mke2fs: Use e4fsprogs programs if available.

[libguestfs.git] / daemon / zero.c

diff --git a/daemon/zero.c b/daemon/zero.c
index 9c803d8..0ade242 100644 (file)
--- a/daemon/zero.c
+++ b/daemon/zero.c
@@ -28,13 +28,11 @@
 #include "actions.h"
 
 int
-do_zero (char *device)
+do_zero (const char *device)
 {
   int fd, i;
   char buf[4096];
 
-  IS_DEVICE (device, -1);
-
   fd = open (device, O_WRONLY);
   if (fd == -1) {
     reply_with_perror ("%s", device);
@@ -43,10 +41,20 @@ do_zero (char *device)
 
   memset (buf, 0, sizeof buf);
 
+  int err = 0;
+  int saved_errno = 0;
   for (i = 0; i < 32; ++i)
-    (void) write (fd, buf, sizeof buf);
-
-  close (fd);
+    if (write (fd, buf, sizeof buf) != sizeof buf) {
+      saved_errno = errno;
+      err = -1;
+    }
+
+  if (close (fd) && saved_errno == 0) {
+    saved_errno = errno;
+    err = -1;
+  }
 
-  return 0;
+  if (saved_errno)
+    errno = saved_errno;
+  return err;
 }