/* * Copyright (C) 2010 Kent Overstreet * Copyright (C) 2014 Datera Inc. */ #include "bcachefs.h" #include "alloc_background.h" #include "alloc_foreground.h" #include "bkey_methods.h" #include "btree_locking.h" #include "btree_update_interior.h" #include "btree_io.h" #include "btree_gc.h" #include "buckets.h" #include "clock.h" #include "debug.h" #include "ec.h" #include "error.h" #include "extents.h" #include "journal.h" #include "journal_io.h" #include "keylist.h" #include "move.h" #include "replicas.h" #include "super-io.h" #include #include #include #include #include #include #include #include static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos) { write_seqcount_begin(&c->gc_pos_lock); c->gc_pos = new_pos; write_seqcount_end(&c->gc_pos_lock); } static inline void gc_pos_set(struct bch_fs *c, struct gc_pos new_pos) { BUG_ON(gc_pos_cmp(new_pos, c->gc_pos) <= 0); __gc_pos_set(c, new_pos); } /* range_checks - for validating min/max pos of each btree node: */ struct range_checks { struct range_level { struct bpos min; struct bpos max; } l[BTREE_MAX_DEPTH]; unsigned depth; }; static void btree_node_range_checks_init(struct range_checks *r, unsigned depth) { unsigned i; for (i = 0; i < BTREE_MAX_DEPTH; i++) r->l[i].min = r->l[i].max = POS_MIN; r->depth = depth; } static void btree_node_range_checks(struct bch_fs *c, struct btree *b, struct range_checks *r) { struct range_level *l = &r->l[b->level]; struct bpos expected_min = bkey_cmp(l->min, l->max) ? btree_type_successor(b->btree_id, l->max) : l->max; bch2_fs_inconsistent_on(bkey_cmp(b->data->min_key, expected_min), c, "btree node has incorrect min key: %llu:%llu != %llu:%llu", b->data->min_key.inode, b->data->min_key.offset, expected_min.inode, expected_min.offset); l->max = b->data->max_key; if (b->level > r->depth) { l = &r->l[b->level - 1]; bch2_fs_inconsistent_on(bkey_cmp(b->data->min_key, l->min), c, "btree node min doesn't match min of child nodes: %llu:%llu != %llu:%llu", b->data->min_key.inode, b->data->min_key.offset, l->min.inode, l->min.offset); bch2_fs_inconsistent_on(bkey_cmp(b->data->max_key, l->max), c, "btree node max doesn't match max of child nodes: %llu:%llu != %llu:%llu", b->data->max_key.inode, b->data->max_key.offset, l->max.inode, l->max.offset); if (bkey_cmp(b->data->max_key, POS_MAX)) l->min = l->max = btree_type_successor(b->btree_id, b->data->max_key); } } /* marking of btree keys/nodes: */ static bool bkey_type_needs_gc(enum bkey_type type) { switch (type) { case BKEY_TYPE_BTREE: case BKEY_TYPE_EXTENTS: case BKEY_TYPE_EC: return true; default: return false; } } static void ptr_gen_recalc_oldest(struct bch_fs *c, const struct bch_extent_ptr *ptr, u8 *max_stale) { struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev); size_t b = PTR_BUCKET_NR(ca, ptr); if (gen_after(ca->oldest_gens[b], ptr->gen)) ca->oldest_gens[b] = ptr->gen; *max_stale = max(*max_stale, ptr_stale(ca, ptr)); } static u8 ptr_gens_recalc_oldest(struct bch_fs *c, enum bkey_type type, struct bkey_s_c k) { const struct bch_extent_ptr *ptr; u8 max_stale = 0; switch (type) { case BKEY_TYPE_BTREE: case BKEY_TYPE_EXTENTS: switch (k.k->type) { case BCH_EXTENT: case BCH_EXTENT_CACHED: { struct bkey_s_c_extent e = bkey_s_c_to_extent(k); extent_for_each_ptr(e, ptr) ptr_gen_recalc_oldest(c, ptr, &max_stale); break; } } break; case BKEY_TYPE_EC: switch (k.k->type) { case BCH_STRIPE: { struct bkey_s_c_stripe s = bkey_s_c_to_stripe(k); for (ptr = s.v->ptrs; ptr < s.v->ptrs + s.v->nr_blocks; ptr++) ptr_gen_recalc_oldest(c, ptr, &max_stale); } } default: break; } return max_stale; } static int ptr_gen_check(struct bch_fs *c, enum bkey_type type, const struct bch_extent_ptr *ptr) { struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev); size_t b = PTR_BUCKET_NR(ca, ptr); struct bucket *g = PTR_BUCKET(ca, ptr); int ret = 0; if (mustfix_fsck_err_on(!g->mark.gen_valid, c, "found ptr with missing gen in alloc btree,\n" "type %u gen %u", type, ptr->gen)) { g->_mark.gen = ptr->gen; g->_mark.gen_valid = 1; set_bit(b, ca->buckets_dirty); } if (mustfix_fsck_err_on(gen_cmp(ptr->gen, g->mark.gen) > 0, c, "%u ptr gen in the future: %u > %u", type, ptr->gen, g->mark.gen)) { g->_mark.gen = ptr->gen; g->_mark.gen_valid = 1; set_bit(b, ca->buckets_dirty); set_bit(BCH_FS_FIXED_GENS, &c->flags); } fsck_err: return ret; } static int ptr_gens_check(struct bch_fs *c, enum bkey_type type, struct bkey_s_c k) { const struct bch_extent_ptr *ptr; int ret = 0; switch (type) { case BKEY_TYPE_BTREE: case BKEY_TYPE_EXTENTS: switch (k.k->type) { case BCH_EXTENT: case BCH_EXTENT_CACHED: { struct bkey_s_c_extent e = bkey_s_c_to_extent(k); extent_for_each_ptr(e, ptr) { ret = ptr_gen_check(c, type, ptr); if (ret) return ret; } break; } } break; case BKEY_TYPE_EC: switch (k.k->type) { case BCH_STRIPE: { struct bkey_s_c_stripe s = bkey_s_c_to_stripe(k); for (ptr = s.v->ptrs; ptr < s.v->ptrs + s.v->nr_blocks; ptr++) { ret = ptr_gen_check(c, type, ptr); if (ret) return ret; } } } break; default: break; } return ret; } /* * For runtime mark and sweep: */ static int bch2_gc_mark_key(struct bch_fs *c, enum bkey_type type, struct bkey_s_c k, bool initial) { struct gc_pos pos = { 0 }; unsigned flags = BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD| (initial ? BCH_BUCKET_MARK_NOATOMIC : 0); int ret = 0; if (initial) { BUG_ON(journal_seq_verify(c) && k.k->version.lo > journal_cur_seq(&c->journal)); if (k.k->version.lo > atomic64_read(&c->key_version)) atomic64_set(&c->key_version, k.k->version.lo); if (test_bit(BCH_FS_REBUILD_REPLICAS, &c->flags) || fsck_err_on(!bch2_bkey_replicas_marked(c, type, k, false), c, "superblock not marked as containing replicas (type %u)", type)) { ret = bch2_mark_bkey_replicas(c, type, k); if (ret) return ret; } ret = ptr_gens_check(c, type, k); if (ret) return ret; } bch2_mark_key(c, type, k, true, k.k->size, pos, NULL, 0, flags); ret = ptr_gens_recalc_oldest(c, type, k); fsck_err: return ret; } static int btree_gc_mark_node(struct bch_fs *c, struct btree *b, bool initial) { enum bkey_type type = btree_node_type(b); struct btree_node_iter iter; struct bkey unpacked; struct bkey_s_c k; u8 stale = 0; int ret; if (!bkey_type_needs_gc(type)) return 0; for_each_btree_node_key_unpack(b, k, &iter, &unpacked) { bch2_bkey_debugcheck(c, b, k); ret = bch2_gc_mark_key(c, type, k, initial); if (ret < 0) return ret; stale = max_t(u8, stale, ret); } return stale; } static int bch2_gc_btree(struct bch_fs *c, enum btree_id btree_id, bool initial) { struct btree_iter iter; struct btree *b; struct range_checks r; unsigned depth = bkey_type_needs_gc(btree_id) ? 