This follows up the previous fix in
commit c3c53926c4 (MDEV-26554).
ha_innobase::delete_table(): Work around the insufficient
metadata locking (MDL) during DML operations by acquiring exclusive
InnoDB table locks on all child tables. Previously, this was only
done on TRUNCATE and ALTER.
ibuf_delete_rec(), btr_cur_optimistic_delete(): Do not invoke
lock_update_delete() during change buffer operations.
The revised trx_t::commit(std::vector<pfs_os_file_t>&) will
hold exclusive lock_sys.latch while invoking fil_delete_tablespace(),
which in turn may invoke ibuf_delete_rec().
dict_index_t::has_locking(): A new predicate, replacing the dummy
!dict_table_is_locking_disabled(index->table). Used for skipping lock
operations during ibuf_delete_rec().
trx_t::commit(std::vector<pfs_os_file_t>&): Release the locks
and remove the table from the cache while holding exclusive
lock_sys.latch.
trx_t::commit_in_memory(): Skip release_locks() if dict_operation holds.
trx_t::commit(): Reset dict_operation before invoking commit_in_memory()
via commit_persist().
lock_release_on_drop(): Release locks while lock_sys.latch is
exclusively locked.
lock_table(): Add a parameter for a pointer to the table.
We must not dereference the table before a lock_sys.latch has
been acquired. If the pointer to the table does not match the table
at that point, the table is invalid and DB_DEADLOCK will be returned.
row_ins_foreign_check_on_constraint(): Improve the checks.
Remove a bogus DB_LOCK_WAIT_TIMEOUT return that was needed
before commit c5fd9aa562 (MDEV-25919).
row_upd_check_references_constraints(),
wsrep_row_upd_check_foreign_constraints(): Simplify checks.
This also fixes MDEV-20198: Instant ALTER TABLE is not crash safe
InnoDB dictionary recovery wrongly used the READ UNCOMMITTED isolation
level, causing some mismatch. For example, if a table was renamed or
replaced in a transaction, according to READ UNCOMMITTED the table might
not exist at all.
We implement READ COMMITTED isolation level for accessing the dictionary
tables SYS_TABLES, SYS_COLUMNS, SYS_INDEXES, SYS_FIELDS, SYS_VIRTUAL,
SYS_FOREIGN, SYS_FOREIGN_COLS. For most of these tables, no secondary
index exists. For the secondary indexes (on SYS_TABLES.ID,
SYS_FOREIGN.FOR_NAME, SYS_FOREIGN.REF_NAME), we will always look up
the primary key in the clustered index and check if the record actually
is a committed version.
dict_check_sys_tables(): Recover tablespaces also from delete-marked
committed records, so that if a matching .ibd file exists, it will
be removed by fil_delete_tablespace() when the committed delete-marked
SYS_INDEXES record of the clustered index is purged
in row_purge_remove_clust_if_poss_low().
fil_ibd_open(): Change the Boolean parameter "validate" to a ternary
one, to suppress error messages when the file might not exist.
It is possible that a .ibd file was deleted and the server shut down
before the SYS_INDEXES and SYS_TABLES records were purged. Hence, if
dict_check_sys_tables() finds a committed delete-marked record,
we must not complain if the tablespace file is not found.
On Windows, we msut treat ERROR_PATH_NOT_FOUND (directory not found)
in the same way as ERROR_FILE_NOT_FOUND. This fixes a few failures where
a previous test successfully executed DROP DATABASE (and deleted all
files and the directory), but a committed delete-marked SYS_TABLES
record had not been purged before server restart.
dict_getnext_system_low(): Do not filter out delete-marked records.
dict_startscan_system(), dict_getnext_system(): Do filter out
delete-marked records, for accessing the INFORMATION_SCHEMA tables.
dict_sys_tables_rec_read(): Return the DB_TRX_ID of the committed
version of the record. This is needed in dict_load_table_low().
dict_load_foreign_cols(), dict_load_foreign(): Add a parameter for
the current transaction identifier. In some DDL operations, the
FOREIGN KEY constraints are being loaded from the data dictionary
before the DDL transaction has been committed. For SYS_FOREIGN
and SYS_FOREIGN_COLS, we must implement the special case of
READ COMMITTED that the changes of the uncommitted current transaction
are visible.
dict_load_foreign(): Validate the table name. We could find a
SYS_FOREIGN.ID via a committed delete-marked secondary index record
that does not match the REF_NAME or FOR_NAME of the secondary index record.
dict_load_index_low(): Optionally take the table as a parameter,
so that table->def_trx_id can be updated in case of a
committed delete-marked SYS_INDEXES record corresponding
to DROP INDEX, but not corresponding to an index stub of ADD INDEX.
dict_load_indexes(): Do not update table->def_trx_id
in case of delete-marked records.
rec_is_metadata(), rec_offs_make_valid(), rec_get_offsets_func(),
row_build_low(): Relax some assertions. We may now have
!index->is_instant() even if a metadata record is present in the index.
Previously, the recovery of instant ADD/DROP COLUMN assumed
that READ UNCOMMITTED of the data dictionary will be performed.
Now, we will have a READ COMMITTED copy of the data dictionary
cache, and a READ UNCOMMITTED copy of the metadata record.
btr_page_reorganize_low(): Correctly update the FIL_PAGE_TYPE
when rolling back an instant ADD/DROP COLUMN operation.
row_rec_to_index_entry_impl(): Relax some assertions,
and disallow accessing "extra" fields. This fixes the recovery
of a crash during an instant ADD COLUMN after a successful
instant DROP COLUMN, in the test innodb.instant_alter_crash.
Tested by: Matthias Leich
