From 17e21a9f248d3d330acdfb2405c23b8d84c9c23a Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 26 Jul 2013 12:32:38 -0700 Subject: bcache: Have btree_split() insert into parent directly The flow control in btree_insert_node() was... fragile... before, this'll use more stack (but since our btrees are never more than depth 1, that shouldn't matter) and it should be significantly clearer and less fragile. Signed-off-by: Kent Overstreet --- drivers/md/bcache/btree.c | 85 ++++++++++++++++++++++------------------------- 1 file changed, 39 insertions(+), 46 deletions(-) (limited to 'drivers/md/bcache') diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 1a7530cd1407..6def7c9a1228 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -2025,15 +2025,16 @@ static bool bch_btree_insert_keys(struct btree *b, struct btree_op *op, static int btree_split(struct btree *b, struct btree_op *op, struct keylist *insert_keys, - struct keylist *parent_keys, struct bkey *replace_key) { bool split; struct btree *n1, *n2 = NULL, *n3 = NULL; uint64_t start_time = local_clock(); struct closure cl; + struct keylist parent_keys; closure_init_stack(&cl); + bch_keylist_init(&parent_keys); n1 = btree_node_alloc_replacement(b, true); if (IS_ERR(n1)) @@ -2078,7 +2079,7 @@ static int btree_split(struct btree *b, struct btree_op *op, bkey_copy_key(&n2->key, &b->key); - bch_keylist_add(parent_keys, &n2->key); + bch_keylist_add(&parent_keys, &n2->key); bch_btree_node_write(n2, &cl); rw_unlock(true, n2); } else { @@ -2087,33 +2088,39 @@ static int btree_split(struct btree *b, struct btree_op *op, bch_btree_insert_keys(n1, op, insert_keys, replace_key); } - bch_keylist_add(parent_keys, &n1->key); + bch_keylist_add(&parent_keys, &n1->key); bch_btree_node_write(n1, &cl); if (n3) { /* Depth increases, make a new root */ - bkey_copy_key(&n3->key, &MAX_KEY); - bch_btree_insert_keys(n3, op, parent_keys, NULL); + bch_btree_insert_keys(n3, op, &parent_keys, NULL); bch_btree_node_write(n3, &cl); closure_sync(&cl); bch_btree_set_root(n3); rw_unlock(true, n3); + + btree_node_free(b); } else if (!b->parent) { /* Root filled up but didn't need to be split */ - - bch_keylist_reset(parent_keys); closure_sync(&cl); bch_btree_set_root(n1); + + btree_node_free(b); } else { + /* Split a non root node */ closure_sync(&cl); - make_btree_freeing_key(b, parent_keys->top); - bch_keylist_push(parent_keys); + make_btree_freeing_key(b, parent_keys.top); + bch_keylist_push(&parent_keys); + + btree_node_free(b); + + bch_btree_insert_node(b->parent, op, &parent_keys, NULL, NULL); + BUG_ON(!bch_keylist_empty(&parent_keys)); } rw_unlock(true, n1); - btree_node_free(b); bch_time_stats_update(&b->c->btree_split_time, start_time); @@ -2139,46 +2146,32 @@ static int bch_btree_insert_node(struct btree *b, struct btree_op *op, atomic_t *journal_ref, struct bkey *replace_key) { - int ret = 0; - struct keylist split_keys; - - bch_keylist_init(&split_keys); + BUG_ON(b->level && replace_key); - do { - BUG_ON(b->level && replace_key); - - if (should_split(b)) { - if (current->bio_list) { - op->lock = b->c->root->level + 1; - ret = -EAGAIN; - } else if (op->lock <= b->c->root->level) { - op->lock = b->c->root->level + 1; - ret = -EINTR; - } else { - struct btree *parent = b->parent; - - ret = btree_split(b, op, insert_keys, - &split_keys, replace_key); - insert_keys = &split_keys; - replace_key = NULL; - b = parent; - if (!ret) - ret = -EINTR; - } + if (should_split(b)) { + if (current->bio_list) { + op->lock = b->c->root->level + 1; + return -EAGAIN; + } else if (op->lock <= b->c->root->level) { + op->lock = b->c->root->level + 1; + return -EINTR; } else { - BUG_ON(write_block(b) != b->sets[b->nsets].data); - - if (bch_btree_insert_keys(b, op, insert_keys, - replace_key)) { - if (!b->level) - bch_btree_leaf_dirty(b, journal_ref); - else - bch_btree_node_write_sync(b); - } + /* Invalidated all iterators */ + return btree_split(b, op, insert_keys, replace_key) ?: + -EINTR; } - } while (!bch_keylist_empty(&split_keys)); + } else { + BUG_ON(write_block(b) != b->sets[b->nsets].data); - return ret; + if (bch_btree_insert_keys(b, op, insert_keys, replace_key)) { + if (!b->level) + bch_btree_leaf_dirty(b, journal_ref); + else + bch_btree_node_write_sync(b); + } + + return 0; + } } int bch_btree_insert_check_key(struct btree *b, struct btree_op *op, -- cgit v1.2.3