bio segment constraints

[Keith Busch]

On Mon, Apr 07, 2025 at 10:14:28AM -0400, Sean Anderson wrote:
> On 4/7/25 03:10, Hannes Reinecke wrote:
> > 
> > The driver surely can. You should be able to set 'max_segment_size' to
> > the logical block size, and that should give you what you want.
> 
> But couldn't I get segments smaller than that? max_segment_size seems like
> it would only restrict the maximum size, leaving the possibility open for
> smaller segments.

If your driver never wants to see segments smaller than the logical
block, you could update your queue_limits dma_alignment to be
logical_block_size - 1. It is 511 by default so works for you only if
logical block size == SECTOR_SIZE.