Implement undo tablespace truncation via normal redo logging.

Implement TRUNCATE TABLE as a combination of RENAME to #sql-ib name,
CREATE, and DROP.

Note: Orphan #sql-ib*.ibd may be left behind if MariaDB Server 10.2
is killed before the DROP operation is committed. If MariaDB Server 10.2
is killed during TRUNCATE, it is also possible that the old table
was renamed to #sql-ib*.ibd but the data dictionary will refer to the
table using the original name.

In MariaDB Server 10.3, RENAME inside InnoDB is transactional,
and #sql-* tables will be dropped on startup. So, this new TRUNCATE
will be fully crash-safe in 10.3.

ha_mroonga::wrapper_truncate(): Pass table options to the underlying
storage engine, now that ha_innobase::truncate() will need them.

rpl_slave_state::truncate_state_table(): Before truncating
mysql.gtid_slave_pos, evict any cached table handles from
the table definition cache, so that there will be no stale
references to the old table after truncating.

== TRUNCATE TABLE ==

WL#6501 in MySQL 5.7 introduced separate log files for implementing
atomic and crash-safe TRUNCATE TABLE, instead of using the InnoDB
undo and redo log. Some convoluted logic was added to the InnoDB
crash recovery, and some extra synchronization (including a redo log
checkpoint) was introduced to make this work. This synchronization
has caused performance problems and race conditions, and the extra
log files cannot be copied or applied by external backup programs.

In order to support crash-upgrade from MariaDB 10.2, we will keep
the logic for parsing and applying the extra log files, but we will
no longer generate those files in TRUNCATE TABLE.

A prerequisite for crash-safe TRUNCATE is a crash-safe RENAME TABLE
(with full redo and undo logging and proper rollback). This will
be implemented in MDEV-14717.

ha_innobase::truncate(): Invoke RENAME, create(), delete_table().
Because RENAME cannot be fully rolled back before MariaDB 10.3
due to missing undo logging, add some explicit rename-back in
case the operation fails.

ha_innobase::delete(): Introduce a variant that takes sqlcom as
a parameter. In TRUNCATE TABLE, we do not want to touch any
FOREIGN KEY constraints.

ha_innobase::create(): Add the parameters file_per_table, trx.
In TRUNCATE, the new table must be created in the same transaction
that renames the old table.

create_table_info_t::create_table_info_t(): Add the parameters
file_per_table, trx.

row_drop_table_for_mysql(): Replace a bool parameter with sqlcom.

row_drop_table_after_create_fail(): New function, wrapping
row_drop_table_for_mysql().

dict_truncate_index_tree_in_mem(), fil_truncate_tablespace(),
fil_prepare_for_truncate(), fil_reinit_space_header_for_table(),
row_truncate_table_for_mysql(), TruncateLogger,
row_truncate_prepare(), row_truncate_rollback(),
row_truncate_complete(), row_truncate_fts(),
row_truncate_update_system_tables(),
row_truncate_foreign_key_checks(), row_truncate_sanity_checks():
Remove.

row_upd_check_references_constraints(): Remove a check for
TRUNCATE, now that the table is no longer truncated in place.

The new test innodb.truncate_foreign uses DEBUG_SYNC to cover some
race-condition like scenarios. The test innodb-innodb.truncate does
not use any synchronization.

We add a redo log subformat to indicate backup-friendly format.
MariaDB 10.4 will remove support for the old TRUNCATE logging,
so crash-upgrade from old 10.2 or 10.3 to 10.4 will involve
limitations.

== Undo tablespace truncation ==

MySQL 5.7 implements undo tablespace truncation. It is only
possible when innodb_undo_tablespaces is set to at least 2.
The logging is implemented similar to the WL#6501 TRUNCATE,
that is, using separate log files and a redo log checkpoint.

We can simply implement undo tablespace truncation within
a single mini-transaction that reinitializes the undo log
tablespace file. Unfortunately, due to the redo log format
of some operations, currently, the total redo log written by
undo tablespace truncation will be more than the combined size
of the truncated undo tablespace. It should be acceptable
to have a little more than 1 megabyte of log in a single
mini-transaction. This will be fixed in MDEV-17138 in
MariaDB Server 10.4.

recv_sys_t: Add truncated_undo_spaces[] to remember for which undo
tablespaces a MLOG_FILE_CREATE2 record was seen.

namespace undo: Remove some unnecessary declarations.

fil_space_t::is_being_truncated: Document that this flag now
only applies to undo tablespaces. Remove some references.

fil_space_t::is_stopping(): Do not refer to is_being_truncated.
This check is for tablespaces of tables. Potentially used
tablespaces are never truncated any more.

buf_dblwr_process(): Suppress the out-of-bounds warning
for undo tablespaces.

fil_truncate_log(): Write a MLOG_FILE_CREATE2 with a nonzero
page number (new size of the tablespace in pages) to inform
crash recovery that the undo tablespace size has been reduced.

