Re: [PATCH V2] block: fail unaligned bio from submit_bio_noacct()

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

On Mon, Mar 25, 2024 at 11:53:45AM -0700, Keith Busch wrote:
> On Sun, Mar 24, 2024 at 09:37:02PM +0800, Ming Lei wrote:
> > @@ -780,6 +793,9 @@ void submit_bio_noacct(struct bio *bio)
> >  		}
> >  	}
> >  
> > +	if (WARN_ON_ONCE(!bio_check_alignment(bio, q)))
> > +		goto end_io;
> > +
> 
> The "status" at this point is "BLK_STS_IOERR", so user space would see
> EIO, but the existing checks return EINVAL. I'm not sure if that's "ok",
> but assuming it is, I think the user visible different behavior should
> be mentioned in the changelog.
> 
> Alternatively, maybe we want an asynchronous way to return EINVAL for

It has to be async way to return it because submit_bio*() returns
void.

> these conditions. It's more informative to a user where the problem is
> than a generic EIO. There is no BLK_STS_ value that translates to
> EINVAL, though, so maybe we need a new block status code like
> BLK_STS_INVALID_REQUEST.

Yeah, I agree, but that is one existed issue. The 'status' should have
been initialized as 'BLK_STS_INVALID_REQUEST' or 'BLK_STS_INVALID' in
submit_bio_noacct(), and all check failure can be thought as -EINVAL.


Thanks, 
Ming