[5/6] btrfs: edit btrfs_add_chunk_map() to use rb helpers

Commit Message

Lee Beckermeyer Dec. 10, 2024, 7:06 p.m. UTC

Edits btrfs_add_chunk_map() to use rb_find_add_cached(). Also adds a
comparison function to use with rb_find_add_cached().

Signed-off-by: Roger L. Beckermeyer III <[e-mail]>
---
 fs/btrfs/volumes.c | 39 ++++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

Patch

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1cccaf9c2b0d..4837761a56c9 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -5513,33 +5513,30 @@  void btrfs_remove_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_ma
 	btrfs_free_chunk_map(map);
 }
 
+static int btrfs_chunk_map_cmp(struct rb_node *rb_node, const struct rb_node *exist_node)
+{
+	struct btrfs_chunk_map *map = rb_entry(rb_node, struct btrfs_chunk_map, rb_node);
+	struct btrfs_chunk_map *exist = rb_entry(exist_node, struct btrfs_chunk_map, rb_node);
+
+	if (map->start == exist->start)
+		return 0;
+	if (map->start < exist->start)
+		return -1;
+	return 1;
+}
+
 EXPORT_FOR_TESTS
 int btrfs_add_chunk_map(struct btrfs_fs_info *fs_info, struct btrfs_chunk_map *map)
 {
-	struct rb_node **p;
-	struct rb_node *parent = NULL;
-	bool leftmost = true;
+	struct rb_node *exist;
 
 	write_lock(&fs_info->mapping_tree_lock);
-	p = &fs_info->mapping_tree.rb_root.rb_node;
-	while (*p) {
-		struct btrfs_chunk_map *entry;
-
-		parent = *p;
-		entry = rb_entry(parent, struct btrfs_chunk_map, rb_node);
-
-		if (map->start < entry->start) {
-			p = &(*p)->rb_left;
-		} else if (map->start > entry->start) {
-			p = &(*p)->rb_right;
-			leftmost = false;
-		} else {
-			write_unlock(&fs_info->mapping_tree_lock);
-			return -EEXIST;
-		}
+	exist = rb_find_add_cached(&map->rb_node, &fs_info->mapping_tree, btrfs_chunk_map_cmp);
+
+	if (exist != NULL) {
+		write_unlock(&fs_info->mapping_tree_lock);
+		return -EEXIST;
 	}
-	rb_link_node(&map->rb_node, parent, p);
-	rb_insert_color_cached(&map->rb_node, &fs_info->mapping_tree, leftmost);
 	chunk_map_device_set_bits(map, CHUNK_ALLOCATED);
 	chunk_map_device_clear_bits(map, CHUNK_TRIMMED);
 	write_unlock(&fs_info->mapping_tree_lock);