After an ignored INSERT IGNORE statement into an empty table, we would
wrongly use the MDEV-515 table-level undo logging for a subsequent
REPLACE statement.

ha_innobase::reset_template(): Clear m_prebuilt->ins_node->bulk_insert
on every statement boundary.

ha_innobase::start_stmt(): Invoke end_bulk_insert().

ha_innobase::extra(): Avoid accessing m_prebuilt->trx. Do not call
thd_to_trx(). Invoke end_bulk_insert() and try to reset bulk_insert
when changing the REPLACE or IGNORE settings.

trx_mod_table_time_t::WAS_BULK: Use a distinct value from BULK.

trx_undo_report_row_operation(): Add debug assertions.

Note: Some calls to end_bulk_insert() may be redundant, but statement
boundaries are not always clear in the API (especially in the
presence of LOCK TABLES or stored procedures).

dict_table_t::n_lock_x_or_s: Keep track of LOCK_S or LOCK_X on the table.

lock_table_other_has_incompatible(): In the likely case that no
transaction is waiting for or holding LOCK_S or LOCK_X on the table,
return early: conflicts cannot exist.

This is based on the idea of Zhai Weixiang, who reported MySQL Bug #72948.

lock_table_has_to_wait_in_queue(), lock_table_dequeue():
Extend the optimization, inspired by
mysql/mysql-server@bb7191d6cbe47e15923143e194c03406cff9024b
by Jakub Łopuszański.

lock_wait(): Replaces lock_wait_suspend_thread(). Wait for the lock to
be granted or the transaction to be killed using mysql_cond_timedwait()
or mysql_cond_wait().

lock_wait_end(): Replaces que_thr_end_lock_wait() and
lock_wait_release_thread_if_suspended().

lock_wait_timeout_task: Remove. The operating system kernel will
resume the mysql_cond_timedwait() in lock_wait(). An added benefit
is that innodb_lock_wait_timeout no longer has a 'jitter' of 1 second,
which was caused by this wake-up task waking up only once per second,
and then waking up any threads for which the timeout (which was only
measured in seconds) was exceeded.

innobase_kill_query(): Set trx->error_state=DB_INTERRUPTED,
so that a call trx_is_interrupted(trx) in lock_wait() can be avoided.

We will protect things more consistently with lock_sys.wait_mutex,
which will be moved below lock_sys.mutex in the latching order.

trx_lock_t::cond: Condition variable for !wait_lock, used with
lock_sys.wait_mutex.

srv_slot_t: Remove. Replaced by trx_lock_t::cond,

lock_grant_after_reset(): Merged to to lock_grant().

lock_rec_get_index_name(): Remove.

lock_sys_t: Introduce wait_pending, wait_count, wait_time, wait_time_max
that are protected by wait_mutex.

trx_lock_t::que_state: Remove.

que_thr_state_t: Remove QUE_THR_COMMAND_WAIT, QUE_THR_LOCK_WAIT.

que_thr_t: Remove is_active, start_running(), stop_no_error().

que_fork_t::n_active_thrs, trx_lock_t::n_active_thrs: Remove.

que_thr_t::fork_type: Remove.

QUE_THR_SUSPENDED, TRX_QUE_COMMITTING: Remove.

Cleanup lock_cancel_waiting_and_release()

LOCK_MAX_N_STEPS_IN_DEADLOCK_CHECK, LOCK_MAX_DEPTH_IN_DEADLOCK_CHECK,
LOCK_RELEASE_INTERVAL: Replace with the bare use of the constants.

lock_rec_create_low(): Remove LOCK_PAGE_BITMAP_MARGIN altogether.
We already have REDZONE_SIZE as a 'safety margin' in AddressSanitizer
builds, to catch any out-of-bounds access.

lock_prdt_add_to_queue(): Avoid a useless search when enqueueing
a waiting lock request.

lock_prdt_lock(): Reduce the size of the trx->mutex critical section.

