The existing non-mempolicy APIs remain unchanged and continue to use the
default allocation behavior.

Signed-off-by: Shivansh Dhiman <redacted>
Signed-off-by: Shivank Garg <redacted>
---
  include/linux/pagemap.h | 40 ++++++++++++++++++++++++++++++++++++++++
  mm/filemap.c            | 30 +++++++++++++++++++++++++-----
  2 files changed, 65 insertions(+), 5 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 47bfc6b1b632..4ae7fa63cb26 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h

@@ -662,15 +662,25 @@ static inline void *detach_page_private(struct page *page)
  
  #ifdef CONFIG_NUMA
  struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order);
+struct folio *filemap_alloc_folio_mpol_noprof(gfp_t gfp, unsigned int order,
+						struct mempolicy *mpol);

  #endif
  
  #define filemap_alloc_folio(...)				\
  	alloc_hooks(filemap_alloc_folio_noprof(__VA_ARGS__))
+#define filemap_alloc_folio_mpol(...)				\
+	alloc_hooks(filemap_alloc_folio_mpol_noprof(__VA_ARGS__))
  
  static inline struct page *__page_cache_alloc(gfp_t gfp)
  {

@@ -762,6 +772,8 @@ static inline fgf_t fgf_set_order(size_t size)
  void *filemap_get_entry(struct address_space *mapping, pgoff_t index);
  struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
  		fgf_t fgp_flags, gfp_t gfp);
+struct folio *__filemap_get_folio_mpol(struct address_space *mapping,
+		pgoff_t index, fgf_t fgp_flags, gfp_t gfp, struct mempolicy *mpol);
  struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
  		fgf_t fgp_flags, gfp_t gfp);
  

@@ -820,6 +832,34 @@ static inline struct folio *filemap_grab_folio(struct address_space *mapping,
  			mapping_gfp_mask(mapping));
  }
  
+/**
+ * filemap_grab_folio_mpol - grab a folio from the page cache
+ * @mapping: The address space to search
+ * @index: The page index
+ * @mpol: The mempolicy to apply

+ *
+ * Same as filemap_grab_folio(), except that it allocates the folio using
+ * given memory policy.
+ *
+ * Return: A found or created folio. ERR_PTR(-ENOMEM) if no folio is found
+ * and failed to create a folio.
+ */
+#ifdef CONFIG_NUMA
+static inline struct folio *filemap_grab_folio_mpol(struct address_space *mapping,
+					pgoff_t index, struct mempolicy *mpol)
+{
+	return __filemap_get_folio_mpol(mapping, index,
+			FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
+			mapping_gfp_mask(mapping), mpol);
+}
+#else
+static inline struct folio *filemap_grab_folio_mpol(struct address_space *mapping,
+					pgoff_t index, struct mempolicy *mpol)
+{
+	return filemap_grab_folio(mapping, index);
+}
+#endif /* CONFIG_NUMA */
+
  /**
   * find_get_page - find and get a page reference
   * @mapping: the address_space to search

diff --git a/mm/filemap.c b/mm/filemap.c
index 804d7365680c..c5ea32702774 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c

@@ -1001,8 +1001,13 @@ int filemap_add_folio(struct address_space *mapping, struct folio *folio,
  EXPORT_SYMBOL_GPL(filemap_add_folio);
  
  #ifdef CONFIG_NUMA
-struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order)
+struct folio *filemap_alloc_folio_mpol_noprof(gfp_t gfp, unsigned int order,
+			struct mempolicy *mpol)
  {
+	if (mpol)
+		return folio_alloc_mpol_noprof(gfp, order, mpol,
+				NO_INTERLEAVE_INDEX, numa_node_id());
+

  	int n;
  	struct folio *folio;
  

@@ -1018,6 +1023,12 @@ struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order)
  	}
  	return folio_alloc_noprof(gfp, order);
  }
+EXPORT_SYMBOL(filemap_alloc_folio_mpol_noprof);
+
+struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order)
+{
+	return filemap_alloc_folio_mpol_noprof(gfp, order, NULL);
+}
  EXPORT_SYMBOL(filemap_alloc_folio_noprof);
  #endif
  

@@ -1881,11 +1892,12 @@ void *filemap_get_entry(struct address_space *mapping, pgoff_t index)
  }
  
  /**
- * __filemap_get_folio - Find and get a reference to a folio.
+ * __filemap_get_folio_mpol - Find and get a reference to a folio.
   * @mapping: The address_space to search.
   * @index: The page index.
   * @fgp_flags: %FGP flags modify how the folio is returned.
   * @gfp: Memory allocation flags to use if %FGP_CREAT is specified.
+ * @mpol: The mempolicy to apply.

   *
   * Looks up the page cache entry at @mapping & @index.
   *

@@ -1896,8 +1908,8 @@ void *filemap_get_entry(struct address_space *mapping, pgoff_t index)
   *
   * Return: The found folio or an ERR_PTR() otherwise.
   */
-struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
-		fgf_t fgp_flags, gfp_t gfp)
+struct folio *__filemap_get_folio_mpol(struct address_space *mapping, pgoff_t index,
+		fgf_t fgp_flags, gfp_t gfp, struct mempolicy *mpol)
  {
  	struct folio *folio;
  

@@ -1967,7 +1979,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
  			err = -ENOMEM;
  			if (order > min_order)
  				alloc_gfp |= __GFP_NORETRY | __GFP_NOWARN;
-			folio = filemap_alloc_folio(alloc_gfp, order);
+			folio = filemap_alloc_folio_mpol(alloc_gfp, order, mpol);
  			if (!folio)
  				continue;
  

@@ -2003,6 +2015,14 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
  		folio_clear_dropbehind(folio);
  	return folio;
  }
+EXPORT_SYMBOL(__filemap_get_folio_mpol);
+
+struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
+		fgf_t fgp_flags, gfp_t gfp)
+{
+	return __filemap_get_folio_mpol(mapping, index,
+			fgp_flags, gfp, NULL);
+}
  EXPORT_SYMBOL(__filemap_get_folio);
  
  static inline struct folio *find_get_entry(struct xa_state *xas, pgoff_t max,