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);
-
- /*
- * XXX: this won't correctly take it account the new min/max keys:
- */
- 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_BTREE_PTR_U64s_MAX * nr_old_nodes)) {
- trace_btree_gc_coalesce_fail(c,
- BTREE_GC_COALESCE_FAIL_KEYLIST_REALLOC);
- return;
- }
-
- as = bch2_btree_update_start(iter, old_nodes[0]->c.level,
- btree_update_reserve_required(c, parent) + nr_old_nodes,
- BTREE_INSERT_NOFAIL|
- BTREE_INSERT_USE_RESERVE);
- 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->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 = bpos_successor(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);
-
- bch2_btree_update_add_new_node(as, 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 (!bpos_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_btree_update_get_open_buckets(as, 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(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;
- int ret = 0;
-
- /* 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()) {
- ret = -ESHUTDOWN;
- break;
- }
-
- 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]));
- }
- bch2_trans_iter_put(&trans, iter);
-
- return bch2_trans_exit(&trans) ?: ret;
-}
-
-/**
- * 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;
projects / linux.git / commitdiff