded / unused code > > > > > > - fix / replace .zfs support > > > > >=20 > > > > > MFC to 10.x/9.x planed? > > > > >=20 > > > >=20 > > > > As I understand it, this does not affect stable/10. > > >=20 > > > Sure? > > > I think ZFS/VFS layers don't change between 9.x and 11.x > > >=20 > >=20 > > No, but as I understand it, a commit to head tickled this bug. avg@ can > > correct me if I am wrong. >=20 > May be I am wrong, I see messages about like issuses in 9.x/10.x. > As I understund this is more clear implementation. > Also, unification in 12.x/10.x take benefit for MFC other ZFS diffs. >=20 I agree with you. I am just unsure if this particular bug affects 10.x and 9.x. Glen --e5bfZ/T2xnjpUIbw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJXrQaNAAoJEAMUWKVHj+KT44IP/2p+8QbGfaZiZ5fmnGMNu3SO xByEFNL9WN8TlZWOXVH9FYgynD3AOlyU0il57+tNvbhUsfh2b1iwThMW0KUaDac8 zGptk97rzO2j5Oe5H3gAhlmk3jnKTAPbcBhAiFuzraLmAvGq/hLxnO4bE/kKkY4W Nzm0L9fOoeCcTE1YRgRobNIWP2WAtE+h5qwTMaww+dsI4dsPtfy2aRzQlbR47y3O k+h5S37vuE9FtX4cBTOmGvH1rmlRnKXJIm+awEAFWswfOVJ4tZCTSCWmmEIlDQ2K oEp68eLtzP3MlRdRVSSpznGNZZjWAGaoTYM+WGXrt+oennQbA6iHiYVNrp5kWg7e TQGwozz33Dx3FNpj4QtO0PQ82lHP4VeMNO9xODBrBYV4uQ8i5kol9heZ3Vm+hpf/ lxjFXvSGHuh55UUMXfffHEUZx2Sook07eKwwnBM3Ohbh+gtESCQmzaYWbtnY5CPk Mw3lF/msGwHGTz2KPIUuzhEzSQRYzz9mcOOT8HViK7kiWXL/2L3YFBiO7T9klfxw IORrn1Eq76x+FxW67rJVGYf5T0RALsy/lCVsd53KR2o6nzrsiDNMG/DTwNWoFy2J c52+gkgDeG0PdnFoJ9kTCL4IP6FMR0SvhkEc5I8PJGXpcOMnfpNBkO3TBVWOArby TipHoLUcDmFUgPiouOnb =BHb/ -----END PGP SIGNATURE----- --e5bfZ/T2xnjpUIbw--