Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
diff --git a/include/linux/radix-tree.h b/include/linux/radix-tree.h
index ffc444c..045b325 100644
--- a/include/linux/radix-tree.h
+++ b/include/linux/radix-tree.h
@@ -230,6 +230,10 @@ unsigned long radix_tree_next_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
unsigned long index, unsigned long max_scan);
+unsigned long radix_tree_next_present(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan);
+unsigned long radix_tree_prev_present(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan);
int radix_tree_preload(gfp_t gfp_mask);
void radix_tree_init(void);
void *radix_tree_tag_set(struct radix_tree_root *root,
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index e796429..e02e3b8 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -984,6 +984,40 @@ unsigned long radix_tree_prev_hole(struct radix_tree_root *root,
}
EXPORT_SYMBOL(radix_tree_prev_hole);
+unsigned long radix_tree_next_present(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan)
+{
+ unsigned long i;
+
+ for (i = 0; i < max_scan; i++) {
+ if (radix_tree_lookup(root, index))
+ break;
+ index++;
+ if (index == 0)
+ break;
+ }
+
+ return index;
+}
+EXPORT_SYMBOL(radix_tree_next_present);
+
+unsigned long radix_tree_prev_present(struct radix_tree_root *root,
+ unsigned long index, unsigned long max_scan)
+{
+ unsigned long i;
+
+ for (i = 0; i < max_scan; i++) {
+ if (radix_tree_lookup(root, index))
+ break;
+ index--;
+ if (index == ULONG_MAX)
+ break;
+ }
+
+ return index;
+}
+EXPORT_SYMBOL(radix_tree_prev_present);
+
/**
* radix_tree_gang_lookup - perform multiple lookup on a radix tree
* @root: radix tree root
--
1.7.9.5
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