Any transaction that has requested a lock must have trx->id!=0.

trx_print_low(): Distinguish non-locking or inactive transaction
objects by displaying the pointer in parentheses.

fill_trx_row(): Do not try to map trx->id to a pointer-based value.

Support membership tests in SSPI with special prefix form

CREATE USER u IDENTIFIED WITH gssapi AS "GROUP:<group_name>"
or
CREATE USER u IDENTIFIED WITH gssapi AS "SID:<sid>"

If user is created as one of the above, after successful SSPI handshake,
this will happen

1) If "GROUP:" prefix is used, then <group_name> is translated to SID
using LookupAccountName() API

2) SSPI user is checked for  SID membership with
ImpersonateSecurityContext() and CheckMembership() APIs

Note, that it <group>/<sid> do not need strictly to refer to an actual
group.
Identity test is also supported, e.g  "GROUP:<users_name>" or
"SID:<user_sid>" will work too.


Well-known SIDs (in SDDL syntax) appear to be supported such as
"SID:WD" will refer to World/Everyone (== "SID:S-1-1-0")
or
"SID:BA" will refer to Administrators (== "SID:S-1-5-32-544")

In UAC environments, for successful checks against Administrators group,
elevation(Run As Administrator) might be necessary, since CheckMembership()
needs groups to be marked as enabled in the token group list.

There are no IO threads anymore.

Added new enum variable `wsrep_mode` which can be used to turn on WSREP
features which are not part of default behaviour.
Added enum `BINLOG_ROW_FORMAT_ONLY`, `REQUIRED_PRIMARY_KEY` and
`STRICT_REPLICATION`. `wsrep-mode=STRICT_REPLICATION` behaves
like variable `wsrep_strict_ddl`.

Variable wsrep_strict_ddl is deprecated and if set we use
new wsrep_mode setting instead.

Reviewed and improved by: Jan Lindström <jan.lindstrom@mariadb.com>

We implement an idea that was suggested by Michael 'Monty' Widenius
in October 2017: When InnoDB is inserting into an empty table or partition,
we can write a single undo log record TRX_UNDO_EMPTY, which will cause
ROLLBACK to clear the table.

For this to work, the insert into an empty table or partition must be
covered by an exclusive table lock that will be held until the transaction
has been committed or rolled back, or the INSERT operation has been
rolled back (and the table is empty again), in lock_table_x_unlock().

Clustered index records that are covered by the TRX_UNDO_EMPTY record
will carry DB_TRX_ID=0 and DB_ROLL_PTR=1<<55, and thus they cannot
be distinguished from what MDEV-12288 leaves behind after purging the
history of row-logged operations.

Concurrent non-locking reads must be adjusted: If the read view was
created before the INSERT into an empty table, then we must continue
to imagine that the table is empty, and not try to read any records.
If the read view was created after the INSERT was committed, then
all records must be visible normally. To implement this, we introduce
the field dict_table_t::bulk_trx_id.

This special handling only applies to the very first INSERT statement
of a transaction for the empty table or partition. If a subsequent
statement in the transaction is modifying the initially empty table again,
we must enable row-level undo logging, so that we will be able to
roll back to the start of the statement in case of an error (such as
duplicate key).

INSERT IGNORE will continue to use row-level logging and locking, because
implementing it would require the ability to roll back the latest row.
Since the undo log that we write only allows us to roll back the entire
statement, we cannot support INSERT IGNORE. We will introduce a
handler::extra() parameter HA_EXTRA_IGNORE_INSERT to indicate to storage
engines that INSERT IGNORE is being executed.

In many test cases, we add an extra record to the table, so that during
the 'interesting' part of the test, row-level locking and logging will
be used.

