From f2d0824bdb799d10cd19427442b8d53b35ec4542 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Sun, 4 Oct 2015 01:56:25 +0100 Subject: [PATCH] lmdb: ITS#8258 fix rebalance/split. The tree height can also increase during rebalance, not just shrink. This can happen if update_key needs to split a parent branch page. Change-Id: Ie232bd9f4a6225b912b912a68f0b35411a632317 --- mdb.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/mdb.c b/mdb.c index 2693a4bb..62720019 100644 --- a/mdb.c +++ b/mdb.c @@ -7846,9 +7846,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst) uint16_t depth = cdst->mc_db->md_depth; mdb_cursor_pop(cdst); rc = mdb_rebalance(cdst); - /* Did the tree shrink? */ - if (depth > cdst->mc_db->md_depth) - snum--; + /* Did the tree height change? */ + if (depth != cdst->mc_db->md_depth) + snum += cdst->mc_db->md_depth - depth; cdst->mc_snum = snum; cdst->mc_top = snum-1; } @@ -8040,7 +8040,7 @@ mdb_rebalance(MDB_cursor *mc) */ if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) { rc = mdb_node_move(&mn, mc); - if (mc->mc_ki[ptop]) { + if (mc->mc_ki[mc->mc_top-1]) { oldki++; } } else { @@ -8254,8 +8254,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno mc->mc_ki[0] = 0; mc->mc_db->md_root = pp->mp_pgno; mdb_debug("root split! new root = %zu", pp->mp_pgno); - mc->mc_db->md_depth++; - new_root = 1; + new_root = mc->mc_db->md_depth++; /* Add left (implicit) pointer. */ if (unlikely((rc = mdb_node_add(mc, 0, NULL, NULL, mp->mp_pgno, 0)) != MDB_SUCCESS)) { @@ -8568,7 +8567,7 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno if (new_root) { int k; /* root split */ - for (k=m3->mc_top; k>=0; k--) { + for (k=new_root; k>=0; k--) { m3->mc_ki[k+1] = m3->mc_ki[k]; m3->mc_pg[k+1] = m3->mc_pg[k]; }