/*
  * @opf:       bio REQ_OP_* and REQ_* flags as one value
- * @tree:      tree so we can call our merge_bio hook
  * @wbc:       optional writeback control for io accounting
  * @page:      page to add to the bio
  * @pg_offset: offset of the new bio or to check whether we are adding
  * @prev_bio_flags:  flags of previous bio to see if we can merge the current one
  * @bio_flags: flags of the current bio to see if we can merge them
  */
-static int submit_extent_page(unsigned int opf, struct extent_io_tree *tree,
+static int submit_extent_page(unsigned int opf,
                              struct writeback_control *wbc,
                              struct page *page, u64 offset,
                              size_t size, unsigned long pg_offset,
        struct bio *bio;
        size_t page_size = min_t(size_t, size, PAGE_SIZE);
        sector_t sector = offset >> 9;
+       struct extent_io_tree *tree = &BTRFS_I(page->mapping->host)->io_tree;
 
        ASSERT(bio_ret);
-       ASSERT(tree == &BTRFS_I(page->mapping->host)->io_tree);
 
        if (*bio_ret) {
                bool contig;
                        continue;
                }
 
-               ret = submit_extent_page(REQ_OP_READ | read_flags, tree, NULL,
+               ret = submit_extent_page(REQ_OP_READ | read_flags, NULL,
                                         page, offset, disk_io_size,
                                         pg_offset, bio,
                                         end_bio_extent_readpage, mirror_num,
                               page->index, cur, end);
                }
 
-               ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
+               ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
                                         page, offset, iosize, pg_offset,
                                         &epd->bio,
                                         end_bio_extent_writepage,
                        struct writeback_control *wbc,
                        struct extent_page_data *epd)
 {
-       struct btrfs_fs_info *fs_info = eb->fs_info;
-       struct extent_io_tree *tree = &BTRFS_I(fs_info->btree_inode)->io_tree;
        u64 offset = eb->start;
        u32 nritems;
        int i, num_pages;
 
                clear_page_dirty_for_io(p);
                set_page_writeback(p);
-               ret = submit_extent_page(REQ_OP_WRITE | write_flags, tree, wbc,
+               ret = submit_extent_page(REQ_OP_WRITE | write_flags, wbc,
                                         p, offset, PAGE_SIZE, 0,
                                         &epd->bio,
                                         end_bio_extent_buffer_writepage,