block: Add BlockBackendRootState

This structure will store some of the state of the root BDS if the BDS
tree is removed, so that state can be restored once a new BDS tree is
inserted.

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

3 files changed, 13 insertions, 0 deletions

diff --git a/include/block/block_int.h b/include/block/block_int.h
index 87215f8..7b76eea 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -26,6 +26,7 @@
 
 #include "block/accounting.h"
 #include "block/block.h"
+#include "block/throttle-groups.h"
 #include "qemu/option.h"
 #include "qemu/queue.h"
 #include "qemu/coroutine.h"
@@ -449,6 +450,15 @@ struct BlockDriverState {
     NotifierWithReturn write_threshold_notifier;
 };
 
+struct BlockBackendRootState {
+    int open_flags;
+    bool read_only;
+    BlockdevDetectZeroesOptions detect_zeroes;
+
+    char *throttle_group;
+    ThrottleState *throttle_state;
+};
+
 static inline BlockDriverState *backing_bs(BlockDriverState *bs)
 {
     return bs->backing ? bs->backing->bs : NULL;
diff --git a/include/qemu/typedefs.h b/include/qemu/typedefs.h
index d4a8f7a..d961362 100644
--- a/include/qemu/typedefs.h
+++ b/include/qemu/typedefs.h
@@ -11,6 +11,7 @@ typedef struct AddressSpace AddressSpace;
 typedef struct AioContext AioContext;
 typedef struct AudioState AudioState;
 typedef struct BlockBackend BlockBackend;
+typedef struct BlockBackendRootState BlockBackendRootState;
 typedef struct BlockDriverState BlockDriverState;
 typedef struct BusClass BusClass;
 typedef struct BusState BusState;
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index eafcef0..52e35a1 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -163,6 +163,8 @@ void blk_add_close_notifier(BlockBackend *blk, Notifier *notify);
 void blk_io_plug(BlockBackend *blk);
 void blk_io_unplug(BlockBackend *blk);
 BlockAcctStats *blk_get_stats(BlockBackend *blk);
+BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
+void blk_update_root_state(BlockBackend *blk);
 
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
                   BlockCompletionFunc *cb, void *opaque);