MDEV-14372: Fix and enable rocksdb.information_schema test

- Make Rdb_binlog_manager::unpack_value to not have a stack overrun
  when it is reading invalid data (which it currently does as we in
  MariaDB do not store binlog coordinates under BINLOG_INFO_INDEX_NUMBER,
  see comments in MDEV-14892 for details).
- We may need to store these coordinates in the future, so instead of
  removing the call of this function, let's make it work properly for
  all possible inputs.

storage/rocksdb/mysql-test/rocksdb/r/information_schema.result

 DROP TABLE IF EXISTS t1;
 DROP TABLE IF EXISTS t2;
 DROP TABLE IF EXISTS t3;
+create table t1 (a int) engine=rocksdb;
+drop table t1;
 select * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 TYPE	NAME	VALUE
 MAX_INDEX_ID	MAX_INDEX_ID	max_index_id
 CF_FLAGS	0	default [0]
 CF_FLAGS	1	__system__ [0]
+DDL_DROP_INDEX_ONGOING	cf_id:0,index_id:max_index_id	
 select count(*) from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 count(*)
-3
+4
 select VALUE into @keysIn from INFORMATION_SCHEMA.ROCKSDB_COMPACTION_STATS where CF_NAME = 'default' and LEVEL = 'Sum' and TYPE = 'KeyIn';
 CREATE TABLE t1 (i1 INT, i2 INT, PRIMARY KEY (i1)) ENGINE = ROCKSDB;
 INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3);
 select * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 TYPE	NAME	VALUE
-BINLOG	FILE	master-bin.000001
-BINLOG	POS	1066
-BINLOG	GTID	uuid:5
 MAX_INDEX_ID	MAX_INDEX_ID	max_index_id
 CF_FLAGS	0	default [0]
 CF_FLAGS	1	__system__ [0]
 select count(*) from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 count(*)
-6
+3
 set global rocksdb_force_flush_memtable_now = true;
 set global rocksdb_compact_cf='default';
 select case when VALUE-@keysIn >= 3 then 'true' else 'false' end from INFORMATION_SCHEMA.ROCKSDB_COMPACTION_STATS where CF_NAME = 'default' and LEVEL = 'Sum' and TYPE = 'KeyIn';
@@ -66,7 +66,7 @@ SHOW GLOBAL VARIABLES LIKE 'ROCKSDB_PAUSE_BACKGROUND_WORK';
 Variable_name	Value
 rocksdb_pause_background_work	ON
 DROP TABLE t3;
-cf_id:0,index_id:267
+cf_id:0,index_id:264
 SET GLOBAL ROCKSDB_PAUSE_BACKGROUND_WORK=0;
 SHOW GLOBAL VARIABLES LIKE 'ROCKSDB_PAUSE_BACKGROUND_WORK';
 Variable_name	Value

storage/rocksdb/mysql-test/rocksdb/t/disabled.def

@@ -72,7 +72,6 @@ blind_delete_without_tx_api: MDEV-12286: rocksdb.blind_delete_without_tx_api tes
 ## Tests that fail for some other reason
 ##
 
-information_schema : MariaRocks: requires GTIDs
 mysqlbinlog_gtid_skip_empty_trans_rocksdb : MariaRocks: requires GTIDs
 rpl_row_triggers : MariaRocks: requires GTIDs
 

storage/rocksdb/mysql-test/rocksdb/t/information_schema-master.opt

---binlog_format=row --gtid_mode=ON --enforce_gtid_consistency --log_slave_updates
+--binlog_format=row --log_slave_updates

storage/rocksdb/mysql-test/rocksdb/t/information_schema.test

@@ -9,6 +9,13 @@ DROP TABLE IF EXISTS t2;
 DROP TABLE IF EXISTS t3;
 --enable_warnings
 
+# MariaDB: the following is for handling the case where the tests
+#   is started on a totally empty datadir, where no MyRocks table has
+#   ever been created). In that case, there is no MAX_INDEX_ID.
+#   Create/drop a table so that we do have MAX_INDEX_ID.
+create table t1 (a int) engine=rocksdb;
+drop table t1;
+
 --let $max_index_id = query_get_value(SELECT * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO where type = 'MAX_INDEX_ID', VALUE, 1)
 --replace_result $max_index_id max_index_id
 select * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
@@ -19,9 +26,10 @@ select VALUE into @keysIn from INFORMATION_SCHEMA.ROCKSDB_COMPACTION_STATS where
 CREATE TABLE t1 (i1 INT, i2 INT, PRIMARY KEY (i1)) ENGINE = ROCKSDB;
 INSERT INTO t1 VALUES (1, 1), (2, 2), (3, 3);
 
