- return syscall(SYS_read, f->fd, buf, len);
+ struct iovec iov[2] = {
+ { .iov_base = buf, .iov_len = len - !!f->buf_size },
+ { .iov_base = f->buf, .iov_len = f->buf_size }
+ };
+ ssize_t cnt;
+
+ cnt = syscall(SYS_readv, f->fd, iov, 2);
+ if (cnt <= 0) {
+ f->flags |= F_EOF ^ ((F_ERR^F_EOF) & cnt);
+ f->rpos = f->rend = 0;
+ return cnt;
+ }
+ if (cnt <= iov[0].iov_len) return cnt;
+ cnt -= iov[0].iov_len;
+ f->rpos = f->buf;
+ f->rend = f->buf + cnt;
+ if (f->buf_size) buf[len-1] = *f->rpos++;
+ return len;