trivial: radix-tree: document wrap-around issue of radix_tree_next_hole()

And some 80-line cleanups.

Signed-off-by: Wu Fengguang <wfg@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index be86b32..a7f5217 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -640,13 +640,14 @@ EXPORT_SYMBOL(radix_tree_tag_get);
  *
  *     Returns: the index of the hole if found, otherwise returns an index
  *     outside of the set specified (in which case 'return - index >= max_scan'
- *     will be true).
+ *     will be true). In rare cases of index wrap-around, 0 will be returned.
  *
  *     radix_tree_next_hole may be called under rcu_read_lock. However, like
- *     radix_tree_gang_lookup, this will not atomically search a snapshot of the
- *     tree at a single point in time. For example, if a hole is created at index
- *     5, then subsequently a hole is created at index 10, radix_tree_next_hole
- *     covering both indexes may return 10 if called under rcu_read_lock.
+ *     radix_tree_gang_lookup, this will not atomically search a snapshot of
+ *     the tree at a single point in time. For example, if a hole is created
+ *     at index 5, then subsequently a hole is created at index 10,
+ *     radix_tree_next_hole covering both indexes may return 10 if called
+ *     under rcu_read_lock.
  */
 unsigned long radix_tree_next_hole(struct radix_tree_root *root,
                                unsigned long index, unsigned long max_scan)