Re: fusefs-kmod broken?

On Mon, Aug 23, 2010 at 02:58:59PM +0200, Ian FREISLICH wrote:
> John Baldwin wrote:
> > The uart thing is a red herring, notice the actual PC value is '0'.  Something
> > in kern_open() invoked a NULL function pointer.  Doing 'l *kern_open+0x35' in
> > kgdb would be a good start of where to look.
> 
> (kgdb) l *kern_open+0x35
> 0xc0649ce5 is in kern_open (/usr/src/sys/kern/vfs_syscalls.c:1040).
> 1035    kern_open(struct thread *td, char *path, enum uio_seg pathseg, int flags,
> 1036        int mode)
> 1037    {
> 1038
> 1039            return (kern_openat(td, AT_FDCWD, path, pathseg, flags, mode));
> 1040    }
> 1041
> 1042    int
> 1043    kern_openat(struct thread *td, int fd, char *path, enum uio_seg pathseg,
> 1044        int flags, int mode)
> 
> That's what my reading seemed indicate.  I had to downgrade the
> system back to 8.0-STABLE at around 21 April 2010, to get the system
> working.
> 
> I'm currently doing a binary search to find offending commit, since
> CURRENT and STABLE panic reliably, and in the same way I'm sure
> that the problem is common to both.
> 
> I'm down to a window of 9 hours.  My money is currently on:
> 
> Working file: sys/kern/vfs_syscalls.c
> Approved by:    re (bz)
> ----------------------------
> revision 1.487.2.7
> date: 2010/04/27 10:47:54;  author: kib;  state: Exp;  lines: +2 -15
> SVN rev 207270 on 2010-04-27 10:47:54Z by kib
> 
> MFC r206547:
> Handle a case in kern_openat() when vn_open() change file type from
> DTYPE_VNODE.
> ----------------------------

Which most likely means that fusesfs filled its own struct fileops
without properly initializing fo_truncate member.