Libguestfs - Aug 2017 - [PATCH] resize: handle empty UUIDs for swap partitions (RHBZ#1482737)

Avoid passing an empty UUID string to mkswap, which mkswap does not
accept (correctly) as new UUID.

In addition, print a warning when the UUID of a swap partition changed,
since it may require manual fixups in the guest.
---
 resize/resize.ml | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/resize/resize.ml b/resize/resize.ml
index fbb2d021b..48c75161d 100644
--- a/resize/resize.ml
+++ b/resize/resize.ml
@@ -1347,9 +1347,20 @@ read the man page virt-resize(1).
         (* Rebuild the swap using the UUID and label of the existing
          * swap partition.
          *)
-        let uuid = g#vfs_uuid target in
+        let orig_uuid = g#vfs_uuid target in
+        let uuid +          match orig_uuid with
+          | "" -> None
+          | uuid -> Some uuid in
         let label = g#vfs_label target in
-        g#mkswap ~uuid ~label target
+        g#mkswap ?uuid ~label target;
+        (* Check whether the UUID could be set, and warn in case it
+         * changed.
+         *)
+        let new_uuid = g#vfs_uuid target in
+        if new_uuid <> orig_uuid then
+          warning (f_"UUID in swap partition %s changed from ‘%s’ to
‘%s’")
+            target orig_uuid new_uuid;
     in
 
     (* Expand partition content as required. *)
-- 
2.13.5

On Fri, Aug 18, 2017 at 10:56:12AM +0200, Pino Toscano
wrote:
> Avoid passing an empty UUID string to mkswap, which mkswap does not
> accept (correctly) as new UUID.
> 
> In addition, print a warning when the UUID of a swap partition changed,
> since it may require manual fixups in the guest.
> ---
>  resize/resize.ml | 15 +++++++++++++--
>  1 file changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/resize/resize.ml b/resize/resize.ml
> index fbb2d021b..48c75161d 100644
> --- a/resize/resize.ml
> +++ b/resize/resize.ml
> @@ -1347,9 +1347,20 @@ read the man page virt-resize(1).
>          (* Rebuild the swap using the UUID and label of the existing
>           * swap partition.
>           *)
> -        let uuid = g#vfs_uuid target in
> +        let orig_uuid = g#vfs_uuid target in
> +        let uuid > +          match orig_uuid with
> +          | "" -> None
> +          | uuid -> Some uuid in
>          let label = g#vfs_label target in
> -        g#mkswap ~uuid ~label target
> +        g#mkswap ?uuid ~label target;
> +        (* Check whether the UUID could be set, and warn in case it
> +         * changed.
> +         *)
> +        let new_uuid = g#vfs_uuid target in
> +        if new_uuid <> orig_uuid then
> +          warning (f_"UUID in swap partition %s changed from ‘%s’ to
‘%s’")
> +            target orig_uuid new_uuid;
>      in
ACK

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
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