commit b0f455599d0f092abc11aa3daba693be1453d29a
author John Snow <jsnow@redhat.com> Tue Mar 12 12:05:49 2019 -0400
committer John Snow <jsnow@redhat.com> Tue Mar 12 12:05:49 2019 -0400
tree dda80da29ffbaccdab7aaea1fb45a5fdcbdc47ce
parent c61b198b63219b489908c87371acae8c986ce4d3

block/dirty-bitmaps: add inconsistent bit

Add an inconsistent bit to dirty-bitmaps that allows us to report a bitmap as
persistent but potentially inconsistent, i.e. if we find bitmaps on a qcow2
that have been marked as "in use".

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: 20190301191545.8728-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

block/dirty-bitmap.c

diff --git a/block/dirty-bitmap.c b/block/dirty-bitmap.c
index e090237..096c1b7 100644
--- a/block/dirty-bitmap.c
+++ b/block/dirty-bitmap.c
@@ -46,6 +46,9 @@
                                    and this bitmap must remain unchanged while
                                    this flag is set. */
     bool persistent;            /* bitmap must be saved to owner disk image */
+    bool inconsistent;          /* bitmap is persistent, but inconsistent.
+                                   It cannot be used at all in any way, except
+                                   a QMP user can remove it. */
     bool migration;             /* Bitmap is selected for migration, it should
                                    not be stored on the next inactivation
                                    (persistent flag doesn't matter until next
@@ -465,6 +468,8 @@
         info->recording = bdrv_dirty_bitmap_recording(bm);
         info->busy = bdrv_dirty_bitmap_busy(bm);
         info->persistent = bm->persistent;
+        info->has_inconsistent = bm->inconsistent;
+        info->inconsistent = bm->inconsistent;
         entry->value = info;
         *plist = entry;
         plist = &entry->next;
@@ -713,6 +718,16 @@
 }
 
 /* Called with BQL taken. */
+void bdrv_dirty_bitmap_set_inconsistent(BdrvDirtyBitmap *bitmap)
+{
+    qemu_mutex_lock(bitmap->mutex);
+    assert(bitmap->persistent == true);
+    bitmap->inconsistent = true;
+    bitmap->disabled = true;
+    qemu_mutex_unlock(bitmap->mutex);
+}
+
+/* Called with BQL taken. */
 void bdrv_dirty_bitmap_set_migration(BdrvDirtyBitmap *bitmap, bool migration)
 {
     qemu_mutex_lock(bitmap->mutex);
@@ -725,6 +740,11 @@
     return bitmap->persistent && !bitmap->migration;
 }
 
+bool bdrv_dirty_bitmap_inconsistent(const BdrvDirtyBitmap *bitmap)
+{
+    return bitmap->inconsistent;
+}
+
 bool bdrv_has_changed_persistent_bitmaps(BlockDriverState *bs)
 {
     BdrvDirtyBitmap *bm;