btrfs: use btrfs_read_node_slot in qgroup_trace_extent_swap

We're open-coding btrfs_read_node_slot() here, replace with the helper.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 78ffbad..db6165e 100644 (file)
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1942,27 +1942,16 @@ static int qgroup_trace_extent_swap(struct btrfs_trans_handle* trans,
                struct btrfs_key dst_key;
 
                if (src_path->nodes[cur_level] == NULL) {
-                       struct btrfs_key first_key;
                        struct extent_buffer *eb;
                        int parent_slot;
-                       u64 child_gen;
-                       u64 child_bytenr;
 
                        eb = src_path->nodes[cur_level + 1];
                        parent_slot = src_path->slots[cur_level + 1];
-                       child_bytenr = btrfs_node_blockptr(eb, parent_slot);
-                       child_gen = btrfs_node_ptr_generation(eb, parent_slot);
-                       btrfs_node_key_to_cpu(eb, &first_key, parent_slot);
 
-                       eb = read_tree_block(fs_info, child_bytenr, child_gen,
-                                            cur_level, &first_key);
+                       eb = btrfs_read_node_slot(eb, parent_slot);
                        if (IS_ERR(eb)) {
                                ret = PTR_ERR(eb);
                                goto out;
-                       } else if (!extent_buffer_uptodate(eb)) {
-                               free_extent_buffer(eb);
-                               ret = -EIO;
-                               goto out;
                        }
 
                        src_path->nodes[cur_level] = eb;