implement vectored I/O (readv/writev)

fs/vfs/main.c

@@ -223,6 +223,47 @@ out_errno:
 	return -1;
 }
 
+ssize_t readv(int fd, const struct iovec *iov, int iovcnt)
+{
+	struct task *t = main_task;
+	file_t fp;
+	size_t bytes;
+	int error;
+
+	error = EBADF;
+	if ((fp = task_getfp(t, fd)) == NULL)
+		goto out_errno;
+
+	error = sys_read(fp, (struct iovec *)iov, iovcnt, &bytes);
+	if (error)
+		goto out_errno;
+
+	return bytes;
+out_errno:
+	errno = error;
+	return -1;
+}
+
+ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
+{
+	struct task *t = main_task;
+	file_t fp;
+	size_t bytes;
+	int error;
+
+	error = EBADF;
+	if ((fp = task_getfp(t, fd)) == NULL)
+		goto out_errno;
+
+	error = sys_write(fp, (struct iovec *)iov, iovcnt, &bytes);
+	if (error)
+		goto out_errno;
+	return bytes;
+out_errno:
+	errno = error;
+	return -1;
+}
+
 #if 0
 static int
 fs_ioctl(struct task *t, struct ioctl_msg *msg)

runtime.cc

@@ -207,16 +207,6 @@ int poll(struct pollfd *fds, nfds_t nfds, int timeout)
     UNIMPLEMENTED("poll");
 }
 
-ssize_t readv(int fd, const struct iovec *iov, int iovcnt)
-{
-    UNIMPLEMENTED("readv");
-}
-
-ssize_t writev(int fd, const struct iovec *iov, int iovcnt)
-{
-    UNIMPLEMENTED("writev");
-}
-
 ssize_t preadv(int fd, const struct iovec *iov, int iovcnt, off_t offset)
 {
     UNIMPLEMENTED("preadv");