Fix: avoid direct reference to meta pages

Relevant info should be copied during txn_begin only.

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index c32057c8a175c25a3f069038754ecd2f285f49de..0c8e6aa0e5609092a37b90a95400474a24903b33 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -1608,9 +1608,9 @@ mdb_txn_renew0(MDB_txn *txn)
                txn->mt_u.dirty_list[0].mid = 0;
                txn->mt_free_pgs = env->me_free_pgs;
                txn->mt_free_pgs[0] = 0;
-               txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
                env->me_txn = txn;
        }
+       txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
 
        /* Copy the DB arrays */
        LAZY_RWLOCK_RDLOCK(&env->me_dblock);
@@ -3380,7 +3380,7 @@ mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **ret)
                }
        }
        if (!p) {
-               if (pgno <= txn->mt_env->me_metas[txn->mt_toggle]->mm_last_pg)
+               if (pgno < txn->mt_next_pgno)
                        p = (MDB_page *)(txn->mt_env->me_map + txn->mt_env->me_psize * pgno);
        }
        *ret = p;