1 files changed, 101 insertions, 63 deletions

diff --git a/mm/rmap.c b/mm/rmap.c
index 9f795b93cf..7a27a2b418 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -798,6 +798,7 @@ struct folio_referenced_arg {
 	unsigned long vm_flags;
 	struct mem_cgroup *memcg;
 };
+
 /*
  * arg: folio_referenced_arg will be passed
  */
@@ -807,17 +808,33 @@ static bool folio_referenced_one(struct folio *folio,
 	struct folio_referenced_arg *pra = arg;
 	DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, address, 0);
 	int referenced = 0;
+	unsigned long start = address, ptes = 0;
 
 	while (page_vma_mapped_walk(&pvmw)) {
 		address = pvmw.address;
 
-		if ((vma->vm_flags & VM_LOCKED) &&
-		    (!folio_test_large(folio) || !pvmw.pte)) {
-			/* Restore the mlock which got missed */
-			mlock_vma_folio(folio, vma, !pvmw.pte);
-			page_vma_mapped_walk_done(&pvmw);
-			pra->vm_flags |= VM_LOCKED;
-			return false; /* To break the loop */
+		if (vma->vm_flags & VM_LOCKED) {
+			if (!folio_test_large(folio) || !pvmw.pte) {
+				/* Restore the mlock which got missed */
+				mlock_vma_folio(folio, vma);
+				page_vma_mapped_walk_done(&pvmw);
+				pra->vm_flags |= VM_LOCKED;
+				return false; /* To break the loop */
+			}
+			/*
+			 * For large folio fully mapped to VMA, will
+			 * be handled after the pvmw loop.
+			 *
+			 * For large folio cross VMA boundaries, it's
+			 * expected to be picked  by page reclaim. But
+			 * should skip reference of pages which are in
+			 * the range of VM_LOCKED vma. As page reclaim
+			 * should just count the reference of pages out
+			 * the range of VM_LOCKED vma.
+			 */
+			ptes++;
+			pra->mapcount--;
+			continue;
 		}
 
 		if (pvmw.pte) {
@@ -842,6 +859,23 @@ static bool folio_referenced_one(struct folio *folio,
 		pra->mapcount--;
 	}
 
+	if ((vma->vm_flags & VM_LOCKED) &&
+			folio_test_large(folio) &&
+			folio_within_vma(folio, vma)) {
+		unsigned long s_align, e_align;
+
+		s_align = ALIGN_DOWN(start, PMD_SIZE);
+		e_align = ALIGN_DOWN(start + folio_size(folio) - 1, PMD_SIZE);
+
+		/* folio doesn't cross page table boundary and fully mapped */
+		if ((s_align == e_align) && (ptes == folio_nr_pages(folio))) {
+			/* Restore the mlock which got missed */
+			mlock_vma_folio(folio, vma);
+			pra->vm_flags |= VM_LOCKED;
+			return false; /* To break the loop */
+		}
+	}
+
 	if (referenced)
 		folio_clear_idle(folio);
 	if (folio_test_clear_young(folio))
@@ -1094,19 +1128,17 @@ int folio_total_mapcount(struct folio *folio)
 }
 
 /**
- * page_move_anon_rmap - move a page to our anon_vma
- * @page:	the page to move to our anon_vma
- * @vma:	the vma the page belongs to
+ * folio_move_anon_rmap - move a folio to our anon_vma
+ * @folio:	The folio to move to our anon_vma
+ * @vma:	The vma the folio belongs to
  *
- * When a page belongs exclusively to one process after a COW event,
- * that page can be moved into the anon_vma that belongs to just that
- * process, so the rmap code will not search the parent or sibling
- * processes.
+ * When a folio belongs exclusively to one process after a COW event,
+ * that folio can be moved into the anon_vma that belongs to just that
+ * process, so the rmap code will not search the parent or sibling processes.
  */
-void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
+void folio_move_anon_rmap(struct folio *folio, struct vm_area_struct *vma)
 {
 	void *anon_vma = vma->anon_vma;
-	struct folio *folio = page_folio(page);
 
