MariaDB data-at-rest encryption (innodb_encrypt_tables)
had repurposed the same unused data field that was repurposed
in MySQL 5.7 (and MariaDB 10.2) for the Split Sequence Number (SSN)
field of SPATIAL INDEX. Because of this, MariaDB was unable to
support encryption on SPATIAL INDEX pages.
Furthermore, InnoDB page checksums skipped some bytes, and there
are multiple variations and checksum algorithms. By default,
InnoDB accepts all variations of all algorithms that ever existed.
This unnecessarily weakens the page checksums.
We hereby introduce two more innodb_checksum_algorithm variants
(full_crc32, strict_full_crc32) that are special in a way:
When either setting is active, newly created data files will
carry a flag (fil_space_t::full_crc32()) that indicates that
all pages of the file will use a full CRC-32C checksum over the
entire page contents (excluding the bytes where the checksum
is stored, at the very end of the page). Such files will always
use that checksum, no matter what the parameter
innodb_checksum_algorithm is assigned to.
For old files, the old checksum algorithms will continue to be
used. The value strict_full_crc32 will be equivalent to strict_crc32
and the value full_crc32 will be equivalent to crc32.
ROW_FORMAT=COMPRESSED tables will only use the old format.
These tables do not support new features, such as larger
innodb_page_size or instant ADD/DROP COLUMN. They may be
deprecated in the future. We do not want an unnecessary
file format change for them.
The new full_crc32() format also cleans up the MariaDB tablespace
flags. We will reserve flags to store the page_compressed
compression algorithm, and to store the compressed payload length,
so that checksum can be computed over the compressed (and
possibly encrypted) stream and can be validated without
decrypting or decompressing the page.
In the full_crc32 format, there no longer are separate before-encryption
and after-encryption checksums for pages. The single checksum is
computed on the page contents that is written to the file.
We do not make the new algorithm the default for two reasons.
First, MariaDB 10.4.2 was a beta release, and the default values
of parameters should not change after beta. Second, we did not
yet implement the full_crc32 format for page_compressed pages.
This will be fixed in MDEV-18644.
This is joint work with Marko Mäkelä.
The following INFORMATION_SCHEMA views were unnecessarily retrieving
the data from the SYS_TABLESPACES table instead of directly fetching
it from the fil_system cache:
information_schema.innodb_tablespaces_encryption
information_schema.innodb_tablespaces_scrubbing
InnoDB always loads all tablespace metadata into memory at startup
and never evicts it while the tablespace exists.
With this fix, accessing these views will be much faster and use less
memory, and include data about all tablespaces, including undo
tablespaces.
The view information_schema.innodb_sys_tablespaces will still reflect
the contents of the SYS_TABLESPACES table.
MDEV-13851 Always check table options in ALTER TABLE…ALGORITHM=INPLACE
In the merge of MySQL 5.7.9 to MariaDB 10.2.2, some code was included
that prevents ADD SPATIAL INDEX from being executed with ALGORITHM=INPLACE.
Also, the constant ADD_SPATIAL_INDEX was introduced as an alias
to ADD_INDEX. We will remove that alias now, and properly implement
the same ADD SPATIAL INDEX restrictions as MySQL 5.7 does:
1. table-rebuilding operations are not allowed if SPATIAL INDEX survive it
2. ALTER TABLE…ADD SPATIAL INDEX…LOCK=NONE is not allowed
ha_innobase::prepare_inplace_alter_table(): If the ALTER TABLE
requires actions within InnoDB, enforce the table options (MDEV-13851).
In this way, we will keep denying ADD SPATIAL INDEX for tables
that use encryption (MDEV-11974), even if ALGORITHM=INPLACE is used.
Encryption stores used key_version to
FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION (offset 26)
field. Spatial indexes store RTREE Split Sequence Number
(FIL_RTREE_SPLIT_SEQ_NUM) in the same field. Both values
can't be stored in same field. Thus, current encryption
implementation does not support encrypting spatial indexes.
fil_space_encrypt(): Do not encrypt page if page type is
FIL_PAGE_RTREE (this is required for background
encryption innodb-encrypt-tables=ON).
create_table_info_t::check_table_options() Do not allow creating
table with ENCRYPTED=YES if table contains spatial index.