0 : 1; unsigned max_stale; int ret = 0; gc_pos_set(c, gc_pos_btree(btree_id, POS_MIN, 0)); if (!c->btree_roots[btree_id].b) return 0; /* * if expensive_debug_checks is on, run range_checks on all leaf nodes: * * and on startup, we have to read every btree node (XXX: only if it was * an unclean shutdown) */ if (initial || expensive_debug_checks(c)) depth = 0; btree_node_range_checks_init(&r, depth); __for_each_btree_node(&iter, c, btree_id, POS_MIN, 0, depth, BTREE_ITER_PREFETCH, b) { btree_node_range_checks(c, b, &r); bch2_verify_btree_nr_keys(b); max_stale = btree_gc_mark_node(c, b, initial); gc_pos_set(c, gc_pos_btree_node(b)); if (!initial) { if (max_stale > 64) bch2_btree_node_rewrite(c, &iter, b->data->keys.seq, BTREE_INSERT_USE_RESERVE| BTREE_INSERT_NOWAIT| BTREE_INSERT_GC_LOCK_HELD); else if (!btree_gc_rewrite_disabled(c) && (btree_gc_always_rewrite(c) || max_stale > 16)) bch2_btree_node_rewrite(c, &iter, b->data->keys.seq, BTREE_INSERT_NOWAIT| BTREE_INSERT_GC_LOCK_HELD); } bch2_btree_iter_cond_resched(&iter); } ret = bch2_btree_iter_unlock(&iter); if (ret) return ret; mutex_lock(&c->btree_root_lock); b = c->btree_roots[btree_id].b; if (!btree_node_fake(b)) bch2_gc_mark_key(c, BKEY_TYPE_BTREE, bkey_i_to_s_c(&b->key), initial); gc_pos_set(c, gc_pos_btree_root(b->btree_id)); mutex_unlock(&c->btree_root_lock); return 0; } static inline int btree_id_gc_phase_cmp(enum btree_id l, enum btree_id r) { return (int) btree_id_to_gc_phase(l) - (int) btree_id_to_gc_phase(r); } static int bch2_gc_btrees(struct bch_fs *c, struct list_head *journal, bool initial) { enum btree_id ids[BTREE_ID_NR]; unsigned i; for (i = 0; i < BTREE_ID_NR; i++) ids[i] = i; bubble_sort(ids, BTREE_ID_NR, btree_id_gc_phase_cmp); for (i = 0; i < BTREE_ID_NR; i++) { enum btree_id id = ids[i]; enum bkey_type type = bkey_type(0, id); int ret = bch2_gc_btree(c, id, initial); if (ret) return ret; if (journal && bkey_type_needs_gc(type)) { struct bkey_i *k, *n; struct jset_entry *j; struct journal_replay *r; int ret; list_for_each_entry(r, journal, list) for_each_jset_key(k, n, j, &r->j) { if (type == bkey_type(j->level, j->btree_id)) { ret = bch2_gc_mark_key(c, type, bkey_i_to_s_c(k), initial); if (ret < 0) return ret; } } } } return 0; } static void mark_metadata_sectors(struct bch_fs *c, struct bch_dev *ca, u64 start, u64 end, enum bch_data_type type, unsigned flags) { u64 b = sector_to_bucket(ca, start); do { unsigned sectors = min_t(u64, bucket_to_sector(ca, b + 1), end) - start; bch2_mark_metadata_bucket(c, ca, b, type, sectors, gc_phase(GC_PHASE_SB), flags); b++; start += sectors; } while (start < end); } void bch2_mark_dev_superblock(struct bch_fs *c, struct bch_dev *ca, unsigned flags) { struct bch_sb_layout *layout = &ca->disk_sb.sb->layout; unsigned i; u64 b; /* * This conditional is kind of gross, but we may be called from the * device add path, before the new device has actually been added to the * running filesystem: */ if (c) { lockdep_assert_held(&c->sb_lock); percpu_down_read_preempt_disable(&c->usage_lock); } else { preempt_disable(); } for (i = 0; i < layout->nr_superblocks; i++) { u64 offset = le64_to_cpu(layout->sb_offset[i]); if (offset == BCH_SB_SECTOR) mark_metadata_sectors(c, ca, 