Commit ee7a5906 authored Jan 04, 2023 by Vishal Moola (Oracle) Committed by Andrew Morton Feb 02, 2023

pagemap: add filemap_grab_folio()

Patch series "Convert to filemap_get_folios_tag()", v5.

This patch series replaces find_get_pages_range_tag() with
filemap_get_folios_tag().  This also allows the removal of multiple calls
to compound_head() throughout.

It also makes a good chunk of the straightforward conversions to folios,
and takes the opportunity to introduce a function that grabs a folio from
the pagecache.


This patch (of 23):

Add function filemap_grab_folio() to grab a folio from the page cache. 
This function is meant to serve as a folio replacement for
grab_cache_page, and is used to facilitate the removal of
find_get_pages_range_tag().

Link: https://lkml.kernel.org/r/20230104211448.4804-1-vishal.moola@gmail.com
Link: https://lkml.kernel.org/r/20230104211448.4804-2-vishal.moola@gmail.com


Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

parent 2cf13384

include/linux/pagemap.h

+20 −0

Original line number	Diff line number	Diff line
		@@ -546,6 +546,26 @@ static inline struct folio filemap_lock_folio(struct address_space mapping,
		return __filemap_get_folio(mapping, index, FGP_LOCK, 0);
		}

		/**
		* filemap_grab_folio - grab a folio from the page cache
		* @mapping: The address space to search
		* @index: The page index
		*
		* Looks up the page cache entry at @mapping & @index. If no folio is found,
		* a new folio is created. The folio is locked, marked as accessed, and
		* returned.
		*
		* Return: A found or created folio. NULL if no folio is found and failed to
		* create a folio.
		*/
		static inline struct folio filemap_grab_folio(struct address_space mapping,
		pgoff_t index)
		{
		return __filemap_get_folio(mapping, index,
		FGP_LOCK \| FGP_ACCESSED \| FGP_CREAT,
		mapping_gfp_mask(mapping));
		}

		/**
		* find_get_page - find and get a page reference
		* @mapping: the address_space to search