diff options
Diffstat (limited to 'libbcachefs/btree_gc.c')
| -rw-r--r-- | libbcachefs/btree_gc.c | 954 |
1 files changed, 954 insertions, 0 deletions
diff --git a/libbcachefs/btree_gc.c b/libbcachefs/btree_gc.c new file mode 100644 index 00000000..0883b9b4 --- /dev/null +++ b/libbcachefs/btree_gc.c @@ -0,0 +1,954 @@ +/* + * Copyright (C) 2010 Kent Overstreet <kent.overstreet@gmail.com> + * Copyright (C) 2014 Datera Inc. + */ + +#include "bcachefs.h" +#include "alloc.h" +#include "bkey_methods.h" +#include "btree_locking.h" +#include "btree_update.h" +#include "btree_io.h" +#include "btree_gc.h" +#include "buckets.h" +#include "clock.h" +#include "debug.h" +#include "error.h" +#include "extents.h" +#include "journal.h" +#include "keylist.h" +#include "move.h" +#include "super-io.h" + +#include <linux/slab.h> +#include <linux/bitops.h> +#include <linux/freezer.h> +#include <linux/kthread.h> +#include <linux/rcupdate.h> +#include <trace/events/bcachefs.h> + +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); + } +} + +u8 bch2_btree_key_recalc_oldest_gen(struct bch_fs *c, struct bkey_s_c k) +{ + const struct bch_extent_ptr *ptr; + u8 max_stale = 0; + + if (bkey_extent_is_data(k.k)) { + struct bkey_s_c_extent e = bkey_s_c_to_extent(k); + + extent_for_each_ptr(e, ptr) { + struct bch_dev *ca = c->devs[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)); + } + } + + return max_stale; +} + +/* + * For runtime mark and sweep: + */ +static u8 bch2_btree_mark_key(struct bch_fs *c, enum bkey_type type, + struct bkey_s_c k) +{ + switch (type) { + case BKEY_TYPE_BTREE: + bch2_gc_mark_key(c, k, c->sb.btree_node_size, true); + return 0; + case BKEY_TYPE_EXTENTS: + bch2_gc_mark_key(c, k, k.k->size, false); + return bch2_btree_key_recalc_oldest_gen(c, k); + default: + BUG(); + } +} + +u8 bch2_btree_mark_key_initial(struct bch_fs *c, enum bkey_type type, + struct bkey_s_c k) +{ + atomic64_set(&c->key_version, + max_t(u64, k.k->version.lo, + atomic64_read(&c->key_version))); + + return bch2_btree_mark_key(c, type, k); +} + +static bool btree_gc_mark_node(struct bch_fs *c, struct btree *b) +{ + if (btree_node_has_ptrs(b)) { + struct btree_node_iter iter; + struct bkey unpacked; + struct bkey_s_c k; + u8 stale = 0; + + for_each_btree_node_key_unpack(b, k, &iter, + btree_node_is_extents(b), + &unpacked) { + bch2_bkey_debugcheck(c, b, k); + stale = max(stale, bch2_btree_mark_key(c, + btree_node_type(b), k)); + } + + if (btree_gc_rewrite_disabled(c)) + return false; + + if (stale > 10) + return true; + } + + if (btree_gc_always_rewrite(c)) + return true; + + return false; +} + +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); +} + +static int bch2_gc_btree(struct bch_fs *c, enum btree_id btree_id) +{ + struct btree_iter iter; + struct btree *b; + bool should_rewrite; + struct range_checks r; + unsigned depth = btree_id == BTREE_ID_EXTENTS ? 