void mark_buffer_dirty(struct buffer_head *bh);
void mark_buffer_write_io_error(struct buffer_head *bh);
-void init_buffer(struct buffer_head *, bh_end_io_t *, void *);
void touch_buffer(struct buffer_head *bh);
void set_bh_page(struct buffer_head *bh,
struct page *page, unsigned long offset);