1 files changed, 30 insertions, 16 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 2d0986a64f1f..96b9e9c30630 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -169,33 +169,35 @@ static int page_cache_tree_insert(struct address_space *mapping,
 static void page_cache_tree_delete(struct address_space *mapping,
                                    struct page *page, void *shadow)
 {
-        struct radix_tree_node *node;
         int i, nr = PageHuge(page) ? 1 : hpage_nr_pages(page);
 
         VM_BUG_ON_PAGE(!PageLocked(page), page);
         VM_BUG_ON_PAGE(PageTail(page), page);
         VM_BUG_ON_PAGE(nr != 1 && shadow, page);
 
-        if (shadow) {
-                mapping->nrexceptional += nr;
-                /*
-                 * Make sure the nrexceptional update is committed before
-                 * the nrpages update so that final truncate racing
-                 * with reclaim does not see both counters 0 at the
-                 * same time and miss a shadow entry.
-                 */
-                smp_wmb();
-        }
-        mapping->nrpages -= nr;
-
         for (i = 0; i < nr; i++) {
-                node = radix_tree_replace_clear_tags(&mapping->page_tree,
-                                page->index + i, shadow);
+                struct radix_tree_node *node;
+                void **slot;
+
+                __radix_tree_lookup(&mapping->page_tree, page->index + i,
+                                    &node, &slot);
+
+                radix_tree_clear_tags(&mapping->page_tree, node, slot);
+
                 if (!node) {
                         VM_BUG_ON_PAGE(nr != 1, page);
-                        return;
+                        /*
+                         * We need a node to properly account shadow
+                         * entries. Don't plant any without. XXX
+                         */
+                        shadow = NULL;
                 }
 
+                radix_tree_replace_slot(slot, shadow);
+
+                if (!node)
+                        break;
+
                 workingset_node_pages_dec(node);
                 if (shadow)
                         workingset_node_shadows_inc(node);
@@ -219,6 +221,18 @@ static void page_cache_tree_delete(struct address_space *mapping,
                                         &node->private_list);
                 }
         }
+
+        if (shadow) {
+                mapping->nrexceptional += nr;
+                /*
+                 * Make sure the nrexceptional update is committed before
+                 * the nrpages update so that final truncate racing
+                 * with reclaim does not see both counters 0 at the
+                 * same time and miss a shadow entry.
+                 */
+                smp_wmb();
+        }
+        mapping->nrpages -= nr;
 }
 
 /*