Re: [PATCH] migration: Truncate state file in xen-save-devices-state

[Dr. David Alan Gilbert]

* Dov Murik (dovmurik@linux.vnet.ibm.com) wrote:
> When running the xen-save-devices-state QMP command, if the filename
> already exists it will be truncated before dumping the devices' state
> into it.
> 
> Signed-off-by: Dov Murik <dovmurik@linux.vnet.ibm.com>
> ---

OK, that looks fine to me, so:

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

> 
> Note that I found the above issue while trying to debug
> xen-load-devices-state which simply fails (prints "Configuration section
> missing" to stderr) directly after xen-save-devices-state (in the same
> VM).  I wonder if I should file a bug report as-is or investigate some
> more.  Advice welcome.

I don't try the xen-* commands normally; I've cc'ing in Stefano and
Anthony.

Dave

> 
> -Dov
> 
> ---
>  migration/savevm.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index 304d98ff78..e1b26672cc 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -2803,7 +2803,8 @@ void qmp_xen_save_devices_state(const char *filename, 
> bool has_live, bool live,
>      vm_stop(RUN_STATE_SAVE_VM);
>      global_state_store_running();
>  
> -    ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT, 0660, 
> errp);
> +    ioc = qio_channel_file_new_path(filename, O_WRONLY | O_CREAT | O_TRUNC,
> +                                    0660, errp);
>      if (!ioc) {
>          goto the_end;
>      }
> -- 
> 2.20.1
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK