We will introduce an optional log record OPT_PAGE_CHECKSUM for recording
page checksums, so that more inconsistencies on crash recovery may be
caught.

mtr_t::page_checksum(const buf_page_t&): Write OPT_PAGE_CHECKSUM
(currently not for ROW_FORMAT=COMPRESSED pages).

mtr_t::do_write(): Write OPT_PAGE_CHECKSUM records for all pages
(currently, in debug builds only).

mtr_t::is_logged(): Return whether log should be written.

mtr_t::set_log_mode_sub(const mtr_t&): Set the logging mode of
a sub-minitransaction when another mini-transaction is holding
latches on some modified pages. When creating or freeing BLOB pages,
we may only write OPT_PAGE_CHECKSUM records in the main mini-transaction,
after all changes have been written to the log.

MTR_LOG_SUB: Log mode for a sub-mini-transaction.

mtr_t::free(): Define non-inline, and invoke MarkFreed.

MarkFreed: For any matching page in the mini-transaction log,
change the first entry to say MTR_MEMO_PAGE_X_MODIFY and any subsequent
entries to MTR_MEMO_PAGE_X_FIX.

FindModified: Simplify a condition. MTR_MEMO_MODIFY can only be set
if MTR_MEMO_PAGE_X_FIX or MTR_MEMO_PAGE_SX_FIX are set.

FindBlockX: Consider also MTR_MEMO_PAGE_X_MODIFY.

recv_sys_t::parse(): Store OPT_PAGE_CHECKSUM records.

log_phys_t::apply(): Validate OPT_PAGE_CHECKSUM records.

log_phys_t::page_checksum(): Validate an OPT_PAGE_CHECKSUM record.

Tested by: Matthias Leich

--debug-dbug=d,intermittent_read_failure is effective after the
database has been started up.

--debug-dbug=d,intermittent_recovery_failure is always effective,
including during recovery.

The approach to handling corruption that was chosen by Oracle in
commit 177d8b0c
is not really useful. Not only did it actually fail to prevent InnoDB
from crashing, but it is making things worse by blocking attempts to
rescue data from or rebuild a partially readable table.

We will try to prevent crashes in a different way: by propagating
errors up the call stack. We will never mark the clustered index
persistently corrupted, so that data recovery may be attempted by
reading from the table, or by rebuilding the table.

This should also fix MDEV-13680 (crash on btr_page_alloc() failure);
it was extensively tested with innodb_file_per_table=0 and a
non-autoextend system tablespace.

We should now avoid crashes in many cases, such as when a page
cannot be read or allocated, or an inconsistency is detected when
attempting to update multiple pages. We will not crash on double-free,
such as on the recovery of DDL in system tablespace in case something
was corrupted.

Crashes on corrupted data are still possible. The fault injection mechanism
that is introduced in the subsequent commit may help catch more of them.

buf_page_import_corrupt_failure: Remove the fault injection, and instead
corrupt some pages using Perl code in the tests.

btr_cur_pessimistic_insert(): Always reserve extents (except for the
change buffer), in order to prevent a subsequent allocation failure.

btr_pcur_open_at_rnd_pos(): Merged to the only caller ibuf_merge_pages().

btr_assert_not_corrupted(), btr_corruption_report(): Remove.
Similar checks are already part of btr_block_get().

FSEG_MAGIC_N_BYTES: Replaces FSEG_MAGIC_N_VALUE.

dict_hdr_get(), trx_rsegf_get_new(), trx_undo_page_get(),
trx_undo_page_get_s_latched(): Replaced with error-checking calls.

trx_rseg_t::get(mtr_t*): Replaces trx_rsegf_get().

trx_rseg_header_create(): Let the caller update the TRX_SYS page if needed.

trx_sys_create_sys_pages(): Merged with trx_sysf_create().

dict_check_tablespaces_and_store_max_id(): Do not access
DICT_HDR_MAX_SPACE_ID, because it was already recovered in dict_boot().
Merge dict_check_sys_tables() with this function.

dir_pathname(): Replaces os_file_make_new_pathname().

row_undo_ins_remove_sec(): Do not modify the undo page by adding
a terminating NUL byte to the record.

btr_decryption_failed(): Report decryption failures

dict_set_corrupted_by_space(), dict_set_encrypted_by_space(),
dict_set_corrupted_index_cache_only(): Remove.

dict_set_corrupted(): Remove the constant parameter dict_locked=false.
Never flag the clustered index corrupted in SYS_INDEXES, because
that would deny further access to the table. It might be possible to
repair the table by executing ALTER TABLE or OPTIMIZE TABLE, in case
no B-tree leaf page is corrupted.

dict_table_skip_corrupt_index(), dict_table_next_uncorrupted_index(),
row_purge_skip_uncommitted_virtual_index(): Remove, and refactor
the callers to read dict_index_t::type only once.

dict_table_is_corrupted(): Remove.

dict_index_t::is_btree(): Determine if the index is a valid B-tree.

