From 568c22c4cc494410147f6ef5435694bd3eca17c3 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Tue, 30 Apr 2013 21:09:09 -0700
Subject: [PATCH] Avoid assert
Due to underfilled branch page. We're in the process of merging/moving
nodes to it because we already know it's underfilled. Took this approach
rather than just removing the assert in mdb_page_search_root, because
that assert may yet catch other situations we don't know about.
(Although, it has been there since the original commit of mdb.c and
has never triggered any other times...)
---
libraries/liblmdb/mdb.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 83dcb2506b..09fc3e29e8 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -4128,6 +4128,28 @@ mdb_page_search_root(MDB_cursor *mc, MDB_val *key, int modify)
return MDB_SUCCESS;
}
+/** Search for the lowest key under the current branch page.
+ * This just bypasses a NUMKEYS check in the current page
+ * before calling mdb_page_search_root(), because the callers
+ * are all in situations where the current page is known to
+ * be underfilled.
+ */
+static int
+mdb_page_search_lowest(MDB_cursor *mc)
+{
+ MDB_page *mp = mc->mc_pg[mc->mc_top];
+ MDB_node *node = NODEPTR(mp, 0);
+ int rc;
+
+ if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(node), &mp)))
+ return rc;
+
+ mc->mc_ki[mc->mc_top] = 0;
+ if ((rc = mdb_cursor_push(mc, mp)))
+ return rc;
+ return mdb_page_search_root(mc, NULL, 0);
+}
+
/** Search for the page a given key should be in.
* Pushes parent pages on the cursor stack. This function just sets up
* the search; it finds the root page for \b mc's database and sets this
@@ -6024,7 +6046,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
unsigned int snum = csrc->mc_snum;
MDB_node *s2;
/* must find the lowest key below src */
- mdb_page_search_root(csrc, NULL, 0);
+ mdb_page_search_lowest(csrc);
if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
key.mv_size = csrc->mc_db->md_pad;
key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
@@ -6047,7 +6069,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
MDB_node *s2;
MDB_val bkey;
/* must find the lowest key below dst */
- mdb_page_search_root(cdst, NULL, 0);
+ mdb_page_search_lowest(cdst);
if (IS_LEAF2(cdst->mc_pg[cdst->mc_top])) {
bkey.mv_size = cdst->mc_db->md_pad;
bkey.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, bkey.mv_size);
@@ -6211,7 +6233,7 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
unsigned int snum = csrc->mc_snum;
MDB_node *s2;
/* must find the lowest key below src */
- mdb_page_search_root(csrc, NULL, 0);
+ mdb_page_search_lowest(csrc);
if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
key.mv_size = csrc->mc_db->md_pad;
key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
--
GitLab