mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()

In __unmap_hugepage_range(), the "page" pointer always points to the first
page of a huge page, which guarantees there is a folio associating with
it.  Convert the "page" pointer to use folio.

Link: https://lkml.kernel.org/r/20250505182345.506888-6-nifan.cxl@gmail.com
Signed-off-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: "Vishal Moola (Oracle)" <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 443b75e116cf4c41c52f3c8951c479d2b7cd5d83..d53caf96a4b2835a82820e576cccb72c01f99805 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5843,11 +5843,11 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                            struct folio *folio, zap_flags_t zap_flags)
 {
        struct mm_struct *mm = vma->vm_mm;
+       const bool folio_provided = !!folio;
        unsigned long address;
        pte_t *ptep;
        pte_t pte;
        spinlock_t *ptl;
-       struct page *page;
        struct hstate *h = hstate_vma(vma);
        unsigned long sz = huge_page_size(h);
        bool adjust_reservation = false;
@@ -5911,14 +5911,13 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                        continue;
                }
 
-               page = pte_page(pte);
                /*
                 * If a folio is supplied, it is because a specific
                 * folio is being unmapped, not a range. Ensure the folio we
                 * are about to unmap is the actual folio of interest.
                 */
-               if (folio) {
-                       if (page_folio(page) != folio) {
+               if (folio_provided) {
+                       if (folio != page_folio(pte_page(pte))) {
                                spin_unlock(ptl);
                                continue;
                        }
@@ -5928,12 +5927,14 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                         * looking like data was lost
                         */
                        set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
+               } else {
+                       folio = page_folio(pte_page(pte));
                }
 
                pte = huge_ptep_get_and_clear(mm, address, ptep, sz);
                tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
                if (huge_pte_dirty(pte))
-                       set_page_dirty(page);
+                       folio_mark_dirty(folio);
                /* Leave a uffd-wp pte marker if needed */
                if (huge_pte_uffd_wp(pte) &&
                    !(zap_flags & ZAP_FLAG_DROP_MARKER))
@@ -5941,7 +5942,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                                        make_pte_marker(PTE_MARKER_UFFD_WP),
                                        sz);
                hugetlb_count_sub(pages_per_huge_page(h), mm);
-               hugetlb_remove_rmap(page_folio(page));
+               hugetlb_remove_rmap(folio);
 
                /*
                 * Restore the reservation for anonymous page, otherwise the
@@ -5950,8 +5951,8 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                 * reservation bit.
                 */
                if (!h->surplus_huge_pages && __vma_private_lock(vma) &&
-                   folio_test_anon(page_folio(page))) {
-                       folio_set_hugetlb_restore_reserve(page_folio(page));
+                   folio_test_anon(folio)) {
+                       folio_set_hugetlb_restore_reserve(folio);
                        /* Reservation to be adjusted after the spin lock */
                        adjust_reservation = true;
                }
@@ -5975,16 +5976,17 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
                                 * count will not be incremented by free_huge_folio.
                                 * Act as if we consumed the reservation.
                                 */
-                               folio_clear_hugetlb_restore_reserve(page_folio(page));
+                               folio_clear_hugetlb_restore_reserve(folio);
                        else if (rc)
                                vma_add_reservation(h, vma, address);
                }
 
-               tlb_remove_page_size(tlb, page, huge_page_size(h));
+               tlb_remove_page_size(tlb, folio_page(folio, 0),
+                                    folio_size(folio));
                /*
                 * If we were instructed to unmap a specific folio, we're done.
                 */
-               if (folio)
+               if (folio_provided)
                        break;
        }
        tlb_end_vma(tlb, vma);