Porting commit 3836098c29ef1b7ff9d5fbde99b690eab73a0df1 (MDEV-26285)
to current versions 10.3+ to fix a problem (MDEV-29447) where field
items that are arguments of a func item may be used before created /
initialised.
MDEV-30275: mariadb names rather than mysql names should be used
* mariadb-service-convert to use mariadbd-safe
* galera_recovery to use mariadbd
* mtr - wsrep use mariadb executables
* debian/mariadb-server.mariadb.init use mariadbd-safe
* debian/tests/smoke uses mariadb instead of mysql as client.
The variable was not really being used for anything. The parameters
innodb_read_io_threads, innodb_write_io_threads have replaced
innodb_file_io_threads.
MDEV-30227 [ERROR] [FATAL] InnoDB: fdatasync() returned 9
fil_space_t::flush<false>(): If the CLOSING flag is set,
the file may already have been closed, resulting in EBADF
being returned by fdatasync(). In any case, the
thread that had set the flag should take care of invoking
os_file_flush_func().
The crash occurred during the execution of FLUSH TABLES...FOR EXPORT.