block: Add BdrvChildRole.get_parent_desc()
For meaningful error messages in the permission system, we need to get
some human-readable description of the parent of a BdrvChild.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Acked-by: Fam Zheng <famz@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index e00d0f4..3177b9f 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -452,6 +452,12 @@
* name), or NULL if the parent can't provide a better name. */
const char* (*get_name)(BdrvChild *child);
+ /* Returns a malloced string that describes the parent of the child for a
+ * human reader. This could be a node-name, BlockBackend name, qdev ID or
+ * QOM path of the device owning the BlockBackend, job type and ID etc. The
+ * caller is responsible for freeing the memory. */
+ char* (*get_parent_desc)(BdrvChild *child);
+
/*
* If this pair of functions is implemented, the parent doesn't issue new
* requests after returning from .drained_begin() until .drained_end() is
