On Tue, Jun 8, 2021 at 6:06 PM Christoph Hellwig <hch@xxxxxx> wrote:
>
> Add a helper to call kmap_local_page on a bvec. There is no need for
> an unmap helper given that kunmap_local accept any address in the mapped
> page.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> include/linux/bvec.h | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/include/linux/bvec.h b/include/linux/bvec.h
> index 883faf5f1523..d64d6c0ceb77 100644
> --- a/include/linux/bvec.h
> +++ b/include/linux/bvec.h
> @@ -7,6 +7,7 @@
> #ifndef __LINUX_BVEC_H
> #define __LINUX_BVEC_H
>
> +#include <linux/highmem.h>
> #include <linux/bug.h>
> #include <linux/errno.h>
> #include <linux/limits.h>
> @@ -183,4 +184,9 @@ static inline void bvec_advance(const struct bio_vec *bvec,
> }
> }
>
> +static inline void *bvec_kmap_local(struct bio_vec *bvec)
> +{
> + return kmap_local_page(bvec->bv_page) + bvec->bv_offset;
> +}
> +
> #endif /* __LINUX_BVEC_H */
Might be useful to add the second sentence of the commit message as
a comment for bvec_kmap_local(). It could be expanded to mention the
single-page bvec caveat too.
Thanks,
Ilya
