bk commit into 5.1 tree (dlenev:1.2517) BUG#28415

[dlenev]

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ChangeSet@stripped, 2007-05-14 22:38:26+04:00, dlenev@stripped +3 -0
  Fix for bug #28415 "Some ALTER TABLE statements no longer work under LOCK
  TABLES" and failures of alter_table.test on Windows which occured after
  pushing fix for bugs #20662, #20903, #24508, #24738 (various problems
  with CREATE TABLE SELECT).
  
  ALTER TABLE statements which were handled using "fast" alter table
  optimization were not properly working under LOCK TABLES if table
  was transactional (for all table types under Windows).
  
  Code implementing "fast" version of ALTER TABLE tried to open and
  lock table using open_ltable() after renaming .FRM files (which
  corresponds to renaming tables in normal case) in some cases
  (for transactional tables or on Windows). This caused problems
  under LOCK TABLES and conflicted with name-lock taken by 
  ALTER TABLE RENAME on target tables.
  
  This patch solves this issue by using reopen_name_locked_table()
  instead of open_ltable().

  mysql-test/include/mix1.inc@stripped, 2007-05-14 22:38:23+04:00, dlenev@stripped +20
-0
    Added test for bug #28415 "Some ALTER TABLE statements no longer work
    under LOCK TABLES" and minimal coverage for fast ALTER TABLE behaviour
    for transactional tables.

  mysql-test/r/innodb_mysql.result@stripped, 2007-05-14 22:38:23+04:00,
dlenev@stripped +11 -0
    Added test for bug #28415 "Some ALTER TABLE statements no longer work
    under LOCK TABLES" and minimal coverage for fast ALTER TABLE behaviour
    for transactional tables.

  sql/sql_table.cc@stripped, 2007-05-14 22:38:23+04:00, dlenev@stripped +40 -4
    mysql_alter_table():
      Fixed handling of transactional tables (and all tables on Windows)
      by "fast" ALTER TABLE.
      Code implementing "fast" version of ALTER TABLE tried to open and
      lock table using open_ltable() after renaming .FRM files (which
      corresponds to renaming tables in normal case) for such tables.
      This caused problems under LOCK TABLES and conflicted with name-lock
      taken by ALTER TABLE RENAME on target tables. We solve this issue by
      using reopen_name_locked_table() instead of open_ltable().

# This is a BitKeeper patch.  What follows are the unified diffs for the
# set of deltas contained in the patch.  The rest of the patch, the part
# that BitKeeper cares about, is below these diffs.
# User:	dlenev
# Host:	mockturtle.local
# Root:	/home/dlenev/src/mysql-5.1-cts-3

--- 1.415/sql/sql_table.cc	2007-05-14 22:38:34 +04:00
+++ 1.416/sql/sql_table.cc	2007-05-14 22:38:34 +04:00
@@ -6673,6 +6673,7 @@ view_err:
   }
   if (! need_copy_table)
   {
+    bool needs_unlink= FALSE;
     if (! table)
     {
       if (new_name != table_name || new_db != db)
@@ -6683,11 +6684,41 @@ view_err:
         table_list->db= new_db;
         table_list->db_length= strlen(new_db);
       }
-
-      VOID(pthread_mutex_unlock(&LOCK_open));
-      if (! (table= open_ltable(thd, table_list, TL_WRITE_ALLOW_READ)))
+      else
+      {
+        /*
+          TODO: Creation of name-lock placeholder here is a temporary
+          work-around. Long term we should change close_cached_table() call
+          which we invoke before table renaming operation in such way that
+          it will leave placeholders for table in table cache/THD::open_tables
+          list. By doing this we will be able easily reopen and relock these
+          tables later and therefore behave under LOCK TABLES in the same way
+          on all platforms.
+        */
+        char  key[MAX_DBKEY_LENGTH];
+        uint  key_length;
+        key_length= create_table_def_key(thd, key, table_list, 0);
+        if (!(name_lock= table_cache_insert_placeholder(thd, key,
+                                                        key_length)))
+        {
+          VOID(pthread_mutex_unlock(&LOCK_open));
+          goto err;
+        }
+        name_lock->next= thd->open_tables;
+        thd->open_tables= name_lock;
+      }
+      table_list->table= name_lock;
+      if (reopen_name_locked_table(thd, table_list, FALSE))
+      {
+        VOID(pthread_mutex_unlock(&LOCK_open));
         goto err;
-      VOID(pthread_mutex_lock(&LOCK_open));
+      }
+      table= table_list->table;
+      /*
+        We can't rely on later close_cached_table() calls to close
+        this instance of the table since it was not properly locked.
+      */
+      needs_unlink= TRUE;
     }
     /* Tell the handler that a new frm file is in place. */
     if (table->file->create_handler_files(path, NULL, CHF_INDEX_FLAG,
@@ -6695,6 +6726,11 @@ view_err:
     {
       VOID(pthread_mutex_unlock(&LOCK_open));
       goto err;
+    }
+    if (needs_unlink)
+    {
+      unlink_open_table(thd, table, FALSE);
+      table= name_lock= 0;
     }
   }
 

--- 1.29/mysql-test/r/innodb_mysql.result	2007-05-14 22:38:34 +04:00
+++ 1.30/mysql-test/r/innodb_mysql.result	2007-05-14 22:38:34 +04:00
@@ -733,4 +733,15 @@ k	a	c
 11	15	1
 12	20	1
 drop table t2;
+drop table if exists t1, t2;
+create table t1 (i int);
+alter table t1 modify i int default 1;
+alter table t1 modify i int default 2, rename t2;
+lock table t2 write;
+alter table t2 modify i int default 3;
+unlock tables;
+lock table t2 write;
+alter table t2 modify i int default 4, rename t1;
+unlock tables;
+drop table t1;
 End of 5.1 tests

--- 1.29/mysql-test/include/mix1.inc	2007-05-14 22:38:34 +04:00
+++ 1.30/mysql-test/include/mix1.inc	2007-05-14 22:38:34 +04:00
@@ -688,4 +688,24 @@ select * from t2;
 
 drop table t2;
 
+
+#
+# Tests for bug #28415 "Some ALTER TABLE statements no longer work
+# under LOCK TABLES" and some aspects of fast ALTER TABLE behaviour
+# for transactional tables.
+#
+--disable_warnings
+drop table if exists t1, t2;
+--enable_warnings
+create table t1 (i int);
+alter table t1 modify i int default 1;
+alter table t1 modify i int default 2, rename t2;
+lock table t2 write;
+alter table t2 modify i int default 3;
+unlock tables;
+lock table t2 write;
+alter table t2 modify i int default 4, rename t1;
+unlock tables;
+drop table t1;
+
 --echo End of 5.1 tests