diff --git a/block/snapshot.c b/block/snapshot.c index a46564e7b7..1d5ab5f90f 100644 --- a/block/snapshot.c +++ b/block/snapshot.c @@ -181,10 +181,24 @@ int bdrv_snapshot_goto(BlockDriverState *bs, { BlockDriver *drv = bs->drv; int ret, open_ret; + int64_t len; if (!drv) { return -ENOMEDIUM; } + + len = bdrv_getlength(bs); + if (len < 0) { + return len; + } + /* We should set all bits in all enabled dirty bitmaps, because dirty + * bitmaps reflect active state of disk and snapshot switch operation + * actually dirties active state. + * TODO: It may make sense not to set all bits but analyze block status of + * current state and destination snapshot and do not set bits corresponding + * to both-zero or both-unallocated areas. */ + bdrv_set_dirty(bs, 0, len); + if (drv->bdrv_snapshot_goto) { return drv->bdrv_snapshot_goto(bs, snapshot_id); }