fil_op_write_log(): Relax assertions, so that MLOG_FILE_CREATE2
can be written for undo tablespaces (without .ibd file suffix)
for a nonzero page number.

os_file_truncate(): Add the parameter allow_shrink=false
so that undo tablespaces can actually be shrunk using this function.

fil_name_parse(): For undo tablespace truncation,
buffer MLOG_FILE_CREATE2 in truncated_undo_spaces[].

recv_read_in_area(): Avoid reading pages for which no redo log
records remain buffered, after recv_addr_trim() removed them.

trx_rseg_header_create(): Add a FIXME comment that we could write
much less redo log.

trx_undo_truncate_tablespace(): Reinitialize the undo tablespace
in a single mini-transaction, which will be flushed to the redo log
before the file size is trimmed.

recv_addr_trim(): Discard any redo logs for pages that were
logged after the new end of a file, before the truncation LSN.
If the rec_list becomes empty, reduce n_addrs. After removing
any affected records, actually truncate the file.

recv_apply_hashed_log_recs(): Invoke recv_addr_trim() right before
applying any log records. The undo tablespace files must be open
at this point.

buf_flush_or_remove_pages(), buf_flush_dirty_pages(),
buf_LRU_flush_or_remove_pages(): Add a parameter for specifying
the number of the first page to flush or remove (default 0).

trx_purge_initiate_truncate(): Remove the log checkpoints, the
extra logging, and some unnecessary crash points. Merge the code
from trx_undo_truncate_tablespace(). First, flush all to-be-discarded
pages (beyond the new end of the file), then trim the space->size
to make the page allocation deterministic. At the only remaining
crash injection point, flush the redo log, so that the recovery
can be tested.

recv_addr_state, recv_addr_t: Define in log0recv.cc only.

Because innodb_file_per_table can be enabled at runtime after it
was disabled at startup, it is better to always register the same
innobase_hton->tablefile_extensions. Besides,
innodb_file_per_table=OFF does not prevent loading tables that may
have been created earlier with the .ibd file extension.

Remove plugin-load option from mariabackup. It does not needed to be an
option (we only need to store the plugin-load value during backup phase,
and reuse the same value during --prepare).

Fix is to read plugin-load from backup-my.cnf during prepare.

Fix exit condition for the log copying thread.

(https://github.com/facebook/rocksdb/issues/4344)
Also, disable /permissive- flag if set, it breaks rocksdb compilation
in 10.3 on older versions of Windows 8.1 SDK.

It uses --slave-use-idempotent-for-recovery which is not available in MariaDB.

Remove the mismatch betwen list of man pages in CMakeLists.txt and
actual files.

Direct IO doesnt work on all filesystems, e.g. it doesnt work on the
disk of kvm-bintar-trusty-amd64.

This regression was introduced in MDEV-16515.
We would fail to drop a temporary table on client disconnect,
because trx_is_interrupted() would hold. To add insult to
injury, in MariaDB 10.1, InnoDB temporary tables are actually
persistent, so the garbage temporary tables will never be dropped.

row_drop_table_for_mysql(): If several iterations of
buf_LRU_drop_page_hash_for_tablespace() are needed,
do not interrupt dropping a temporary table even after
the transaction was marked as killed.

Server shutdown will still terminate the loop, and also DROP TABLE
of persistent tables will keep checking if the execution was aborted.

This reverts commit 75dfd4ac.

It uses a feature that's not available in MariaDB

It uses a feature that's not available in MariaDB

Plugin version name fixed.

Let '\\' and '/' symbols to be part of a group name.

           Field_iterator_table_ref::set_field_iterator

Several functions that processed different prepare statements missed
the DT_INIT flag in last parameter of the open_normal_and_derived_tables()
calls. It made context analysis of derived tables dependent on the order in
which the derived tables were processed by mysql_handle_derived(). This
order was induced by the order of SELECTs in all_select_list.
In 10.4 the order of SELECTs in all_select_list became different and lack
of the DT_INIT flags in some open_normal_and_derived_tables() call became
critical as some derived tables were not identified as such.

Merged https://github.com/MariaDB/server/pull/617 authored by
Colin Mollenhour.

Move up-to this revision in the upstream:

  commit de1e8c7bfe7c875ea284b55040e8f3cd3a56fcc2
  Author: Abhinav Sharma <abhinavsharma@fb.com>
  Date:   Thu Aug 23 14:34:39 2018 -0700

      Log updates to semi-sync whitelist in the error log

      Summary:
      Plugin variable changes are not logged in the error log even when
      log_global_var_changes is enabled. Logging updates to whitelist will help in
      debugging.

      Reviewed By: guokeno0

      Differential Revision: D9483807

      fbshipit-source-id: e111cda773d

MDEV-14851: galera_recovery to read correct configuration file sections