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@xxxxxxxxxx>
---
lib/radix-tree.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
--- mmotm.orig/lib/radix-tree.c 2011-07-08 18:57:14.810702665 -0700
+++ mmotm/lib/radix-tree.c 2011-07-19 11:11:21.285234139 -0700
@@ -576,7 +576,6 @@ int radix_tree_tag_get(struct radix_tree
{
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
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--;
--
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