From: David Howells Date: Thu, 12 Aug 2021 20:54:58 +0000 (+0100) Subject: folio: Add a function to change the private data attached to a folio X-Git-Tag: v6.6.17~8819^2~3 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a19672f6b9718df247a9087a266150dbe833022e;p=platform%2Fkernel%2Flinux-rpi.git folio: Add a function to change the private data attached to a folio Add a function, folio_change_private(), that will change the private data attached to a folio, without the need to twiddle the private bit or the refcount. It assumes that folio_add_private() has already been called on the page. Signed-off-by: David Howells Reviewed-by: Matthew Wilcox (Oracle) Tested-by: Jeff Layton Tested-by: Dominique Martinet Tested-by: kafs-testing@auristor.com Link: https://lore.kernel.org/r/162981149911.1901565.17776700811659843340.stgit@warthog.procyon.org.uk/ Link: https://lore.kernel.org/r/163005743485.2472992.5100702469503007023.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163584180781.4023316.5037526301198034310.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/163649324326.309189.17817587229450840783.stgit@warthog.procyon.org.uk/ # v4 Link: https://lore.kernel.org/r/163657848531.834781.14269656212269187893.stgit@warthog.procyon.org.uk/ # v5 --- diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 6a30916..1f560ae 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -280,6 +280,25 @@ static inline void folio_attach_private(struct folio *folio, void *data) } /** + * folio_change_private - Change private data on a folio. + * @folio: Folio to change the data on. + * @data: Data to set on the folio. + * + * Change the private data attached to a folio and return the old + * data. The page must previously have had data attached and the data + * must be detached before the folio will be freed. + * + * Return: Data that was previously attached to the folio. + */ +static inline void *folio_change_private(struct folio *folio, void *data) +{ + void *old = folio_get_private(folio); + + folio->private = data; + return old; +} + +/** * folio_detach_private - Detach private data from a folio. * @folio: Folio to detach data from. *