[dm-devel] [PATCH] bio: have bio_kmap_irq return the size of mapped data (fwd)

[Mikulas Patocka]

On Wed, 8 Nov 2017, Christoph Hellwig wrote:

> On Tue, Nov 07, 2017 at 04:45:17PM -0500, Mikulas Patocka wrote:
> > Hi
> > 
> > I need the function bio_kmap_irq in the driver that I am developing, but 
> > it doesn't return the size of the mapped data. I've made this patch to fix 
> > it.
> 
> To be honest I think we should just remove bio_kmap_irq.  It is currently
> unused and assumes there is only a single bvec to map.

It could be removed from include/linux/bio.h and moved to my driver. But 
if we leave it in bio.h, it could be used by others as well.

bio_kmap_irq can iterate over the whole bio if we use bio_advance on the 
bio.

> I think you're much better off using a proper bvec iterator in your
> caller and then call bvec_kmap_irq/bvec_kunmap_irq manually.

Mikulas