// SPDX-License-Identifier: GPL-2.0 /* * 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 "keylist.h" #include "move.h" #include "recovery.h" #include "replicas.h" #include "super-io.h" #include "trace.h" #include #include #include #include #include #include #include static inline void __gc_pos_set(struct bch_fs *c, struct gc_pos new_pos) { preempt_disable(); write_seqcount_begin(&c->gc_pos_lock); c->gc_pos = new_pos; write_seqcount_end(&c->gc_pos_lock); preempt_enable(); } 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->c.level]; struct bpos expected_min = bkey_cmp(l->min, l->max) ? btree_type_successor(b->c.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->c.level > r->depth) { l = &r->l[b->c.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->c.btree_id, b->data->max_key); } } /* marking of btree keys/nodes: */ static int bch2_gc_mark_key(struct bch_fs *c, struct bkey_s_c k, u8 *max_stale, bool initial) { struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k); const struct bch_extent_ptr *ptr; unsigned flags = BTREE_TRIGGER_GC| (initial ? BTREE_TRIGGER_NOATOMIC : 0); int ret = 0; if (initial) { BUG_ON(journal_seq_verify(c) && k.k->version.lo > journal_cur_seq(&c->journal)); /* XXX change to fsck check */ if (fsck_err_on(k.k->version.lo > atomic64_read(&c->key_version), c, "key version number higher than recorded: %llu > %llu", 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, k, false), c, "superblock not marked as containing replicas (type %u)", k.k->type)) { ret = bch2_mark_bkey_replicas(c, k); if (ret) return ret; } bkey_for_each_ptr(ptrs, ptr) { struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev); struct bucket *g = PTR_BUCKET(ca, ptr, true); struct bucket *g2 = PTR_BUCKET(ca, ptr, false); if (mustfix_fsck_err_on(!g->gen_valid, c, "bucket %u:%zu data type %s ptr gen %u missing in alloc btree", ptr->dev, PTR_BUCKET_NR(ca, ptr), bch2_data_types[ptr_data_type(k.k, ptr)], ptr->gen)) { g2->_mark.gen = g->_mark.gen = ptr->gen; g2->gen_valid = g->gen_valid = true; } if (mustfix_fsck_err_on(gen_cmp(ptr->gen, g->mark.gen) > 0, c, "bucket %u:%zu data type %s ptr gen in the future: %u > %u", ptr->dev, PTR_BUCKET_NR(ca, ptr), bch2_data_types[ptr_data_type(k.k, ptr)], ptr->gen, g->mark.gen)) { g2->_mark.gen = g->_mark.gen = ptr->gen; g2->gen_valid = g->gen_valid = true; g2->_mark.data_type = 0; g2->_mark.dirty_sectors = 0; g2->_mark.cached_sectors = 0; set_bit(BCH_FS_FIXED_GENS, &c->flags); } } } bkey_for_each_ptr(ptrs, ptr) { struct bch_dev *ca = bch_dev_bkey_exists(c, ptr->dev); struct bucket *g = PTR_BUCKET(ca, ptr, true); if (gen_after(g->oldest_gen, ptr->gen)) g->oldest_gen = ptr->gen; *max_stale = max(*max_stale, ptr_stale(ca, ptr)); } bch2_mark_key(c, k, 0, k.k->size, NULL, 0, flags); fsck_err: return ret; } static bool pos_in_journal_keys(struct journal_keys *journal_keys, enum btree_id id, struct bpos pos) { struct journal_key *k = journal_key_search(journal_keys, id, pos); return k && k->btree_id == id && !bkey_cmp(k->k->k.p, pos); } static int btree_gc_mark_node(struct bch_fs *c, struct btree *b, u8 *max_stale, struct journal_keys *journal_keys, bool initial) { struct btree_node_iter iter; struct bkey unpacked; struct bkey_s_c k; int ret = 0; *max_stale = 0; if (!btree_node_type_needs_gc(btree_node_type(b))) return 0; for_each_btree_node_key_unpack(b, k, &iter, &unpacked) { if (!b->c.level && journal_keys && pos_in_journal_keys(journal_keys, b->c.btree_id, k.k->p)) continue; bch2_bkey_debugcheck(c, b, k); ret = bch2_gc_mark_key(c, k, max_stale, initial); if (ret) break; } return ret; } static int bch2_gc_btree(struct bch_fs *c, enum btree_id btree_id, struct journal_keys *journal_keys, bool initial, bool metadata_only) { struct btree_trans trans; struct btree_iter *iter; struct btree *b; struct range_checks r; unsigned depth = metadata_only ? 