0, BCH_SB_SECTOR, BCH_DATA_SB, flags); mark_metadata_sectors(c, ca, offset, offset + (1 << layout->sb_max_size_bits), BCH_DATA_SB, flags); } if (c) spin_lock(&c->journal.lock); for (i = 0; i < ca->journal.nr; i++) { b = ca->journal.buckets[i]; bch2_mark_metadata_bucket(c, ca, b, BCH_DATA_JOURNAL, ca->mi.bucket_size, gc_phase(GC_PHASE_SB), flags); } if (c) { percpu_up_read_preempt_enable(&c->usage_lock); spin_unlock(&c->journal.lock); } else { preempt_enable(); } } static void bch2_mark_superblocks(struct bch_fs *c) { struct bch_dev *ca; unsigned i; mutex_lock(&c->sb_lock); gc_pos_set(c, gc_phase(GC_PHASE_SB)); for_each_online_member(ca, c, i) bch2_mark_dev_superblock(c, ca, BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD); mutex_unlock(&c->sb_lock); } /* Also see bch2_pending_btree_node_free_insert_done() */ static void bch2_mark_pending_btree_node_frees(struct bch_fs *c) { struct gc_pos pos = { 0 }; struct bch_fs_usage stats = { 0 }; struct btree_update *as; struct pending_btree_node_free *d; mutex_lock(&c->btree_interior_update_lock); gc_pos_set(c, gc_phase(GC_PHASE_PENDING_DELETE)); for_each_pending_btree_node_free(c, as, d) if (d->index_update_done) bch2_mark_key(c, BKEY_TYPE_BTREE, bkey_i_to_s_c(&d->key), true, 0, pos, &stats, 0, BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD); /* * Don't apply stats - pending deletes aren't tracked in * bch_alloc_stats: */ mutex_unlock(&c->btree_interior_update_lock); } static void bch2_mark_allocator_buckets(struct bch_fs *c) { struct bch_dev *ca; struct open_bucket *ob; size_t i, j, iter; unsigned ci; percpu_down_read_preempt_disable(&c->usage_lock); spin_lock(&c->freelist_lock); gc_pos_set(c, gc_pos_alloc(c, NULL)); for_each_member_device(ca, c, ci) { fifo_for_each_entry(i, &ca->free_inc, iter) bch2_mark_alloc_bucket(c, ca, i, true, gc_pos_alloc(c, NULL), BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD); for (j = 0; j < RESERVE_NR; j++) fifo_for_each_entry(i, &ca->free[j], iter) bch2_mark_alloc_bucket(c, ca, i, true, gc_pos_alloc(c, NULL), BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD); } spin_unlock(&c->freelist_lock); for (ob = c->open_buckets; ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); ob++) { spin_lock(&ob->lock); if (ob->valid) { gc_pos_set(c, gc_pos_alloc(c, ob)); ca = bch_dev_bkey_exists(c, ob->ptr.dev); bch2_mark_alloc_bucket(c, ca, PTR_BUCKET_NR(ca, &ob->ptr), true, gc_pos_alloc(c, ob), BCH_BUCKET_MARK_MAY_MAKE_UNAVAILABLE| BCH_BUCKET_MARK_GC_LOCK_HELD); } spin_unlock(&ob->lock); } percpu_up_read_preempt_enable(&c->usage_lock); } static void bch2_gc_start(struct bch_fs *c) { struct bch_dev *ca; struct bucket_array *buckets; struct bucket_mark new; unsigned i; size_t b; int cpu; percpu_down_write(&c->usage_lock); /* * Indicates to buckets code that gc is now in progress - done under * usage_lock to avoid racing with bch2_mark_key(): */ __gc_pos_set(c, gc_phase(GC_PHASE_START)); /* Save a copy of the existing bucket stats while we recompute them: */ for_each_member_device(ca, c, i) { ca->usage_cached = __bch2_dev_usage_read(ca); for_each_possible_cpu(cpu) { struct bch_dev_usage *p = per_cpu_ptr(ca->usage_percpu, cpu); memset(p, 0, sizeof(*p)); } } c->usage_cached = __bch2_fs_usage_read(c); for_each_possible_cpu(cpu) { struct