 	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);
 	VM_BUG_ON_VMA(!anon_vma, vma);
@@ -1118,31 +1150,25 @@ void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)
 	 * folio_test_anon()) will not see one without the other.
 	 */
 	WRITE_ONCE(folio->mapping, anon_vma);
-	SetPageAnonExclusive(page);
 }
 
 /**
- * __page_set_anon_rmap - set up new anonymous rmap
- * @folio:	Folio which contains page.
- * @page:	Page to add to rmap.
- * @vma:	VM area to add page to.
+ * __folio_set_anon - set up a new anonymous rmap for a folio
+ * @folio:	The folio to set up the new anonymous rmap for.
+ * @vma:	VM area to add the folio to.
  * @address:	User virtual address of the mapping
- * @exclusive:	the page is exclusively owned by the current process
+ * @exclusive:	Whether the folio is exclusive to the process.
  */
-static void __page_set_anon_rmap(struct folio *folio, struct page *page,
-	struct vm_area_struct *vma, unsigned long address, int exclusive)
+static void __folio_set_anon(struct folio *folio, struct vm_area_struct *vma,
+			     unsigned long address, bool exclusive)
 {
 	struct anon_vma *anon_vma = vma->anon_vma;
 
 	BUG_ON(!anon_vma);
 
-	if (folio_test_anon(folio))
-		goto out;
-
 	/*
-	 * If the page isn't exclusively mapped into this vma,
-	 * we must use the _oldest_ possible anon_vma for the
-	 * page mapping!
+	 * If the folio isn't exclusive to this vma, we must use the _oldest_
+	 * possible anon_vma for the folio mapping!
 	 */
 	if (!exclusive)
 		anon_vma = anon_vma->root;
@@ -1156,9 +1182,6 @@ static void __page_set_anon_rmap(struct folio *folio, struct page *page,
 	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
 	WRITE_ONCE(folio->mapping, (struct address_space *) anon_vma);
 	folio->index = linear_page_index(vma, address);
-out:
-	if (exclusive)
-		SetPageAnonExclusive(page);
 }
 
 /**
@@ -1207,7 +1230,7 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
 	atomic_t *mapped = &folio->_nr_pages_mapped;
 	int nr = 0, nr_pmdmapped = 0;
 	bool compound = flags & RMAP_COMPOUND;
-	bool first = true;
+	bool first;
 
 	/* Is page being mapped by PTE? Is this its first map to be added? */
 	if (likely(!compound)) {
@@ -1236,24 +1259,40 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
 		}
 	}
 
-	VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
-	VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
-
 	if (nr_pmdmapped)
 		__lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr_pmdmapped);
 	if (nr)
 		__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
 
-	if (likely(!folio_test_ksm(folio))) {
-		/* address might be in next vma when migration races vma_merge */
-		if (first)
-			__page_set_anon_rmap(folio, page, vma, address,
-					     !!(flags & RMAP_EXCLUSIVE));
-		else
-			__page_check_anon_rmap(folio, page, vma, address);
+	if (unlikely(!folio_test_anon(folio))) {
+		VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio);
+		/*
+		 * For a PTE-mapped large folio, we only know that the single
+		 * PTE is exclusive. Further, __folio_set_anon() might not get
+		 * folio->index right when not given the address of the head
+		 * page.
+		 */
+		VM_WARN_ON_FOLIO(folio_test_large(folio) && !compound, folio);
+		__folio_set_anon(folio, vma, address,
+				 !!(flags & RMAP_EXCLUSIVE));
+	} else if (likely(!folio_test_ksm(folio))) {
+		__page_check_anon_rmap(folio, page, vma, address);
 	}
+	if (flags & RMAP_EXCLUSIVE)
+		SetPageAnonExclusive(page);
+	/* While PTE-mapping a THP we have a PMD and a PTE mapping. */
+	VM_WARN_ON_FOLIO((atomic_read(&page->_mapcount) > 0 ||
+			  (folio_test_large(folio) && folio_entire_mapcount(folio) > 1)) &&
+			 PageAnonExclusive(page), folio);
 
