BTRFS_ROOT_UNFINISHED_DROP
unfinished_drop = test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);
set_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state);
if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state)) {
if (test_bit(BTRFS_ROOT_UNFINISHED_DROP, &root->state))