1 : expensive_debug_checks(c) ? 0 : !btree_node_type_needs_gc(btree_id) ? 1 : 0; u8 max_stale = 0; int ret = 0; bch2_trans_init(&trans, c, 0, 0); gc_pos_set(c, gc_pos_btree(btree_id, POS_MIN, 0)); btree_node_range_checks_init(&r, depth); __for_each_btree_node(&trans, iter, btree_id, POS_MIN, 0, depth, BTREE_ITER_PREFETCH, b) { btree_node_range_checks(c, b, &r); bch2_verify_btree_nr_keys(b); gc_pos_set(c, gc_pos_btree_node(b)); ret = btree_gc_mark_node(c, b, &max_stale, journal_keys, initial); if (ret) break; 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_trans_cond_resched(&trans); } ret = bch2_trans_exit(&trans) ?: ret; if (ret) return ret; mutex_lock(&c->btree_root_lock); b = c->btree_roots[btree_id].b; if (!btree_node_fake(b)) ret = bch2_gc_mark_key(c, bkey_i_to_s_c(&b->key), &max_stale, initial); gc_pos_set(c, gc_pos_btree_root(b->c.btree_id)); mutex_unlock(&c->btree_root_lock); return ret; } 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 journal_keys *journal_keys, bool initial, bool metadata_only) { 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 btree_node_type type = __btree_node_type(0, id); int ret = bch2_gc_btree(c, id, journal_keys, initial, metadata_only); if (ret) return ret; if (journal_keys && !metadata_only && btree_node_type_needs_gc(type)) { struct journal_key *j; u8 max_stale; int ret; for_each_journal_key(*journal_keys, j) if (j->btree_id == id) { ret = bch2_gc_mark_key(c, bkey_i_to_s_c(j->k), &max_stale, initial); if (ret) 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(&c->mark_lock); } 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); } 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(&c->mark_lock); } 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, BTREE_TRIGGER_GC); 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 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_i_to_s_c(&d->key), 0, 0, NULL, 0, BTREE_TRIGGER_GC); 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(&c->mark_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), BTREE_TRIGGER_GC); 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), BTREE_TRIGGER_GC); } 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), BTREE_TRIGGER_GC); } spin_unlock(&ob->lock); } percpu_up_read(&c->mark_lock); } static void bch2_gc_free(struct bch_fs *c) { struct bch_dev *ca; unsigned i; genradix_free(&c->stripes[1]); for_each_member_device(ca, c, i) { kvpfree(rcu_dereference_protected(ca->buckets[1], 1), sizeof(struct bucket_array) + ca->mi.nbuckets * sizeof(struct bucket)); ca->buckets[1] = NULL; free_percpu(ca->usage[1]); ca->usage[1] = NULL; } free_percpu(c->usage_gc); c->usage_gc = NULL; } static int bch2_gc_done(struct bch_fs *c, bool initial, bool metadata_only) { struct bch_dev *ca; bool verify = !metadata_only && (!initial || (c->sb.compat & (1ULL << BCH_COMPAT_FEAT_ALLOC_INFO))); unsigned i; int ret = 0; #define copy_field(_f, _msg, ...) \ if (dst->_f != src->_f) { \ if (verify) \ fsck_err(c, _msg ": got %llu, should be %llu" \ , ##__VA_ARGS__, dst->_f, src->_f); \ dst->_f = src->_f; \ } #define copy_stripe_field(_f, _msg, ...) \ if (dst->_f != src->_f) { \ if (verify) \ fsck_err(c, "stripe %zu has wrong "_msg \ ": got %u, should be %u", \ dst_iter.pos, ##__VA_ARGS__, \ dst->_f, src->_f); \ dst->_f = src->_f; \ dst->dirty = true; \ } #define copy_bucket_field(_f) \ if (dst->b[b].mark._f != src->b[b].mark._f) { \ if (verify) \ fsck_err(c, "dev %u bucket %zu has wrong " #_f \ ": got %u, should be %u", i, b, \ dst->b[b].mark._f, src->b[b].mark._f); \ dst->b[b]._mark._f = src->b[b].mark._f; \ } #define copy_dev_field(_f, _msg, ...) \ copy_field(_f, "dev %u has wrong " _msg, i, ##__VA_ARGS__) #define copy_fs_field(_f, _msg, ...) \ copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__) if (!metadata_only) { struct genradix_iter dst_iter = genradix_iter_init(&c->stripes[0], 0); struct genradix_iter src_iter = genradix_iter_init(&c->stripes[1], 0); struct stripe *dst, *src; unsigned i; c->ec_stripes_heap.used = 0; while ((dst = genradix_iter_peek(&dst_iter, &c->stripes[0])) && (src = genradix_iter_peek(&src_iter, &c->stripes[1]))) { BUG_ON(src_iter.pos != dst_iter.pos); copy_stripe_field(alive, "alive"); copy_stripe_field(sectors, "sectors"); copy_stripe_field(algorithm, "algorithm"); copy_stripe_field(nr_blocks, "nr_blocks"); copy_stripe_field(nr_redundant, "nr_redundant"); copy_stripe_field(blocks_nonempty, "blocks_nonempty"); for (i = 0; i < ARRAY_SIZE(dst->block_sectors); i++) copy_stripe_field(block_sectors[i], "block_sectors[%u]", i); if (dst->alive) bch2_stripes_heap_insert(c, dst, dst_iter.pos); genradix_iter_advance(&dst_iter, &c->stripes[0]); genradix_iter_advance(&src_iter, &c->stripes[1]); } } for_each_member_device(ca, c, i) { struct bucket_array *dst = __bucket_array(ca, 0); struct bucket_array *src = __bucket_array(ca, 1); size_t b; for (b = 0; b < src->nbuckets; b++) { copy_bucket_field(gen); copy_bucket_field(data_type); copy_bucket_field(owned_by_allocator); copy_bucket_field(stripe); copy_bucket_field(dirty_sectors); copy_bucket_field(cached_sectors); dst->b[b].oldest_gen = src->b[b].oldest_gen; } }; for (i = 0; i < ARRAY_SIZE(c->usage); i++) bch2_fs_usage_acc_to_base(c, i); bch2_dev_usage_from_buckets(c); { unsigned nr = fs_usage_u64s(c); struct bch_fs_usage *dst = c->usage_base; struct bch_fs_usage *src = (void *) bch2_acc_percpu_u64s((void *) c->usage_gc, nr); copy_fs_field(hidden, "hidden"); copy_fs_field(btree, "btree"); if (!metadata_only) { copy_fs_field(data, "data"); copy_fs_field(cached, "cached"); copy_fs_field(reserved, "reserved"); copy_fs_field(nr_inodes,"nr_inodes"); for (i = 0; i < BCH_REPLICAS_MAX; i++) copy_fs_field(persistent_reserved[i], "persistent_reserved[%i]", i); } for (i = 0; i < c->replicas.nr; i++) { struct bch_replicas_entry *e = cpu_replicas_entry(&c->replicas, i); char buf[80]; if (metadata_only && (e->data_type == BCH_DATA_USER || e->data_type == BCH_DATA_CACHED)) continue; bch2_replicas_entry_to_text(&PBUF(buf), e); copy_fs_field(replicas[i], "%s", buf); } } #undef copy_fs_field #undef copy_dev_field #undef copy_bucket_field #undef copy_stripe_field #undef copy_field fsck_err: return ret; } static int bch2_gc_start(struct bch_fs *c, bool metadata_only) { struct bch_dev *ca; unsigned i; int ret; BUG_ON(c->usage_gc); c->usage_gc = __alloc_percpu_gfp(fs_usage_u64s(c) * sizeof(u64), sizeof(u64), GFP_KERNEL); if (!c->usage_gc) return -ENOMEM; for_each_member_device(ca, c, i) { BUG_ON(ca->buckets[1]); BUG_ON(ca->usage[1]); ca->buckets[1] = kvpmalloc(sizeof(struct bucket_array) + ca->mi.nbuckets * sizeof(struct bucket), GFP_KERNEL|__GFP_ZERO); if (!ca->buckets[1]) { percpu_ref_put(&ca->ref); return -ENOMEM; } ca->usage[1] = alloc_percpu(struct bch_dev_usage); if (!ca->usage[1]) { percpu_ref_put(&ca->ref); return -ENOMEM; } } ret = bch2_ec_mem_alloc(c, true); if (ret) return ret; percpu_down_write(&c->mark_lock); /* * indicate to stripe code that we need to allocate for the gc stripes * radix tree, too */ gc_pos_set(c, gc_phase(GC_PHASE_START)); for_each_member_device(ca, c, i) { struct bucket_array *dst = __bucket_array(ca, 1); struct bucket_array *src = __bucket_array(ca, 0); size_t b; dst->first_bucket = src->first_bucket; dst->nbuckets = src->nbuckets; for (b = 0; b < src->nbuckets; b++) { struct bucket *d = &dst->b[b]; struct bucket *s = &src->b[b]; d->_mark.gen = dst->b[b].oldest_gen = s->mark.gen; d->gen_valid = s->gen_valid; if (metadata_only && (s->mark.data_type == BCH_DATA_USER || s->mark.data_type == BCH_DATA_CACHED)) { d->_mark = s->mark; d->_mark.owned_by_allocator = 0; } } }; percpu_up_write(&c->mark_lock); return 0; } /** * bch2_gc - 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 */ int bch2_gc(struct bch_fs *c, struct journal_keys *journal_keys, bool initial, bool metadata_only) { struct bch_dev *ca; u64 start_time = local_clock(); unsigned i, iter = 0; int ret; trace_gc_start(c); down_write(&c->gc_lock); again: ret = bch2_gc_start(c, metadata_only); if (ret) goto out; bch2_mark_superblocks(c); ret = bch2_gc_btrees(c, journal_keys, initial, metadata_only); if (ret) goto out; bch2_mark_pending_btree_node_frees(c); bch2_mark_allocator_buckets(c); c->gc_count++; out: if (!ret && (test_bit(BCH_FS_FIXED_GENS, &c->flags) || (!iter && test_restart_gc(c)))) { /* * XXX: make sure gens we fixed got saved */ if (iter++ <= 2) { bch_info(c, "Fixed gens, restarting mark and sweep:"); clear_bit(BCH_FS_FIXED_GENS, &c->flags); __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING)); percpu_down_write(&c->mark_lock); bch2_gc_free(c); percpu_up_write(&c->mark_lock); /* flush fsck errors, reset counters */ bch2_flush_fsck_errs(c); goto again; } bch_info(c, "Unable to fix bucket gens, looping"); ret = -EINVAL; } if (!ret) { bch2_journal_block(&c->journal); percpu_down_write(&c->mark_lock); ret = bch2_gc_done(c, initial, metadata_only); bch2_journal_unblock(&c->journal); } else { percpu_down_write(&c->mark_lock); } /* Indicates that gc is no longer in progress: */ __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING)); bch2_gc_free(c); percpu_up_write(&c->mark_lock); 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); return ret; } /* 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_skip_noops(k, vstruct_last(s2))) { 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->c.lock); bch2_btree_node_free_never_inserted(c, n2); six_unlock_intent(&n2->c.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->c.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]->c.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); /* * 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; } } for (i = 0; i < nr_new_nodes; i++) six_unlock_intent(&new_nodes[i]->c.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_trans trans; 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]; bch2_trans_init(&trans, c, 0, 0); /* * 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(&trans, iter, 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]->c.lock, lock_seq[i])) break; if (merge[i]->c.level != merge[0]->c.level) { six_unlock_intent(&merge[i]->c.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]->c.lock.state.seq; six_unlock_intent(&merge[i]->c.lock); } lock_seq[0] = merge[0]->c.lock.state.seq; if (kthread && kthread_should_stop()) { bch2_trans_exit(&trans); return -ESHUTDOWN; } bch2_trans_cond_resched(&trans); /* * 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_trans_exit(&trans); } /** * bch_coalesce - coalesce adjacent nodes with low occupancy */ void bch2_coalesce(struct bch_fs *c) { enum btree_id id; 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); 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); int ret; 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); ret = bch2_gc(c, NULL, false, false); if (ret) bch_err(c, "btree gc failed: %i", ret); 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; }