btrfs: open code rbtree search in split_state

Preparatory work to remove tree_insert from extent_io.c, the rbtree
search loop is a known and simple so it can be open coded.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 3395474..4b30048 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -607,7 +607,8 @@ static int insert_state(struct extent_io_tree *tree,
 static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
                       struct extent_state *prealloc, u64 split)
 {
-       struct rb_node *node;
+       struct rb_node *parent = NULL;
+       struct rb_node **node;
 
        if (tree->private_data && is_data_inode(tree->private_data))
                btrfs_split_delalloc_extent(tree->private_data, orig, split);
@@ -617,12 +618,27 @@ static int split_state(struct extent_io_tree *tree, struct extent_state *orig,
        prealloc->state = orig->state;
        orig->start = split;
 
-       node = tree_insert(&tree->state, &orig->rb_node, prealloc->end,
-                          &prealloc->rb_node, NULL, NULL);
-       if (node) {
-               free_extent_state(prealloc);
-               return -EEXIST;
+       parent = &orig->rb_node;
+       node = &parent;
+       while (*node) {
+               struct tree_entry *entry;
+
+               parent = *node;
+               entry = rb_entry(parent, struct tree_entry, rb_node);
+
+               if (prealloc->end < entry->start) {
+                       node = &(*node)->rb_left;
+               } else if (prealloc->end > entry->end) {
+                       node = &(*node)->rb_right;
+               } else {
+                       free_extent_state(prealloc);
+                       return -EEXIST;
+               }
        }
+
+       rb_link_node(&prealloc->rb_node, parent, node);
+       rb_insert_color(&prealloc->rb_node, &tree->state);
+
        return 0;
 }