Concurrent calls to log_checkpoint_low() were possible from multiple
threads, and they could cause redundant writes of FILE_CHECKPOINT
records that refer to the same checkpoint. Let us simplify the logic
by making the dedicated buf_flush_page_cleaner() thread responsible
for checkpoints.
log_t::write_checkpoint(lsn_t end_lsn): Add the parameter checkpoint,
which will replace the data member log_sys.next_checkpoint_lsn.
log_sys.checkpoint_pending: Remove. Only the buf_flush_page_cleaner()
thread will write checkpoints or initiate page writes.
log_checkpoint_low(), log_checkpoint(): Remove the return value,
because there cannot be any concurrent log checkpoint in progress.
buf_flush_wait(): Add a parameter for waiting for a full checkpoint.
This function replaces buf_flush_wait_flushed().
log_t::checkpoint_margin(): Replaces log_checkpoint_margin().
lot_t::write_buf(): Remove a call set_check_for_checkpoint(false)
that commit 7443ad1c8a (MDEV-32374)
had added. The flag should only be cleared when the checkpoint has
advanced far enough.
log_make_checkpoint(): Simply wrap buf_flush_sync_batch(0, true).
buf_flush_sync_batch(): Add the parameter bool checkpoint, to wait
for an empty FILE_CHECKPOINT record to be written. Outside recovery,
pass lsn=0.
buf_flush_sync_for_checkpoint(): On shutdown, update the systemd
watchdog and keep flushing until a final checkpoint has been written.
buf_flush_page_cleaner(): Revise the shutdown logic so that all
changes will be written out and a checkpoint with just a FILE_CHECKPOINT
record can be written.
buf_flush_buffer_pool(): Remove.
buf_flush_wait_flushed(): Require the caller to acquire
buf_pool.flush_list_mutex.
logs_empty_and_mark_files_at_shutdown(): Simplify the logic,
and return the shutdown LSN.
fil_names_clear(): Fix an off-by-one error that would prevent
removal from fil_system.named_spaces.
innodb_shutdown(): Always invoke logs_empty_and_mark_files_at_shutdown().
srv_undo_tablespaces_reinit(): Simplify the logic and remove the
fault injection point after_reinit_undo_abort, which would cause
a failure on Microsoft Windows. Changing innodb_undo_tablespaces is
not fully crash-safe.
Reviewed by: Thirunarayanan Balathandayuthapani
Tested by: Saahil Alam
bf363a573a