bch_fs_usage *p = per_cpu_ptr(c->usage_percpu, cpu); memset(p->replicas, 0, sizeof(p->replicas)); memset(p->buckets, 0, sizeof(p->buckets)); } percpu_up_write(&c->usage_lock); /* Clear bucket marks: */ for_each_member_device(ca, c, i) { down_read(&ca->bucket_lock); buckets = bucket_array(ca); for (b = buckets->first_bucket; b < buckets->nbuckets; b++) { bucket_cmpxchg(buckets->b + b, new, ({ new.owned_by_allocator = 0; new.data_type = 0; new.cached_sectors = 0; new.dirty_sectors = 0; new.stripe = 0; })); ca->oldest_gens[b] = new.gen; } up_read(&ca->bucket_lock); } } /** * bch_gc - recompute bucket marks and oldest_gen, rewrite btree nodes */ void bch2_gc(struct bch_fs *c) { struct bch_dev *ca; u64 start_time = local_clock(); unsigned i; int ret; /* * Walk _all_ references to buckets, and recompute them: * * Order matters here: * - Concurrent GC relies on the fact that we have a total ordering for * everything that GC walks - see gc_will_visit_node(), * gc_will_visit_root() * * - also, references move around in the course of index updates and * various other crap: everything needs to agree on the ordering * references are allowed to move around in - e.g., we're allowed to * start with a reference owned by an open_bucket (the allocator) and * move it to the btree, but not the reverse. * * This is necessary to ensure that gc doesn't miss references that * move around - if references move backwards in the ordering GC * uses, GC could skip past them */ trace_gc_start(c); /* * Do this before taking gc_lock - bch2_disk_reservation_get() blocks on * gc_lock if sectors_available goes to 0: */ bch2_recalc_sectors_available(c); down_write(&c->gc_lock); if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) goto out; bch2_gc_start(c); bch2_mark_superblocks(c); ret = bch2_gc_btrees(c, NULL, false); if (ret) { bch_err(c, "btree gc failed: %d", ret); set_bit(BCH_FS_GC_FAILURE, &c->flags); goto out; } bch2_mark_pending_btree_node_frees(c); bch2_mark_allocator_buckets(c); /* Indicates that gc is no longer in progress: */ gc_pos_set(c, gc_phase(GC_PHASE_DONE)); c->gc_count++; out: up_write(&c->gc_lock); trace_gc_end(c); bch2_time_stats_update(&c->times[BCH_TIME_btree_gc], start_time); /* * Wake up allocator in case it was waiting for buckets * because of not being able to inc gens */ for_each_member_device(ca, c, i) bch2_wake_allocator(ca); /* * At startup, allocations can happen directly instead of via the * allocator thread - issue wakeup in case they blocked on gc_lock: */ closure_wake_up(&c->freelist_wait); } /* Btree coalescing */ static void recalc_packed_keys(struct btree *b) { struct bset *i = btree_bset_first(b); struct bkey_packed *k; memset(&b->nr, 0, sizeof(b->nr)); BUG_ON(b->nsets != 1); vstruct_for_each(i, k) btree_keys_account_key_add(&b->nr, 0, k); } static void bch2_coalesce_nodes(struct bch_fs *c, struct btree_iter *iter, struct btree *old_nodes[GC_MERGE_NODES]) { struct btree *parent = btree_node_parent(iter, old_nodes[0]); unsigned i, nr_old_nodes, nr_new_nodes, u64s = 0; unsigned blocks = btree_blocks(c) * 2 / 3; struct btree *new_nodes[GC_MERGE_NODES]; struct btree_update *as; struct keylist keylist; struct bkey_format_state format_state; struct bkey_format new_format; memset(new_nodes, 