-	mlock_vma_folio(folio, vma, compound);
+	/*
+	 * For large folio, only mlock it if it's fully mapped to VMA. It's
+	 * not easy to check whether the large folio is fully mapped to VMA
+	 * here. Only mlock normal 4K folio and leave page reclaim to handle
+	 * large folio.
+	 */
+	if (!folio_test_large(folio))
+		mlock_vma_folio(folio, vma);
 }
 
 /**
@@ -1290,7 +1329,8 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
 	}
 
 	__lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr);
-	__page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+	__folio_set_anon(folio, vma, address, true);
+	SetPageAnonExclusive(&folio->page);
 }
 
 /**
@@ -1352,7 +1392,9 @@ void folio_add_file_rmap_range(struct folio *folio, struct page *page,
 	if (nr)
 		__lruvec_stat_mod_folio(folio, NR_FILE_MAPPED, nr);
 
-	mlock_vma_folio(folio, vma, compound);
+	/* See comments in page_add_anon_rmap() */
+	if (!folio_test_large(folio))
+		mlock_vma_folio(folio, vma);
 }
 
 /**
@@ -1463,7 +1505,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma,
 	 * it's only reliable while mapped.
 	 */
 
-	munlock_vma_folio(folio, vma, compound);
+	munlock_vma_folio(folio, vma);
 }
 
 /*
@@ -1528,7 +1570,8 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 		if (!(flags & TTU_IGNORE_MLOCK) &&
 		    (vma->vm_flags & VM_LOCKED)) {
 			/* Restore the mlock which got missed */
-			mlock_vma_folio(folio, vma, false);
+			if (!folio_test_large(folio))
+				mlock_vma_folio(folio, vma);
 			page_vma_mapped_walk_done(&pvmw);
 			ret = false;
 			break;
@@ -2540,22 +2583,16 @@ void rmap_walk_locked(struct folio *folio, struct rmap_walk_control *rwc)
  *
  * RMAP_COMPOUND is ignored.
  */
-void hugepage_add_anon_rmap(struct page *page, struct vm_area_struct *vma,
+void hugepage_add_anon_rmap(struct folio *folio, struct vm_area_struct *vma,
 			    unsigned long address, rmap_t flags)
 {
-	struct folio *folio = page_folio(page);
-	struct anon_vma *anon_vma = vma->anon_vma;
-	int first;
+	VM_WARN_ON_FOLIO(!folio_test_anon(folio), folio);
 
-	BUG_ON(!folio_test_locked(folio));
-	BUG_ON(!anon_vma);
-	/* address might be in next vma when migration races vma_merge */
-	first = atomic_inc_and_test(&folio->_entire_mapcount);
-	VM_BUG_ON_PAGE(!first && (flags & RMAP_EXCLUSIVE), page);
-	VM_BUG_ON_PAGE(!first && PageAnonExclusive(page), page);
-	if (first)
-		__page_set_anon_rmap(folio, page, vma, address,
-				     !!(flags & RMAP_EXCLUSIVE));
+	atomic_inc(&folio->_entire_mapcount);
+	if (flags & RMAP_EXCLUSIVE)
+		SetPageAnonExclusive(&folio->page);
+	VM_WARN_ON_FOLIO(folio_entire_mapcount(folio) > 1 &&
+			 PageAnonExclusive(&folio->page), folio);
 }
 
 void hugepage_add_new_anon_rmap(struct folio *folio,
@@ -2565,6 +2602,7 @@ void hugepage_add_new_anon_rmap(struct folio *folio,
 	/* increment count (starts at -1) */
 	atomic_set(&folio->_entire_mapcount, 0);
 	folio_clear_hugetlb_restore_reserve(folio);
-	__page_set_anon_rmap(folio, &folio->page, vma, address, 1);
+	__folio_set_anon(folio, vma, address, true);
+	SetPageAnonExclusive(&folio->page);
 }
 #endif /* CONFIG_HUGETLB_PAGE */