block/dirty-bitmaps: add block_dirty_bitmap_check function

Instead of checking against busy, inconsistent, or read only directly,
use a check function with permissions bits that let us streamline the
checks without reproducing them in many places.

Included in this patch are permissions changes that simply add the
inconsistent check to existing permissions call spots, without
addressing existing bugs.

In general, this means that busy+readonly checks become BDRV_BITMAP_DEFAULT,
which checks against all three conditions. busy-only checks become
BDRV_BITMAP_ALLOW_RO.

Notably, remove allows inconsistent bitmaps, so it doesn't follow the pattern.

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: 20190301191545.8728-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/migration/block-dirty-bitmap.c b/migration/block-dirty-bitmap.c
index 7057fff242..a09befeef9 100644
--- a/migration/block-dirty-bitmap.c
+++ b/migration/block-dirty-bitmap.c
@@ -274,6 +274,7 @@ static int init_dirty_bitmap_migration(void)
     BdrvDirtyBitmap *bitmap;
     DirtyBitmapMigBitmapState *dbms;
     BdrvNextIterator it;
+    Error *local_err = NULL;
 
     dirty_bitmap_mig_state.bulk_completed = false;
     dirty_bitmap_mig_state.prev_bs = NULL;
@@ -301,15 +302,9 @@ static int init_dirty_bitmap_migration(void)
                 goto fail;
             }
 
-            if (bdrv_dirty_bitmap_busy(bitmap)) {
-                error_report("Can't migrate a bitmap that is in use by another operation: '%s'",
-                             bdrv_dirty_bitmap_name(bitmap));
-                goto fail;
-            }
-
-            if (bdrv_dirty_bitmap_readonly(bitmap)) {
-                error_report("Can't migrate read-only dirty bitmap: '%s",
-                             bdrv_dirty_bitmap_name(bitmap));
+            if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT,
+                                        &local_err)) {
+                error_report_err(local_err);
                 goto fail;
             }