On Mon, Aug 18, 2025 at 04:10:32PM +0800, Yu Kuai wrote: > Why? We just set the flag for mdraid disks first, and then inherit to > top devices that is stacked by mdraid, so md raid limits should always > be relevant. I still don't understand the problem that you said :( The point is the fact how mdraid calculates the opt_io is somewhere between ireelevant and wrong for any layer above. The layers above just care about the value. And to calculate the value you don't need a special flag. mdraid can simply override io_opt (or better max_hw_sectors) after stacking the lower level devices with a few lines of code (and hopefully a good comment).
