Re: [PATCH] PM: hibernate: Drain trailing zero pages on userspace restore

[Alberto Garcia <berto@igalia.com>]

On Mon, Mar 09, 2026 at 01:12:50AM +0100, Alberto Garcia wrote:
>  	case SNAPSHOT_ATOMIC_RESTORE:
> +		/*
> +		 * We need to call snapshot_write_next() one last time
> +		 * before finalizing in order to process any trailing
> +		 * zero pages.
> +		 */
> +		error = snapshot_write_next(&data->handle);
> +		if (error < 0)
> +			break;

I realized that this patch assumes that userspace calls
SNAPSHOT_ATOMIC_RESTORE only after having written the full image,
but if that happens earlier I'm not sure that it's safe to call
snapshot_write_next().

An alternative solution would be to do it at the beginning of
snapshot_write_finalize() if handle->cur > nr_meta_pages + 1.

If you think that's a better idea I can send v2 of the patch.

Regards,

Berto