From: Hugh Dickins <hughd@google.com>
Date: Wed, 28 Sep 2011 00:50:00 +0000 (+1000)
Subject: radix_tree: clean away saw_unset_tag leftovers
X-Git-Tag: next-20110929~2^2~199
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a1985a95252b3bbdefeac098627d87335d24fb7d;p=karo-tx-linux.git

radix_tree: clean away saw_unset_tag leftovers

radix_tree_tag_get()'s BUG (when it sees a tag after saw_unset_tag) was
unsafe and removed in 2.6.34, but the pointless saw_unset_tag left behind.

Remove it now, and return 0 as soon as we see unset tag - we already rely
upon the root tag to be correct, returning 0 immediately if it's not set.

Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <>
---

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index a2f9da59c197..d9df7454519c 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -576,7 +576,6 @@ int radix_tree_tag_get(struct radix_tree_root *root,
 {
 	unsigned int height, shift;
 	struct radix_tree_node *node;
-	int saw_unset_tag = 0;
 
 	/* check the root's tag bit */
 	if (!root_tag_get(root, tag))
@@ -603,15 +602,10 @@ int radix_tree_tag_get(struct radix_tree_root *root,
 			return 0;
 
 		offset = (index >> shift) & RADIX_TREE_MAP_MASK;
-
-		/*
-		 * This is just a debug check.  Later, we can bale as soon as
-		 * we see an unset tag.
-		 */
 		if (!tag_get(node, tag, offset))
-			saw_unset_tag = 1;
+			return 0;
 		if (height == 1)
-			return !!tag_get(node, tag, offset);
+			return 1;
 		node = rcu_dereference_raw(node->slots[offset]);
 		shift -= RADIX_TREE_MAP_SHIFT;
 		height--;