+ if (close (fd) == -1) {
+ reply_with_perror ("close: %s", device);
+ return -1;
+ }
+
+ return 0;
+}
+
+int
+do_zero_device (const char *device)
+{
+ int64_t size = do_blockdev_getsize64 (device);
+ if (size == -1)
+ return -1;
+
+ int fd = open (device, O_WRONLY);
+ if (fd == -1) {
+ reply_with_perror ("%s", device);
+ return -1;
+ }
+
+ char buf[1024*1024];
+ memset (buf, 0, sizeof buf);
+
+ while (size > 0) {
+ size_t n = (size_t) size > sizeof buf ? sizeof buf : (size_t) size;
+ ssize_t r = write (fd, buf, n);
+ if (r == -1) {
+ reply_with_perror ("write: %s (with %" PRId64 " bytes left to write)",
+ device, size);
+ close (fd);
+ return -1;
+ }
+ size -= r;
+ }
+
+ if (close (fd) == -1) {
+ reply_with_perror ("close: %s", device);
+ return -1;