0 : 1; + int ret; + + /* + * if expensive_debug_checks is on, run range_checks on all leaf nodes: + */ + if (expensive_debug_checks(c)) + depth = 0; + + btree_node_range_checks_init(&r, depth); + + for_each_btree_node(&iter, c, btree_id, POS_MIN, depth, b) { + btree_node_range_checks(c, b, &r); + + bch2_verify_btree_nr_keys(b); + + should_rewrite = btree_gc_mark_node(c, b); + + gc_pos_set(c, gc_pos_btree_node(b)); + + if (should_rewrite) + bch2_btree_node_rewrite(&iter, b, NULL); + + 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; + bch2_btree_mark_key(c, BKEY_TYPE_BTREE, bkey_i_to_s_c(&b->key)); + gc_pos_set(c, gc_pos_btree_root(b->btree_id)); + + mutex_unlock(&c->btree_root_lock); + return 0; +} + +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; + + for_each_member_device(ca, c, ci) { + spin_lock(&ca->freelist_lock); + + fifo_for_each_entry(i, &ca->free_inc, iter) + bch2_mark_alloc_bucket(ca, &ca->buckets[i], true); + + for (j = 0; j < RESERVE_NR; j++) + fifo_for_each_entry(i, &ca->free[j], iter) + bch2_mark_alloc_bucket(ca, &ca->buckets[i], true); + + spin_unlock(&ca->freelist_lock); + } + + for (ob = c->open_buckets; + ob < c->open_buckets + ARRAY_SIZE(c->open_buckets); + ob++) { + const struct bch_extent_ptr *ptr; + + mutex_lock(&ob->lock); + open_bucket_for_each_ptr(ob, ptr) { + ca = c->devs[ptr->dev]; + bch2_mark_alloc_bucket(ca, PTR_BUCKET(ca, ptr), true); + } + mutex_unlock(&ob->lock); + } +} + +static void mark_metadata_sectors(struct bch_dev *ca, u64 start, u64 end, + enum bucket_data_type type) +{ + u64 b = start >> ca->bucket_bits; + + do { + bch2_mark_metadata_bucket(ca, ca->buckets + b, type, true); + b++; + } while (b < end >> ca->bucket_bits); +} + +static void bch2_dev_mark_superblocks(struct bch_dev *ca) +{ + struct bch_sb_layout *layout = &ca->disk_sb.sb->layout; + unsigned i; + + for (i = 0; i < layout->nr_superblocks; i++) { + if (layout->sb_offset[i] == BCH_SB_SECTOR) + mark_metadata_sectors(ca, 0, BCH_SB_SECTOR, + BUCKET_SB); + + mark_metadata_sectors(ca, + layout->sb_offset[i], + layout->sb_offset[i] + + (1 << layout->sb_max_size_bits), + BUCKET_SB); + } +} + +/* + * Mark non btree metadata - prios, journal + */ +void bch2_mark_dev_metadata(struct bch_fs *c, struct bch_dev *ca) +{ + unsigned i; + u64 b; + + lockdep_assert_held(&c->sb_lock); + + bch2_dev_mark_superblocks(ca); + + spin_lock(&c->journal.lock); + + for (i = 0; i < ca->journal.nr; i++) { + b = ca->journal.buckets[i]; + bch2_mark_metadata_bucket(ca, ca->buckets + b, + BUCKET_JOURNAL, true); + } + + spin_unlock(&c->journal.lock); + + spin_lock(&ca->prio_buckets_lock); + + for (i = 0; i < prio_buckets(ca) * 2; i++) { + b = ca->prio_buckets[i]; + if (b) + bch2_mark_metadata_bucket(ca, ca->buckets + b, + BUCKET_PRIOS, true); + } + + spin_unlock(&ca->prio_buckets_lock); +} + +static void bch2_mark_metadata(struct bch_fs *c) +{ + struct bch_dev *ca; + unsigned i; + + mutex_lock(&c->sb_lock); + gc_pos_set(c, gc_phase(GC_PHASE_SB_METADATA)); + + for_each_online_member(ca, c, i) + bch2_mark_dev_metadata(c, ca); + 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 bch_fs_usage stats = { 0 }; + struct btree_interior_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_gc_mark_key(c, bkey_i_to_s_c(&d->key), + c->sb.btree_node_size, true, + &stats); + /* + * Don't apply stats - pending deletes aren't tracked in + * bch_alloc_stats: + */ + + mutex_unlock(&c->btree_interior_update_lock); +} + +/** + * bch_gc - recompute bucket marks and oldest_gen, rewrite btree nodes + */ +void bch2_gc(struct bch_fs *c) +{ + struct bch_dev *ca; + struct bucket *g; + struct bucket_mark new; + u64 start_time = local_clock(); + unsigned i; + int cpu; + + /* + * 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 + */ + + if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) + return; + + 