Added option --read-only (Thanks to Markus Benning)

myisam/myisamchk.c

@@ -45,6 +45,7 @@ static const char *set_charset_name;
 static CHARSET_INFO *set_charset;
 static long opt_myisam_block_size;
 static const char *my_progname_short;
+static int stopwords_inited= 0;
 
 static const char *type_names[]=
 { "?","char","binary", "short", "long", "float",
@@ -861,7 +862,7 @@ static int myisamchk(MI_CHECK *param, my_string filename)
   }
   else
   {
-    if (share->fulltext_index)
+    if (share->fulltext_index && !stopwords_inited++)
       ft_init_stopwords();
 
     if (!(param->testflag & T_READONLY))

sql/init.cc

@@ -38,13 +38,11 @@ void unireg_init(ulong options)
   init_my_atof();			/* use our atof */
 #endif
   my_abort_hook=unireg_abort;		/* Abort with close of databases */
-  f_fyllchar=' ';			/* Input fill char */
 
   VOID(strmov(reg_ext,".frm"));
   for (i=0 ; i < 6 ; i++)		// YYMMDDHHMMSS
     dayord.pos[i]=i;
   specialflag=SPECIAL_SAME_DB_NAME;
-  blob_newline='^';			/* Convert newline in blobs to this */
   /* Make a tab of powers of 10 */
   for (i=0,nr=1.0; i < array_elements(log_10) ; i++)
   {					/* It's used by filesort... */

sql/mysql_priv.h

@@ -627,7 +627,6 @@ extern char language[LIBLEN],reg_ext[FN_EXTLEN];
 extern char glob_hostname[FN_REFLEN], mysql_home[FN_REFLEN];
 extern char pidfile_name[FN_REFLEN], time_zone[30], *opt_init_file;
 extern char log_error_file[FN_REFLEN];
-extern char blob_newline;
 extern double log_10[32];
 extern ulonglong keybuff_size;
 extern ulong refresh_version,flush_version, thread_id,query_id,opened_tables;
@@ -675,8 +674,8 @@ extern uint volatile thread_count, thread_running, global_read_lock;
 extern my_bool opt_sql_bin_update, opt_safe_user_create, opt_no_mix_types;
 extern my_bool opt_safe_show_db, opt_local_infile, lower_case_table_names;
 extern my_bool opt_slave_compressed_protocol, use_temp_pool;
+extern my_bool opt_readonly;
 extern my_bool opt_enable_named_pipe;
-extern char f_fyllchar;
 
 extern MYSQL_LOG mysql_log,mysql_update_log,mysql_slow_log,mysql_bin_log;
 extern FILE *bootstrap_file;

sql/mysqld.cc

@@ -289,7 +289,7 @@ my_bool opt_enable_named_pipe= 0;
 my_bool opt_local_infile, opt_external_locking, opt_slave_compressed_protocol;
 uint delay_key_write_options= (uint) DELAY_KEY_WRITE_ON;
 
-static bool opt_do_pstack = 0;
+static my_bool opt_do_pstack = 0;
 static ulong opt_specialflag=SPECIAL_ENGLISH;
 
 static ulong opt_myisam_block_size;
@@ -306,6 +306,7 @@ my_bool opt_safe_user_create = 0, opt_no_mix_types = 0;
 my_bool lower_case_table_names, opt_old_rpl_compat;
 my_bool opt_show_slave_auth_info, opt_sql_bin_update = 0;
 my_bool opt_log_slave_updates= 0, opt_console= 0;
+my_bool opt_readonly = 0;
 
 volatile bool  mqh_used = 0;
 FILE *bootstrap_file=0;
@@ -376,7 +377,7 @@ const char *localhost=LOCAL_HOST;
 const char *delayed_user="DELAYED";
 uint master_port = MYSQL_PORT, master_connect_retry = 60;
 uint report_port = MYSQL_PORT;
-bool master_ssl = 0;
+my_bool master_ssl = 0;
 