---let $MASTER_UUID = query_get_value(SELECT @@SERVER_UUID, @@SERVER_UUID, 1)
+# No binlog coordinates in MariaDB: --let $MASTER_UUID = query_get_value(SELECT @@SERVER_UUID, @@SERVER_UUID, 1)
 --let $max_index_id = query_get_value(SELECT * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO where type = 'MAX_INDEX_ID', VALUE, 1)
---replace_result $MASTER_UUID uuid $max_index_id max_index_id
+# No binlog coordinates in MariaDB: --replace_result $MASTER_UUID uuid $max_index_id max_index_id
+--replace_result $max_index_id max_index_id
 select * from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 select count(*) from INFORMATION_SCHEMA.ROCKSDB_GLOBAL_INFO;
 

storage/rocksdb/rdb_datadic.cc

@@ -4261,7 +4261,7 @@ bool Rdb_binlog_manager::read(char *const binlog_name,
     std::string value;
     rocksdb::Status status = m_dict->get_value(m_key_slice, &value);
     if (status.ok()) {
-      if (!unpack_value((const uchar *)value.c_str(), binlog_name, binlog_pos,
+      if (!unpack_value((const uchar *)value.c_str(), value.size(), binlog_name, binlog_pos,
                         binlog_gtid))
         ret = true;
     }
@@ -4331,35 +4331,60 @@ Rdb_binlog_manager::pack_value(uchar *const buf, const char *const binlog_name,
   @return     true on error
 */
 bool Rdb_binlog_manager::unpack_value(const uchar *const value,
+                                      size_t value_size_arg,
                                       char *const binlog_name,
                                       my_off_t *const binlog_pos,
                                       char *const binlog_gtid) const {
   uint pack_len = 0;
+  intmax_t value_size= value_size_arg;
 
   DBUG_ASSERT(binlog_pos != nullptr);
 
+  if ((value_size -= Rdb_key_def::VERSION_SIZE) < 0)
+    return true;
   // read version
   const uint16_t version = rdb_netbuf_to_uint16(value);
+
   pack_len += Rdb_key_def::VERSION_SIZE;
   if (version != Rdb_key_def::BINLOG_INFO_INDEX_NUMBER_VERSION)
     return true;
 
+  if ((value_size -= sizeof(uint16)) < 0)
+    return true;
+
   // read binlog file name length
   const uint16_t binlog_name_len = rdb_netbuf_to_uint16(value + pack_len);
   pack_len += sizeof(uint16);
+
+  if (binlog_name_len >= (FN_REFLEN+1))
+    return true;
+
+  if ((value_size -= binlog_name_len) < 0)
+    return true;
+
   if (binlog_name_len) {
     // read and set binlog name
     memcpy(binlog_name, value + pack_len, binlog_name_len);
     binlog_name[binlog_name_len] = '\0';
     pack_len += binlog_name_len;
 
+    if ((value_size -= sizeof(uint32)) < 0)
+      return true;
     // read and set binlog pos
     *binlog_pos = rdb_netbuf_to_uint32(value + pack_len);
     pack_len += sizeof(uint32);
 
+    if ((value_size -= sizeof(uint16)) < 0)
+      return true;
     // read gtid length
     const uint16_t binlog_gtid_len = rdb_netbuf_to_uint16(value + pack_len);
     pack_len += sizeof(uint16);
+
+    if (binlog_gtid_len >= GTID_BUF_LEN)
+      return true;
+    if ((value_size -= binlog_gtid_len) < 0)
+      return true;
+
     if (binlog_gtid && binlog_gtid_len > 0) {
       // read and set gtid
       memcpy(binlog_gtid, value + pack_len, binlog_gtid_len);

storage/rocksdb/rdb_datadic.h

@@ -46,6 +46,8 @@ class Rdb_field_packing;
 class Rdb_cf_manager;
 class Rdb_ddl_manager;
 
+const uint32_t GTID_BUF_LEN = 60;
+
 /*
   @brief
   Field packing context.
@@ -1154,7 +1156,8 @@ class Rdb_binlog_manager {
   rocksdb::Slice pack_value(uchar *const buf, const char *const binlog_name,
                             const my_off_t &binlog_pos,
                             const char *const binlog_gtid) const;
-  bool unpack_value(const uchar *const value, char *const binlog_name,
+  bool unpack_value(const uchar *const value, size_t value_size,
+                    char *const binlog_name,
                     my_off_t *const binlog_pos, char *const binlog_gtid) const;
 
   std::atomic<Rdb_tbl_def *> m_slave_gtid_info_tbl;

storage/rocksdb/rdb_i_s.cc

@@ -729,7 +729,6 @@ static int rdb_i_s_global_info_fill_table(
   DBUG_ASSERT(tables != nullptr);
 
   static const uint32_t INT_BUF_LEN = 21;
-  static const uint32_t GTID_BUF_LEN = 60;
   static const uint32_t CF_ID_INDEX_BUF_LEN = 60;
 
   int ret = 0;