1 files changed, 28 insertions, 4 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index abd7403aba41..54287d443806 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -661,8 +661,8 @@ unsigned long shmem_partial_swap_usage(struct address_space *mapping,
                         swapped++;
 
                 if (need_resched()) {
+                        slot = radix_tree_iter_resume(slot, &iter);
                         cond_resched_rcu();
-                        slot = radix_tree_iter_next(&iter);
                 }
         }
 
@@ -1049,6 +1049,30 @@ static void shmem_evict_inode(struct inode *inode)
         clear_inode(inode);
 }
 
+static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
+{
+        struct radix_tree_iter iter;
+        void **slot;
+        unsigned long found = -1;
+        unsigned int checked = 0;
+
+        rcu_read_lock();
+        radix_tree_for_each_slot(slot, root, &iter, 0) {
+                if (*slot == item) {
+                        found = iter.index;
+                        break;
+                }
+                checked++;
+                if ((checked % 4096) != 0)
+                        continue;
+                slot = radix_tree_iter_resume(slot, &iter);
+                cond_resched_rcu();
+        }
+
+        rcu_read_unlock();
+        return found;
+}
+
 /*
  * If swap found in inode, free it and move page from swapcache to filecache.
  */
@@ -1062,7 +1086,7 @@ static int shmem_unuse_inode(struct shmem_inode_info *info,
         int error = 0;
 
         radswap = swp_to_radix_entry(swap);
-        index = radix_tree_locate_item(&mapping->page_tree, radswap);
+        index = find_swap_entry(&mapping->page_tree, radswap);
         if (index == -1)
                 return -EAGAIN; /* tell shmem_unuse we found nothing */
 
@@ -2447,8 +2471,8 @@ static void shmem_tag_pins(struct address_space *mapping)
                 }
 
                 if (need_resched()) {
+                        slot = radix_tree_iter_resume(slot, &iter);
                         cond_resched_rcu();
-                        slot = radix_tree_iter_next(&iter);
                 }
         }
         rcu_read_unlock();
@@ -2517,8 +2541,8 @@ static int shmem_wait_for_pins(struct address_space *mapping)
                         spin_unlock_irq(&mapping->tree_lock);
 continue_resched:
                         if (need_resched()) {
+                                slot = radix_tree_iter_resume(slot, &iter);
                                 cond_resched_rcu();
-                                slot = radix_tree_iter_next(&iter);
                         }
                 }
                 rcu_read_unlock();