On Sun, Jun 24, 2007 at 06:23:45AM +0200, Nick Piggin wrote: > I'd just like to take the chance also to ask about a VM/FS meetup some > time around kernel summit (maybe take a big of time during UKUUG or so). I won't be around until a day or two before KS, so I'd prefer to have it after KS if possible. > I don't want to do it in the VM summit, because that kind of alienates > the filesystem guys. What I want to talk about is anything and everything > that the VM can do better to help the fs and vice versa. I'd like to > stay away from memory management where not too applicable to the fs. As more of a filesystem person I wouldn't mind it being attached to a VM conf. In the worst case we'll just rename it VM/FS conference. When and where is it scheduled? > - the address space operations APIs, and their page based nature. I think > it would be nice to generally move toward offset,length based ones as > much as possible because it should give more efficiency and flexibility > in the filesystem. > > - write_begin API if it is still an issue by that date. Hope not :) > > - truncate races > > - fsblock if it hasn't been shot down by then Don't forget high order pagecache please. > - how to make complex API changes without having to fix most things > yourself. More issues: - aio once again - refactoring the dio code to separate locking down user VM and doing the actual page based I/O. I've seen valid requests from kernel initiated direct I/O from a few real world linux users. - generic code for delayed allocation and writeout using efficient multi-page allocator calls. I'll hopefully have an example (lifted XFS code) by then - what to do about reads/writes from kernelspace. Currently we have some places (loop mostly) calling directly into ->prepare_write / ->commit_write which is completely wrong from the layerin perspective and a locking nightmare for distributed or generally more complex filesystems. And we have a lot of places using set_fs/set_ds and calling into ->write. The first category could probably be covered by using the splice infrastructure, but for the latter we'd want something more optimal and less hacky, especially given all the overhead related avoiding deadlocks involing the user address space in the generic write path. Maybe it's time for generic_file_kernel_write? - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
