NEW API: add a new api wipefs

Add the new api wipefs to erase the filesystem signatures
on a device but now erase any data.

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>

TODO

@@ -318,8 +318,6 @@ Display the structure of an image file as a PS.
 Greater use of blkid / libblkid
 -------------------------------
 
-guestfs_zero should use wipefs.  See wipefs(8).
-
 There are various useful functions in libblkid for listing partitions,
 devices etc which we are essentially duplicating in the daemon.  It
 would make more sense to just use libblkid for this.

daemon/zero.c

@@ -72,6 +72,30 @@ do_zero (const char *device)
   return 0;
 }
 
+int
+optgroup_wipefs_available (void)
+{
+  return prog_exists ("wipefs");
+}
+
+int
+do_wipefs (const char *device)
+{
+  int r;
+  char *err = NULL;
+
+  const char *wipefs[] = {"wipefs", "-a", device, NULL};
+  r = commandv (NULL, &err, wipefs);
+  if (r == -1) {
+    reply_with_error ("%s", err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+  return 0;
+}
+
 int
 do_zero_device (const char *device)
 {

generator/generator_actions.ml

@@ -6660,6 +6660,22 @@ List the files in C<directory> in the format of 'ls -laZ'.
 This command is mostly useful for interactive sessions.  It
 is I<not> intended that you try to parse the output string.");
 
+  ("wipefs", (RErr, [Device "device"], []), 306, [Optional "wipefs"],
+   [InitBasicFSonLVM, Always, TestRun (
+      [["wipefs"; "/dev/VG/LV"]])],
+   "wipe a filesystem signature from a device",
+   "\
+This command erases filesystem or RAID signatures from
+the specified C<device> to make the filesystem invisible to libblkid.
+
+This does not erase the filesystem itself nor any other data from the
+C<device>.
+
+Compare with C<guestfs_zero> which zeroes the first few blocks of a
+device.
+
+=back");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions

src/MAX_PROC_NR

@@ -1 +1 @@
-305
+306