bzr commit into mysql-5.0-bugteam branch (gshchepa:2711) Bug#40021

[Gleb Shchepa]

#At file:///work/bzr/5.0-bugteam-40021/

 2711 Gleb Shchepa	2008-11-10
      Bug #40021: Renaming view fails, archived .frm for view is
                  missing after downgrade
      
      Obsolete arc/ directory and view .frm file backup support
      has been removed by the patch for bug 17823. However, that
      bugfix caused a problem with "live downgrades" of the
      server: if we rename some view 4 times under 5.1.29/5.0.72
      and then try to rename it under 5.1.28/5.0.70 on the same
      database, the server fails with a error:
      
        query 'RENAME TABLE ... TO ...' failed: 6: Error on
        delete of '....frm-0001' (Errcode: 2)
      
      Also .frm file of that view may be lost (renamed to .frm~).
      
      The server failed because it tried to rename latest 3
      backup .frm files renaming the view: the server used an
      integer value of the "revision" field of .frm file to
      extract those file names. After the fix for bug 17823 those
      files were not created/maintained any more, however the
      "revision" field was incremented as usual. So, the server
      failed renaming non existent files.
      
      This fix solves the problem by removing the support for
      "revision" .frm file field:
      1. New server silently ignores existent "revision" fields
         in old .frm files and never write it down;
      2. Old server assumes, that missing "revision" field in new
         .frm files means default value of 0.
      3. Accordingly to the fix for bug 17823 the new server
         drops arc/ directory on alter/rename view, so after
         "live downgrade" old server begins maintenance of the
         arc/ directory from scratch without conflicts with .frm
         files.
modified:
  sql/parse_file.cc
  sql/parse_file.h
  sql/sql_db.cc
  sql/sql_trigger.cc
  sql/sql_view.cc
  sql/table.h

per-file messages:
  sql/parse_file.cc
    1. write_parameter(): the max_versions parameter has been
       removed;
    2. sql_create_definition_file(): removal of dead code;
    3. rename_in_schema_file(): revision and num_view_backups
       parameters and dead code have been removed;
  sql/parse_file.h
    sql_create_definition_file and rename_in_schema_file
    functions: obsolete versions, revision and num_view_backups
    parameters have been removed;
  sql/sql_db.cc
    Commentary update.
  sql/sql_trigger.cc
    sql_create_definition_file() calls have been updates to
    new parameter lists.
  sql/sql_view.cc
    1. The mysql_create_view function code is used for both
       CREATE VIEW and ALTER queries, but query cache is
       necessary for ALTER command only. Check for a non first
       view revision has been replaced with a direct check for
       ALTER query.
    2. The num_view_backups global constant has been removed.
    3. view_parameters: the "revision" .frm field support has
       been removed.
    4. sql_create_definition_file and rename_in_schema_file
       function calls have been updates to new parameter lists.
  sql/table.h
    TABLE_LIST: the revision field has been removed.
=== modified file 'sql/parse_file.cc'
--- a/sql/parse_file.cc	2008-09-30 12:50:28 +0000
+++ b/sql/parse_file.cc	2008-11-10 17:53:10 +0000
@@ -205,7 +205,6 @@ write_parameter(IO_CACHE *file, gptr bas
     base		base address for parameter reading (structure like
 			TABLE)
     parameters		parameters description
-    max_versions	number of versions to save
 
   RETURN
     FALSE - OK
@@ -215,8 +214,7 @@ write_parameter(IO_CACHE *file, gptr bas
 my_bool
 sql_create_definition_file(const LEX_STRING *dir, const LEX_STRING *file_name,
 			   const LEX_STRING *type,
-			   gptr base, File_option *parameters,
-			   uint max_versions)
+			   gptr base, File_option *parameters)
 {
   File handler;
   IO_CACHE file;
@@ -269,55 +267,6 @@ sql_create_definition_file(const LEX_STR
   }
 
   path[path_end]='\0';
-#ifdef FRM_ARCHIVE
-  // archive copies management: disabled unused feature (see bug #17823).
-  if (!access(path, F_OK))
-  {
-    if (old_version != ULONGLONG_MAX && max_versions != 0)
-    {
-      // save backup
-      char path_arc[FN_REFLEN];
-      // backup old version
-      char path_to[FN_REFLEN];
-
-      // check archive directory existence
-      fn_format(path_arc, "arc", dir->str, "", MY_UNPACK_FILENAME);
-      if (access(path_arc, F_OK))
-      {
-	if (my_mkdir(path_arc, 0777, MYF(MY_WME)))
-	{
-	  DBUG_RETURN(TRUE);
-	}
-      }
-
-      my_snprintf(path_to, FN_REFLEN, "%s/%s-%04lu",
-		  path_arc, file_name->str, (ulong) old_version);
-      if (my_rename(path, path_to, MYF(MY_WME)))
-      {
-	DBUG_RETURN(TRUE);
-      }
-
-      // remove very old version
-      if (old_version > max_versions)
-      {
-	my_snprintf(path_to, FN_REFLEN, "%s/%s-%04lu",
-		    path_arc, file_name->str,
-		    (ulong)(old_version - max_versions));
-	if (!access(path_arc, F_OK) && my_delete(path_to, MYF(MY_WME)))
-	{
-	  DBUG_RETURN(TRUE);
-	}
-      }
-    }
-    else
-    {
-      if (my_delete(path, MYF(MY_WME)))	// no backups
-      {
-	DBUG_RETURN(TRUE);
-      }
-    }
-  }
-#endif//FRM_ARCHIVE
 
