From 0c4c6fe72a57f812e4486cd017298f730df19c23 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Thu, 27 Sep 2012 05:01:53 -0700
Subject: [PATCH] ITS#7385, check further for bad splits
More for 48ef27b6f5c804eca6a9d27f8dd2b4ded376f8af
Our definition of "large" data item needs to be smaller to
handle more cases where a bad split is possible
---
libraries/libmdb/mdb.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 807294c28d..d15fa7c8a7 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -6117,15 +6117,19 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
* This check is only needed when the data items are
* relatively large, such that being off by one will
* make the difference between success or failure.
- * When the size of the data items is much smaller than
- * one-half of a page, this check is irrelevant.
+ *
+ * It's also relevant if a page happens to be laid out
+ * such that one half of its nodes are all "small" and
+ * the other half of its nodes are "large." If the new
+ * item is also "large" and falls on the half with
+ * "large" nodes, it also may not fit.
*/
if (IS_LEAF(mp)) {
unsigned int psize, nsize;
/* Maximum free space in an empty page */
pmax = mc->mc_txn->mt_env->me_psize - PAGEHDRSZ;
nsize = mdb_leaf_size(mc->mc_txn->mt_env, newkey, newdata);
- if ((nkeys < 20) || (nsize > pmax/4)) {
+ if ((nkeys < 20) || (nsize > pmax/16)) {
if (newindx <= split_indx) {
psize = nsize;
newpos = 0;
--
GitLab