Re: [PATCH 1/7] ubi: block: Refactor sg list processing for highmem

From: Christoph Hellwig
Date: Thu Aug 10 2023 - 12:08:20 EST


On Thu, Aug 10, 2023 at 06:00:12PM +0200, Richard Weinberger wrote:
> Currently sg_virt() is used while filling the sg list from LEB data.
> This approach cannot work with highmem.
>
> Refactor ubi_eba_read_leb_sg() to use kmap_atomic() for sg list
> access.
> Since kmap_atomic() disables preempt a bounce buffer is needed.
> kmap_local_page() is not used to allow easy backporting of this patch
> to older kernels.
>
> The followup patches in this series will switch to kmap_sg()
> and we can remove our own helper and the bounce buffer.

Please just use kmap_local and avoid the bounce buffering.