Re: [PATCH v2 3/5] block: Remove a DMA segment boundary mask check

[Ming Lei <ming.lei@redhat.com>]

On Thu, Mar 26, 2026 at 08:51:46AM -0700, Bart Van Assche wrote:
> On 3/26/26 7:51 AM, Ming Lei wrote:
> > On Wed, Mar 25, 2026 at 02:37:13PM -0700, Bart Van Assche wrote:
> > > diff --git a/block/blk-settings.c b/block/blk-settings.c
> > > index 13f5457f9f4e..8538e50afe2c 100644
> > > --- a/block/blk-settings.c
> > > +++ b/block/blk-settings.c
> > > @@ -447,15 +447,9 @@ int blk_validate_limits(struct queue_limits *lim)
> > >   	if (!lim->max_discard_segments)
> > >   		lim->max_discard_segments = 1;
> > > -	/*
> > > -	 * By default there is no limit on the segment boundary alignment,
> > > -	 * but if there is one it can't be smaller than the page size as
> > > -	 * that would break all the normal I/O patterns.
> > > -	 */
> > > +	/* By default there is no limit on the segment boundary alignment. */
> > >   	if (!lim->seg_boundary_mask)
> > >   		lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
> > > -	if (WARN_ON_ONCE(lim->seg_boundary_mask < BLK_MIN_SEGMENT_SIZE - 1))
> > > -		return -EINVAL;
> > 
> > Please fold this change into the real code for reducing
> > BLK_MIN_SEGMENT_SIZE, then it provides consistent handling/view about
> > ->seg_boundary_mask and BLK_MIN_SEGMENT_SIZE.
> 
> Hmm ... wouldn't combining these two patches into a single patch violate
> the "one change per patch" rule?

OK, looks it is two things.

But why do you remove the check? Looks you just encourage driver to use insane
lim->seg_boundary_mask. IMO, it is just fragile.

Thanks,
Ming