   {
     // rename temporary file
@@ -346,8 +295,6 @@ err_w_file:
     schema            name of given schema           
     old_name          original file name
     new_name          new file name
-    revision          revision number
-    num_view_backups  number of backups
 
   RETURN
     0 - OK 
@@ -356,8 +303,7 @@ err_w_file:
 */
 my_bool rename_in_schema_file(THD *thd,
                               const char *schema, const char *old_name, 
-                              const char *new_name, ulonglong revision, 
-                              uint num_view_backups)
+                              const char *new_name)
 {
   char old_path[FN_REFLEN], new_path[FN_REFLEN], arc_path[FN_REFLEN];
 
@@ -376,23 +322,6 @@ my_bool rename_in_schema_file(THD *thd,
   strxnmov(arc_path, FN_REFLEN, mysql_data_home, "/", schema, "/arc", NullS);
   (void) unpack_filename(arc_path, arc_path);
   
-#ifdef FRM_ARCHIVE
-  if (revision > 0 && !access(arc_path, F_OK))
-  {
-    ulonglong limit= ((revision > num_view_backups) ?
-                      revision - num_view_backups : 0);
-    for (; revision > limit ; revision--)
-    {
-      my_snprintf(old_path, FN_REFLEN, "%s/%s%s-%04lu",
-		  arc_path, old_name, reg_ext, (ulong)revision);
-      (void) unpack_filename(old_path, old_path);
-      my_snprintf(new_path, FN_REFLEN, "%s/%s%s-%04lu",
-		  arc_path, new_name, reg_ext, (ulong)revision);
-      (void) unpack_filename(new_path, new_path);
-      my_rename(old_path, new_path, MYF(0));
-    }
-  }
-#else//FRM_ARCHIVE
   { // remove obsolete 'arc' directory and files if any
     MY_DIR *new_dirp;
     if ((new_dirp = my_dir(arc_path, MYF(MY_DONT_SORT))))
@@ -401,7 +330,6 @@ my_bool rename_in_schema_file(THD *thd,
       (void) mysql_rm_arc_files(thd, new_dirp, arc_path);
     }
   }
-#endif//FRM_ARCHIVE
   return 0;
 }
 

=== modified file 'sql/parse_file.h'
--- a/sql/parse_file.h	2008-09-30 12:50:28 +0000
+++ b/sql/parse_file.h	2008-11-10 17:53:10 +0000
@@ -81,11 +81,10 @@ File_parser *sql_parse_prepare(const LEX
 my_bool
 sql_create_definition_file(const LEX_STRING *dir, const  LEX_STRING *file_name,
 			   const LEX_STRING *type,
-			   gptr base, File_option *parameters, uint versions);
+			   gptr base, File_option *parameters);
 my_bool rename_in_schema_file(THD *thd,
                               const char *schema, const char *old_name,
-                              const char *new_name, ulonglong revision,
-                              uint num_view_backups);
+                              const char *new_name);
 
 class File_parser: public Sql_alloc
 {

=== modified file 'sql/sql_db.cc'
--- a/sql/sql_db.cc	2008-09-30 12:50:28 +0000
+++ b/sql/sql_db.cc	2008-11-10 17:53:10 +0000
@@ -909,7 +909,6 @@ static long mysql_rm_known_files(THD *th
       /* .frm archive:
         Those archives are obsolete, but following code should
         exist to remove existent "arc" directories.
-        See #ifdef FRM_ARCHIVE directives for obsolete code.
       */
       char newpath[FN_REFLEN];
       MY_DIR *new_dirp;
@@ -1069,7 +1068,6 @@ static my_bool rm_dir_w_symlink(const ch
   NOTE
     A support of "arc" directories is obsolete, however this
     function should exist to remove existent "arc" directories.
-    See #ifdef FRM_ARCHIVE directives for obsolete code.
 */
 long mysql_rm_arc_files(THD *thd, MY_DIR *dirp, const char *org_path)
 {

=== modified file 'sql/sql_trigger.cc'
--- a/sql/sql_trigger.cc	2008-07-14 21:41:30 +0000
+++ b/sql/sql_trigger.cc	2008-11-10 17:53:10 +0000
@@ -479,7 +479,7 @@ bool Table_triggers_list::create_trigger
   trigname.trigger_table.length= tables->table_name_length;
 
   if (sql_create_definition_file(&dir, &trigname_file, &trigname_file_type,
-                                 (gptr)&trigname, trigname_file_parameters, 0))
+                                 (gptr)&trigname, trigname_file_parameters))
     return 1;
 
