[PATCH v3 16/33] radix-tree: Create node_tag_set()

Matthew Wilcox
2016-11-28T20:04:20Z

From: Matthew Wilcox <willy@linux.intel.com>

Similar to node_tag_clear(), factor node_tag_set() out of
radix_tree_range_tag_if_tagged().

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
---
lib/radix-tree.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 3f49417..c72da89 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -990,6 +990,22 @@ static void node_tag_clear(struct radix_tree_root *root,
root_tag_clear(root, tag);
}

+static void node_tag_set(struct radix_tree_root *root,
+ struct radix_tree_node *node,
+ unsigned int tag, unsigned int offset)
+{
+ while (node) {
+ if (tag_get(node, tag, offset))
+ return;
+ tag_set(node, tag, offset);
+ offset = node->offset;
+ node = node->parent;
+ }
+
+ if (!root_tag_get(root, tag))
+ root_tag_set(root, tag);
+}
+
/**
* radix_tree_tag_clear - clear a tag on a radix tree node
* @root: radix tree root
@@ -1228,7 +1244,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
unsigned long nr_to_tag,
unsigned int iftag, unsigned int settag)
{
- struct radix_tree_node *parent, *node, *child;
+ struct radix_tree_node *node, *child;
unsigned long maxindex;
unsigned long tagged = 0;
unsigned long index = *first_indexp;
@@ -1263,22 +1279,8 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
continue;
}

- /* tag the leaf */
tagged++;
- tag_set(node, settag, offset);
-
- /* walk back up the path tagging interior nodes */
- parent = node;
- for (;;) {
- offset = parent->offset;
- parent = parent->parent;
- if (!parent)
- break;
- /* stop if we find a node with the tag already set */
- if (tag_get(parent, settag, offset))
- break;
- tag_set(parent, settag, offset);
- }
+ node_tag_set(root, node, settag, offset);
next:
/* Go to next entry in node */
index = ((index >> node->shift) + 1) << node->shift;
@@ -1300,12 +1302,7 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
if (tagged >= nr_to_tag)
break;
}
- /*
- * We need not to tag the root tag if there is no tag which is set with
- * settag within the range from *first_indexp to last_index.
- */
- if (tagged > 0)
- root_tag_set(root, settag);
+
*first_indexp = index;

return tagged;
--
2.10.2