On Thu, Jul 04 2002, Andrew Morton wrote: > Jens Axboe wrote: > > > > ... > > > We just want ext3/jbd to make sure that it only calls bh2jh on > > > an unlocked buffer... is that easy? > > > > That's the question indeed, someone with a good grasp of jbd should make > > that call. If that is the only 'violator' (depending on your point of > > view), then yes lets just fix that up and say that the above is pb > > private is valid. > > We really don't want to do this, please. Changing things so > that we can only run bh2jh() and, particularly, journal_add_journal_head() > on a locked buffer would involve fairly unpleasant surgery against > parts of ext3 which are already prone to exploding. Like > do_get_write_access(). > > If it was needed for 2.5 then hmm, maybe. But as this is only a > 2.4 problem then I really don't think we should risk breaking > or slowing down the filesystem for this. > > Look, it's easy: delete buffer_head.b_inode (which is only used as > a boolean), move its function to a b_state bit. Add a new > buffer_head.ext3_hack and we can use that for pointing at the journal_head. Thank you, this is what I was looking for (if you look further up, I was advocating this very thing). Slimming down buffer_head and just add the ext3 hack is perfectly acceptable to me. Which just means that device mapper needs to do the stacking properly, EOD. -- Jens Axboe _______________________________________________ linux-lvm mailing list linux-lvm@sistina.com http://lists.sistina.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://www.sistina.com/lvm/Pages/howto.html
