On Thu, Oct 15, 2020 at 09:46:29PM +0000, Satya Tangirala wrote:

+/**
+ * blk_ksm_init_passthrough() - Init a passthrough keyslot manager
+ * @ksm: The keyslot manager to init
+ *
+ * Initialize a passthrough keyslot manager.
+ * Called by e.g. storage drivers to set up a keyslot manager in their
+ * request_queue, when the storage driver wants to manage its keys by itself.
+ * This is useful for inline encryption hardware that doesn't have the concept
+ * of keyslots, and for layered devices.
+ *
+ * See blk_ksm_init() for more details about the parameters.
+ */
+void blk_ksm_init_passthrough(struct blk_keyslot_manager *ksm)
+{
+	memset(ksm, 0, sizeof(*ksm));
+	init_rwsem(&ksm->lock);
+}
+EXPORT_SYMBOL_GPL(blk_ksm_init_passthrough);

The last paragraph of the comment ("See blk_ksm_init() for more details about
the parameters.") isn't useful and should be removed.

Otherwise this patch looks fine.  You can add:

Reviewed-by: Eric Biggers <redacted>

- Eric