Re: + fs-introduce-write_begin-write_end-and-perform_write-aops.patch added to -mm tree

Jan Kara
2007-06-14T09:52:50Z

> On Wed, 2007-06-13 at 13:43 +0200, Nick Piggin wrote:
> ..
> >
> > > 5) ext3_write_end:
> > > Before write_begin/write_end patch set we have folowing locking
> > > order:
> > > stop_journal(handle);
> > > unlock_page(page);
> > > But now order is oposite:
> > > unlock_page(page);
> > > stop_journal(handle);
> > > Can we got any race condition now? I'm not sure is it actual problem,
> > > may be somebody cant describe this.
> >
> > Can we just change it to the original order? That would seem to be
> > safest unless one of the ext3 devs explicitly acks it.
Sorry, I've missed beginning of this thread. But what problems can
exactly cause this ordering change? ext3_journal_stop has no need to be
protected by the page lock - it can be even better that it's not
protected as it can trigger commit and all that would happen
unnecessarily under page lock...

Honza

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