Re: panic: lock "aiomtx" already initialized

On Thu, Aug 09, 2007 at 06:48:42AM +0300, Kostik Belousov wrote:
> On Wed, Aug 08, 2007 at 03:59:55PM -0400, Kris Kennaway wrote:
> > From stress2's random syscall test:
> > 
> > db> wh
> > Tracing pid 45777 tid 100465 td 0xc61b7000
> > kdb_enter(c077f50d,2,c0782352,ed0fab84,2,...) at kdb_enter+0x33
> > panic(c0782352,c0788b88,c5e1107c,20000,0,...) at panic+0xed
> > lock_init(c5e1107c,c07c67c4,c0788b88,0,20000) at lock_init+0x8c
> > mtx_init(c5e1107c,c0788b88,0,0,79400d31,...) at mtx_init+0x9f
> > aio_init_aioinfo(c61c4ab0,c057d463,c07e6520,9579c960,31a964,...) at aio_init_aioinfo+0x4b
> > aio_aqueue(c61b7000,79400d31,0,2,1,...) at aio_aqueue+0x8d
> > oaio_read(c61b7000,ed0facf8,4,c078503a,c07c2250,...) at oaio_read+0x32
> > syscall(ed0fad38) at syscall+0x14f
> > Xint0x80_syscall() at Xint0x80_syscall+0x20
> > --- syscall (318, FreeBSD ELF32, oaio_read), eip = 0x280c0969, esp = 0xbfbfe5f0, ebp = 0xbfbfe638 ---
> > db> x/s 0xc0782352
> > 0xc0782352:     lock "%s" %p already initialized
> > db> x/s 0xc0788b88
> > 0xc0788b88:     aiomtx
> > db> show lock 0xc5e1107c
> >  class: sleep mutex
> >  name: aiomtx
> >  flags: {DEF}
> >  state: {UNOWNED}
> > 
> 
> This patch should fix the problem:
> 
> diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c
> index 7610da8..47580b6 100644
> --- a/sys/kern/vfs_aio.c
> +++ b/sys/kern/vfs_aio.c
> _at__at_ -719,6 +719,7 _at__at_ restart:
>  	}
>  	AIO_UNLOCK(ki);
>  	taskqueue_drain(taskqueue_aiod_bio, &ki->kaio_task);
> +	mtx_destroy(&ki->kaio_mtx);
>  	uma_zfree(kaio_zone, ki);
>  	p->p_aioinfo = NULL;
>  }
> 
> It seems that you shall use a lot of quickly exit()ing processes all of
> them using aio to reliable reproduce the problem.

I'll try to see if I can reproduce the panic, later on today.

- Peter