qcow2: discard bitmap when removed

Bitmap data may take a lot of disk space, so it's better to discard it
always.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-id: 1551346019-293202-1-git-send-email-andrey.shinkevich@virtuozzo.com
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[mreitz: Use the commit message proposed by Vladimir]
Signed-off-by: Max Reitz <mreitz@redhat.com>

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index e53a160..8a75366 100644 (file)
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -202,7 +202,7 @@ static void clear_bitmap_table(BlockDriverState *bs, uint64_t *bitmap_table,
             continue;
         }
 
-        qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_OTHER);
+        qcow2_free_clusters(bs, addr, s->cluster_size, QCOW2_DISCARD_ALWAYS);
         bitmap_table[i] = 0;
     }
 }