X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fradix-tree.c;h=2a087e0f98633cf00724ef0ef7b411d9f60b609e;hb=4d7b4ac22fbec1a03206c6cde353f2fd6942f828;hp=0871582aa29de45fa8ff6f372cd8e8622c3fcc46;hpb=7da23b86e14b77c094b11a9fa5ef5b3758fc9193;p=~andy%2Flinux

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 0871582aa29..2a087e0f986 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -555,6 +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)
@@ -595,12 +599,8 @@ 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;
-		}
+		if (height == 1)
+			return !!tag_get(node, tag, offset);
 		node = rcu_dereference_raw(node->slots[offset]);
 		shift -= RADIX_TREE_MAP_SHIFT;
 		height--;