btrfs: open code rbtree search in insert_state

The rbtree search is a known pattern and can be open coded, allowing to
remove the tree_insert and further cleanups.

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

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 4b30048..5e0d5a6 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -368,42 +368,6 @@ void free_extent_state(struct extent_state *state)
        }
 }
 
-static struct rb_node *tree_insert(struct rb_root *root,
-                                  struct rb_node *search_start,
-                                  u64 offset,
-                                  struct rb_node *node,
-                                  struct rb_node ***p_in,
-                                  struct rb_node **parent_in)
-{
-       struct rb_node **p;
-       struct rb_node *parent = NULL;
-       struct tree_entry *entry;
-
-       if (p_in && parent_in) {
-               p = *p_in;
-               parent = *parent_in;
-               goto do_insert;
-       }
-
-       p = search_start ? &search_start : &root->rb_node;
-       while (*p) {
-               parent = *p;
-               entry = rb_entry(parent, struct tree_entry, rb_node);
-
-               if (offset < entry->start)
-                       p = &(*p)->rb_left;
-               else if (offset > entry->end)
-                       p = &(*p)->rb_right;
-               else
-                       return parent;
-       }
-
-do_insert:
-       rb_link_node(node, parent, p);
-       rb_insert_color(node, root);
-       return NULL;
-}
-
 /**
  * Search @tree for an entry that contains @offset. Such entry would have
  * entry->start <= offset && entry->end >= offset.
@@ -561,11 +525,12 @@ static void set_state_bits(struct extent_io_tree *tree,
  */
 static int insert_state(struct extent_io_tree *tree,
                        struct extent_state *state, u64 start, u64 end,
-                       struct rb_node ***p,
-                       struct rb_node **parent,
+                       struct rb_node ***node_in,
+                       struct rb_node **parent_in,
                        u32 *bits, struct extent_changeset *changeset)
 {
-       struct rb_node *node;
+       struct rb_node **node;
+       struct rb_node *parent;
 
        if (end < start) {
                btrfs_err(tree->fs_info,
@@ -577,15 +542,36 @@ static int insert_state(struct extent_io_tree *tree,
 
        set_state_bits(tree, state, bits, changeset);
 
-       node = tree_insert(&tree->state, NULL, end, &state->rb_node, p, parent);
-       if (node) {
-               struct extent_state *found;
-               found = rb_entry(node, struct extent_state, rb_node);
-               btrfs_err(tree->fs_info,
-                      "found node %llu %llu on insert of %llu %llu",
-                      found->start, found->end, start, end);
-               return -EEXIST;
+       /* Caller provides the exact tree location */
+       if (node_in && parent_in) {
+               node = *node_in;
+               parent = *parent_in;
+               goto insert_new;
        }
+
+       node = &tree->state.rb_node;
+       while (*node) {
+               struct tree_entry *entry;
+
+               parent = *node;
+               entry = rb_entry(parent, struct tree_entry, rb_node);
+
+               if (end < entry->start) {
+                       node = &(*node)->rb_left;
+               } else if (end > entry->end) {
+                       node = &(*node)->rb_right;
+               } else {
+                       btrfs_err(tree->fs_info,
+                              "found node %llu %llu on insert of %llu %llu",
+                              entry->start, entry->end, start, end);
+                       return -EEXIST;
+               }
+       }
+
+insert_new:
+       rb_link_node(&state->rb_node, parent, node);
+       rb_insert_color(&state->rb_node, &tree->state);
+
        merge_state(tree, state);
        return 0;
 }