On Thu, Jul 15, 2021 at 04:34:58AM +0100, Matthew Wilcox (Oracle) wrote: > Add folio_get_private() which mirrors page_private() -- ie folio private > data is the same as page private data. The only difference is that these > return a void * instead of an unsigned long, which matches the majority > of users. > > Turn attach_page_private() into folio_attach_private() and reimplement > attach_page_private() as a wrapper. No filesystem which uses page private > data currently supports compound pages, so we're free to define the rules. > attach_page_private() may only be called on a head page; if you want > to add private data to a tail page, you can call set_page_private() > directly (and shouldn't increment the page refcount! That should be > done when adding private data to the head page / folio). > > This saves 813 bytes of text with the distro-derived config that I'm > testing due to removing the calls to compound_head() in get_page() > & put_page(). > > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> > Reviewed-by: Christoph Hellwig <hch@xxxxxx> > Acked-by: Jeff Layton <jlayton@xxxxxxxxxx> > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> > Acked-by: Vlastimil Babka <vbabka@xxxxxxx> > Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx> > Reviewed-by: David Howells <dhowells@xxxxxxxxxx> > --- > include/linux/mm_types.h | 11 +++++++++ > include/linux/pagemap.h | 48 ++++++++++++++++++++++++---------------- > 2 files changed, 40 insertions(+), 19 deletions(-) Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
