On Fri 18-04-08 12:54:47, Andreas Dilger wrote: > On Apr 16, 2008 11:38 +0200, Jan Kara wrote: > > On Tue 15-04-08 11:08:52, Mingming Cao wrote: > > > I guess this reserve locking ordering allows support writepages() for > > > ext3/4? What other the benefits? > > > > Yes, that is one advantage. The other one (which I care about the most) > > is that transaction commit code can take page_lock in the new locking order > > which is necessary for the new ordered mode rewrite. > > My understanding is that the main reason for the ordered mode rewrite is > specifically to allow delalloc to still support ordered mode semantics. > If the lock ordering is changed, and the jbd ordered mode is changed, but > we don't support that with delalloc then we will have made a lot of changes > (and likely introduced some bugs) with little benefit. Yes, with ordered mode rewrite, handling of data=ordered,delalloc is going to be much simpler. But not that it would be my main motivation... Honza -- Jan Kara <jack@xxxxxxx> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
