[Libguestfs] [PATCH 1/2] inspection: Handle MD devices in fstab

[Richard W.M. Jones]

On Tue, Nov 29, 2011 at 12:18:46PM +0000, Matthew Booth wrote:
> On 11/29/2011 08:58 AM, Richard W.M. Jones wrote:
> >On Fri, Nov 25, 2011 at 05:32:42PM +0000, Matthew Booth wrote:
> >>  static int
> >>  check_fstab (guestfs_h *g, struct inspect_fs *fs)
> >>  {
> >>+  /* Generate a map of MD device paths listed in /etc/mdadm.conf to MD device
> >>+   * paths in the guestfs appliance */
> >>+  Hash_table *md_map;
> >>+  if (map_md_devices (g,&md_map) == -1) return -1;
> >
> >I'm pretty sure this is still wrong ...
> >
> >If /etc/mdadm.conf doesn't exist(?) or isn't parsable, map_md_devices
> >returns -1.  It doesn't set error(), which could be bad, since it
> >returns -1 from check_fstab which requires you to set error().
> 
> No, it doesn't. If augeas can't parse /etc/mdadm.conf, the match
> will return an empty list, not an error. In that case it follows
> this code path:
> 
>   if (matches[0] == NULL) {
>     debug(g, "Appliance has MD devices, but augeas returned no array
> matches "
>              "in mdadm.conf");
>     guestfs___free_string_list(matches);
>     return 0;
>   }
> 
> It returns 0, not -1, and the map has been explicitly set to NULL above.
> 
> >What it _should_ do is not to call error(), and allow md_map to be
> >NULL, not returning from check_fstab, but continuing.  Then the other
> >functions have to be changed to deal with md_map being NULL.
> >
> >Try creating some guests with /etc/mdadm.conf being
> >bogus/empty/missing and make sure that inspection can properly handle
> >them without an error.
> 
> I already specifically tested that.

OK, in that case ACK.

I'm going to test it a bit here too.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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