Commit d2d605e4 authored by unknown's avatar unknown
Browse files

bug#21965 - replication 

  fix deadlock if master switches log file in parallell with "show master logs"
  


sql/log.cc:
  add raw_get_current_log which dont take log mutex
sql/sql_class.h:
  add raw_get_current_log which dont take log mutex
sql/sql_repl.cc:
  Fix lock order i.e first log_lock then index_lock
parent 5d82bec5

sql/log.cc

+7 −2
Original line number Diff line number Diff line
@@ -409,13 +409,18 @@ shutdown the MySQL server and restart it.", log_name, errno); 
int MYSQL_LOG::get_current_log(LOG_INFO* linfo)

{

  pthread_mutex_lock(&LOCK_log);

  int ret = raw_get_current_log(linfo);

  pthread_mutex_unlock(&LOCK_log);

  return ret;

}



int MYSQL_LOG::raw_get_current_log(LOG_INFO* linfo)

{

  strmake(linfo->log_file_name, log_file_name, sizeof(linfo->log_file_name)-1);

  linfo->pos = my_b_tell(&log_file);

  pthread_mutex_unlock(&LOCK_log);

  return 0;

}





/*

  Move all data up in a file in an filename index file

sql/sql_class.h

+1 −0
Original line number Diff line number Diff line
@@ -177,6 +177,7 @@ class MYSQL_LOG 
		   bool need_mutex);

  int find_next_log(LOG_INFO* linfo, bool need_mutex);

  int get_current_log(LOG_INFO* linfo);

  int raw_get_current_log(LOG_INFO* linfo);

  uint next_file_id();

  inline bool is_open() { return log_type != LOG_CLOSED; }

  inline char* get_index_fname() { return index_file_name;}

sql/sql_repl.cc

+6 −2
Original line number Diff line number Diff line
@@ -1359,10 +1359,14 @@ int show_binlogs(THD* thd) 
                                           MYSQL_TYPE_LONGLONG));

  if (protocol->send_fields(&field_list, 1))

    DBUG_RETURN(1);

  

  pthread_mutex_lock(mysql_bin_log.get_log_lock());

  mysql_bin_log.lock_index();

  index_file=mysql_bin_log.get_index_file();

  

  mysql_bin_log.get_current_log(&cur);

  mysql_bin_log.raw_get_current_log(&cur); // dont take mutex

  pthread_mutex_unlock(mysql_bin_log.get_log_lock()); // lockdep, OK

  

  cur_dir_len= dirname_length(cur.log_file_name);



  reinit_io_cache(index_file, READ_CACHE, (my_off_t) 0, 0, 0);