btrfs: update tree_insert() to use rb helpers

Update tree_insert() to use rb_find_add_cached().
add cmp_refs_node in rb_find_add_cached() to compare.

Since we're here, also make comp_data_refs() and comp_refs() accept
both parameters as const.

Signed-off-by: Roger L. Beckermeyer III <beckerlee3@gmail.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c
index 30f7079fa28eac73f0522d81feb9641d88875813..98c5b61dabe88cae4bcdc89c0966f7b62a3d7714 100644 (file)
--- a/fs/btrfs/delayed-ref.c
+++ b/fs/btrfs/delayed-ref.c
@@ -268,8 +268,8 @@ int btrfs_delayed_refs_rsv_refill(struct btrfs_fs_info *fs_info,
 /*
  * compare two delayed data backrefs with same bytenr and type
  */
-static int comp_data_refs(struct btrfs_delayed_ref_node *ref1,
-                         struct btrfs_delayed_ref_node *ref2)
+static int comp_data_refs(const struct btrfs_delayed_ref_node *ref1,
+                         const struct btrfs_delayed_ref_node *ref2)
 {
        if (ref1->data_ref.objectid < ref2->data_ref.objectid)
                return -1;
@@ -282,8 +282,8 @@ static int comp_data_refs(struct btrfs_delayed_ref_node *ref1,
        return 0;
 }
 
-static int comp_refs(struct btrfs_delayed_ref_node *ref1,
-                    struct btrfs_delayed_ref_node *ref2,
+static int comp_refs(const struct btrfs_delayed_ref_node *ref1,
+                    const struct btrfs_delayed_ref_node *ref2,
                     bool check_seq)
 {
        int ret = 0;
@@ -317,34 +317,25 @@ static int comp_refs(struct btrfs_delayed_ref_node *ref1,
        return 0;
 }
 
+static int cmp_refs_node(const struct rb_node *new, const struct rb_node *exist)
+{
+       const struct btrfs_delayed_ref_node *new_node =
+               rb_entry(new, struct btrfs_delayed_ref_node, ref_node);
+       const struct btrfs_delayed_ref_node *exist_node =
+               rb_entry(exist, struct btrfs_delayed_ref_node, ref_node);
+
+       return comp_refs(new_node, exist_node, true);
+}
+
 static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root,
                struct btrfs_delayed_ref_node *ins)
 {
-       struct rb_node **p = &root->rb_root.rb_node;
        struct rb_node *node = &ins->ref_node;
-       struct rb_node *parent_node = NULL;
-       struct btrfs_delayed_ref_node *entry;
-       bool leftmost = true;
-
-       while (*p) {
-               int comp;
-
-               parent_node = *p;
-               entry = rb_entry(parent_node, struct btrfs_delayed_ref_node,
-                                ref_node);
-               comp = comp_refs(ins, entry, true);
-               if (comp < 0) {
-                       p = &(*p)->rb_left;
-               } else if (comp > 0) {
-                       p = &(*p)->rb_right;
-                       leftmost = false;
-               } else {
-                       return entry;
-               }
-       }
+       struct rb_node *exist;
 
-       rb_link_node(node, parent_node, p);
-       rb_insert_color_cached(node, root, leftmost);
+       exist = rb_find_add_cached(node, root, cmp_refs_node);
+       if (exist)
+               return rb_entry(exist, struct btrfs_delayed_ref_node, ref_node);
        return NULL;
 }