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); + + lg_global_lock(&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_POS_MIN); + + /* 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->s, 0, sizeof(p->s)); + p->persistent_reserved = 0; + } + + lg_global_unlock(&c->usage_lock); + + /* Clear bucket marks: */ + for_each_member_device(ca, c, i) + for_each_bucket(g, ca) { + bucket_cmpxchg(g, new, ({ + new.owned_by_allocator = 0; + new.data_type = 0; + new.cached_sectors = 0; + new.dirty_sectors = 0; + })); + ca->oldest_gens[g - ca->buckets] = new.gen; + } + + /* Walk allocator's references: */ + bch2_mark_allocator_buckets(c); + + /* Walk btree: */ + while (c->gc_pos.phase < (int) BTREE_ID_NR) { + int ret = c->btree_roots[c->gc_pos.phase].b + ? bch2_gc_btree(c, (int) c->gc_pos.phase) + : 0; + + if (ret) { + bch_err(c, "btree gc failed: %d", ret); + set_bit(BCH_FS_GC_FAILURE, &c->flags); + up_write(&c->gc_lock); + return; + } + + gc_pos_set(c, gc_phase(c->gc_pos.phase + 1)); + } + + bch2_mark_metadata(c); + bch2_mark_pending_btree_node_frees(c); + + for_each_member_device(ca, c, i) + atomic_long_set(&ca->saturated_count, 0); + + /* Indicates that gc is no longer in progress: */ + gc_pos_set(c, gc_phase(GC_PHASE_DONE)); + + up_write(&c->gc_lock); + trace_gc_end(c); + bch2_time_stats_update(&c->btree_gc_time, 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); +} + +/* Btree coalescing */ + +static void recalc_packed_keys(struct btree *b) +{ + struct bkey_packed *k; + + memset(&b->nr, 0, sizeof(b->nr)); + + BUG_ON(b->nsets != 1); + + for (k = btree_bkey_first(b, b->set); + k != btree_bkey_last(b, b->set); + k = bkey_next(k)) + btree_keys_account_key_add(&b->nr, 0, k); +} + +static void bch2_coalesce_nodes(struct btree *old_nodes[GC_MERGE_NODES], + struct btree_iter *iter) +{ + struct btree *parent = iter->nodes[old_nodes[0]->level + 1]; + struct bch_fs *c = iter->c; + 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_interior_update *as; + struct btree_reserve *res; + 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, 0); + + /* 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; + + res = bch2_btree_reserve_get(c, parent, nr_old_nodes, + BTREE_INSERT_NOFAIL| + BTREE_INSERT_USE_RESERVE, + NULL); + if (IS_ERR(res)) { + trace_btree_gc_coalesce_fail(c, + BTREE_GC_COALESCE_FAIL_RESERVE_GET); + 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); + goto out; + } + + /* 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); + goto out; + } + + trace_btree_gc_coalesce(c, parent, nr_old_nodes); + + as = bch2_btree_interior_update_alloc(c); + + for (i = 0; i < nr_old_nodes; i++) + bch2_btree_interior_update_will_free_node(c, 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(c, old_nodes[i], + new_format, res); + + /* + * 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, &as->cl, SIX_LOCK_intent, -1); + } + + /* + * 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(parent, iter, &keylist, res, as); + + BUG_ON(!bch2_keylist_empty(&keylist)); + + BUG_ON(iter->nodes[old_nodes[0]->level] != old_nodes[0]); + + BUG_ON(!bch2_btree_iter_node_replace(iter, new_nodes[0])); + + for (i = 0; i < nr_new_nodes; i++) + bch2_btree_open_bucket_put(c, new_nodes[i]); + + /* Free the old nodes and update our sliding window */ + for (i = 0; i < nr_old_nodes; i++) { + bch2_btree_node_free_inmem(iter, old_nodes[i]); + 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); + } + } +out: + bch2_keylist_free(&keylist, NULL); + bch2_btree_reserve_put(c, res); +} + +static int bch2_coalesce_btree(struct bch_fs *c, enum btree_id btree_id) +{ + struct btree_iter iter; + struct btree *b; + 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, 0, b, U8_MAX) { + 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(merge, &iter); + + 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 (test_bit(BCH_FS_GC_STOPPING, &c->flags)) { + 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 (iter.nodes[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) +{ + u64 start_time; + enum btree_id id; + + if (test_bit(BCH_FS_GC_FAILURE, &c->flags)) + return; + + down_read(&c->gc_lock); + trace_gc_coalesce_start(c); + start_time = local_clock(); + + 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; + } + } + + bch2_time_stats_update(&c->btree_coalesce_time, start_time); + 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) { + unsigned long next = last + c->capacity / 16; + + while (atomic_long_read(&clock->now) < next) { + set_current_state(TASK_INTERRUPTIBLE); + + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); + return 0; + } + + if (atomic_read(&c->kick_gc) != last_kick) { + __set_current_state(TASK_RUNNING); + break; + } + + bch2_io_clock_schedule_timeout(clock, next); + try_to_freeze(); + } + + last = atomic_long_read(&clock->now); + last_kick = atomic_read(&c->kick_gc); + + bch2_gc(c); + if (!btree_gc_coalesce_disabled(c)) + bch2_coalesce(c); + + debug_check_no_locks_held(); + } + + return 0; +} + +void bch2_gc_thread_stop(struct bch_fs *c) +{ + set_bit(BCH_FS_GC_STOPPING, &c->flags); + + if (c->gc_thread) + kthread_stop(c->gc_thread); + + c->gc_thread = NULL; + clear_bit(BCH_FS_GC_STOPPING, &c->flags); +} + +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, "bcache_gc"); + if (IS_ERR(p)) + return PTR_ERR(p); + + c->gc_thread = p; + wake_up_process(c->gc_thread); + return 0; +} + +/* Initial GC computes bucket marks during startup */ + +static void bch2_initial_gc_btree(struct bch_fs *c, enum btree_id id) +{ + struct btree_iter iter; + struct btree *b; + struct range_checks r; + + btree_node_range_checks_init(&r, 0); + + if (!c->btree_roots[id].b) + return; + + /* + * We have to hit every btree node before starting journal replay, in + * order for the journal seq blacklist machinery to work: + */ + for_each_btree_node(&iter, c, id, POS_MIN, 0, b) { + btree_node_range_checks(c, b, &r); + + if (btree_node_has_ptrs(b)) { + struct btree_node_iter node_iter; + struct bkey unpacked; + struct bkey_s_c k; + + for_each_btree_node_key_unpack(b, k, &node_iter, + btree_node_is_extents(b), + &unpacked) + bch2_btree_mark_key_initial(c, btree_node_type(b), k); + } + + bch2_btree_iter_cond_resched(&iter); + } + + bch2_btree_iter_unlock(&iter); + + bch2_btree_mark_key(c, BKEY_TYPE_BTREE, + bkey_i_to_s_c(&c->btree_roots[id].b->key)); +} + +int bch2_initial_gc(struct bch_fs *c, struct list_head *journal) +{ + enum btree_id id; + + for (id = 0; id < BTREE_ID_NR; id++) + bch2_initial_gc_btree(c, id); + + if (journal) + bch2_journal_mark(c, journal); + + bch2_mark_metadata(c); + + /* + * 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); + + return 0; +} |