On (01/08/18 14:51), Yu Zhao wrote:
[..]
> int zpool_shrink(struct zpool *zpool, unsigned int pages,
> unsigned int *reclaimed)
> {
> - return zpool->driver->shrink(zpool->pool, pages, reclaimed);
> + return zpool_shrinkable(zpool) ?
> + zpool->driver->shrink(zpool->pool, pages, reclaimed) : -EINVAL;
> }
>
> /**
> @@ -355,6 +356,20 @@ u64 zpool_get_total_size(struct zpool *zpool)
> return zpool->driver->total_size(zpool->pool);
> }
>
> +/**
> + * zpool_shrinkable() - Test if zpool is shrinkable
> + * @pool The zpool to test
> + *
> + * Zpool is only shrinkable when it's created with struct
> + * zpool_ops.evict and its driver implements struct zpool_driver.shrink.
> + *
> + * Returns: true if shrinkable; false otherwise.
> + */
> +bool zpool_shrinkable(struct zpool *zpool)
> +{
> + return zpool->ops && zpool->ops->evict && zpool->driver->shrink;
> +}
just a side note,
it might be a bit confusing and maybe there is a better
name for it. zsmalloc is shrinkable (we register a shrinker
callback), but not in the way zpool defines it.
-ss
