/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _BCACHEFS_BTREE_GC_H #define _BCACHEFS_BTREE_GC_H #include "bkey.h" #include "btree_gc_types.h" #include "btree_types.h" int bch2_check_topology(struct bch_fs *); int bch2_check_allocations(struct bch_fs *); /* * For concurrent mark and sweep (with other index updates), we define a total * ordering of _all_ references GC walks: * * Note that some references will have the same GC position as others - e.g. * everything within the same btree node; in those cases we're relying on * whatever locking exists for where those references live, i.e. the write lock * on a btree node. * * That locking is also required to ensure GC doesn't pass the updater in * between the updater adding/removing the reference and updating the GC marks; * without that, we would at best double count sometimes. * * That part is important - whenever calling bch2_mark_pointers(), a lock _must_ * be held that prevents GC from passing the position the updater is at. * * (What about the start of gc, when we're clearing all the marks? GC clears the * mark with the gc pos seqlock held, and bch_mark_bucket checks against the gc * position inside its cmpxchg loop, so crap magically works). */ /* Position of (the start of) a gc phase: */ static inline struct gc_pos gc_phase(enum gc_phase phase) { return (struct gc_pos) { .phase = phase, }; } static inline struct gc_pos gc_pos_btree(enum btree_id btree, unsigned level, struct bpos pos) { return (struct gc_pos) { .phase = GC_PHASE_btree, .btree = btree, .level = level, .pos = pos, }; } /* * GC position of the pointers within a btree node: note, _not_ for &b->key * itself, that lives in the parent node: */ static inline struct gc_pos gc_pos_btree_node(struct btree *b) { return gc_pos_btree(b->c.btree_id, b->c.level, b->key.k.p); } static inline int gc_btree_order(enum btree_id btree) { if (btree == BTREE_ID_alloc) return -2; if (btree == BTREE_ID_stripes) return -1; return btree; } static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r) { return cmp_int(l.phase, r.phase) ?: cmp_int(gc_btree_order(l.btree), gc_btree_order(r.btree)) ?: cmp_int(l.level, r.level) ?: bpos_cmp(l.pos, r.pos); } static inline bool gc_visited(struct bch_fs *c, struct gc_pos pos) { unsigned seq; bool ret; do { seq = read_seqcount_begin(&c->gc_pos_lock); ret = gc_pos_cmp(pos, c->gc_pos) <= 0; } while (read_seqcount_retry(&c->gc_pos_lock, seq)); return ret; } int bch2_gc_gens(struct bch_fs *); void bch2_gc_gens_async(struct bch_fs *); void bch2_fs_gc_init(struct bch_fs *); #endif /* _BCACHEFS_BTREE_GC_H */