highmem: Add folio_release_kmap()

This is the folio equivalent of unmap_and_put_page(), which remains as
a wrapper for it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230921200746.3303942-1-willy@infradead.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-09-21 21:07:38 +01:00 committed by Jan Kara
parent bceef326bc
commit 3de6047f18

View file

@ -551,10 +551,24 @@ static inline void folio_zero_range(struct folio *folio,
zero_user_segments(&folio->page, start, start + length, 0, 0);
}
static inline void unmap_and_put_page(struct page *page, void *addr)
/**
* folio_release_kmap - Unmap a folio and drop a refcount.
* @folio: The folio to release.
* @addr: The address previously returned by a call to kmap_local_folio().
*
* It is common, eg in directory handling to kmap a folio. This function
* unmaps the folio and drops the refcount that was being held to keep the
* folio alive while we accessed it.
*/
static inline void folio_release_kmap(struct folio *folio, void *addr)
{
kunmap_local(addr);
put_page(page);
folio_put(folio);
}
static inline void unmap_and_put_page(struct page *page, void *addr)
{
folio_release_kmap(page_folio(page), addr);
}
#endif /* _LINUX_HIGHMEM_H */