mm/memcg: Add folio_lruvec_lock() and similar functions

These are the folio equivalents of lock_page_lruvec() and similar
functions.  Also convert lruvec_memcg_debug() to take a folio.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

6 files changed, 61 insertions, 36 deletions

diff --git a/mm/compaction.c b/mm/compaction.c
index 37dfdf2b2287..fbc60f964c38 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1032,7 +1032,7 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
 			compact_lock_irqsave(&lruvec->lru_lock, &flags, cc);
 			locked = lruvec;
 
-			lruvec_memcg_debug(lruvec, page);
+			lruvec_memcg_debug(lruvec, page_folio(page));
 
 			/* Try get exclusive access under lock */
 			if (!skip_updated) {
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d49986a10d83..e5ea5f775d5c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2405,7 +2405,8 @@ static void __split_huge_page_tail(struct page *head, int tail,
 static void __split_huge_page(struct page *page, struct list_head *list,
 		pgoff_t end)
 {
-	struct page *head = compound_head(page);
+	struct folio *folio = page_folio(page);
+	struct page *head = &folio->page;
 	struct lruvec *lruvec;
 	struct address_space *swap_cache = NULL;
 	unsigned long offset = 0;
@@ -2424,7 +2425,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
 	}
 
 	/* lock lru list/PageCompound, ref frozen by page_ref_freeze */
-	lruvec = lock_page_lruvec(head);
+	lruvec = folio_lruvec_lock(folio);
 
 	for (i = nr - 1; i >= 1; i--) {
 		__split_huge_page_tail(head, i, lruvec, list);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ea4f879d2771..8dab23a71fc4 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1126,67 +1126,88 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg,
 }
 
 #ifdef CONFIG_DEBUG_VM
-void lruvec_memcg_debug(struct lruvec *lruvec, struct page *page)
+void lruvec_memcg_debug(struct lruvec *lruvec, struct folio *folio)
 {
 	struct mem_cgroup *memcg;
 
 	if (mem_cgroup_disabled())
 		return;
 
-	memcg = page_memcg(page);
+	memcg = folio_memcg(folio);
 
 	if (!memcg)
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != root_mem_cgroup, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != root_mem_cgroup, folio);
 	else
-		VM_BUG_ON_PAGE(lruvec_memcg(lruvec) != memcg, page);
+		VM_BUG_ON_FOLIO(lruvec_memcg(lruvec) != memcg, folio);
 }
 #endif
 
 /**
- * lock_page_lruvec - lock and return lruvec for a given page.
- * @page: the page
+ * folio_lruvec_lock - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
  *
  * These functions are safe to use under any of the following conditions:
- * - page locked
- * - PageLRU cleared
- * - lock_page_memcg()
- * - page->_refcount is zero
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held.
  */
-struct lruvec *lock_page_lruvec(struct page *page)
+struct lruvec *folio_lruvec_lock(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock(&lruvec->lru_lock);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irq(struct page *page)
+/**
+ * folio_lruvec_lock_irq - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irq(struct folio *folio)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock_irq(&lruvec->lru_lock);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }
 
-struct lruvec *lock_page_lruvec_irqsave(struct page *page, unsigned long *flags)
+/**
+ * folio_lruvec_lock_irqsave - Lock the lruvec for a folio.
+ * @folio: Pointer to the folio.
+ * @flags: Pointer to irqsave flags.
+ *
+ * These functions are safe to use under any of the following conditions:
+ * - folio locked
+ * - folio_test_lru false
+ * - folio_memcg_lock()
+ * - folio frozen (refcount of 0)
+ *
+ * Return: The lruvec this folio is on with its lock held and interrupts
+ * disabled.
+ */
+struct lruvec *folio_lruvec_lock_irqsave(struct folio *folio,
+		unsigned long *flags)
 {
-	struct folio *folio = page_folio(page);
-	struct lruvec *lruvec;
+	struct lruvec *lruvec = folio_lruvec(folio);
 
-	lruvec = folio_lruvec(folio);
 	spin_lock_irqsave(&lruvec->lru_lock, *flags);
-
-	lruvec_memcg_debug(lruvec, page);
+	lruvec_memcg_debug(lruvec, folio);
 
 	return lruvec;
 }
diff --git a/mm/rmap.c b/mm/rmap.c
index 6aebd1747251..059556dbefec 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -34,7 +34,7 @@
  *                   mapping->private_lock (in __set_page_dirty_buffers)
  *                     lock_page_memcg move_lock (in __set_page_dirty_buffers)
  *                       i_pages lock (widely used)
- *                         lruvec->lru_lock (in lock_page_lruvec_irq)
+ *                         lruvec->lru_lock (in folio_lruvec_lock_irq)
  *                   inode->i_lock (in set_page_dirty's __mark_inode_dirty)
  *                   bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
  *                     sb_lock (within inode_lock in fs/fs-writeback.c)
diff --git a/mm/swap.c b/mm/swap.c
index 65a74c89e7cf..d1fc964def12 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -80,10 +80,11 @@ static DEFINE_PER_CPU(struct lru_pvecs, lru_pvecs) = {
 static void __page_cache_release(struct page *page)
 {
 	if (PageLRU(page)) {
+		struct folio *folio = page_folio(page);
 		struct lruvec *lruvec;
 		unsigned long flags;
 
-		lruvec = lock_page_lruvec_irqsave(page, &flags);
+		lruvec = folio_lruvec_lock_irqsave(folio, &flags);
 		del_page_from_lru_list(page, lruvec);
 		__clear_page_lru_flags(page);
 		unlock_page_lruvec_irqrestore(lruvec, flags);
@@ -350,11 +351,12 @@ static inline void activate_page_drain(int cpu)
 
 static void activate_page(struct page *page)
 {
+	struct folio *folio = page_folio(page);
 	struct lruvec *lruvec;
 
-	page = compound_head(page);
+	page = &folio->page;
 	if (TestClearPageLRU(page)) {
-		lruvec = lock_page_lruvec_irq(page);
+		lruvec = folio_lruvec_lock_irq(folio);
 		__activate_page(page, lruvec);
 		unlock_page_lruvec_irq(lruvec);
 		SetPageLRU(page);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 74296c2d1fed..8694e1549bcd 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2090,6 +2090,7 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
  */
 int isolate_lru_page(struct page *page)
 {
+	struct folio *folio = page_folio(page);
 	int ret = -EBUSY;
 
 	VM_BUG_ON_PAGE(!page_count(page), page);
@@ -2099,7 +2100,7 @@ int isolate_lru_page(struct page *page)
 		struct lruvec *lruvec;
 
 		get_page(page);
-		lruvec = lock_page_lruvec_irq(page);
+		lruvec = folio_lruvec_lock_irq(folio);
 		del_page_from_lru_list(page, lruvec);
 		unlock_page_lruvec_irq(lruvec);
 		ret = 0;