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authorRoss Zwisler <ross.zwisler@linux.intel.com>2016-05-20 17:02:38 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-20 17:58:30 -0700
commit4589ba6d0f439e4673830fdc65099179832ddde5 (patch)
tree2c6dc6832b3fa40765038f1e37f3adfd6c41198d
parent00f47b581105b91f8f18edd3074322ae609a8bc5 (diff)
radix-tree: rewrite radix_tree_tag_get
Use the new multi-order support functions to rewrite radix_tree_tag_get() Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Jan Kara <jack@suse.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--lib/radix-tree.c44
1 files changed, 18 insertions, 26 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index ee56562e0a2d..b1ca74489bc2 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -831,45 +831,37 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
int radix_tree_tag_get(struct radix_tree_root *root,
unsigned long index, unsigned int tag)
{
- unsigned int height, shift;
- struct radix_tree_node *node;
+ struct radix_tree_node *node, *parent;
+ unsigned long maxindex;
+ unsigned int shift;
- /* check the root's tag bit */
if (!root_tag_get(root, tag))
return 0;
- node = rcu_dereference_raw(root->rnode);
+ shift = radix_tree_load_root(root, &node, &maxindex);
+ if (index > maxindex)
+ return 0;
if (node == NULL)
return 0;
- if (!radix_tree_is_indirect_ptr(node))
- return (index == 0);
- node = indirect_to_ptr(node);
-
- height = node->path & RADIX_TREE_HEIGHT_MASK;
- if (index > radix_tree_maxindex(height))
- return 0;
+ while (radix_tree_is_indirect_ptr(node)) {
+ int offset;
- shift = (height - 1) * RADIX_TREE_MAP_SHIFT;
+ shift -= RADIX_TREE_MAP_SHIFT;
+ offset = (index >> shift) & RADIX_TREE_MAP_MASK;
- for ( ; ; ) {
- int offset;
+ parent = indirect_to_ptr(node);
+ offset = radix_tree_descend(parent, &node, offset);
- if (node == NULL)
+ if (!node)
return 0;
- node = indirect_to_ptr(node);
-
- offset = (index >> shift) & RADIX_TREE_MAP_MASK;
- if (!tag_get(node, tag, offset))
+ if (!tag_get(parent, tag, offset))
return 0;
- if (height == 1)
- return 1;
- node = rcu_dereference_raw(node->slots[offset]);
- if (!radix_tree_is_indirect_ptr(node))
- return 1;
- shift -= RADIX_TREE_MAP_SHIFT;
- height--;
+ if (node == RADIX_TREE_RETRY)
+ break;
}
+
+ return 1;
}
EXPORT_SYMBOL(radix_tree_tag_get);