diff options
author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-01-11 10:04:40 -0500 |
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committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-09-27 09:27:29 -0400 |
commit | 85d0a2ed3747da7f9aedacb72478bbedf06f9f2e (patch) | |
tree | fa38c8b1516f7bca2fbf384a3e4bf96b32dd0977 /include/linux/pagemap.h | |
parent | 889a3747b3b7661b089ba4eae081a3b6bb351a23 (diff) |
mm: Handle per-folio private data
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@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Diffstat (limited to 'include/linux/pagemap.h')
-rw-r--r-- | include/linux/pagemap.h | 48 |
1 files changed, 29 insertions, 19 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index f3ec26551082..b0f5bf1cb540 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -184,42 +184,52 @@ static inline bool page_cache_get_speculative(struct page *page) } /** - * attach_page_private - Attach private data to a page. - * @page: Page to attach data to. - * @data: Data to attach to page. + * folio_attach_private - Attach private data to a folio. + * @folio: Folio to attach data to. + * @data: Data to attach to folio. * - * Attaching private data to a page increments the page's reference count. - * The data must be detached before the page will be freed. + * Attaching private data to a folio increments the page's reference count. + * The data must be detached before the folio will be freed. */ -static inline void attach_page_private(struct page *page, void *data) +static inline void folio_attach_private(struct folio *folio, void *data) { - get_page(page); - set_page_private(page, (unsigned long)data); - SetPagePrivate(page); + folio_get(folio); + folio->private = data; + folio_set_private(folio); } /** - * detach_page_private - Detach private data from a page. - * @page: Page to detach data from. + * folio_detach_private - Detach private data from a folio. + * @folio: Folio to detach data from. * - * Removes the data that was previously attached to the page and decrements + * Removes the data that was previously attached to the folio and decrements * the refcount on the page. * - * Return: Data that was attached to the page. + * Return: Data that was attached to the folio. */ -static inline void *detach_page_private(struct page *page) +static inline void *folio_detach_private(struct folio *folio) { - void *data = (void *)page_private(page); + void *data = folio_get_private(folio); - if (!PagePrivate(page)) + if (!folio_test_private(folio)) return NULL; - ClearPagePrivate(page); - set_page_private(page, 0); - put_page(page); + folio_clear_private(folio); + folio->private = NULL; + folio_put(folio); return data; } +static inline void attach_page_private(struct page *page, void *data) +{ + folio_attach_private(page_folio(page), data); +} + +static inline void *detach_page_private(struct page *page) +{ + return folio_detach_private(page_folio(page)); +} + #ifdef CONFIG_NUMA extern struct page *__page_cache_alloc(gfp_t gfp); #else |