Re: panic: vput: negative ref cnt

Am 04.04.2009 um 13:55 schrieb Mark Powell:

> Hi,
>  Getting a reproducable panic during backups:
>
> panic: vput: negative ref cnt
> cpuid = 0
> KDB: enter: panic
> [thread pid 3521 tid 100374 ]
> Stopped at	kdb_enter+0x3d: movq	$0,0x654104(%rip)
> db> bt
> Tracing pid 3521 tid 100374 0xffffff008c79e380
> kdb_enter() at kdb_enter+0x3d
> panic() at panic+0x176
> vput() at vput+0x10c
> dounmount() at dounmount0x421
> unmount() at unmount+0x24b
> syscall() at syscall+0x1bf
> Xfast_syscall() at Xfast_syscall+0xab
> --- syscall (22, FreeBSD ELF64, unmount), rip = 0x800695d7c, rsp =  
> 0x7fffffffe218, rbp = 0 ---
>
> My script takes a zfs snapshot, mounts the snapshot, backs it up  
> using star, then umounts the snapshot. The panic seems to occur on  
> the umount.

This is a different panic from the one I was getting, but appears to  
occur under the same circumstances.

I managed to avoid the panic by keeping the snapshot until the next  
run of my backup script, and not unmounting anything.

See <http://lists.freebsd.org/pipermail/freebsd-current/2009-February/003513.html 
 >


Stefan

-- 
Stefan Bethke <stb_at_lassitu.de>   Fon +49 151 14070811