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Commit 3fa36acb authored by Hugh Dickins's avatar Hugh Dickins Committed by Linus Torvalds
Browse files

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: default avatarHugh Dickins <hughd@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 0dabec93

lib/radix-tree.c

+2 −8
Original line number Diff line number Diff line
@@ -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--;