[PATCH 22/30] radix-tree: Rewrite radix_tree_tag_set

Matthew Wilcox
2016-04-06T21:24:28Z

From: Ross Zwisler <ross.zwisler@linux.intel.com>

Use the new multi-order support functions to rewrite radix_tree_tag_set()

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
lib/radix-tree.c | 37 +++++++++++++++++--------------------
1 file changed, 17 insertions(+), 20 deletions(-)

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index efcb8ed4b96b..6d9b328705a1 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -729,35 +729,32 @@ EXPORT_SYMBOL(radix_tree_lookup);
void *radix_tree_tag_set(struct radix_tree_root *root,
unsigned long index, unsigned int tag)
{
- unsigned int height, shift;
- struct radix_tree_node *slot;
-
- height = root->height;
- BUG_ON(index > radix_tree_maxindex(height));
+ struct radix_tree_node *node, *parent;
+ unsigned long maxindex;
+ unsigned int shift;

- slot = indirect_to_ptr(root->rnode);
- shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ shift = radix_tree_load_root(root, &node, &maxindex);
+ BUG_ON(index > maxindex);

- while (height > 0) {
- int offset;
+ while (radix_tree_is_indirect_ptr(node)) {
+ unsigned offset;

- offset = (index >> shift) & RADIX_TREE_MAP_MASK;
- if (!tag_get(slot, tag, offset))
- tag_set(slot, tag, offset);
- slot = slot->slots[offset];
- BUG_ON(slot == NULL);
- if (!radix_tree_is_indirect_ptr(slot))
- break;
- slot = indirect_to_ptr(slot);
shift -= RADIX_TREE_MAP_SHIFT;
- height--;
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+
+ parent = indirect_to_ptr(node);
+ offset = radix_tree_descend(parent, &node, offset);
+ BUG_ON(!node);
+
+ if (!tag_get(parent, tag, offset))
+ tag_set(parent, tag, offset);
}

/* set the root's tag bit */
- if (slot && !root_tag_get(root, tag))
+ if (!root_tag_get(root, tag))
root_tag_set(root, tag);

- return slot;
+ return node;
}
EXPORT_SYMBOL(radix_tree_tag_set);

--
2.8.0.rc3