Replicas will continue to use row-level logging and locking until
MDEV-24622 has been addressed. Likewise, this optimization will be
disabled in Galera cluster until MDEV-24623 enables it.

dict_table_t::bulk_trx_id: The latest active or committed transaction
that initiated an insert into an empty table or partition.
Protected by exclusive table lock and a clustered index leaf page latch.

ins_node_t::bulk_insert: Whether bulk insert was initiated.

trx_t::mod_tables: Use C++11 style accessors (emplace instead of insert).
Unlike earlier, this collection will cover also temporary tables.

trx_mod_table_time_t: Add start_bulk_insert(), end_bulk_insert(),
is_bulk_insert(), was_bulk_insert().

trx_undo_report_row_operation(): Before accessing any undo log pages,
invoke trx->mod_tables.emplace() in order to determine whether undo
logging was disabled, or whether this is the first INSERT and we are
supposed to write a TRX_UNDO_EMPTY record.

row_ins_clust_index_entry_low(): If we are inserting into an empty
clustered index leaf page, set the ins_node_t::bulk_insert flag for
the subsequent trx_undo_report_row_operation() call.

lock_rec_insert_check_and_lock(), lock_prdt_insert_check_and_lock():
Remove the redundant parameter 'flags' that can be checked in the caller.

btr_cur_ins_lock_and_undo(): Simplify the logic. Correctly write
DB_TRX_ID,DB_ROLL_PTR after invoking trx_undo_report_row_operation().

trx_mark_sql_stat_end(), ha_innobase::extra(HA_EXTRA_IGNORE_INSERT),
ha_innobase::external_lock(): Invoke trx_t::end_bulk_insert() so that
the next statement will not be covered by table-level undo logging.

ReadView::changes_visible(trx_id_t) const: New accessor for the case
where the trx_id_t is not read from a potentially corrupted index page
but directly from the memory. In this case, we can skip a sanity check.

row_sel(), row_sel_try_search_shortcut(), row_search_mvcc():
row_sel_try_search_shortcut_for_mysql(),
row_merge_read_clustered_index(): Check dict_table_t::bulk_trx_id.

row_sel_clust_sees(): Replaces lock_clust_rec_cons_read_sees().

lock_sec_rec_cons_read_sees(): Replaced with lower-level code.

btr_root_page_init(): Refactored from btr_create().

dict_index_t::clear(), dict_table_t::clear(): Empty an index or table,
for the ROLLBACK of an INSERT operation.

ROW_T_EMPTY, ROW_OP_EMPTY: Note a concurrent ROLLBACK of an INSERT
into an empty table.

This is joint work with Thirunarayanan Balathandayuthapani,
who created a working prototype.
Thanks to Matthias Leich for extensive testing.

In commit 03ca6495 (MDEV-24142)
we replaced a debug data structure that holds information about
S-latch holders with a std::set, which does not allow duplicates.

The assertion failed in btr_search_guess_on_hash() in an
s_lock_try() operation.

The reason why recursive S-latch requests are not normally allowed
is that if some other thread has enqueued a waiting X-lock, then
further S-latch requests will block until the exclusive lock has been
granted and released. If a thread were already holding one S-latch
while waiting for the X-latch to be granted and released by another
thread, the two threads would deadlock.

However, the nonblocking s_lock_try() is perfectly fine;
it will immediately return failure in case of conflict.

sux_lock::readers: Use std::unordered_multiset instead of std::set.

sux_lock::s_lock_register(): Allow 'duplicate' requests. Blocking-mode
latch acquisitions are already covered by !have_s() assertions.

sux_lock::s_unlock(): Erase only one element from readers.

buf_page_try_get(): Revert to s_lock_try(). It had been previously
changed to the more intrusive u_lock_try() in response to the
debug check failing.

We may end up with an empty leaf page (containing only an ADD COLUMN
metadata record) that is not the root page.

innobase_add_instant_try(): Disable an optimization for a non-canonical
empty table that contains a metadata record somewhere else than in
the root page.

btr_pcur_store_position(): Tolerate a non-canonical empty table.

