mm/hugetlb: convert restore_reserve_on_error() to folios

Use the hugetlb folio flag macros inside restore_reserve_on_error() and
update the comments to reflect the use of folios.

Link: https://lkml.kernel.org/r/20230113223057.173292-8-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/hugetlb.c

@@ -2819,22 +2819,23 @@ static long vma_del_reservation(struct hstate *h,
 void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
 			unsigned long address, struct page *page)
 {
+	struct folio *folio = page_folio(page);
 	long rc = vma_needs_reservation(h, vma, address);
 
-	if (HPageRestoreReserve(page)) {
+	if (folio_test_hugetlb_restore_reserve(folio)) {
 		if (unlikely(rc < 0))
 			/*
 			 * Rare out of memory condition in reserve map
-			 * manipulation.  Clear HPageRestoreReserve so that
-			 * global reserve count will not be incremented
+			 * manipulation.  Clear hugetlb_restore_reserve so
+			 * that global reserve count will not be incremented
 			 * by free_huge_page.  This will make it appear
-			 * as though the reservation for this page was
+			 * as though the reservation for this folio was
 			 * consumed.  This may prevent the task from
-			 * faulting in the page at a later time.  This
+			 * faulting in the folio at a later time.  This
 			 * is better than inconsistent global huge page
 			 * accounting of reserve counts.
 			 */
-			ClearHPageRestoreReserve(page);
+			folio_clear_hugetlb_restore_reserve(folio);
 		else if (rc)
 			(void)vma_add_reservation(h, vma, address);
 		else
@@ -2845,7 +2846,7 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
 			 * This indicates there is an entry in the reserve map
 			 * not added by alloc_huge_page.  We know it was added
 			 * before the alloc_huge_page call, otherwise
-			 * HPageRestoreReserve would be set on the page.
+			 * hugetlb_restore_reserve would be set on the folio.
 			 * Remove the entry so that a subsequent allocation
 			 * does not consume a reservation.
 			 */
@@ -2854,12 +2855,12 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
 				/*
 				 * VERY rare out of memory condition.  Since
 				 * we can not delete the entry, set
-				 * HPageRestoreReserve so that the reserve
-				 * count will be incremented when the page
+				 * hugetlb_restore_reserve so that the reserve
+				 * count will be incremented when the folio
 				 * is freed.  This reserve will be consumed
 				 * on a subsequent allocation.
 				 */
-				SetHPageRestoreReserve(page);
+				folio_set_hugetlb_restore_reserve(folio);
 		} else if (rc < 0) {
 			/*
 			 * Rare out of memory condition from
@@ -2875,12 +2876,12 @@ void restore_reserve_on_error(struct hstate *h, struct vm_area_struct *vma,
 				/*
 				 * For private mappings, no entry indicates
 				 * a reservation is present.  Since we can
-				 * not add an entry, set SetHPageRestoreReserve
-				 * on the page so reserve count will be
+				 * not add an entry, set hugetlb_restore_reserve
+				 * on the folio so reserve count will be
 				 * incremented when freed.  This reserve will
 				 * be consumed on a subsequent allocation.
 				 */
-				SetHPageRestoreReserve(page);
+				folio_set_hugetlb_restore_reserve(folio);
 		} else
 			/*
 			 * No reservation present, do nothing