[libvirt] [PATCH] storage: util: Properly ignore errors when backing volume is inaccessible

[Jiri Denemark]

On Tue, Jan 30, 2018 at 11:50:31 +0100, Peter Krempa wrote:
> Commit 000e9504559 tried to fix improper bracketing when refreshing disk
> volume stats for a backing volume. Unfortunately the condition is still
> wrong as in cases as the backing store being inaccessible
> storageBackendUpdateVolTargetInfo returns -2 if instructed to ignore
> errors. The condition does not take this into account.
> 
> Dumping XML of a volume which has inacessible backing store would then
> result into:
> 
>  # virsh vol-dumpxml http.img --pool default
>  error: An error occurred, but the cause is unknown
> 
> Properly ignore -2 for backing volumes.
> 
> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1540022
> ---
>  src/storage/storage_util.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/storage/storage_util.c b/src/storage/storage_util.c
> index 9e1b63a436..61a87b37b6 100644
> --- a/src/storage/storage_util.c
> +++ b/src/storage/storage_util.c
> @@ -1918,7 +1918,7 @@ virStorageBackendUpdateVolInfo(virStorageVolDefPtr vol,
>                                                   withBlockVolFormat,
>                                                   VIR_STORAGE_VOL_OPEN_DEFAULT |
>                                                   VIR_STORAGE_VOL_OPEN_NOERROR,
> -                                                 readflags)) < 0)
> +                                                 readflags)) == -1)
>          return ret;
> 
>      return 0;

Reviewed-by: Jiri Denemark <jdenemar at redhat.com>