Re: [PATCH v5 07/12] md: support to align bio to limits

On Thu, Jan 15, 2026 at 01:12:35AM +0800, Yu Kuai wrote:
> For personalities that report optimal IO size, it indicates that users
> can get the best IO bandwidth if they issue IO with this size. However
> there is also an implicit condition that IO should also be aligned to the
> optimal IO size.
> 
> Currently, bio will only be split by limits, if bio offset is not aligned
> to limits, then all split bio will not be aligned. This patch add a new
> feature to align bio to limits first, and following patches will support
> this for each personality if necessary.

This feels a bit odd and mixes up different things as right now
nothing in the block layer splits to the opt_io size.  If you want
a boundary that is split on, the chunk_size limit seems to be what
you want, and the existing code would do the work based on that.