On Tue, Jun 22, 2021 at 01:15:08PM +0100, Matthew Wilcox (Oracle) wrote: > This allows us to map a portion of a folio. Callers can only expect > to access up to the next page boundary. > > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> This looks sensible to me: Reviewed-by: Christoph Hellwig <hch@xxxxxx> While we're at it: flushing incoherent mappings for use with kmap has been a complete mess. I've been trying to fix this with kunmap_local_dirty, but that could use another review, as well as a folio version probably give that one prime use case of folios is to have them mapped into userspace.