1 files changed, 13 insertions, 16 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 61ba5e405791..ea89840fc65f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -644,7 +644,9 @@ repeat:
         pagep = radix_tree_lookup_slot(&mapping->page_tree, offset);
         if (pagep) {
                 page = radix_tree_deref_slot(pagep);
-                if (unlikely(!page || page == RADIX_TREE_RETRY))
+                if (unlikely(!page))
+                        goto out;
+                if (radix_tree_deref_retry(page))
                         goto repeat;
 
                 if (!page_cache_get_speculative(page))
@@ -660,6 +662,7 @@ repeat:
                         goto repeat;
                 }
         }
+out:
         rcu_read_unlock();
 
         return page;
@@ -777,12 +780,11 @@ repeat:
                 page = radix_tree_deref_slot((void **)pages[i]);
                 if (unlikely(!page))
                         continue;
-                /*
-                 * this can only trigger if nr_found == 1, making livelock
-                 * a non issue.
-                 */
-                if (unlikely(page == RADIX_TREE_RETRY))
+                if (radix_tree_deref_retry(page)) {
+                        if (ret)
+                                start = pages[ret-1]->index;
                         goto restart;
+                }
 
                 if (!page_cache_get_speculative(page))
                         goto repeat;
@@ -830,11 +832,7 @@ repeat:
                 page = radix_tree_deref_slot((void **)pages[i]);
                 if (unlikely(!page))
                         continue;
-                /*
-                 * this can only trigger if nr_found == 1, making livelock
-                 * a non issue.
-                 */
-                if (unlikely(page == RADIX_TREE_RETRY))
+                if (radix_tree_deref_retry(page))
                         goto restart;
 
                 if (page->mapping == NULL || page->index != index)
@@ -887,11 +885,7 @@ repeat:
                 page = radix_tree_deref_slot((void **)pages[i]);
                 if (unlikely(!page))
                         continue;
-                /*
-                 * this can only trigger if nr_found == 1, making livelock
-                 * a non issue.
-                 */
-                if (unlikely(page == RADIX_TREE_RETRY))
+                if (radix_tree_deref_retry(page))
                         goto restart;
 
                 if (!page_cache_get_speculative(page))
@@ -1029,6 +1023,9 @@ find_page:
                                 goto page_not_up_to_date;
                         if (!trylock_page(page))
                                 goto page_not_up_to_date;
+                        /* Did it get truncated before we got the lock? */
+                        if (!page->mapping)
+                                goto page_not_up_to_date_locked;
                         if (!mapping->a_ops->is_partially_uptodate(page,
                                                                 desc, offset))
                                 goto page_not_up_to_date_locked;