Re: 2.4.23aa1 ext3 oops

[Marcelo Tosatti <marcelo.tosatti@cyclades.com>]

Jamie, 

Did you try the patch I suggested for you to revert  ?

On Thu, 11 Dec 2003, Jamie Clark wrote:

> OK, no deadlock yet with 2.4.23aa1 however it oopsed under 
> ext3_file_write() in __mark_inode_dirty().
> 
> Just to recap: this test is dual PIII, running several bonnie++ loads on 
> an ext3+noatime+quota filesystem
> mounted off
> 
>  From the oops the fault happens on the last instruction of:
> 
>         movl $0,8(%ebx)
>         movl $0,4(%edx)
>         movl 100(%edi),%eax 
>         movl %edx,4(%eax)    <-- here
> 
> which appears to be this code in inode.c  [line 221+]
> 
>                 if (!(inode->i_state & (I_LOCK|I_FREEING|I_CLEAR)) &&
>                     !list_empty(&inode->i_hash)) {
>                         list_del(&inode->i_list);
>                         list_add(&inode->i_list, &sb->s_dirty);
> 
> After a quick browse of the assembler output the zeroing would appear to 
> be part of the list_del inline, and edi seems to equate to &sb. If I 
> have read that correctly then the 
> oops happens at the beginning of
> the list_add() inline and eax is the head of the s_dirty list - pointing 
> into oblivion.
> 
> __mark_inode_dirty() does not appear to take sb_lock before adding to 
> the s_dirty list. Could that
> be the culprit?   I'm completely unfamiliar with linux kernel so I might 
> be way off here.
> 
> -Jamie
> 
> Andrea Arcangeli wrote:
> 
> >On Tue, Nov 04, 2003 at 07:52:40PM +0800, Jamie Clark wrote:
> >  
> >
> >>I made the quick fix (disabling rq_mergeable) and started the load test.
> >>Will let it run for a week or so.
> >>    
> >>
> >
> >does your later recent email means it deadlocked again even with this
> >disabled?
> >
> >Could you try again with 2.4.23aa1 again just in case?
> >
> >  
> >
> >>FYI an observation from my last test: the read latency seems to be much
> >>improved and more consistent under this kernel (2.4.23pre6aa3, before
> >>the oops and before this fix).  The maximum latency seemed steady over
> >>the whole test without any of the longish pauses that showed up under
> >>2.4.19. Quite a difference.
> >>    
> >>
> >
> >nice to hear! thanks.
> >  
> >
>