Bug#35410528 : INSTANT DDL crashes 8.0.32 after upgrading from 5.7.41

Background:
 When tables are loaded in mem cache (dict_table_t) they go through
 fill_dict_table() which makes sure all in mem metadata is updated
 for the tables correctly.

 But in case of upgrade from 5.7, tables are loaded in dict_table_t
 cache from dict_load_table(). And then it remains in cache to be used.

Issue:
 During upgrade, when the table is loaded from dict_load_table(), it
 doesn't set the initial/current/total/_column_count metadata of
 dict_table_t. Which causes issues when table is used after INSTANT
 ADD/DROP DDL.

 Note this is done only once and next server restarts, the table is
 loaded from fill_dict_table() function. And this is why if there is a
 restart after upgrade, the issue is not seen.

Fix:
 Made sure when the table is loaded from dict_load_table() during
 upgrade, the column count metadata is also set correctly.

Change-Id: I7729a9e03683737bfe8b3025203f31551b710f70

Author: mayprasa

storage/innobase/dict/dict0load.cc

@@ -1621,56 +1621,48 @@ static inline space_id_t dict_check_sys_tables(bool validate) {
   return max_space_id;
 }
 
-/** Loads definitions for table columns. */
-static void dict_load_columns(dict_table_t *table, /*!< in/out: table */
-                              mem_heap_t *heap)    /*!< in/out: memory heap
-                                                   for temporary storage */
-{
-  dict_table_t *sys_columns;
-  dict_index_t *sys_index;
-  btr_pcur_t pcur;
-  dtuple_t *tuple;
-  dfield_t *dfield;
-  const rec_t *rec;
-  byte *buf;
-  ulint i;
-  mtr_t mtr;
-  ulint n_skipped = 0;
-
+/** Load columns in an innodb cached table object from SYS_COLUMNS table.
+@param[in, out]  table  Table cache object
+@param[in, out]  heap   memory heap for temporary storage */
+static void dict_load_columns(dict_table_t *table, mem_heap_t *heap) {
   ut_ad(dict_sys_mutex_own());
 
+  mtr_t mtr;
   mtr_start(&mtr);
 
-  sys_columns = dict_table_get_low("SYS_COLUMNS");
-  sys_index = UT_LIST_GET_FIRST(sys_columns->indexes);
+  dict_table_t *sys_columns = dict_table_get_low("SYS_COLUMNS");
+  dict_index_t *sys_index = UT_LIST_GET_FIRST(sys_columns->indexes);
   ut_ad(!dict_table_is_comp(sys_columns));
 
   ut_ad(name_of_col_is(sys_columns, sys_index, DICT_FLD__SYS_COLUMNS__NAME,
                        "NAME"));
   ut_ad(name_of_col_is(sys_columns, sys_index, DICT_FLD__SYS_COLUMNS__PREC,
                        "PREC"));
 
-  tuple = dtuple_create(heap, 1);
-  dfield = dtuple_get_nth_field(tuple, 0);
+  dtuple_t *tuple = dtuple_create(heap, 1);
+  dfield_t *dfield = dtuple_get_nth_field(tuple, 0);
 
-  buf = static_cast<byte *>(mem_heap_alloc(heap, 8));
+  byte *buf = static_cast<byte *>(mem_heap_alloc(heap, 8));
   mach_write_to_8(buf, table->id);
 
   dfield_set_data(dfield, buf, 8);
   dict_index_copy_types(tuple, sys_index, 1);
 
+  btr_pcur_t pcur;
   pcur.open_on_user_rec(sys_index, tuple, PAGE_CUR_GE, BTR_SEARCH_LEAF, &mtr,
                         UT_LOCATION_HERE);
 
   ut_ad(table->n_t_cols == static_cast<ulint>(table->n_cols) +
                                static_cast<ulint>(table->n_v_cols));
 
-  for (i = 0; i + DATA_N_SYS_COLS < table->n_t_cols + n_skipped; i++) {
+  size_t non_v_cols = 0;
+  size_t n_skipped = 0;
+  for (size_t i = 0; i + DATA_N_SYS_COLS < table->n_t_cols + n_skipped; i++) {
     const char *err_msg;
     const char *name = nullptr;
     ulint nth_v_col = ULINT_UNDEFINED;
 
-    rec = pcur.get_rec();
+    const rec_t *rec = pcur.get_rec();
 
     ut_a(pcur.is_on_user_rec());
 
@@ -1684,6 +1676,11 @@ static void dict_load_columns(dict_table_t *table, /*!< in/out: table */
       ib::fatal(UT_LOCATION_HERE, ER_IB_MSG_195) << err_msg;
     }
 
+    if (nth_v_col == ULINT_UNDEFINED) {
+      /* Not a virtual column */
+      non_v_cols++;
+    }
+
     /* Note: Currently we have one DOC_ID column that is
     shared by all FTS indexes on a table. And only non-virtual
     column can be used for FULLTEXT index */
@@ -1727,6 +1724,11 @@ static void dict_load_columns(dict_table_t *table, /*!< in/out: table */
 
   pcur.close();
   mtr_commit(&mtr);
+
+  /* The table is getting upgraded from 5.7 where there was no row version */
+  table->initial_col_count = table->current_col_count = table->total_col_count =
+      non_v_cols;
+  table->current_row_version = 0;
 }
 
 /** Loads definitions for index fields.

storage/innobase/include/dict0mem.h

@@ -2132,7 +2132,7 @@ struct dict_table_t {
   uint32_t total_col_count{0};
 
   /** Set if table is upgraded instant table */
-  unsigned m_upgraded_instant : 1;
+  bool m_upgraded_instant{false};
 
   /** table dynamic metadata status, protected by dict_persist->mutex */
   std::atomic<table_dirty_status> dirty_status;
@@ -2531,13 +2531,11 @@ detect this and will eventually quit sooner. */
   bool has_instant_drop_cols() const { return (get_n_instant_drop_cols() > 0); }
 
   /** Set table to be upgraded table with INSTANT ADD columns in V1. */
-  void set_upgraded_instant() { m_upgraded_instant = 1; }
+  void set_upgraded_instant() { m_upgraded_instant = true; }
 
   /** Checks if table is upgraded table with INSTANT ADD columns in V1.
   @return       true if it is, false otherwise */
-  bool is_upgraded_instant() const {
-    return (m_upgraded_instant == 1) ? true : false;
-  }
+  bool is_upgraded_instant() const { return m_upgraded_instant; }
 
   /** Check whether the table is corrupted.
   @return true if the table is corrupted, otherwise false */