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-rw-r--r--lib/radix-tree.c76
1 files changed, 33 insertions, 43 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8329a2e950eb..8df0df2835b4 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -1033,14 +1033,13 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
unsigned long nr_to_tag,
unsigned int iftag, unsigned int settag)
{
- unsigned int height = root->height;
- struct radix_tree_node *node = NULL;
- struct radix_tree_node *slot;
- unsigned int shift;
+ struct radix_tree_node *slot, *node = NULL;
+ unsigned long maxindex;
+ unsigned int shift = radix_tree_load_root(root, &slot, &maxindex);
unsigned long tagged = 0;
unsigned long index = *first_indexp;
- last_index = min(last_index, radix_tree_maxindex(height));
+ last_index = min(last_index, maxindex);
if (index > last_index)
return 0;
if (!nr_to_tag)
@@ -1049,80 +1048,71 @@ unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root,
*first_indexp = last_index + 1;
return 0;
}
- if (height == 0) {
+ if (!radix_tree_is_indirect_ptr(slot)) {
*first_indexp = last_index + 1;
root_tag_set(root, settag);
return 1;
}
- shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
- slot = indirect_to_ptr(root->rnode);
+ node = indirect_to_ptr(slot);
+ shift -= RADIX_TREE_MAP_SHIFT;
for (;;) {
unsigned long upindex;
- int offset;
+ unsigned offset;
offset = (index >> shift) & RADIX_TREE_MAP_MASK;
- if (!slot->slots[offset])
+ offset = radix_tree_descend(node, &slot, offset);
+ if (!slot)
goto next;
- if (!tag_get(slot, iftag, offset))
+ if (!tag_get(node, iftag, offset))
goto next;
- if (shift) {
- node = slot;
- slot = slot->slots[offset];
- if (radix_tree_is_indirect_ptr(slot)) {
- slot = indirect_to_ptr(slot);
- shift -= RADIX_TREE_MAP_SHIFT;
- continue;
- } else {
- slot = node;
- node = node->parent;
- }
+ /* Sibling slots never have tags set on them */
+ if (radix_tree_is_indirect_ptr(slot)) {
+ node = indirect_to_ptr(slot);
+ shift -= RADIX_TREE_MAP_SHIFT;
+ continue;
}
/* tag the leaf */
- tagged += 1 << shift;
- tag_set(slot, settag, offset);
+ tagged++;
+ tag_set(node, settag, offset);
+ slot = node->parent;
/* walk back up the path tagging interior nodes */
- upindex = index;
- while (node) {
+ upindex = index >> shift;
+ while (slot) {
upindex >>= RADIX_TREE_MAP_SHIFT;
offset = upindex & RADIX_TREE_MAP_MASK;
/* stop if we find a node with the tag already set */
- if (tag_get(node, settag, offset))
+ if (tag_get(slot, settag, offset))
break;
- tag_set(node, settag, offset);
- node = node->parent;
+ tag_set(slot, settag, offset);
+ slot = slot->parent;
}
- /*
- * Small optimization: now clear that node pointer.
- * Since all of this slot's ancestors now have the tag set
- * from setting it above, we have no further need to walk
- * back up the tree setting tags, until we update slot to
- * point to another radix_tree_node.
- */
- node = NULL;
-
-next:
+ next:
/* Go to next item at level determined by 'shift' */
index = ((index >> shift) + 1) << shift;
/* Overflow can happen when last_index is ~0UL... */
if (index > last_index || !index)
break;
- if (tagged >= nr_to_tag)
- break;
- while (((index >> shift) & RADIX_TREE_MAP_MASK) == 0) {
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
+ while (offset == 0) {
/*
* We've fully scanned this node. Go up. Because
* last_index is guaranteed to be in the tree, what
* we do below cannot wander astray.
*/
- slot = slot->parent;
+ node = node->parent;
shift += RADIX_TREE_MAP_SHIFT;
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
}
+ if (is_sibling_entry(node, node->slots[offset]))
+ goto next;
+ if (tagged >= nr_to_tag)
+ break;
}
/*
* We need not to tag the root tag if there is no tag which is set with