diff options
Diffstat (limited to 'lib/radix-tree.c')
| -rw-r--r-- | lib/radix-tree.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/lib/radix-tree.c b/lib/radix-tree.c index 6b79e9026e24..534878e6cf11 100644 --- a/lib/radix-tree.c +++ b/lib/radix-tree.c @@ -1035,6 +1035,49 @@ radix_tree_gang_lookup(struct radix_tree_root *root, void **results, EXPORT_SYMBOL(radix_tree_gang_lookup); /** + * radix_tree_gang_lookup_index - perform multiple lookup on a radix tree + * @root: radix tree root + * @results: where the results of the lookup are placed + * @indices: where their indices should be placed + * @first_index: start the lookup from this key + * @max_items: place up to this many items at *results + * + * Performs an index-ascending scan of the tree for present items. Places + * them at *@results and returns the number of items which were placed at + * *@results. The indices are placed in @indices. + * + * The implementation is naive. + * + * Just one difference from radix_tree_gang_lookup, the indices are also + * collected along with the results of lookup. + */ +unsigned int +radix_tree_gang_lookup_index(struct radix_tree_root *root, void **results, + unsigned long *indices, unsigned long first_index, + unsigned int max_items) +{ + struct radix_tree_iter iter; + void **slot; + unsigned int ret = 0; + + if (unlikely(!max_items)) + return 0; + + radix_tree_for_each_slot(slot, root, &iter, first_index) { + results[ret] = indirect_to_ptr(rcu_dereference_raw(*slot)); + if (!results[ret]) + continue; + if (indices) + indices[ret] = iter.index; + if (++ret == max_items) + break; + } + + return ret; +} +EXPORT_SYMBOL(radix_tree_gang_lookup_index); + +/** * radix_tree_gang_lookup_slot - perform multiple slot lookup on radix tree * @root: radix tree root * @results: where the results of the lookup are placed |