[RFC PATCH 05/19] mm: hugetlb: Allow alloc_hugetlb_folio() to be parametrized by subpool and hstate

[Ackerley Tng <ackerleytng@google.com>]

subpool_inode() and hstate_inode() are hugetlbfs-specific.

By allowing subpool and hstate to be specified, hugetlb is further
modularized from hugetlbfs.

Signed-off-by: Ackerley Tng <ackerleytng@google.com>
---
 include/linux/hugetlb.h |  3 +++
 mm/hugetlb.c            | 16 ++++++++++++----
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 2457d7a21974..14df89d1642c 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -747,6 +747,9 @@ struct huge_bootmem_page {
 };
 
 int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list);
+struct folio *alloc_hugetlb_folio_from_subpool(
+	struct hugepage_subpool *spool, struct hstate *h,
+	struct vm_area_struct *vma, unsigned long addr, int avoid_reserve);
 struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 				unsigned long addr, int avoid_reserve);
 struct folio *alloc_hugetlb_folio_nodemask(struct hstate *h, int preferred_nid,
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9da419b930df..99ab4bbdb2ce 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3008,11 +3008,10 @@ int isolate_or_dissolve_huge_page(struct page *page, struct list_head *list)
 	return ret;
 }
 
-struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
-				    unsigned long addr, int avoid_reserve)
+struct folio *alloc_hugetlb_folio_from_subpool(
+	struct hugepage_subpool *spool, struct hstate *h,
+	struct vm_area_struct *vma, unsigned long addr, int avoid_reserve)
 {
-	struct hugepage_subpool *spool = subpool_vma(vma);
-	struct hstate *h = hstate_vma(vma);
 	struct folio *folio;
 	long map_chg, map_commit;
 	long gbl_chg;
@@ -3139,6 +3138,15 @@ struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
 	return ERR_PTR(-ENOSPC);
 }
 
+struct folio *alloc_hugetlb_folio(struct vm_area_struct *vma,
+				    unsigned long addr, int avoid_reserve)
+{
+	struct hugepage_subpool *spool = subpool_vma(vma);
+	struct hstate *h = hstate_vma(vma);
+
+	return alloc_hugetlb_folio_from_subpool(spool, h, vma, addr, avoid_reserve);
+}
+
 int alloc_bootmem_huge_page(struct hstate *h, int nid)
 	__attribute__ ((weak, alias("__alloc_bootmem_huge_page")));
 int __alloc_bootmem_huge_page(struct hstate *h, int nid)
-- 
2.41.0.rc0.172.g3f132b7071-goog