int bch2_gc_gens(struct bch_fs *);
void bch2_gc_thread_stop(struct bch_fs *);
int bch2_gc_thread_start(struct bch_fs *);
-void bch2_mark_dev_superblock(struct bch_fs *, struct bch_dev *, unsigned);
/*
* For concurrent mark and sweep (with other index updates), we define a total