MDEV-30860 Race condition between buffer pool flush and log file deletion in mariadb-backup --prepare

srv_start(): If we are going to close the log file in
mariadb-backup --prepare, call buf_flush_sync() before
calling recv_sys.debug_free() to ensure that the log file
will not be accessed.

This fixes a rather rare failure in the test
mariabackup.innodb_force_recovery where buf_flush_page_cleaner()
would invoke log_checkpoint_low() because !recv_recovery_is_on()
would hold due to the fact that recv_sys.debug_free() had
already been called. Then, the log write for the checkpoint
would fail because srv_start() had invoked log_sys.log.close_file().

0 files changed, 0 insertions, 0 deletions