diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/block.c b/block.c index 45f653a88b..580cb77a70 100644 --- a/block.c +++ b/block.c @@ -84,6 +84,9 @@ static BlockDriverState *bdrv_open_inherit(const char *filename, BdrvChildRole child_role, Error **errp); +static bool bdrv_recurse_has_child(BlockDriverState *bs, + BlockDriverState *child); + static void bdrv_replace_child_noperm(BdrvChild *child, BlockDriverState *new_bs); static void bdrv_remove_file_or_backing_child(BlockDriverState *bs, @@ -2673,6 +2676,7 @@ static void bdrv_replace_child_noperm(BdrvChild *child, int drain_saldo; assert(!child->frozen); + assert(old_bs != new_bs); if (old_bs && new_bs) { assert(bdrv_get_aio_context(old_bs) == bdrv_get_aio_context(new_bs)); @@ -2892,6 +2896,12 @@ static int bdrv_attach_child_noperm(BlockDriverState *parent_bs, assert(parent_bs->drv); + if (bdrv_recurse_has_child(child_bs, parent_bs)) { + error_setg(errp, "Making '%s' a %s child of '%s' would create a cycle", + child_bs->node_name, child_name, parent_bs->node_name); + return -EINVAL; + } + bdrv_get_cumulative_perm(parent_bs, &perm, &shared_perm); bdrv_child_perm(parent_bs, child_bs, NULL, child_role, NULL, perm, shared_perm, &perm, &shared_perm); |