 ulong master_retry_count=0;
 ulong bytes_sent = 0L, bytes_received = 0L;
@@ -404,8 +405,7 @@ ulong slow_launch_threads = 0;
 char mysql_real_data_home[FN_REFLEN],
      language[LIBLEN],reg_ext[FN_EXTLEN],
      mysql_charsets_dir[FN_REFLEN], *charsets_list,
-     blob_newline,f_fyllchar,max_sort_char,*mysqld_user,*mysqld_chroot,
-     *opt_init_file;
+     max_sort_char,*mysqld_user,*mysqld_chroot, *opt_init_file;
 char *language_ptr= language;
 char mysql_data_home_buff[2], *mysql_data_home=mysql_real_data_home;
 #ifndef EMBEDDED_LIBRARY
@@ -3143,6 +3143,7 @@ enum options {
   OPT_QUERY_CACHE_TYPE, OPT_RECORD_BUFFER,
   OPT_RECORD_RND_BUFFER, OPT_RELAY_LOG_SPACE_LIMIT,
   OPT_SLAVE_NET_TIMEOUT, OPT_SLAVE_COMPRESSED_PROTOCOL, OPT_SLOW_LAUNCH_TIME,
+  OPT_READONLY,
   OPT_SORT_BUFFER, OPT_TABLE_CACHE,
   OPT_THREAD_CONCURRENCY, OPT_THREAD_CACHE_SIZE,
   OPT_TMP_TABLE_SIZE, OPT_THREAD_STACK,
@@ -3927,6 +3928,11 @@ replicating a LOAD DATA INFILE command",
    "Number of seconds to wait for more data from a master/slave connection before aborting the read.",
    (gptr*) &slave_net_timeout, (gptr*) &slave_net_timeout, 0,
    GET_ULONG, REQUIRED_ARG, SLAVE_NET_TIMEOUT, 1, LONG_TIMEOUT, 0, 1, 0},
+  {"read-only", OPT_READONLY,
+   "Make all tables readonly, with the expections for replications (slave) threads and users with the SUPER privilege",
+   (gptr*) &opt_readonly,
+   (gptr*) &opt_readonly,
+   0, GET_BOOL, NO_ARG, 0, 0, 1, 0, 1, 0},
   {"slow_launch_time", OPT_SLOW_LAUNCH_TIME,
    "If creating the thread takes longer than this value (in seconds), the Slow_launch_threads counter will be incremented.",
    (gptr*) &slow_launch_time, (gptr*) &slow_launch_time, 0, GET_ULONG,

sql/set_var.cc

@@ -204,6 +204,8 @@ sys_var_bool_ptr	sys_slave_compressed_protocol("slave_compressed_protocol",
 						      &opt_slave_compressed_protocol);
 sys_var_long_ptr	sys_slave_net_timeout("slave_net_timeout",
 					      &slave_net_timeout);
+sys_var_bool_ptr	sys_readonly("read_only",
+				     &opt_readonly);
 sys_var_long_ptr	sys_slow_launch_time("slow_launch_time",
 					     &slow_launch_time);
 sys_var_thd_ulong	sys_sort_buffer("sort_buffer_size",
@@ -375,6 +377,7 @@ sys_var *sys_variables[]=
   &sys_slave_compressed_protocol,
   &sys_slave_net_timeout,
   &sys_slave_skip_counter,
+  &sys_readonly,
   &sys_slow_launch_time,
   &sys_sort_buffer,
   &sys_sql_big_tables,
@@ -522,6 +525,7 @@ struct show_var_st init_vars[]= {
 #endif /* HAVE_QUERY_CACHE */
   {sys_server_id.name,	      (char*) &sys_server_id,		    SHOW_SYS},
   {sys_slave_net_timeout.name,(char*) &sys_slave_net_timeout,	    SHOW_SYS},
+  {sys_readonly.name,         (char*) &sys_readonly,                SHOW_SYS},
   {"skip_external_locking",   (char*) &my_disable_locking,          SHOW_MY_BOOL},
   {"skip_networking",         (char*) &opt_disable_networking,      SHOW_BOOL},
   {"skip_show_database",      (char*) &opt_skip_show_db,            SHOW_BOOL},

sql/sql_parse.cc

@@ -1330,6 +1330,18 @@ mysql_execute_command(void)
        !tables_ok(thd,tables)))
     DBUG_VOID_RETURN;
   
+  /*
+    When option readonly is set deny operations which change tables.
+    Except for the replication thread and the 'super' users.
+  */
+  if (opt_readonly &&
+      !(thd->slave_thread || (thd->master_access & SUPER_ACL)) &&
+      (uc_update_queries[lex->sql_command] > 0))
+  {
+    send_error(&thd->net,ER_CANT_UPDATE_WITH_READLOCK);
+    DBUG_VOID_RETURN;
+  }
+
   statistic_increment(com_stat[lex->sql_command],&LOCK_status);
   switch (lex->sql_command) {
   case SQLCOM_SELECT: