[Qemu-devel] [PATCH 18/22] qcow2-dirty-bitmaps: disallow stroing bitmap to other bs

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

Check, that bitmap is stored to the owning bs.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/dirty-bitmap.c         | 12 ++++++++++++
 block/qcow2-dirty-bitmap.c   |  5 +++++
 include/block/dirty-bitmap.h |  2 ++
 3 files changed, 19 insertions(+)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index 87ee4d7..9625f4a 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -485,3 +485,15 @@ BdrvDirtyBitmap *bdrv_load_dirty_bitmap(BlockDriverState *bs, const char *name,
     }
     return NULL;
 }
+
+bool bdrv_has_dirty_bitmap(BlockDriverState *bs, const BdrvDirtyBitmap *bitmap)
+{
+    BdrvDirtyBitmap *bm, *next;
+    QLIST_FOREACH_SAFE(bm, &bs->dirty_bitmaps, list, next) {
+        if (bm == bitmap) {
+            return true;
+        }
+    }
+
+    return false;
+}
diff --git a/block/qcow2-dirty-bitmap.c b/block/qcow2-dirty-bitmap.c
index f210fee..70c6e36 100644
--- a/block/qcow2-dirty-bitmap.c
+++ b/block/qcow2-dirty-bitmap.c
@@ -757,6 +757,11 @@ void qcow2_bitmap_store(BlockDriverState *bs,
     uint64_t size = bdrv_dirty_bitmap_size(bitmap);
     int granularity = bdrv_dirty_bitmap_granularity(bitmap);
 
+    if (!bdrv_has_dirty_bitmap(bs, bitmap)) {
+        error_setg(errp, "Can't store bitmap to the other node.");
+        return;
+    }
+
     /* find/create dirty bitmap */
     bm = find_bitmap_by_name(bs, name);
     if (bm == NULL) {
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 66ba3f8..af76ac1 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -62,4 +62,6 @@ void bdrv_finalize_persistent_dirty_bitmaps(BlockDriverState *bs);
 BdrvDirtyBitmap *bdrv_load_dirty_bitmap(BlockDriverState *bs, const char *name,
                                         Error **errp);
 
+bool bdrv_has_dirty_bitmap(BlockDriverState *bs, const BdrvDirtyBitmap *bitmap);
+
 #endif
-- 
1.8.3.1