Re: [Libguestfs] [PATCH] mltools, options: support --allow-discards when decrypting LUKS devices

Richard W.M. Jones
Wed, 22 Jan 2020 09:50:34 -0000

On Wed, Jan 22, 2020 at 10:14:38AM +0100, Jan Synacek
wrote:
> -val inspect_decrypt : Guestfs.guestfs -> key_store -> unit
> +val inspect_decrypt : Guestfs.guestfs -> ?allow_discards:bool ->
key_store -> unit
>
>  (** Simple implementation of decryption: look for any [crypto_LUKS]
>      partitions and decrypt them, then rescan for VGs.  This only works
>      for Fedora whole-disk encryption. *)

Documentation here needs a short explanation of what the
new allow_discards parameter does, and what the default is.

> diff --git a/options/decrypt.c b/options/decrypt.c
> index 683cf5e..0f24a7a 100644
> --- a/options/decrypt.c
> +++ b/options/decrypt.c
> @@ -71,7 +71,7 @@ make_mapname (const char *device, char *mapname, size_t
len)
>   * encryption schemes.
>   */
>  void
> -inspect_do_decrypt (guestfs_h *g, struct key_store *ks)
> +inspect_do_decrypt (guestfs_h *g, struct key_store *ks, int allowdiscards)
>  {
>    CLEANUP_FREE_STRING_LIST char **partitions = guestfs_list_partitions
(g);
>    if (partitions == NULL)
> @@ -101,7 +101,8 @@ inspect_do_decrypt (guestfs_h *g, struct key_store *ks)
>           * is set?  This might break 'mount_ro'.
>           */
>          guestfs_push_error_handler (g, NULL, NULL);
> -        r = guestfs_luks_open (g, partitions[i], keys[j], mapname);
> +        r = guestfs_luks_open_opts (g, partitions[i], keys[j], mapname,
> +			            GUESTFS_LUKS_OPEN_OPTS_ALLOWDISCARDS, allowdiscards, -1);

Obviously this means this patch depends on the API change :-)

[...]
>  /* in decrypt.c */
> -extern void inspect_do_decrypt (guestfs_h *g, struct key_store *ks);
> +extern void inspect_do_decrypt (guestfs_h *g, struct key_store *ks, int
allowdiscards);

> -  inspect_do_decrypt (g, ks);
> +  inspect_do_decrypt (g, ks, 0);

Kind of wonder if we want to use a C bool here instead of an int.

Rich.

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