On Sat, Mar 28, 2020 at 10:11:57AM +0800, Ming Lei wrote: > On Sat, Mar 28, 2020 at 2:18 AM Keith Busch <kbusch@xxxxxxxxxx> wrote: > > > > This is actually even more confusing. We do not support 256MB transfers > > within a single command in the pci nvme driver anymore. The max is 4MB, > > so I don't see how increasing the max segments will help: you should be > > hitting the 'max_sectors' limit if you don't hit the segment limit first. > > That looks a bug for passthrough req, because 'max_sectors' limit is only > checked in bio_add_pc_page(), not done in blk_rq_append_bio(), something > like the following seems required: Shouldn't bio_map_user_iov() or bio_copy_user_iov() have caught the length limit before proceeding to blk_rq_append_bio()?
