block: Convert bs->backing_hd to BdrvChild
This is the final step in converting all of the BlockDriverState
pointers that block drivers use to BdrvChild.
After this patch, bs->children contains the full list of child nodes
that are referenced by a given BDS, and these children are only
referenced through BdrvChild, so that updating the pointer in there is
enough for changing edges in the graph.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
diff --git a/include/block/block_int.h b/include/block/block_int.h
index 98936c9..90971c0 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -378,8 +378,7 @@
QDict *full_open_options;
char exact_filename[PATH_MAX];
- BlockDriverState *backing_hd;
- BdrvChild *backing_child;
+ BdrvChild *backing;
BdrvChild *file;
NotifierList close_notifiers;
@@ -458,6 +457,11 @@
NotifierWithReturn write_threshold_notifier;
};
+static inline BlockDriverState *backing_bs(BlockDriverState *bs)
+{
+ return bs->backing ? bs->backing->bs : NULL;
+}
+
/* Essential block drivers which must always be statically linked into qemu, and
* which therefore can be accessed without using bdrv_find_format() */
@@ -496,7 +500,7 @@
*
* May be called from .bdrv_detach_aio_context() to detach children from the
* current #AioContext. This is only needed by block drivers that manage their
- * own children. Both ->file and ->backing_hd are automatically handled and
+ * own children. Both ->file and ->backing are automatically handled and
* block drivers should not call this function on them explicitly.
*/
void bdrv_detach_aio_context(BlockDriverState *bs);
@@ -506,7 +510,7 @@
*
* May be called from .bdrv_attach_aio_context() to attach children to the new
* #AioContext. This is only needed by block drivers that manage their own
- * children. Both ->file and ->backing_hd are automatically handled and block
+ * children. Both ->file and ->backing are automatically handled and block
* drivers should not call this function on them explicitly.
*/
void bdrv_attach_aio_context(BlockDriverState *bs,
