1 files changed, 47 insertions, 47 deletions
diff --git a/mm/page_owner.c b/mm/page_owner.c
index 2d6360eaccbb..cc4a6916eec6 100644
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -229,17 +229,19 @@ static void dec_stack_record_count(depot_stack_handle_t handle,
 			handle);
 }
 
-static inline void __update_page_owner_handle(struct page_ext *page_ext,
+static inline void __update_page_owner_handle(struct page *page,
 					      depot_stack_handle_t handle,
 					      unsigned short order,
 					      gfp_t gfp_mask,
 					      short last_migrate_reason, u64 ts_nsec,
 					      pid_t pid, pid_t tgid, char *comm)
 {
-	int i;
+	struct page_ext_iter iter;
+	struct page_ext *page_ext;
 	struct page_owner *page_owner;
 
-	for (i = 0; i < (1 << order); i++) {
+	rcu_read_lock();
+	for_each_page_ext(page, 1 << order, page_ext, iter) {
 		page_owner = get_page_owner(page_ext);
 		page_owner->handle = handle;
 		page_owner->order = order;
@@ -252,20 +254,22 @@ static inline void __update_page_owner_handle(struct page_ext *page_ext,
 			sizeof(page_owner->comm));
 		__set_bit(PAGE_EXT_OWNER, &page_ext->flags);
 		__set_bit(PAGE_EXT_OWNER_ALLOCATED, &page_ext->flags);
-		page_ext = page_ext_next(page_ext);
 	}
+	rcu_read_unlock();
 }
 
-static inline void __update_page_owner_free_handle(struct page_ext *page_ext,
+static inline void __update_page_owner_free_handle(struct page *page,
 						   depot_stack_handle_t handle,
 						   unsigned short order,
 						   pid_t pid, pid_t tgid,
 						   u64 free_ts_nsec)
 {
-	int i;
+	struct page_ext_iter iter;
+	struct page_ext *page_ext;
 	struct page_owner *page_owner;
 
-	for (i = 0; i < (1 << order); i++) {
+	rcu_read_lock();
+	for_each_page_ext(page, 1 << order, page_ext, iter) {
 		page_owner = get_page_owner(page_ext);
 		/* Only __reset_page_owner() wants to clear the bit */
 		if (handle) {
@@ -275,8 +279,8 @@ static inline void __update_page_owner_free_handle(struct page_ext *page_ext,
 		page_owner->free_ts_nsec = free_ts_nsec;
 		page_owner->free_pid = current->pid;
 		page_owner->free_tgid = current->tgid;
-		page_ext = page_ext_next(page_ext);
 	}
+	rcu_read_unlock();
 }
 
 void __reset_page_owner(struct page *page, unsigned short order)
@@ -293,11 +297,17 @@ void __reset_page_owner(struct page *page, unsigned short order)
 
 	page_owner = get_page_owner(page_ext);
 	alloc_handle = page_owner->handle;
+	page_ext_put(page_ext);
 
-	handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
-	__update_page_owner_free_handle(page_ext, handle, order, current->pid,
+	/*
+	 * Do not specify GFP_NOWAIT to make gfpflags_allow_spinning() == false
+	 * to prevent issues in stack_depot_save().
+	 * This is similar to try_alloc_pages() gfp flags, but only used
+	 * to signal stack_depot to avoid spin_locks.
+	 */
+	handle = save_stack(__GFP_NOWARN);
+	__update_page_owner_free_handle(page, handle, order, current->pid,
 					current->tgid, free_ts_nsec);
-	page_ext_put(page_ext);
 
 	if (alloc_handle != early_handle)
 		/*
@@ -313,19 +323,13 @@ void __reset_page_owner(struct page *page, unsigned short order)
 noinline void __set_page_owner(struct page *page, unsigned short order,
 					gfp_t gfp_mask)
 {
-	struct page_ext *page_ext;
 	u64 ts_nsec = local_clock();
 	depot_stack_handle_t handle;
 
 	handle = save_stack(gfp_mask);
-
-	page_ext = page_ext_get(page);
-	if (unlikely(!page_ext))
-		return;
-	__update_page_owner_handle(page_ext, handle, order, gfp_mask, -1,
+	__update_page_owner_handle(page, handle, order, gfp_mask, -1,
 				   ts_nsec, current->pid, current->tgid,
 				   current->comm);
-	page_ext_put(page_ext);
 	inc_stack_record_count(handle, gfp_mask, 1 << order);
 }
 
