Date: Thu, 10 May 2012 12:39:00 +0200 From: Peter Holm <peter@holm.cc> To: Mateusz Guzik <mjguzik@gmail.com> Cc: Doug Barton <dougb@freebsd.org>, Sergey Kandaurov <pluknet@gmail.com>, freebsd-current <freebsd-current@freebsd.org>, mckusick@freebsd.org Subject: Re: panic, seems related to r234386 Message-ID: <20120510103900.GA77554@x2.osted.lan> In-Reply-To: <20120510102118.GA26472@dft-labs.eu> References: <4FA6F324.4080107@FreeBSD.org> <CAE-mSOJBHPP4E_2Hme5nwf0fGfckyRBWeAe9=kodHMmS6eQy%2Bg@mail.gmail.com> <4FA82269.6080406@FreeBSD.org> <20120507201153.GA19942@dft-labs.eu> <20120508194514.GA10688@x2.osted.lan> <20120510102118.GA26472@dft-labs.eu>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, May 10, 2012 at 12:21:18PM +0200, Mateusz Guzik wrote:
> On Tue, May 08, 2012 at 09:45:14PM +0200, Peter Holm wrote:
> > On Mon, May 07, 2012 at 10:11:53PM +0200, Mateusz Guzik wrote:
> > > On Mon, May 07, 2012 at 12:28:41PM -0700, Doug Barton wrote:
> > > > On 05/06/2012 15:19, Sergey Kandaurov wrote:
> > > > > On 7 May 2012 01:54, Doug Barton <dougb@freebsd.org> wrote:
> > > > >> I got this with today's current, previous (working) kernel is r232719.
> > > > >>
> > > > >> panic: _mtx_lock_sleep: recursed on non-recursive mutex struct mount mtx
> > > > >> @ /frontier/svn/head/sys/kern/vfs_subr.c:4595
> > > >
> > > > ...
> > > >
> > > > > Please try this patch.
> > > > >
> > > > > Index: fs/ext2fs/ext2_vfsops.c
> > > > > ===================================================================
> > > > > --- fs/ext2fs/ext2_vfsops.c (revision 235108)
> > > > > +++ fs/ext2fs/ext2_vfsops.c (working copy)
> > > > > @@ -830,7 +830,6 @@
> > > > > /*
> > > > > * Write back each (modified) inode.
> > > > > */
> > > > > - MNT_ILOCK(mp);
> > > > > loop:
> > > > > MNT_VNODE_FOREACH_ALL(vp, mp, mvp) {
> > > > > if (vp->v_type == VNON) {
> > > > >
> > > >
> > > > Didn't help, sorry. I put 234385 through some pretty heavy load
> > > > yesterday, and everything was fine. As soon as I move up to 234386, the
> > > > panic triggered again. So I cleaned everything up, applied your patch,
> > > > built a kernel from scratch, and rebooted. It was Ok for a few seconds
> > > > after boot, then panic'ed again, I think in a different place, but I'm
> > > > not sure because subsequent attempts to fsck the file systems caused new
> > > > panics which overwrote the old ones before they could be saved.
> > > >
> > >
> > > Another MNT_ILOCK was hiding few lines below, try this patch:
> > >
> > > http://student.agh.edu.pl/~mjguzik/patches/ext2fs-ilock.patch
> > >
> > > I've tested this a bit and I believe this fixes your problem.
> > >
> >
> > Gave this a spin and found what looks like a deadlock:
> >
> > http://people.freebsd.org/~pho/stress/log/ext2fs.txt
> >
> > Not a new problem, it would seem. Same issue with 8.3-PRERELEASE r232656M.
> >
>
> pid 2680 (fts) holds lock for vnode cb4be414 and tries to lock cc0ac15c
> pid 2581 (openat) holds lock for vnode cc0ac15c and tries to lock cb4be414
>
> openat calls rmdir foo/bar and ext2_rmdir unlocks and tries to lock
> again foo's vnode.
>
> This is fairly easly reproducible with concurrently running mkdir and fts
> testcase programs that are provided by stress2.
>
> I'll try to come up with a patch by the end of the week.
>
Great. Thank you for looking at this.
- Peter
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20120510103900.GA77554>