New API: guestfs_shutdown: Cleanly shutdown the backend.

The new API splits orderly close into a two-step process:

  if (guestfs_shutdown (g) == -1) {
    /* handle the error, eg. qemu error */
  }
  guestfs_close (g);

Note that the explicit shutdown step is only necessary in the case
where you have made changes to the disk image and want to handle write
errors.  Read the documentation for further information.

This change also:

 - deprecates guestfs_kill_subprocess

 - turns guestfs_kill_subprocess into the same as guestfs_shutdown

 - changes guestfish and other tools to call shutdown + close
   where necessary (not for read-only tools)

 - updates documentation

 - updates examples

1 files changed, 3 insertions, 1 deletions

diff --git a/rescue/virt-rescue.c b/rescue/virt-rescue.c
index 684baeb9..f1f8d85c 100644
--- a/rescue/virt-rescue.c
+++ b/rescue/virt-rescue.c
@@ -341,7 +341,9 @@ main (int argc, char *argv[])
    */
   guestfs_set_error_handler (g, NULL, NULL);
 
-  /* We expect launch to fail, so ignore the return value. */
+  /* We expect launch to fail, so ignore the return value, and don't
+   * bother with explicit guestfs_shutdown either.
+   */
   ignore_value (guestfs_launch (g));
 
   guestfs_close (g);