@@ -344,44 +348,42 @@ void __set_page_owner_migrate_reason(struct page *page, int reason)
 
 void __split_page_owner(struct page *page, int old_order, int new_order)
 {
-	int i;
-	struct page_ext *page_ext = page_ext_get(page);
+	struct page_ext_iter iter;
+	struct page_ext *page_ext;
 	struct page_owner *page_owner;
 
-	if (unlikely(!page_ext))
-		return;
-
-	for (i = 0; i < (1 << old_order); i++) {
+	rcu_read_lock();
+	for_each_page_ext(page, 1 << old_order, page_ext, iter) {
 		page_owner = get_page_owner(page_ext);
 		page_owner->order = new_order;
-		page_ext = page_ext_next(page_ext);
 	}
-	page_ext_put(page_ext);
+	rcu_read_unlock();
 }
 
 void __folio_copy_owner(struct folio *newfolio, struct folio *old)
 {
-	int i;
-	struct page_ext *old_ext;
-	struct page_ext *new_ext;
+	struct page_ext *page_ext;
+	struct page_ext_iter iter;
 	struct page_owner *old_page_owner;
 	struct page_owner *new_page_owner;
 	depot_stack_handle_t migrate_handle;
 
-	old_ext = page_ext_get(&old->page);
-	if (unlikely(!old_ext))
+	page_ext = page_ext_get(&old->page);
+	if (unlikely(!page_ext))
 		return;
 
-	new_ext = page_ext_get(&newfolio->page);
-	if (unlikely(!new_ext)) {
-		page_ext_put(old_ext);
+	old_page_owner = get_page_owner(page_ext);
+	page_ext_put(page_ext);
+
+	page_ext = page_ext_get(&newfolio->page);
+	if (unlikely(!page_ext))
 		return;
-	}
 
-	old_page_owner = get_page_owner(old_ext);
-	new_page_owner = get_page_owner(new_ext);
+	new_page_owner = get_page_owner(page_ext);
+	page_ext_put(page_ext);
+
 	migrate_handle = new_page_owner->handle;
-	__update_page_owner_handle(new_ext, old_page_owner->handle,
+	__update_page_owner_handle(&newfolio->page, old_page_owner->handle,
 				   old_page_owner->order, old_page_owner->gfp_mask,
 				   old_page_owner->last_migrate_reason,
 				   old_page_owner->ts_nsec, old_page_owner->pid,
@@ -391,7 +393,7 @@ void __folio_copy_owner(struct folio *newfolio, struct folio *old)
 	 * will be freed after migration. Keep them until then as they may be
 	 * useful.
 	 */
-	__update_page_owner_free_handle(new_ext, 0, old_page_owner->order,
+	__update_page_owner_free_handle(&newfolio->page, 0, old_page_owner->order,
 					old_page_owner->free_pid,
 					old_page_owner->free_tgid,
 					old_page_owner->free_ts_nsec);
@@ -400,14 +402,12 @@ void __folio_copy_owner(struct folio *newfolio, struct folio *old)
 	 * for the new one and the old folio otherwise there will be an imbalance
 	 * when subtracting those pages from the stack.
 	 */
-	for (i = 0; i < (1 << new_page_owner->order); i++) {
+	rcu_read_lock();
+	for_each_page_ext(&old->page, 1 << new_page_owner->order, page_ext, iter) {
+		old_page_owner = get_page_owner(page_ext);
 		old_page_owner->handle = migrate_handle;
-		old_ext = page_ext_next(old_ext);
-		old_page_owner = get_page_owner(old_ext);
 	}
-
-	page_ext_put(new_ext);
-	page_ext_put(old_ext);
+	rcu_read_unlock();
 }
 
 void pagetypeinfo_showmixedcount_print(struct seq_file *m,
@@ -507,7 +507,7 @@ static inline int print_page_owner_memcg(char *kbuf, size_t count, int ret,
 
 	rcu_read_lock();
 	memcg_data = READ_ONCE(page->memcg_data);
-	if (!memcg_data)
+	if (!memcg_data || PageTail(page))
 		goto out_unlock;
 
 	if (memcg_data & MEMCG_DATA_OBJEXTS)
@@ -813,7 +813,7 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
 				goto ext_put_continue;
 
 			/* Found early allocated page */
-			__update_page_owner_handle(page_ext, early_handle, 0, 0,
+			__update_page_owner_handle(page, early_handle, 0, 0,
 						   -1, local_clock(), current->pid,
 						   current->tgid, current->comm);
 			count++;