folio_wait_bit_killable
int folio_wait_bit_killable(struct folio *folio, int bit_nr);
return folio_wait_bit_killable(folio, PG_locked);
EXPORT_SYMBOL(folio_wait_bit_killable);
ret = folio_wait_bit_killable(folio, PG_private_2);
if (folio_wait_bit_killable(folio, PG_writeback))