MDEV-24659 Assertion !fsp_is_system_temporary(bpage->id().space()) failed in buf_flush_relocate_on_flush_list()

When commit 5eb53955 (MDEV-12227)
removed the pages of temporary tables from the buf_pool.flush_list,
an adjustment to the buffer pool resizing was forgotten.

buf_pool_t::realloc(): Do not invoke buf_flush_relocate_on_flush_list()
for pages that belong to the temporary tablespace. Also, deduplicate
some code at the end.

buf_page_t::set_corrupt_id(): Tolerate oldest_modification()==1
(the dummy value) for temporary tablespace pages. The revised
buf_pool_t::realloc() may invoke this on dirty temporary tablespace pages.

Ever since commit 947efe17
InnoDB no longer writes binlog position in one place.
It will not at all be written to the TRX_SYS page, and
instead it will be written to the undo log header page that
changes the transaction state.

trx_rseg_mem_restore(): Recover the information from the latest
written page.

fts_optimize_request_sync_table() can avoid the repetitive
FTS SYNC request of the table if the table already has FTS_SYNC
message in fts_optimize_wq queue.

Reviewed-by: Marko Mäkelä

MDEV-24463 : galera.galera_sst_mysqldump_with_key MTR failed: 'INSERT failed: 1213: Deadlock found when trying to get lock

We need to complete SST if both new and old start positions are
not same as initial positions. If they are initial positions
just set local uuid and seqno.

While reusing the cached undo log block, mtr expects the page
write to change while writing the trx id. cached undo log block
could contain bytes which were originally written for some other
transaction. So InnoDB should make mtr to do MAYBE_NOP while reusing
cached undo log block.

Reviewed-by: Marko Mäkelä

fts_optimize_callback() could be called after processing
FTS_MSG_STOP due to timer initiated callback. This issue
is caused by commit 38fd7b7d
(MDEV-21452). In that case, fts_optimize_callback() should
check whether it processed FTS_MSG_STOP already.

Reviewed-by: Marko Mäkelä

I_S tables were materialized too late, an attempt to use table
statistics before the table was created caused a crash.

Let's move table creation up. it only needs read_set to
be calculated properly, this happens in JOIN::optimize_inner(),
after semijoin transformation.

Note that tables are not populated at that point, so most of the
statistics would make no sense anyway. But at least field sizes
will be correct. And it won't crash.

The problem was that update_timing_fields_for_event() didn't release all
MDL locks it took.

MDEV-24596 : Assertion `state_ == s_exec || state_ == s_quitting' failed in wsrep::client_state::disable_streaming

There were multiple problems here
* wsrep_trx_fragment_size should not be set when wsrep is disabled or provider is not loaded
* wsrep_trx_fragment_unit should not be set when wsrep is disabled or provider is not loaded
* wsrep_debug has no effect if wsrep is disabled or provider is not loaded
* wsrep_start_position should not be set when wsrep is disabled or provider is not loaded any other value than default
* wsrep_start_position should be changed only when we are joiner or initialized
* wsrep_start_position should be allowed to set only a value that exits, thus
we need to add error handling to wsrep_sst_complete

Sample log error message generated:

mysql-test/var/log/mysqld.2.err:2021-01-21 13:02:30 8 [Note] Slave SQL thread exiting, replication stopped in log 'master-bin.000001' at position 329, master: 127.0.0.1:16000
mysql-test/var/log/mysqld.2.err:2021-01-21 13:02:30 7 [Note] Slave I/O thread exiting, read up to log 'master-bin.000001', position 329, master 127.0.0.1:16000
mysql-test/var/log/mysqld.2.err:2021-01-21 13:02:30 12 [Note] Slave SQL thread exiting, replication stopped in log 'master-bin.000001' at position 329; GTID position '', master: 127.0.0.1:16000

Reviewer: knielsen@knielsen-hq.org, Andrei and Sachin