maria-developers team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Sergey!

On Feb 09, svoj@xxxxxxxxxxx wrote:
> revision-id: 6ff2c0a05155f985484e23bd8611eb95f045907f
> parent(s): f13939061d468a47985dee0268652a6fe2db7862
> committer: Sergey Vojtovich
> branch nick: 10.1
> timestamp: 2015-02-09 16:12:00 +0400
> message:
> 
> MDEV-5309 - RENAME TABLE does not check for existence of the table's engine
> 
> When RENAME TABLE is executed, it apparently does not check whether the engine
> is available (unlike ALTER TABLE .. RENAME, which does). It means that if the
> engine in question was not loaded on some reason, the table might become
> unusable, since the engine won't know about the change.
> 
> With this patch RENAME TABLE fails if storage engine is not available.
.... 
> diff --git a/sql/sql_table.cc b/sql/sql_table.cc
> index e9a1ae9..f1096da 100644
> --- a/sql/sql_table.cc
> +++ b/sql/sql_table.cc
> @@ -5172,18 +5172,19 @@ bool mysql_create_table(THD *thd, TABLE_LIST *create_table,
>        error= my_errno;
>      (void) file->ha_create_partitioning_metadata(to, from, CHF_RENAME_FLAG);
>    }
> -  else if (!file || !(error=file->ha_rename_table(from_base, to_base)))
> +  else if (!file)
>    {
> +    error= ER_UNKNOWN_STORAGE_ENGINE;
> +  }
> +  else if (!(error= file->ha_rename_table(from_base, to_base)))
> +  {
>      if (!(flags & NO_FRM_RENAME) && rename_file_ext(from,to,reg_ext))
>      {
>        error= my_errno;
> -      if (file)
> -      {
>          if (error == ENOENT)
>            error= 0; // this is ok if file->ha_rename_table() succeeded
>          else
>            file->ha_rename_table(to_base, from_base); // Restore old file name
> -      }
>      }
>    }
>    delete file;

May be you'd rather fix it in the caller? Let's state that the first
argument of mysql_rename_table() can never be NULL.

While mysql_rename_table() is called in many places, the only place
where it can actually get a NULL hton is sql_rename.cc, if
ha_table_exists() returns hton=NULL.

I'd add the check here and simplified mysql_rename_table().

Regards,
Sergei