mm: keep page cache radix tree nodes in check

[cascardo/linux.git] / mm / list_lru.c

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 72f9dec..f1a0db1 100644 (file)
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -87,11 +87,20 @@ restart:
 
                ret = isolate(item, &nlru->lock, cb_arg);
                switch (ret) {
+               case LRU_REMOVED_RETRY:
+                       assert_spin_locked(&nlru->lock);
                case LRU_REMOVED:
                        if (--nlru->nr_items == 0)
                                node_clear(nid, lru->active_nodes);
                        WARN_ON_ONCE(nlru->nr_items < 0);
                        isolated++;
+                       /*
+                        * If the lru lock has been dropped, our list
+                        * traversal is now invalid and so we have to
+                        * restart from scratch.
+                        */
+                       if (ret == LRU_REMOVED_RETRY)
+                               goto restart;
                        break;
                case LRU_ROTATE:
                        list_move_tail(item, &nlru->list);
@@ -103,6 +112,7 @@ restart:
                         * The lru lock has been dropped, our list traversal is
                         * now invalid and so we have to restart from scratch.
                         */
+                       assert_spin_locked(&nlru->lock);
                        goto restart;
                default:
                        BUG();
@@ -114,7 +124,7 @@ restart:
 }
 EXPORT_SYMBOL_GPL(list_lru_walk_node);
 
-int list_lru_init(struct list_lru *lru)
+int list_lru_init_key(struct list_lru *lru, struct lock_class_key *key)
 {
        int i;
        size_t size = sizeof(*lru->node) * nr_node_ids;
@@ -126,12 +136,14 @@ int list_lru_init(struct list_lru *lru)
        nodes_clear(lru->active_nodes);
        for (i = 0; i < nr_node_ids; i++) {
                spin_lock_init(&lru->node[i].lock);
+               if (key)
+                       lockdep_set_class(&lru->node[i].lock, key);
                INIT_LIST_HEAD(&lru->node[i].list);
                lru->node[i].nr_items = 0;
        }
        return 0;
 }
-EXPORT_SYMBOL_GPL(list_lru_init);
+EXPORT_SYMBOL_GPL(list_lru_init_key);
 
 void list_lru_destroy(struct list_lru *lru)
 {