zfs: Fatal trap 12: page fault while in kernel mode

[Juergen Unger]

Hi Pawel,

On Wed, Jul 29, 2009 at 10:47:23AM +0200, Pawel Jakub Dawidek wrote:
> On Tue, Jul 28, 2009 at 12:50:26PM +0300, Andriy Gapon wrote:
> > on 27/07/2009 22:58 O. Hartmann said the following:
> > > Juergen Unger wrote:
> > [snip]
> > >>> _sx_xlock(3c,0,874aa28d,70f,8ae9a9f8,...) at _sx_xlock+0x43
> > >>> dmu_buf_update_user(0,8ae9a9f8,0,0,0,...) at dmu_buf_update_user+0x35
> > >>> zfs_znode_dmu_fini(8ae9a9f8,874b312d,1114,110b,879ab000,...) at zfs_znode_dmu_f3
> > >>> zfs_freebsd_reclaim(fcd29c3c,1,0,8ec63754,fcd29c60,...) at zfs_freebsd_reclaim+0
> > >>> VOP_RECLAIM_APV(874b65a0,fcd29c3c,0,0,8ec637c8,...) at VOP_RECLAIM_APV+0xa5
> > >>> vgonel(8ec637c8,0,80c77037,386,0,...) at vgonel+0x1a4
> > >>> vnlru_free(80f2a0f0,0,80c77037,300,3e8,...) at vnlru_free+0x2d5
> > >>> vnlru_proc(0,fcd29d38,80c652bc,33e,871932a8,...) at vnlru_proc+0x80
> > >>> fork_exit(8090d960,0,fcd29d38) at fork_exit+0xb8
> > >>> fork_trampoline() at fork_trampoline+0x8
>[snip]
> > P.S. I see that zfs_inactive checks for z_dbuf being NULL and there is the
> > following comment:
> > /*
> >  * The fs has been unmounted, or we did a
> >  * suspend/resume and this file no longer exists.
> >  */
> > Maybe zfs_freebsd_reclaim should do the same?
> 
> Yes, you might be right.
> 
> Could you guys, who can reproduce it, try this patch:
> 
> 	http://people.freebsd.org/~pjd/patches/zfs_vnops.c.2.patch

I tried the patch, restarted the whole thing yesterday morning
and after less then 24 hours and approximately 3215 zfs-receive
jobs it do not crashes anymore, but the last started zfs-receive
jobs is hanging, cannot be killed, even not with -9.  Even other
zfs commands are hanging and cannot be killed, while zpool commands
seems to be not affected.

root  86397  0.0  0.0  3920  1308  ??  D     3:18AM   0:00.29 zfs receive -Fv zzzz/203
root   5001  0.0  0.0  3920  1208   0  D+   10:45AM   0:00.00 zfs list -t snapshot
root   5477  0.0  0.0  3920  1240   3  D+   11:08AM   0:00.00 zfs list

also the sync command I tried to execute hangs forever:

root   5457  0.0  0.0  1528   492   2- D+   11:05AM   0:00.04 sync

Other parts of the system which do not have something todo with zfs
are still working well.   I will leave the machine running in this
state, is there something I can do to retrieve other usefull information
for you?

thnx in advance,
 Juergen

-- 
ENOSIG