init_rwsem(&gcbmap->b_sem);
lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
init_rwsem(&gcbmap->b_sem);
lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;