[PATCH 6.6 42/48] mm: add page_rmappable_folio() wrapper

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hugh Dickins <hughd@xxxxxxxxxx>

commit 23e4883248f0472d806c8b3422ba6257e67bf1a5 upstream.

folio_prep_large_rmappable() is being used repeatedly along with a
conversion from page to folio, a check non-NULL, a check order > 1: wrap
it all up into struct folio *page_rmappable_folio(struct page *).

Link: https://lkml.kernel.org/r/8d92c6cf-eebe-748-e29c-c8ab224c741@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Nhat Pham <nphamcs@xxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Tejun heo <tj@xxxxxxxxxx>
Cc: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Cc: Yang Shi <shy828301@xxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 mm/internal.h   |    9 +++++++++
 mm/mempolicy.c  |   17 +++--------------
 mm/page_alloc.c |    8 ++------
 3 files changed, 14 insertions(+), 20 deletions(-)

--- a/mm/internal.h
+++ b/mm/internal.h
@@ -415,6 +415,15 @@ static inline void folio_set_order(struc
 
 void folio_undo_large_rmappable(struct folio *folio);
 
+static inline struct folio *page_rmappable_folio(struct page *page)
+{
+	struct folio *folio = (struct folio *)page;
+
+	if (folio && folio_order(folio) > 1)
+		folio_prep_large_rmappable(folio);
+	return folio;
+}
+
 static inline void prep_compound_head(struct page *page, unsigned int order)
 {
 	struct folio *folio = (struct folio *)page;
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2200,10 +2200,7 @@ struct folio *vma_alloc_folio(gfp_t gfp,
 		mpol_cond_put(pol);
 		gfp |= __GFP_COMP;
 		page = alloc_page_interleave(gfp, order, nid);
-		folio = (struct folio *)page;
-		if (folio && order > 1)
-			folio_prep_large_rmappable(folio);
-		goto out;
+		return page_rmappable_folio(page);
 	}
 
 	if (pol->mode == MPOL_PREFERRED_MANY) {
@@ -2213,10 +2210,7 @@ struct folio *vma_alloc_folio(gfp_t gfp,
 		gfp |= __GFP_COMP;
 		page = alloc_pages_preferred_many(gfp, order, node, pol);
 		mpol_cond_put(pol);
-		folio = (struct folio *)page;
-		if (folio && order > 1)
-			folio_prep_large_rmappable(folio);
-		goto out;
+		return page_rmappable_folio(page);
 	}
 
 	if (unlikely(IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && hugepage)) {
@@ -2310,12 +2304,7 @@ EXPORT_SYMBOL(alloc_pages);
 
 struct folio *folio_alloc(gfp_t gfp, unsigned order)
 {
-	struct page *page = alloc_pages(gfp | __GFP_COMP, order);
-	struct folio *folio = (struct folio *)page;
-
-	if (folio && order > 1)
-		folio_prep_large_rmappable(folio);
-	return folio;
+	return page_rmappable_folio(alloc_pages(gfp | __GFP_COMP, order));
 }
 EXPORT_SYMBOL(folio_alloc);
 
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4464,12 +4464,8 @@ struct folio *__folio_alloc(gfp_t gfp, u
 		nodemask_t *nodemask)
 {
 	struct page *page = __alloc_pages(gfp | __GFP_COMP, order,
-			preferred_nid, nodemask);
-	struct folio *folio = (struct folio *)page;
-
-	if (folio && order > 1)
-		folio_prep_large_rmappable(folio);
-	return folio;
+					preferred_nid, nodemask);
+	return page_rmappable_folio(page);
 }
 EXPORT_SYMBOL(__folio_alloc);