block: Make bdrv_states public

When inserting a BDS tree into a BB, we will need to add the root BDS to
this list. Since we will want to do that in the blockdev-insert-medium
implementation in blockdev.c, we will need access to it there.

This patch is not exactly elegant, but bdrv_states will be removed in
the future anyway because we no longer need it since we have BBs.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -73,8 +73,7 @@ struct BdrvDirtyBitmap {
 
 #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
 
-static QTAILQ_HEAD(, BlockDriverState) bdrv_states =
-    QTAILQ_HEAD_INITIALIZER(bdrv_states);
+struct BdrvStates bdrv_states = QTAILQ_HEAD_INITIALIZER(bdrv_states);
 
 static QTAILQ_HEAD(, BlockDriverState) graph_bdrv_states =
     QTAILQ_HEAD_INITIALIZER(graph_bdrv_states);

include/block/block_int.h

@@ -473,6 +473,8 @@ extern BlockDriver bdrv_file;
 extern BlockDriver bdrv_raw;
 extern BlockDriver bdrv_qcow2;
 
+extern QTAILQ_HEAD(BdrvStates, BlockDriverState) bdrv_states;
+
 /**
  * bdrv_setup_io_funcs:
  *