On Fri, 14 Mar 2008 10:24:12 -0400 Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote: > On Fri, Mar 14, 2008 at 02:51:35PM +0100, Jens Axboe wrote: > > Are you sure? Seems to me that st builds its own list with > > get_user_pages() for direct io, where will that get bounced? The block > > layer will only bounce things that are mapped directly, so if st used > > blk_rq_map_kern() and inserted that request in the queue, we could > > proceed with killing that check in st. > > Which shouldn't be all too difficult and would be the right thing to > do. We really need someone to sit down and convert st/osst/sg to use > the proper block layer helpers. I've been working on this (hopefully, I'll submit an updated patchset this week). I think that the main problem was a lack of motivation for these changes. I bet that nobody reviewed the patchset that Mike posted the last time. Hopefully, the new patchset will be reviewed and merged. With sg chaining, drain, padding, etc, building a scatterlist is much complicated than in the past. I believe that we should kill home-made scatterlist code and convert the users to use the block layer to avoid potential scatterlist bugs. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
