Full_Name: Hallvard B Furuseth Version: mdb.master 27aaecc744955d08d2bfe7a3ca786d742267c5bd OS: Linux x86_64 URL: Submission from: (NULL) (193.69.163.163) Submitted by: hallvard

If the malloc at mdb_page_malloc() line 1348 fails, me_pgfirst has already been incremented and those pages can be lost.

I'll fix that one. Not this, however:

If a child transaction aborts, it loses pages it used up: It does not give them back to me_pghead, nor to the parent's mt_free_pgs. It does not rewind me_pgfirst/me_last to their state at txn_begin.

This program illustrates. The DB grows to 107 pages. mdb_stat can see 10 of them, same as if everything was done in the main txn. MainDB will have max 1 entry while running.

#include <lmdb.h> #include <stdio.h> #include <stdlib.h>

int main(void) { int rc, i; MDB_val key = { sizeof(i), &i }, data = { 0, "" }; MDB_env *env; MDB_txn *txn, *ctxn; MDB_dbi dbi; # define dbname "test.mdb" # define E(e) { rc = (e); if (rc) { fprintf(stderr, "%d: %s: %s\n", \ __LINE__, #e, mdb_strerror(rc)); return rc; } } E(mdb_env_create(&env)); E(mdb_env_open(env, dbname, MDB_NOSYNC|MDB_NOSUBDIR, 0666)); for (i = 0; i < 100; ) { E(mdb_txn_begin(env, NULL, 0, &txn)); if (!i) { E(mdb_dbi_open(txn, NULL, MDB_CREATE, &dbi)); } else { E(mdb_txn_begin(env, txn, 0, &ctxn)); E(mdb_put(ctxn, dbi, &key, &data, 0)); mdb_txn_abort(ctxn); E(mdb_del(txn, dbi, &key, NULL)); } i++; E(mdb_put(txn, dbi, &key, &data, 0)); E(mdb_txn_commit(txn)); if (i % 20 == 0) system("du " dbname); } mdb_env_close(env); return 0; }