block/dirty-bitmap: add recording and busy properties

The current API allows us to report a single status, which we've defined as:

Frozen: has a successor, treated as qmp_locked, may or may not be enabled.
Locked: no successor, qmp_locked. may or may not be enabled.
Disabled: Not frozen or locked, disabled.
Active: Not frozen, locked, or disabled.

The problem is that both "Frozen" and "Locked" mean nearly the same thing,
and that both of them do not intuit whether they are recording guest writes
or not.

This patch deprecates that status field and introduces two orthogonal
properties instead to replace it.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190223000614.13894-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index c6d4acebfa..101383b3af 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -226,6 +226,13 @@ DirtyBitmapStatus bdrv_dirty_bitmap_status(BdrvDirtyBitmap *bitmap)
     }
 }
 
+/* Called with BQL taken.  */
+static bool bdrv_dirty_bitmap_recording(BdrvDirtyBitmap *bitmap)
+{
+    return !bitmap->disabled || (bitmap->successor &&
+                                 !bitmap->successor->disabled);
+}
+
 /**
  * Create a successor bitmap destined to replace this bitmap after an operation.
  * Requires that the bitmap is not frozen and has no successor.
@@ -448,6 +455,8 @@ BlockDirtyInfoList *bdrv_query_dirty_bitmaps(BlockDriverState *bs)
         info->has_name = !!bm->name;
         info->name = g_strdup(bm->name);
         info->status = bdrv_dirty_bitmap_status(bm);
+        info->recording = bdrv_dirty_bitmap_recording(bm);
+        info->busy = bdrv_dirty_bitmap_user_locked(bm);
         info->persistent = bm->persistent;
         entry->value = info;
         *plist = entry;