[PATCH 01/23] pagemap: Add filemap_grab_folio()

Vishal Moola (Oracle)
2022-09-01T22:02:47Z

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().

Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
---
include/linux/pagemap.h | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 0178b2040ea3..4d3092d6b2c0 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -547,6 +547,26 @@ 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
--
2.36.1