/* * This file is only for sharing some helpers from read_write.c with compat.c. * Don't use anywhere else. */  typedef ssize_t (*io_fn_t)(struct file *, char __user *, size_t, loff_t *);typedef ssize_t (*iov_fn_t)(struct kiocb *, const struct iovec *,		unsigned long, loff_t); ssize_t do_sync_readv_writev(struct file *filp, const struct iovec *iov,		unsigned long nr_segs, size_t len, loff_t *ppos, iov_fn_t fn);ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,		unsigned long nr_segs, loff_t *ppos, io_fn_t fn);