BUF_GET_NO_LATCH, BUF_EVICT_IF_IN_POOL: Remove.

UNIV_BTR_DEBUG: Remove. Any inconsistency will no longer trigger
assertion failures, but error codes being returned.

buf_corrupt_page_release(): Replaced with a direct call to
buf_pool.corrupted_evict().

fil_invalid_page_access_msg(): Never crash on an invalid read;
let the caller of buf_page_get_gen() decide.

btr_pcur_t::restore_position(): Propagate failure status to the caller
by returning CORRUPTED.

opt_search_plan_for_table(): Simplify the code.

row_purge_del_mark(), row_purge_upd_exist_or_extern_func(),
row_undo_ins_remove_sec_rec(), row_undo_mod_upd_del_sec(),
row_undo_mod_del_mark_sec(): Avoid mem_heap_create()/mem_heap_free()
when no secondary indexes exist.

row_undo_mod_upd_exist_sec(): Simplify the code.

row_upd_clust_step(), dict_load_table_one(): Return DB_TABLE_CORRUPT
if the clustered index (and therefore the table) is corrupted, similar
to what we do in row_insert_for_mysql().

fut_get_ptr(): Replace with buf_page_get_gen() calls.

buf_page_get_gen(): Return nullptr and *err=DB_CORRUPTION
if the page is marked as freed. For other modes than
BUF_GET_POSSIBLY_FREED or BUF_PEEK_IF_IN_POOL this will
trigger a debug assertion failure. For BUF_GET_POSSIBLY_FREED,
we will return nullptr for freed pages, so that the callers
can be simplified. The purge of transaction history will be
a new user of BUF_GET_POSSIBLY_FREED, to avoid crashes on
corrupted data.

buf_page_get_low(): Never crash on a corrupted page, but simply
return nullptr.

fseg_page_is_allocated(): Replaces fseg_page_is_free().

fts_drop_common_tables(): Return an error if the transaction
was rolled back.

fil_space_t::set_corrupted(): Report a tablespace as corrupted if
it was not reported already.

fil_space_t::io(): Invoke fil_space_t::set_corrupted() to report
out-of-bounds page access or other errors.

Clean up mtr_t::page_lock()

buf_page_get_low(): Validate the page identifier (to check for
recently read corrupted pages) after acquiring the page latch.

buf_page_t::read_complete(): Flag uninitialized (all-zero) pages
with DB_FAIL. Return DB_PAGE_CORRUPTED on page number mismatch.

mtr_t::defer_drop_ahi(): Renamed from mtr_defer_drop_ahi().

recv_sys_t::free_corrupted_page(): Only set_corrupt_fs()
if any log records exist for the page. We do not mind if read-ahead
produces corrupted (or all-zero) pages that were not actually needed
during recovery.

recv_recover_page(): Return whether the operation succeeded.

recv_sys_t::recover_low(): Simplify the logic. Check for recovery error.

Thanks to Matthias Leich for testing this extensively and to the
authors of https://rr-project.org for making it easy to diagnose
and fix any failures that were found during the testing.

The types btr_latch_mode and mtr_memo_type_t are partly derived from
rw_lock_type_t. Despite that, some code for converting between them
is using conditions instead of bitwise arithmetics.

Let us define btr_latch_mode in such a way that more conversions to
rw_lock_type_t are possible by bitwise and.

Some SPATIAL INDEX code that assumed !(BTR_MODIFY_TREE & BTR_MODIFY_LEAF)
was adjusted.

fil_space_t::is_freed(): Check if a page is in freed_ranges.

fil_space_t::flush_freed(): Replaces buf_flush_freed_pages().

This was broken in 54e2e701 (MDEV-25524).

btr_page_split_and_insert(): Declare all parameters nonnull.
btr_pessimistic_scrub() was removed
in commit a5584b13 (MDEV-15528).

mtr_t::modify(): Set the m_made_dirty flag if needed,
so that buf_pool_t::insert_into_flush_list() will be invoked
while holding log_sys.flush_order_mutex.

This is something that was should have been part of
commit b212f1da (MDEV-22107).

mtr_t::is_empty(): Replaces mtr_t::get_log() and mtr_t::get_memo().

mtr_t::get_log_size(): Replaces mtr_t::get_log().

mtr_t::print(): Remove, unused function.

ReleaseBlocks::ReleaseBlocks(): Remove an unused parameter.

Fixup

Accept JSON values for the JSON fields.

