dirty-bitmap: Expose persistent flag to 'query-block'

Since qemu currently doesn't flush persistent bitmaps to disk until
shutdown (which might be MUCH later), it's useful if 'query-block'
at least shows WHICH bitmaps will (eventually) make it to persistent
storage.  Update affected iotests.
Signed-off-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NJohn Snow <jsnow@redhat.com>
Message-id: 20190204210512.27458-1-eblake@redhat.com
Signed-off-by: NJohn Snow <jsnow@redhat.com>

block/dirty-bitmap.c

@@ -440,6 +440,7 @@ 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->persistent = bm->persistent;
         entry->value = info;
         *plist = entry;
         plist = &entry->next;

qapi/block-core.json

@@ -450,11 +450,14 @@
 #
 # @status: current status of the dirty bitmap (since 2.4)
 #
+# @persistent: true if the bitmap will eventually be flushed to persistent
+#              storage (since 4.0)
+#
 # Since: 1.3
 ##
 { 'struct': 'BlockDirtyInfo',
   'data': {'*name': 'str', 'count': 'int', 'granularity': 'uint32',
-           'status': 'DirtyBitmapStatus'} }
+           'status': 'DirtyBitmapStatus', 'persistent': 'bool' } }
 
 ##
 # @Qcow2BitmapInfoFlags:

tests/qemu-iotests/124

@@ -350,6 +350,7 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
         self.assert_qmp(result, 'return[0]/dirty-bitmaps[0]/count', 458752)
         self.assert_qmp(result, 'return[0]/dirty-bitmaps[0]/granularity', 65536)
         self.assert_qmp(result, 'return[0]/dirty-bitmaps[0]/status', 'active')
+        self.assert_qmp(result, 'return[0]/dirty-bitmaps[0]/persistent', False)
 
         # Prepare a cluster_size=128k backup target without a backing file.
         (target, _) = bitmap0.new_target()

tests/qemu-iotests/236.out

@@ -25,12 +25,14 @@ write -P0xcd 0x3ff0000 64k
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapB",
+        "persistent": false,
         "status": "active"
       },
       {
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapA",
+        "persistent": false,
         "status": "active"
       }
     ]
@@ -85,12 +87,14 @@ write -P0xcd 0x3ff0000 64k
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapB",
+        "persistent": false,
         "status": "active"
       },
       {
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapA",
+        "persistent": false,
         "status": "active"
       }
     ]
@@ -183,18 +187,21 @@ write -P0xea 0x3fe0000 64k
         "count": 393216,
         "granularity": 65536,
         "name": "bitmapC",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapB",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 458752,
         "granularity": 65536,
         "name": "bitmapA",
+        "persistent": false,
         "status": "disabled"
       }
     ]
@@ -247,18 +254,21 @@ write -P0xea 0x3fe0000 64k
         "count": 393216,
         "granularity": 65536,
         "name": "bitmapC",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapB",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 458752,
         "granularity": 65536,
         "name": "bitmapA",
+        "persistent": false,
         "status": "disabled"
       }
     ]
@@ -304,24 +314,28 @@ write -P0xea 0x3fe0000 64k
         "count": 458752,
         "granularity": 65536,
         "name": "bitmapD",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 393216,
         "granularity": 65536,
         "name": "bitmapC",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 262144,
         "granularity": 65536,
         "name": "bitmapB",
+        "persistent": false,
         "status": "disabled"
       },
       {
         "count": 458752,
         "granularity": 65536,
         "name": "bitmapA",
+        "persistent": false,
         "status": "disabled"
       }
     ]