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Diffstat (limited to 'c_src/libbcachefs/btree_gc.h')
-rw-r--r-- | c_src/libbcachefs/btree_gc.h | 114 |
1 files changed, 0 insertions, 114 deletions
diff --git a/c_src/libbcachefs/btree_gc.h b/c_src/libbcachefs/btree_gc.h deleted file mode 100644 index 607575f8..00000000 --- a/c_src/libbcachefs/btree_gc.h +++ /dev/null @@ -1,114 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _BCACHEFS_BTREE_GC_H -#define _BCACHEFS_BTREE_GC_H - -#include "bkey.h" -#include "btree_types.h" - -int bch2_check_topology(struct bch_fs *); -int bch2_gc(struct bch_fs *, bool, bool); -int bch2_gc_gens(struct bch_fs *); -void bch2_gc_thread_stop(struct bch_fs *); -int bch2_gc_thread_start(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, - .pos = POS_MIN, - .level = 0, - }; -} - -static inline int gc_pos_cmp(struct gc_pos l, struct gc_pos r) -{ - return cmp_int(l.phase, r.phase) ?: - bpos_cmp(l.pos, r.pos) ?: - cmp_int(l.level, r.level); -} - -static inline enum gc_phase btree_id_to_gc_phase(enum btree_id id) -{ - switch (id) { -#define x(name, v, ...) case BTREE_ID_##name: return GC_PHASE_BTREE_##name; - BCH_BTREE_IDS() -#undef x - default: - BUG(); - } -} - -static inline struct gc_pos gc_pos_btree(enum btree_id id, - struct bpos pos, unsigned level) -{ - return (struct gc_pos) { - .phase = btree_id_to_gc_phase(id), - .pos = pos, - .level = level, - }; -} - -/* - * 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->key.k.p, b->c.level); -} - -/* - * GC position of the pointer to a btree root: we don't use - * gc_pos_pointer_to_btree_node() here to avoid a potential race with - * btree_split() increasing the tree depth - the new root will have level > the - * old root and thus have a greater gc position than the old root, but that - * would be incorrect since once gc has marked the root it's not coming back. - */ -static inline struct gc_pos gc_pos_btree_root(enum btree_id id) -{ - return gc_pos_btree(id, SPOS_MAX, BTREE_MAX_DEPTH); -} - -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; -} - -static inline void bch2_do_gc_gens(struct bch_fs *c) -{ - atomic_inc(&c->kick_gc); - if (c->gc_thread) - wake_up_process(c->gc_thread); -} - -#endif /* _BCACHEFS_BTREE_GC_H */ |