- Fixed wrong DBUG_ASSERT when waiting for big-block-read
- Update S3_pagecache_reads counter when reading a block from S3.
  Before this patch the variable value was always 0

Reviewer: Oleksandr Byelkin <sanja@mariadb.com>

The assert happens in 10.6 with the following command:

./mtr --no-reorder --verbose-restart main.update_ignore_216 main.upgrade_MDEV-19650 main.upgrade_MDEV-23102-1 main.upgrade_MDEV-23102-2 main.upgrade_geometrycolumn_procedure_definer main.upgrade_mdev_24363 main.varbinary sys_vars.aria_log_file_size_basic

Reviewer: Oleksandr Byelkin <sanja@mariadb.com>

comp_thread_ctxt_t: Remove ctrl_mutex, ctrl_cond, started. We do not
actually need them for anything.

destroy_worker_thread(): Split from destroy_worker_threads().

create_worker_threads(): We already initialize
thd->data_avail=FALSE and thd->cancelled=FALSE before
invoking pthread_create(). If any thread creation fails,
clean up by destroy_worker_thread().

compress_worker_thread_func(): Assume that thd->started and
thd->data_avail are already initialized.

Reviewed by: Vladislav Vaintroub

ER_CHECK_NO_SUCH_TABLE was raised because a view does not have
the corresponding TABLE instance connected to TABLE_LIST and the
server interprets the absence as the absence of the table itself.

To fix the problem, we add a check to ensure that the target table
to be swapped with a partition is not a view.

Reviewed by: Nayuta Yanagisawa

MDEV-27862 Galera should replicate nextval()-related changes in sequences with INCREMENT <> 0, at least NOCACHE ones with engine=InnoDB

Sequence storage engine is not transactionl so cache will be written in
stmt_cache that is not replicated in cluster. To fix this replicate
what is available in both trans_cache and stmt_cache.

Sequences will only work when NOCACHE keyword is used when sequnce is
created. If WSREP is enabled and we don't have this keyword report error
indicting that sequence will not work correctly in cluster.

When binlog is enabled statement cache will be cleared in transaction
before COMMIT so cache generated from sequence will not be replicated.
We need to keep cache until replication.

Tests are re-recorded because of replication changes that were
introducted with this PR.
Reviewed-by: Jan Lindström <jan.lindstrom@mariadb.com>

wsrep_server_incoming_address function always returned value of the
wsrep_node_incoming_address even when actual incoming address
was resolved to inc_addr variable. Fixed by returning inc_addr
if it does contain incoming address.

no need to run all alter tests three times with no changes whatsoever

The symtom of the bug was that check table on an S3 table when using
--s3_slave-ignore-updates=1 could print "9 when updating keyfile"

If the connecting user doesn't have alter table privilege this isn't
allowed.

This patch removes enable / disable key commands that should never have been here

Closes #2002

For compatibility reasons, add the option to the MariaDB client without
any functional changes besides simply accepting the option and emitting
a warning that it is obsolete.

In MySQL this security related option is compulsory in certain use
cases. When users switch to MariaDB, this client command that used to
work starts failing without a sensible error message. In worst case
users resort to re-installing the mysql client from MySQL.

In MariaDB the option is obsolete and should simply be ignored. Users
however don't have any opportunity to learn that unless the client
program tells them so.

Before:

    mysql --enable-cleartext-plugin ...
    mysql: unknown option '--enable-cleartext-plugin'

    (program terminates)

After:

    mysql --enable-cleartext-plugin ...
    WARNING: option '--enable-cleartext-plugin' is obsolete.

    (program executes)

All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the
BSD-new license. I am contributing on behalf of my employer Amazon Web
Services, Inc.

srv_do_purge(): In commit edde1f6e
when the de-facto 32-bit trx_sys_t::history_size() was replaced with
32-bit trx_sys.rseg_history_len, some more variables were changed
from ulint (size_t) to uint32_t.

The history list length is the number of committed transactions whose
undo logs are waiting to be purged. Each TRX_RSEG_HISTORY list is
storing the number of entries in a 32-bit field and each transaction
will occupy at least one undo log page. It is thinkable that the
length of each TRX_RSEG_HISTORY list may approach the maximum
representable number. The number cannot be exceeded, because the
rollback segment header is allocated from the same tablespace as
the undo log header pages it is pointing to, and because the page
numbers of a tablespace are stored in 32 bits. In any case, it is
possible that the total number of unpurged committed transactions
cannot be represented in 32 but 39 bits (corresponding to
128 rollback segments and undo tablespaces).

aio_uring::thread_routine(): Handle -EINTR from io_uring_wait_cqe()
in the same way as aio_linux::getevent_thread_routine() does it:
simply ignore it and invoke the system call again.

Reviewed by: Vladislav Vaintroub

page_cur_insert_rec_low(): When checking for common bytes with
the preceding record, exclude the header bytes of next_rec
that could have been updated by this function.

The scenario where this caused corruption was an insert of
a node pointer record. The child page number was written as
0x203 but recovered as 0x103 because the n_owned field of next_rec
was changed from 1 to 2 before the comparison was invoked.

- InnoDB fails to create a fts cache while loading the innodb fts
table which is stored in system tablespace. InnoDB should create
the fts cache while loading FTS_DOC_ID column from system column.