   /*
@@ -569,7 +569,7 @@ bool Table_triggers_list::create_trigger
   /* Create trigger definition file. */
 
   if (!sql_create_definition_file(&dir, &file, &triggers_file_type,
-                                  (gptr)this, triggers_file_parameters, 0))
+                                  (gptr)this, triggers_file_parameters))
     return 0;
 
 err_with_cleanup:
@@ -656,7 +656,7 @@ static bool save_trigger_file(Table_trig
   file.str= file_buff;
 
   return sql_create_definition_file(&dir, &file, &triggers_file_type,
-                                    (gptr)triggers, triggers_file_parameters, 0);
+                                    (gptr)triggers, triggers_file_parameters);
 }
 
 
@@ -1427,7 +1427,7 @@ Table_triggers_list::change_table_name_i
     trigname.trigger_table= *new_table_name;
 
     if (sql_create_definition_file(&dir, &trigname_file, &trigname_file_type,
-        (gptr)&trigname, trigname_file_parameters, 0))
+        (gptr)&trigname, trigname_file_parameters))
       return trigger;
   }
 

=== modified file 'sql/sql_view.cc'
--- a/sql/sql_view.cc	2008-10-27 10:22:38 +0000
+++ b/sql/sql_view.cc	2008-11-10 17:53:10 +0000
@@ -660,7 +660,7 @@ bool mysql_create_view(THD *thd, TABLE_L
   }
 
   VOID(pthread_mutex_unlock(&LOCK_open));
-  if (view->revision != 1)
+  if (lex->sql_command != SQLCOM_CREATE_VIEW)
     query_cache_invalidate3(thd, view, 0);
   start_waiting_global_read_lock(thd);
   if (res)
@@ -682,8 +682,6 @@ err:
 static const int revision_number_position= 8;
 /* index of last required parameter for making view */
 static const int required_view_parameters= 10;
-/* number of backups */
-static const int num_view_backups= 3;
 
 /*
   table of VIEW .frm field descriptors
@@ -716,9 +714,6 @@ static File_option view_parameters[]=
  {{(char*) STRING_WITH_LEN("with_check_option")},
   my_offsetof(TABLE_LIST, with_check),
   FILE_OPTIONS_ULONGLONG},
- {{(char*) STRING_WITH_LEN("revision")},
-  my_offsetof(TABLE_LIST, revision),
-  FILE_OPTIONS_REV},
  {{(char*) STRING_WITH_LEN("timestamp")},
   my_offsetof(TABLE_LIST, timestamp),
   FILE_OPTIONS_TIMESTAMP},
@@ -933,7 +928,7 @@ loop_out:
   }
 
   if (sql_create_definition_file(&dir, &file, view_file_type,
-				 (gptr)view, view_parameters, num_view_backups))
+				 (gptr)view, view_parameters))
   {
     error= thd->net.report_error? -1 : 1;
     goto err;
@@ -1868,8 +1863,7 @@ mysql_rename_view(THD *thd,
       goto err;
 
     /* rename view and it's backups */
-    if (rename_in_schema_file(thd, view->db, view->table_name, new_name, 
-                              view_def.revision - 1, num_view_backups))
+    if (rename_in_schema_file(thd, view->db, view->table_name, new_name))
       goto err;
 
     strxnmov(dir_buff, FN_REFLEN, mysql_data_home, "/", view->db, "/", NullS);
@@ -1883,12 +1877,10 @@ mysql_rename_view(THD *thd,
                   - file_buff);
 
     if (sql_create_definition_file(&pathstr, &file, view_file_type,
-                                   (gptr)&view_def, view_parameters,
-                                   num_view_backups)) 
+                                   (gptr)&view_def, view_parameters))
     {
       /* restore renamed view in case of error */
-      rename_in_schema_file(thd, view->db, new_name, view->table_name, 
-                            view_def.revision - 1, num_view_backups);
+      rename_in_schema_file(thd, view->db, new_name, view->table_name);
       goto err;
     }
   } else

=== modified file 'sql/table.h'
--- a/sql/table.h	2008-10-07 21:34:00 +0000
+++ b/sql/table.h	2008-11-10 17:53:10 +0000
@@ -657,7 +657,6 @@ struct TABLE_LIST
   st_lex_user   definer;                /* definer of view */
   ulonglong	file_version;		/* version of file's field set */
   ulonglong     updatable_view;         /* VIEW can be updated */
-  ulonglong	revision;		/* revision control number */
   ulonglong	algorithm;		/* 0 any, 1 tmp tables , 2 merging */
   ulonglong     view_suid;              /* view is suid (TRUE dy default) */
   ulonglong     with_check;             /* WITH CHECK OPTION */