From owner-freebsd-current@FreeBSD.ORG Mon Jul 2 21:58:29 2012 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B29451065670; Mon, 2 Jul 2012 21:58:29 +0000 (UTC) (envelope-from cattelan@thebarn.com) Received: from x.digitalelves.com (x.digitalelves.com [209.98.77.55]) by mx1.freebsd.org (Postfix) with ESMTP id 79AED8FC17; Mon, 2 Jul 2012 21:58:29 +0000 (UTC) Received: from Russells-Lion-Hackintosh.local (c-66-41-26-220.hsd1.mn.comcast.net [66.41.26.220]) (authenticated bits=0) by x.digitalelves.com (8.14.5/8.14.5) with ESMTP id q62LwOof083241 (version=TLSv1/SSLv3 cipher=DHE-RSA-CAMELLIA256-SHA bits=256 verify=NO); Mon, 2 Jul 2012 16:58:26 -0500 (CDT) (envelope-from cattelan@thebarn.com) Message-ID: <4FF21980.2090607@thebarn.com> Date: Mon, 02 Jul 2012 16:58:24 -0500 From: Russell Cattelan User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Alexander Kabaev References: <20120702061219.GA16671@infradead.org> <20120702150339.GA7226@kan.dyndns.org> In-Reply-To: <20120702150339.GA7226@kan.dyndns.org> X-Enigmail-Version: 1.4.2 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig63054884B80B5C3C56A7DE05" X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: Christoph Hellwig , Attilio Rao , freebsd-current@freebsd.org, "C. P. Ghost" , FreeBSD FS Subject: Re: MPSAFE VFS -- List of upcoming actions X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Jul 2012 21:58:29 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig63054884B80B5C3C56A7DE05 Content-Type: multipart/mixed; boundary="------------030107020906030202000708" This is a multi-part message in MIME format. --------------030107020906030202000708 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 7/2/12 10:03 AM, Alexander Kabaev wrote: > On Mon, Jul 02, 2012 at 02:12:20AM -0400, Christoph Hellwig wrote: >> On Sun, Jul 01, 2012 at 03:52:05PM +0200, Attilio Rao wrote: >>> anything by SoC involved people about NTFS and certainly I don't see = a >>> plan to get XFS locked. >> >> Stupid question, but what amount of locking does XFS in FreeBSD still >> need? I'm one of the maintainer of XFS on Linux, and while I know >> FreeBSD imported a really old version compared to the current one the >> codebases on IRIX and later Linux never relied on any global Giant-sty= le >> locking. So if there is anything to fix it would be the in the small >> bits of FreeBSD-specific code. >> >=20 > When I stopped being interested in XFS, I left is marked as non-MPSAFE > entirely because of the lack of proper testing and because VFS locking > was still evolving, there was no officially proper way of locking the > FS and no other FS in the tree was MPSAFE. At that time the only > problematic area was around inode instantiation, but sereval other > lockingi changes have made it into the tree since then, namely ones tha= t > deal with insmntque and also VOP_LOOKUP changes. To mark XFS MPSAFE, on= e > needs to simply audit the code and make sure it still makse sense for t= oday's > VFS, which is not a huge amount of work. One step further woule be to t= ake > most of the XFS from under the exclusive vnode locking to improve the > performance. >=20 > And there is a third option - just let current XFS port die and start w= ith > newer version. >=20 I like option 3. The current code is way way out of date and doesn't even reflect the last round of sync up I did. Unless somebody says "hey I'm using XFS" we could just let the current code go and reintroduce a current port if it ever receives the needed attention. Unfortunately I think there were would have be be some sponsorship of the effort since getting xfs fully supported would require some significant developer hours. If anybody is interesting in the current state of things here is my git tree that I cleaned up and put online during BSDCan. http://git.digitalelves.com/?p=3DFreeBSD_xfs.git;a=3Dsummary xfs-FreeBSD_7 has the last somewhat functional code. This was based on a code drop from linux XFS at the time. Log recovery was just starting to come to life (very simple recovery would work) Write was working to the point there you could do a single thread to the fs and have the data cmp back with the original file. Read also still works but is unstable. xfs-FreeBSD_9 is quick code drop I did a month or so ago. I does not compile as many of the linux files moved around so not all the compat stuff lines up and some new compat code needs to written. -Russell --------------030107020906030202000708-- --------------enig63054884B80B5C3C56A7DE05 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (Darwin) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk/yGYAACgkQNRmM+OaGhBhcYQCfYSzCjbJVmv+IMrdwoxARmHbs aVkAnRbx2YzxZrT6AY76vuB53sCTUZp9 =Ajfl -----END PGP SIGNATURE----- --------------enig63054884B80B5C3C56A7DE05--