[PATCH v3 4/6] mm/hugetlb: add hugetlb_set_folio_subpool() helper

[Sidhartha Kumar <sidhartha.kumar@oracle.com>]

Allows hugetlb subpool information to be set through a folio.

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
 fs/hugetlbfs/inode.c    | 4 ++--
 include/linux/hugetlb.h | 8 +++++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index c2e9c0cdbd81..d9e08c445e2f 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -1152,9 +1152,9 @@ static int hugetlbfs_migrate_folio(struct address_space *mapping,
 		return rc;
 
 	if (hugetlb_folio_subpool(src)) {
-		hugetlb_set_page_subpool(&dst->page,
+		hugetlb_set_folio_subpool(dst,
 					hugetlb_folio_subpool(src));
-		hugetlb_set_page_subpool(&src->page, NULL);
+		hugetlb_set_folio_subpool(src, NULL);
 	}
 
 	if (mode != MIGRATE_SYNC_NO_COPY)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 1e7c4007386e..0bcaca694ab7 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -757,10 +757,16 @@ static inline struct hugepage_subpool *hugetlb_page_subpool(struct page *hpage)
 	return hugetlb_folio_subpool(page_folio(hpage));
 }
 
+static inline void hugetlb_set_folio_subpool(struct folio *folio,
+					struct hugepage_subpool *subpool)
+{
+	folio_set_private_1(folio, (unsigned long)subpool);
+}
+
 static inline void hugetlb_set_page_subpool(struct page *hpage,
 					struct hugepage_subpool *subpool)
 {
-	set_page_private(hpage + SUBPAGE_INDEX_SUBPOOL, (unsigned long)subpool);
+	hugetlb_set_folio_subpool(page_folio(hpage), subpool);
 }
 
 static inline struct hstate *hstate_file(struct file *f)
-- 
2.31.1