- balance_dirty_pages_ratelimited_nr(
- root->fs_info->btree_inode->i_mapping, 1);
-}
-
-void btrfs_set_buffer_defrag(struct extent_buffer *buf)
-{
- struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
- struct inode *btree_inode = root->fs_info->btree_inode;
- set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
- buf->start + buf->len - 1, EXTENT_DEFRAG, GFP_NOFS);
-}
-
-void btrfs_set_buffer_defrag_done(struct extent_buffer *buf)
-{
- struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
- struct inode *btree_inode = root->fs_info->btree_inode;
- set_extent_bits(&BTRFS_I(btree_inode)->io_tree, buf->start,
- buf->start + buf->len - 1, EXTENT_DEFRAG_DONE,
- GFP_NOFS);
-}
-
-int btrfs_buffer_defrag(struct extent_buffer *buf)
-{
- struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
- struct inode *btree_inode = root->fs_info->btree_inode;
- return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
- buf->start, buf->start + buf->len - 1, EXTENT_DEFRAG, 0);
-}
-
-int btrfs_buffer_defrag_done(struct extent_buffer *buf)
-{
- struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
- struct inode *btree_inode = root->fs_info->btree_inode;
- return test_range_bit(&BTRFS_I(btree_inode)->io_tree,
- buf->start, buf->start + buf->len - 1,
- EXTENT_DEFRAG_DONE, 0);
-}
+ /*
+ * looks as though older kernels can get into trouble with
+ * this code, they end up stuck in balance_dirty_pages forever
+ */
+ struct extent_io_tree *tree;
+ u64 num_dirty;
+ u64 start = 0;
+ unsigned long thresh = 16 * 1024 * 1024;
+ tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;