On Thu, 2017-01-12 at 12:46 +0100, Ilya Dryomov wrote: > On Thu, Jan 12, 2017 at 12:37 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Jan 12, 2017 at 12:13:31PM +0100, Ilya Dryomov wrote: > > > > > > > > It would be a significant and wide-reaching change, but I've been > > > meaning to look into switching to iov_iter for a couple of releases > > > now. There is a lot of ugly code in net/ceph/messenger.c to hangle > > > iteration over "page vectors", "page lists" and "bio lists". All of it > > > predates iov_iter proliferation and is mostly incomplete anyway: IIRC > > > you can send out of a pagelist but can't recv into a pagelist, etc. > > > > Wait a sec... Is it done from the same thread that has issued a syscall? > > If so, we certainly could just pass iov_iter without bothering with any > > form of ..._get_pages(); if not, we'll need at least to get from iovec > > to bio_vec, since userland addresses make sense only in the caller's > > context... > > No, not necessarily - it's also used by rbd (all of net/ceph has two > users: fs/ceph and drivers/block/rbd.c). > > ...and note that the actual send/receive is done from workqueue context (AFAICT), so we might be operating over the array from a completely different thread context from where it was submitted. I think we do need to get page references at the point of submission like this. -- Jeff Layton <jlayton@xxxxxxxxxx> -- 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
