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| author | Marko Mäkelä <marko.makela@mariadb.com> | 2018-12-13 17:57:10 +0200 |
|---|---|---|
| committer | Marko Mäkelä <marko.makela@mariadb.com> | 2018-12-13 17:57:18 +0200 |
| commit | 1a780eefc9ff8050b44bca07c981bd6a42bdbaf6 (patch) | |
| tree | 1fceeee919d3d71a244b60f9c1a644a91b84de38 /storage/innobase/innodb.cmake | |
| parent | 2e5aea4bab65544a44c7983759f80c5823780f76 (diff) | |
| download | mariadb-git-1a780eefc9ff8050b44bca07c981bd6a42bdbaf6.tar.gz | |
MDEV-17958 Make bug-endian innodb_checksum_algorithm=crc32 optional
In MySQL 5.7, it was noticed that files are not portable between
big-endian and little-endian processor architectures
(such as SPARC and x86), because the original implementation of
innodb_checksum_algorithm=crc32 was not byte order agnostic.
A byte order agnostic implementation of innodb_checksum_algorithm=crc32
was only added to MySQL 5.7, not backported to 5.6. Consequently,
MariaDB Server versions 10.0 and 10.1 only contain the CRC-32C
implementation that works incorrectly on big-endian architectures,
and MariaDB Server 10.2.2 got the byte-order agnostic CRC-32C
implementation from MySQL 5.7.
MySQL 5.7 introduced a "legacy crc32" variant that is functionally
equivalent to the big-endian version of the original crc32 implementation.
Thanks to this variant, old data files can be transferred from big-endian
systems to newer versions.
Introducing new variants of checksum algorithms (without introducing
new names for them, or something on the pages themselves to identify
the algorithm) generally is a bad idea, because each checksum algorithm
is like a lottery ticket. The more algorithms you try, the more likely
it will be for the checksum to match on a corrupted page.
So, essentially MySQL 5.7 weakened innodb_checksum_algorithm=crc32,
and MariaDB 10.2.2 inherited this weakening.
We introduce a build option that together with MDEV-17957
makes innodb_checksum_algorithm=strict_crc32 strict again
by only allowing one variant of the checksum to match.
WITH_INNODB_BUG_ENDIAN_CRC32: A new cmake option for enabling the
bug-compatible "legacy crc32" checksum. This is only enabled on
big-endian systems by default, to facilitate an upgrade from
MariaDB 10.0 or 10.1. Checked by #ifdef INNODB_BUG_ENDIAN_CRC32.
ut_crc32_byte_by_byte: Remove (unused function).
legacy_big_endian_checksum: Remove. This variable seems to have
unnecessarily complicated the logic. When the weakening is enabled,
we must always fall back to the buggy checksum.
buf_page_check_crc32(): A helper function to compute one or
two CRC-32C variants.
Diffstat (limited to 'storage/innobase/innodb.cmake')
| -rw-r--r-- | storage/innobase/innodb.cmake | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/storage/innobase/innodb.cmake b/storage/innobase/innodb.cmake index 7272585dcce..b24343afacd 100644 --- a/storage/innobase/innodb.cmake +++ b/storage/innobase/innodb.cmake @@ -25,6 +25,7 @@ INCLUDE(lzma.cmake) INCLUDE(bzip2.cmake) INCLUDE(snappy.cmake) INCLUDE(numa) +INCLUDE(TestBigEndian) MYSQL_CHECK_LZ4() MYSQL_CHECK_LZO() @@ -32,6 +33,7 @@ MYSQL_CHECK_LZMA() MYSQL_CHECK_BZIP2() MYSQL_CHECK_SNAPPY() MYSQL_CHECK_NUMA() +TEST_BIG_ENDIAN(IS_BIG_ENDIAN) IF(CMAKE_CROSSCOMPILING) # Use CHECK_C_SOURCE_COMPILES instead of CHECK_C_SOURCE_RUNS when @@ -123,6 +125,11 @@ ELSEIF(WITH_INNODB_ROOT_GUESS) ADD_DEFINITIONS(-DBTR_CUR_ADAPT) ENDIF() +OPTION(WITH_INNODB_BUG_ENDIAN_CRC32 "Weaken innodb_checksum_algorithm=crc32 by supporting upgrade from big-endian systems running 5.6/10.0/10.1" ${IS_BIG_ENDIAN}) +IF(WITH_INNODB_BUG_ENDIAN_CRC32) + ADD_DEFINITIONS(-DINNODB_BUG_ENDIAN_CRC32) +ENDIF() + OPTION(WITH_INNODB_EXTRA_DEBUG "Enable extra InnoDB debug checks" OFF) IF(WITH_INNODB_EXTRA_DEBUG) IF(NOT CMAKE_BUILD_TYPE STREQUAL "Debug") |