On Thu, Jul 17, 2025 at 12:29:27AM +0800, Yu Kuai wrote: >> If opt_io_size is (chunk_size * data_disks), setting new max_hw_sectors as rounddown(current max_hw_sectors, opt_io_size) is good idea. > > I think round down max_hw_sectors to io_opt(chunk_size * data_disks) will > really > make things much easier, perhaps Christoph means this way. All you need to > do is to > handle not aligned bio and split that part, and for aligned bio fall back > to use > bio_split_to_limits(). If the raid5 code can handle multiple stripes per I/O, than you just need to round it down, yes. I assumed it could only handle a single full or partial stripe at a time, but I guess I was wrong.
