Re: 2.6.18 ext3 panic.

Jan Kara
2006-10-11T14:22:21Z

> Jan Kara wrote:
>
> > Umm, but these two traces confuse me:
> >1) They are different traces that those you wrote about initially,
> >aren't they? Because here we would not call sync_dirty_buffer() from
> >journal_dirty_data().
> > BTW: Does this buffer trace lead to that Oops in submit_bh()? I guess not
> >as the buffer is not dirty...
>
> They do wind up at the same oops, from the same "testcase" (i.e. beat the
> tar out of the filesystem with multiple fsx's and fsstress...)
>
> The buffer is not dirty at that tracepoint because it has just done
> if (locked && test_clear_buffer_dirty(bh)) {
> prior to the tracepoint...
Oh, I see. OK.

>
> See the whole traces at
>
> http://people.redhat.com/esandeen/traces/eric_ext3_oops1.txt
> http://people.redhat.com/esandeen/traces/eric_ext3_oops2.txt
Hmm, those traces look really useful. I just have to digest them ;).

> As an aside, when we do journal_unmap_buffer... should it stay on
> t_sync_datalist?
Yes, it should and it seems it really was removed from it at some
point. Only later journal_dirty_data() came and filed it back to the
BJ_SyncData list. And the buffer remained unmapped till the commit time
and then *bang*... It may even be a race in ext3 itself that it called
journal_dirty_data() on an unmapped buffer but I have to read some more
code.

Bye
Honza
--
Jan Kara <jack@suse.cz>
SuSE CR Labs