0, sizeof(new_nodes)); bch2_keylist_init(&keylist, NULL); /* Count keys that are not deleted */ for (i = 0; i < GC_MERGE_NODES && old_nodes[i]; i++) u64s += old_nodes[i]->nr.live_u64s; nr_old_nodes = nr_new_nodes = i; /* Check if all keys in @old_nodes could fit in one fewer node */ if (nr_old_nodes <= 1 || __vstruct_blocks(struct btree_node, c->block_bits, DIV_ROUND_UP(u64s, nr_old_nodes - 1)) > blocks) return; /* Find a format that all keys in @old_nodes can pack into */ bch2_bkey_format_init(&format_state); for (i = 0; i < nr_old_nodes; i++) __bch2_btree_calc_format(&format_state, old_nodes[i]); new_format = bch2_bkey_format_done(&format_state); /* Check if repacking would make any nodes too big to fit */ for (i = 0; i < nr_old_nodes; i++) if (!bch2_btree_node_format_fits(c, old_nodes[i], &new_format)) { trace_btree_gc_coalesce_fail(c, BTREE_GC_COALESCE_FAIL_FORMAT_FITS); return; } if (bch2_keylist_realloc(&keylist, NULL, 0, (BKEY_U64s + BKEY_EXTENT_U64s_MAX) * nr_old_nodes)) { trace_btree_gc_coalesce_fail(c, BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC); return; } as = bch2_btree_update_start(c, iter->btree_id, btree_update_reserve_required(c, parent) + nr_old_nodes, BTREE_INSERT_NOFAIL| BTREE_INSERT_USE_RESERVE, NULL); if (IS_ERR(as)) { trace_btree_gc_coalesce_fail(c, BTREE_GC_COALESCE_FAIL_RESERVE_GET); bch2_keylist_free(&keylist, NULL); return; } trace_btree_gc_coalesce(c, old_nodes[0]); for (i = 0; i < nr_old_nodes; i++) bch2_btree_interior_update_will_free_node(as, old_nodes[i]); /* Repack everything with @new_format and sort down to one bset */ for (i = 0; i < nr_old_nodes; i++) new_nodes[i] = __bch2_btree_node_alloc_replacement(as, old_nodes[i], new_format); /* * Conceptually we concatenate the nodes together and slice them * up at different boundaries. */ for (i = nr_new_nodes - 1; i > 0; --i) { struct btree *n1 = new_nodes[i]; struct btree *n2 = new_nodes[i - 1]; struct bset *s1 = btree_bset_first(n1); struct bset *s2 = btree_bset_first(n2); struct bkey_packed *k, *last = NULL; /* Calculate how many keys from @n2 we could fit inside @n1 */ u64s = 0; for (k = s2->start; k < vstruct_last(s2) && vstruct_blocks_plus(n1->data, c->block_bits, u64s + k->u64s) <= blocks; k = bkey_next(k)) { last = k; u64s += k->u64s; } if (u64s == le16_to_cpu(s2->u64s)) { /* n2 fits entirely in n1 */ n1->key.k.p = n1->data->max_key = n2->data->max_key; memcpy_u64s(vstruct_last(s1), s2->start, le16_to_cpu(s2->u64s)); le16_add_cpu(&s1->u64s, le16_to_cpu(s2->u64s)); set_btree_bset_end(n1, n1->set); six_unlock_write(&n2->lock); bch2_btree_node_free_never_inserted(c, n2); six_unlock_intent(&n2->lock); memmove(new_nodes + i - 1, new_nodes + i, sizeof(new_nodes[0]) * (nr_new_nodes - i)); new_nodes[--nr_new_nodes] = NULL; } else if (u64s) { /* move part of n2 into n1 */ n1->key.k.p = n1->data->max_key = bkey_unpack_pos(n1, last); n2->data->min_key = btree_type_successor(iter->btree_id, n1->data->max_key); memcpy_u64s(vstruct_last(s1), s2->start, u64s); le16_add_cpu(&s1->u64s, u64s); memmove(s2->start, vstruct_idx(s2, u64s), (le16_to_cpu(s2->u64s) - u64s) * sizeof(u64)); s2->u64s = cpu_to_le16(le16_to_cpu(s2->u64s) - u64s); set_btree_bset_end(n1, n1->set); set_btree_bset_end(n2, n2->set); } } for (i = 0; i < nr_new_nodes; i++) { struct btree *n = new_nodes[i]; recalc_packed_keys(n); btree_node_reset_sib_u64s(n); bch2_btree_build_aux_trees(n); six_unlock_write(&n->lock); bch2_btree_node_write(c, n, SIX_LOCK_intent); } /* * The keys for the old nodes get deleted. We don't want to insert keys * that compare equal to the keys for the new nodes we'll also be * inserting - we can't because keys on a keylist must be strictly * greater than the previous keys, and we also don't need to since the * key for the new node will serve the same purpose (overwriting the key * for the old node). */ for (i = 0; i < nr_old_nodes; i++) { struct bkey_i delete; unsigned j; for (j = 0; j < nr_new_nodes; j++) if (!bkey_cmp(old_nodes[i]->key.k.p, new_nodes[j]->key.k.p)) goto next; bkey_init(&delete.k); delete.k.p = old_nodes[i]->key.k.p; bch2_keylist_add_in_order(&keylist, &delete); next: i = i; } /* * Keys for the new nodes get inserted: bch2_btree_insert_keys() only * does the lookup once and thus expects the keys to be in sorted order * so we have to make sure the new keys are correctly ordered with * respect to the deleted keys added in the previous loop */ for (i = 0; i < nr_new_nodes; i++) bch2_keylist_add_in_order(&keylist, &new_nodes[i]->key); /* Insert the newly coalesced nodes */ bch2_btree_insert_node(as, parent, iter, &keylist, 0); BUG_ON(!bch2_keylist_empty(&keylist)); BUG_ON(iter->l[old_nodes[0]->level].b != old_nodes[0]); bch2_btree_iter_node_replace(iter, new_nodes[0]); for (i = 0; i < nr_new_nodes; i++) bch2_open_buckets_put(c, &new_nodes[i]->ob); /* Free the old nodes and update our sliding window */ for (i = 0; i < nr_old_nodes; i++) { bch2_btree_node_free_inmem(c, old_nodes[i], iter); six_unlock_intent(&old_nodes[i]->lock); /* * the index update might have triggered a split, in which case * the nodes we coalesced - the new nodes we just created - * might not be sibling nodes anymore - don't add them to the * sliding window (except the first): */ if (!i) { old_nodes[i] = new_nodes[i]; } else { old_nodes[i] = NULL; if (new_nodes[i]) six_unlock_intent(&new_nodes[i]->lock); } } bch2_btree_update_done(as); bch2_keylist_free(&keylist, NULL); } static int bch2_coalesce_btree(struct bch_fs *c, enum btree_id btree_id) { struct btree_iter iter; struct btree *b; bool kthread = (current->flags & PF_KTHREAD) != 0; unsigned i; /* Sliding window of adjacent btree nodes */ struct btree *merge[GC_MERGE_NODES]; u32 lock_seq[GC_MERGE_NODES]; /* * XXX: We don't have a good way of positively matching on sibling nodes * that have the same parent - this code works by handling the cases * where they might not have the same parent, and is thus fragile. Ugh. * * Perhaps redo this to use multiple linked iterators? */ memset(merge, 0, sizeof(merge)); __for_each_btree_node(&iter, c, btree_id, POS_MIN, BTREE_MAX_DEPTH, 0, BTREE_ITER_PREFETCH, b) { memmove(merge + 1, merge, sizeof(merge) - sizeof(merge[0])); memmove(lock_seq + 1, lock_seq, sizeof(lock_seq) - sizeof(lock_seq[0])); merge[0] = b; for (i = 1; i < GC_MERGE_NODES; i++) { if (!merge[i] || !six_relock_intent(&merge[i]->lock, lock_seq[i])) break; if (merge[i]->level != merge[0]->level) { six_unlock_intent(&merge[i]->lock); break; } } memset(merge + i, 0, (GC_MERGE_NODES - i) * sizeof(merge[0])); bch2_coalesce_nodes(c, &iter, merge); for (i = 1; i < GC_MERGE_NODES && merge[i]; i++) { lock_seq[i] = merge[i]->lock.state.seq; six_unlock_intent(&merge[i]->lock); } lock_seq[0] = merge[0]->lock.state.seq; if (kthread && kthread_should_stop()) { bch2_btree_iter_unlock(&iter); return -ESHUTDOWN; } bch2_btree_iter_cond_resched(&iter); /* * If the parent node wasn't relocked, it might have been split * and the nodes in our sliding window might not have the same * parent anymore - blow away the sliding window: */ if (btree_iter_node(&iter, iter.level + 1) && !btree_node_intent_locked(&iter, iter.level + 1)) memset(merge + 1, 0, (GC_MERGE_NODES - 1) * sizeof(merge[0])); } return bch2_btree_iter_unlock(&iter); } /** * bch_coalesce - coalesce adjacent nodes with low occupancy */ void bch2_coalesce(struct bch_fs *c) { enum btree_id id; if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) return; down_read(&c->gc_lock); trace_gc_coalesce_start(c); for (id = 0; id < BTREE_ID_NR; id++) { int ret = c->btree_roots[id].b ? bch2_coalesce_btree(c, id) : 0; if (ret) { if (ret != -ESHUTDOWN) bch_err(c, "btree coalescing failed: %d", ret); set_bit(BCH_FS_GC_FAILURE, &c->flags); return; } } trace_gc_coalesce_end(c); up_read(&c->gc_lock); } static int bch2_gc_thread(void *arg) { struct bch_fs *c = arg; struct io_clock *clock = &c->io_clock[WRITE]; unsigned long last = atomic_long_read(&clock->now); unsigned last_kick = atomic_read(&c->kick_gc); set_freezable(); while (1) { while (1) { set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) { __set_current_state(TASK_RUNNING); return 0; } if (atomic_read(&c->kick_gc) != last_kick) break; if (c->btree_gc_periodic) { unsigned long next = last + c->capacity / 16; if (atomic_long_read(&clock->now) >= next) break; bch2_io_clock_schedule_timeout(clock, next); } else { schedule(); } try_to_freeze(); } __set_current_state(TASK_RUNNING); last = atomic_long_read(&clock->now); last_kick = atomic_read(&c->kick_gc); bch2_gc(c); debug_check_no_locks_held(); } return 0; } void bch2_gc_thread_stop(struct bch_fs *c) { struct task_struct *p; p = c->gc_thread; c->gc_thread = NULL; if (p) { kthread_stop(p); put_task_struct(p); } } int bch2_gc_thread_start(struct bch_fs *c) { struct task_struct *p; BUG_ON(c->gc_thread); p = kthread_create(bch2_gc_thread, c, "bch_gc"); if (IS_ERR(p)) return PTR_ERR(p); get_task_struct(p); c->gc_thread = p; wake_up_process(p); return 0; } /* Initial GC computes bucket marks during startup */ int bch2_initial_gc(struct bch_fs *c, struct list_head *journal) { unsigned iter = 0; int ret = 0; down_write(&c->gc_lock); again: bch2_gc_start(c); bch2_mark_superblocks(c); ret = bch2_gc_btrees(c, journal, true); if (ret) goto err; if (test_bit(BCH_FS_FIXED_GENS, &c->flags)) { if (iter++ > 2) { bch_info(c, "Unable to fix bucket gens, looping"); ret = -EINVAL; goto err; } bch_info(c, "Fixed gens, restarting initial mark and sweep:"); clear_bit(BCH_FS_FIXED_GENS, &c->flags); goto again; } /* * Skip past versions that might have possibly been used (as nonces), * but hadn't had their pointers written: */ if (c->sb.encryption_type) atomic64_add(1 << 16, &c->key_version); gc_pos_set(c, gc_phase(GC_PHASE_DONE)); set_bit(BCH_FS_INITIAL_GC_DONE, &c->flags); err: up_write(&c->gc_lock); return ret; }