Re: [PATCH 08/16] dm-writecache: use bvec_kmap_local instead of bvec_kmap_irq

From: Christoph Hellwig
Date: Tue Jun 08 2021 - 12:38:09 EST

On Tue, Jun 08, 2021 at 09:30:56AM -0700, Bart Van Assche wrote:
> >From one of the functions called by kunmap_local():
> unsigned long addr = (unsigned long) vaddr & PAGE_MASK;
> This won't work well if bvec->bv_offset >= PAGE_SIZE I assume?

It won't indeed. Both the existing and new helpers operate on single
page bvecs only, and all callers only use those. I should have
probably mentioned that in the cover letter and documented the
assumptions in the code, though.