dma-buf: warn about containers in dma_resv object

Drivers should not add containers as shared fences to the dma_resv
object, instead each fence should be added individually.

Signed-off-by: Christian König <[e-mail]>
Reviewed-by: Daniel Vetter <[e-mail]>
Reviewed-by: Thomas Hellström <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/dma-buf/dma-resv.c

···
 
 	dma_resv_assert_held(obj);
 
+	/* Drivers should not add containers here, instead add each fence
+	 * individually.
+	 */
+	WARN_ON(dma_fence_is_container(fence));
+
 	fobj = dma_resv_shared_list(obj);
 	count = fobj->shared_count;