Re: [Qemu-devel] [PATCH v2 3/6] migration: Check field save returns

[Peter Xu]

On Mon, Sep 25, 2017 at 12:29:14PM +0100, Dr. David Alan Gilbert (git) wrote:
> From: "Dr. David Alan Gilbert" <address@hidden>
> 
> Check the return values from vmstate_save_state for fields and also the
> return values from 'put' for fields that use that.
> 
> Signed-off-by: Dr. David Alan Gilbert <address@hidden>
> ---
>  migration/vmstate.c | 15 ++++++++++++---
>  1 file changed, 12 insertions(+), 3 deletions(-)
> 
> diff --git a/migration/vmstate.c b/migration/vmstate.c
> index ae8abd3c32..848e8448c6 100644
> --- a/migration/vmstate.c
> +++ b/migration/vmstate.c
> @@ -347,6 +347,7 @@ int vmstate_save_state(QEMUFile *f, const 
> VMStateDescription *vmsd,
>              }
>              for (i = 0; i < n_elems; i++) {
>                  void *curr_elem = first_elem + size * i;
> +                ret = 0;
>  
>                  vmsd_desc_field_start(vmsd, vmdesc_loop, field, i, n_elems);
>                  old_offset = qemu_ftell_fast(f);
> @@ -357,11 +358,19 @@ int vmstate_save_state(QEMUFile *f, const 
> VMStateDescription *vmsd,
>                  if (!curr_elem && size) {
>                      /* if null pointer write placeholder and do not follow */
>                      assert(field->flags & VMS_ARRAY_OF_POINTER);
> -                    vmstate_info_nullptr.put(f, curr_elem, size, NULL, NULL);
> +                    ret = vmstate_info_nullptr.put(f, curr_elem, size, NULL,
> +                                                   NULL);
>                  } else if (field->flags & VMS_STRUCT) {
> -                    vmstate_save_state(f, field->vmsd, curr_elem, 
> vmdesc_loop);
> +                    ret = vmstate_save_state(f, field->vmsd, curr_elem,
> +                                             vmdesc_loop);
>                  } else {
> -                    field->info->put(f, curr_elem, size, field, vmdesc_loop);
> +                    ret = field->info->put(f, curr_elem, size, field,
> +                                     vmdesc_loop);
> +                }
> +                if (ret) {
> +                    error_report("Save of field %s/%s failed",
> +                                 vmsd->name, field->name);

I would prefer to prefix the function name (also there is one
error_report in previous patch) but that's optional.

Reviewed-by: Peter Xu <address@hidden>

> +                    return ret;
>                  }
>  
>                  written_bytes = qemu_ftell_fast(f) - old_offset;
> -- 
> 2.13.5
> 

-- 
Peter Xu