1 files changed, 24 insertions, 2 deletions

diff --git a/mm/truncate.c b/mm/truncate.c
index 0db9258319f0..e5cc39ab0751 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -25,6 +25,9 @@
 static void clear_exceptional_entry(struct address_space *mapping,
                                     pgoff_t index, void *entry)
 {
+        struct radix_tree_node *node;
+        void **slot;
+
         /* Handled by shmem itself */
         if (shmem_mapping(mapping))
                 return;
@@ -35,8 +38,27 @@ static void clear_exceptional_entry(struct address_space *mapping,
          * without the tree itself locked.  These unlocked entries
          * need verification under the tree lock.
          */
-        if (radix_tree_delete_item(&mapping->page_tree, index, entry) == entry)
-                mapping->nrshadows--;
+        if (!__radix_tree_lookup(&mapping->page_tree, index, &node, &slot))
+                goto unlock;
+        if (*slot != entry)
+                goto unlock;
+        radix_tree_replace_slot(slot, NULL);
+        mapping->nrshadows--;
+        if (!node)
+                goto unlock;
+        workingset_node_shadows_dec(node);
+        /*
+         * Don't track node without shadow entries.
+         *
+         * Avoid acquiring the list_lru lock if already untracked.
+         * The list_empty() test is safe as node->private_list is
+         * protected by mapping->tree_lock.
+         */
+        if (!workingset_node_shadows(node) &&
+            !list_empty(&node->private_list))
+                list_lru_del(&workingset_shadow_nodes, &node->private_list);
+        __radix_tree_delete_node(&mapping->page_tree, node);
+unlock:
         spin_unlock_irq(&mapping->tree_lock);
 }