Re: [PATCH] fs/vboxsf: Replace kmap() with kmap_local_{page, folio}()

From: Matthew Wilcox
Date: Tue Jun 27 2023 - 13:48:31 EST


On Tue, Jun 27, 2023 at 06:51:15AM -0700, Sumitra Sharma wrote:
> +++ b/fs/vboxsf/file.c
> @@ -234,7 +234,7 @@ static int vboxsf_read_folio(struct file *file, struct folio *folio)
> u8 *buf;
> int err;
>
> - buf = kmap(page);
> + buf = kmap_local_folio(folio, off);

Did you test this? 'off' is the offset in the _file_. Whereas
kmap_local_folio() takes the offset within the _folio_. They have
different types (loff_t vs size_t) to warn you that they're different
things.