[Qemu-devel] [PATCH v21 17/30] block: introduce persistent dirty bitmaps

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

New field BdrvDirtyBitmap.persistent means, that bitmap should be saved
by format driver in .bdrv_close and .bdrv_inactivate. No format driver
supports it for now.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block/dirty-bitmap.c         | 26 ++++++++++++++++++++++++++
 block/qcow2-bitmap.c         |  1 +
 include/block/dirty-bitmap.h |  5 +++++
 3 files changed, 32 insertions(+)

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index da7d1ec867..07779a0f89 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -53,6 +53,7 @@ struct BdrvDirtyBitmap {
                                    this flag is set. */
     bool autoload;              /* For persistent bitmaps: bitmap must be
                                    autoloaded on image opening */
+    bool persistent;            /* bitmap must be saved to owner disk image */
     QLIST_ENTRY(BdrvDirtyBitmap) list;
 };
 
@@ -79,6 +80,7 @@ void bdrv_dirty_bitmap_make_anon(BdrvDirtyBitmap *bitmap)
     assert(!bdrv_dirty_bitmap_frozen(bitmap));
     g_free(bitmap->name);
     bitmap->name = NULL;
+    bitmap->persistent = false;
     bitmap->autoload = false;
 }
 
@@ -248,6 +250,8 @@ BdrvDirtyBitmap *bdrv_dirty_bitmap_abdicate(BlockDriverState *bs,
     bitmap->name = NULL;
     successor->name = name;
     bitmap->successor = NULL;
+    successor->persistent = bitmap->persistent;
+    bitmap->persistent = false;
     successor->autoload = bitmap->autoload;
     bitmap->autoload = false;
     bdrv_release_dirty_bitmap(bs, bitmap);
@@ -588,3 +592,25 @@ bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap)
 {
     return bitmap->autoload;
 }
+
+void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap, bool persistent)
+{
+    bitmap->persistent = persistent;
+}
+
+bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap)
+{
+    return bitmap->persistent;
+}
+
+bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs)
+{
+    BdrvDirtyBitmap *bm;
+    QLIST_FOREACH(bm, &bs->dirty_bitmaps, list) {
+        if (bm->persistent && !bm->readonly) {
+            return true;
+        }
+    }
+
+    return false;
+}
diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index ee6d8f75a9..52e4616b8c 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -794,6 +794,7 @@ bool qcow2_load_autoloading_dirty_bitmaps(BlockDriverState *bs, Error **errp)
                 goto fail;
             }
 
+            bdrv_dirty_bitmap_set_persistance(bitmap, true);
             bdrv_dirty_bitmap_set_autoload(bitmap, true);
             bm->flags |= BME_FLAG_IN_USE;
             created_dirty_bitmaps =
diff --git a/include/block/dirty-bitmap.h b/include/block/dirty-bitmap.h
index 9416f9233f..721f025850 100644
--- a/include/block/dirty-bitmap.h
+++ b/include/block/dirty-bitmap.h
@@ -82,4 +82,9 @@ bool bdrv_has_readonly_bitmaps(BlockDriverState *bs);
 void bdrv_dirty_bitmap_set_autoload(BdrvDirtyBitmap *bitmap, bool autoload);
 bool bdrv_dirty_bitmap_get_autoload(const BdrvDirtyBitmap *bitmap);
 
+void bdrv_dirty_bitmap_set_persistance(BdrvDirtyBitmap *bitmap,
+                                                bool persistent);
+bool bdrv_dirty_bitmap_get_persistance(BdrvDirtyBitmap *bitmap);
+bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs);
+
 #endif
-- 
2.11.1