1 files changed, 20 insertions, 21 deletions

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 92cdd9936e3d..05da38bcc298 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -28,7 +28,6 @@
 #include <linux/slab.h>
 #include <linux/notifier.h>
 #include <linux/cpu.h>
-#include <linux/gfp.h>
 #include <linux/string.h>
 #include <linux/bitops.h>
 #include <linux/rcupdate.h>
@@ -364,7 +363,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
         unsigned int height, shift;
         struct radix_tree_node *node, **slot;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (node == NULL)
                 return NULL;
 
@@ -384,7 +383,7 @@ static void *radix_tree_lookup_element(struct radix_tree_root *root,
         do {
                 slot = (struct radix_tree_node **)
                         (node->slots + ((index>>shift) & RADIX_TREE_MAP_MASK));
-                node = rcu_dereference(*slot);
+                node = rcu_dereference_raw(*slot);
                 if (node == NULL)
                         return NULL;
 
@@ -556,6 +555,10 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
  *
  *  0: tag not present or not set
  *  1: tag set
+ *
+ * Note that the return value of this function may not be relied on, even if
+ * the RCU lock is held, unless tag modification and node deletion are excluded
+ * from concurrency.
  */
 int radix_tree_tag_get(struct radix_tree_root *root,
                         unsigned long index, unsigned int tag)
@@ -568,7 +571,7 @@ int radix_tree_tag_get(struct radix_tree_root *root,
         if (!root_tag_get(root, tag))
                 return 0;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (node == NULL)
                 return 0;
 
@@ -596,13 +599,9 @@ int radix_tree_tag_get(struct radix_tree_root *root,
                  */
                 if (!tag_get(node, tag, offset))
                         saw_unset_tag = 1;
-                if (height == 1) {
-                        int ret = tag_get(node, tag, offset);
-
-                        BUG_ON(ret && saw_unset_tag);
-                        return !!ret;
-                }
-                node = rcu_dereference(node->slots[offset]);
+                if (height == 1)
+                        return !!tag_get(node, tag, offset);
+                node = rcu_dereference_raw(node->slots[offset]);
                 shift -= RADIX_TREE_MAP_SHIFT;
                 height--;
         }
@@ -657,7 +656,7 @@ EXPORT_SYMBOL(radix_tree_next_hole);
  *
  *      Returns: the index of the hole if found, otherwise returns an index
  *      outside of the set specified (in which case 'index - return >= max_scan'
- *      will be true). In rare cases of wrap-around, LONG_MAX will be returned.
+ *      will be true). In rare cases of wrap-around, ULONG_MAX will be returned.
  *
  *      radix_tree_next_hole may be called under rcu_read_lock. However, like
  *      radix_tree_gang_lookup, this will not atomically search a snapshot of
@@ -675,7 +674,7 @@ unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
                 if (!radix_tree_lookup(root, index))
                         break;
                 index--;
-                if (index == LONG_MAX)
+                if (index == ULONG_MAX)
                         break;
         }
 
@@ -711,7 +710,7 @@ __lookup(struct radix_tree_node *slot, void ***results, unsigned long index,
                 }
 
                 shift -= RADIX_TREE_MAP_SHIFT;
-                slot = rcu_dereference(slot->slots[i]);
+                slot = rcu_dereference_raw(slot->slots[i]);
                 if (slot == NULL)
                         goto out;
         }
@@ -758,7 +757,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
         unsigned long cur_index = first_index;
         unsigned int ret;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (!node)
                 return 0;
 
@@ -787,7 +786,7 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results,
                         slot = *(((void ***)results)[ret + i]);
                         if (!slot)
                                 continue;
-                        results[ret + nr_found] = rcu_dereference(slot);
+                        results[ret + nr_found] = rcu_dereference_raw(slot);
                         nr_found++;
                 }
                 ret += nr_found;
@@ -826,7 +825,7 @@ radix_tree_gang_lookup_slot(struct radix_tree_root *root, void ***results,
         unsigned long cur_index = first_index;
         unsigned int ret;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (!node)
                 return 0;
 
@@ -915,7 +914,7 @@ __lookup_tag(struct radix_tree_node *slot, void ***results, unsigned long index,
                         }
                 }
                 shift -= RADIX_TREE_MAP_SHIFT;
-                slot = rcu_dereference(slot->slots[i]);
+                slot = rcu_dereference_raw(slot->slots[i]);
                 if (slot == NULL)
                         break;
         }
@@ -951,7 +950,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
         if (!root_tag_get(root, tag))
                 return 0;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (!node)
                 return 0;
 
@@ -980,7 +979,7 @@ radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results,
                         slot = *(((void ***)results)[ret + i]);
                         if (!slot)
                                 continue;
-                        results[ret + nr_found] = rcu_dereference(slot);
+                        results[ret + nr_found] = rcu_dereference_raw(slot);
                         nr_found++;
                 }
                 ret += nr_found;
@@ -1020,7 +1019,7 @@ radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results,
         if (!root_tag_get(root, tag))
                 return 0;
 
-        node = rcu_dereference(root->rnode);
+        node = rcu_dereference_raw(root->rnode);
         if (!node)
                 return 0;