xfs_hooks_add
return xfs_hooks_add(&mp->m_dir_update_hooks, &hook->dirent_hook);
return xfs_hooks_add(&xg->xg_rmap_update_hooks, &hook->rmap_hook);
int xfs_hooks_add(struct xfs_hooks *chain, struct xfs_hook *hook);
error = xfs_hooks_add(&qi->qi_apply_dqtrx_hooks, &hook->apply_hook);
error = xfs_hooks_add(&qi->qi_mod_ino_dqtrx_hooks, &hook->mod_hook);