If an encrypted table is created during backup, then
mariabackup --backup could wrongly fail.
This caused a failure of the test mariabackup.huge_lsn once on buildbot.
This is due to the way how InnoDB creates .ibd files. It would first
write a dummy page 0 with no encryption information. Due to this,
xb_fil_cur_open() could wrongly interpret that the table is not encrypted.
Subsequently, page_is_corrupted() would compare the computed page
checksum to the wrong checksum. (There are both "before" and "after"
checksums for encrypted pages.)
To work around this problem, we introduce a Boolean option
--backup-encrypted that is enabled by default. With this option,
Mariabackup will assume that a nonzero key_version implies that the
page is encrypted. We need this option in order to be able to copy
encrypted tables from MariaDB 10.1 or 10.2, because unencrypted pages
that were originally created before MySQL 5.1.48 could contain nonzero
garbage in the fields that were repurposed for encryption.
Later, MDEV-18128 would clean up the way how .ibd files are created,
to remove the need for this option.
page_is_corrupted(): Add missing const qualifiers, and do not check
space->crypt_data unless --skip-backup-encrypted has been specified.
xb_fil_cur_read(): After a failed page read, output a page dump.
- Refactor code to isolate page validation in page_is_corrupted() function.
- Introduce --extended-validation parameter(default OFF) for mariabackup
--backup to enable decryption of encrypted uncompressed pages during
backup.
- mariabackup would still always check checksum on encrypted data,
it is needed to detect partially written pages.
Write a test case that computes valid crc32 checksums for
an encrypted page, but zeroes out the payload area, so
that the checksum after decryption fails.
xb_fil_cur_read(): Validate the page number before trying
any checksum calculation or decrypting or decompression.
Also, skip zero-filled pages. For page_compressed pages,
ensure that the FIL_PAGE_TYPE was changed. Also, reject
FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED if no decryption was attempted.
Problem:
=======
Mariabackup seems to fail to verify the pages of compressed tables.
The reason is that both fil_space_verify_crypt_checksum() and
buf_page_is_corrupted() will skip the validation for compressed pages.
Fix:
====
Mariabackup should call fil_page_decompress() for compressed and encrypted
compressed page. After that, call buf_page_is_corrupted() to
check the page corruption.
The initial fix only covered a part of Mariabackup.
This fix hardens InnoDB and XtraDB in a similar way, in order
to reduce the probability of mistaking a corrupted encrypted page
for a valid unencrypted one.
This is based on work by Thirunarayanan Balathandayuthapani.
fil_space_verify_crypt_checksum(): Assert that key_version!=0.
Let the callers guarantee that. Now that we have this assertion,
we also know that buf_page_is_zeroes() cannot hold.
Also, remove all diagnostic output and related parameters,
and let the relevant callers emit such messages.
Last but not least, validate the post-encryption checksum
according to the innodb_checksum_algorithm (only accepting
one checksum for the strict variants), and no longer
try to validate the page as if it was unencrypted.
buf_page_is_zeroes(): Move to the compilation unit of the only callers,
and declare static.
xb_fil_cur_read(), buf_page_check_corrupt(): Add a condition before
calling fil_space_verify_crypt_checksum(). This is a non-functional
change.
buf_dblwr_process(): Validate the page only as encrypted or unencrypted,
but not both.
After validating the post-encryption checksum on an encrypted page,
Mariabackup should decrypt the page and validate the pre-encryption
checksum as well. This should reduce the probability of accepting
invalid pages as valid ones.
This is a backport and refactoring of a patch that was
originally written by Thirunarayanan Balathandayuthapani
for the 10.2 branch.
extra/mariabackup/fil_cur.cc:361:42: warning: format specifies type 'unsigned long' but the argument has type 'ib_int64_t' (aka 'long long') [-Wformat]
extra/mariabackup/fil_cur.cc:376:9: warning: format specifies type 'unsigned long' but the argument has type 'ib_int64_t' (aka 'long long') [-Wformat]
sql/handler.cc:6196:45: warning: format specifies type 'unsigned long' but the argument has type 'wsrep_trx_id_t' (aka 'unsigned long long') [-Wformat]
sql/log.cc:1681:16: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
sql/log.cc:1687:16: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
sql/wsrep_sst.cc:1388:86: warning: format specifies type 'long' but the argument has type 'wsrep_seqno_t' (aka 'long long') [-Wformat]
sql/wsrep_sst.cc:232:86: warning: format specifies type 'long' but the argument has type 'wsrep_seqno_t' (aka 'long long') [-Wformat]
storage/connect/filamdbf.cpp:450:47: warning: format specifies type 'short' but the argument has type 'int' [-Wformat]
storage/connect/filamdbf.cpp:970:47: warning: format specifies type 'short' but the argument has type 'int' [-Wformat]
storage/connect/inihandl.cpp:197:16: warning: address of array 'key->name' will always evaluate to 'true' [-Wpointer-bool-conversion]
storage/innobase/btr/btr0scrub.cc:151:17: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/buf/buf0buf.cc:5085:8: warning: nonnull parameter 'bpage' will evaluate to 'true' on first encounter [-Wpointer-bool-conversion]
storage/innobase/fil/fil0crypt.cc:2454:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/handler/ha_innodb.cc:18685:7: warning: format specifies type 'unsigned long' but the argument has type 'wsrep_trx_id_t' (aka 'unsigned long long') [-Wformat]
storage/innobase/row/row0mysql.cc:3319:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/innobase/row/row0mysql.cc:3327:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/maria/ma_norec.c:35:10: warning: implicit conversion from 'int' to 'my_bool' (aka 'char') changes value from 131 to -125 [-Wconstant-conversion]
storage/maria/ma_norec.c:42:10: warning: implicit conversion from 'int' to 'my_bool' (aka 'char') changes value from 131 to -125 [-Wconstant-conversion]
storage/maria/ma_test2.c:1009:12: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
storage/maria/ma_test2.c:1010:12: warning: format specifies type 'unsigned long' but the argument has type 'size_t' (aka 'unsigned int') [-Wformat]
storage/mroonga/ha_mroonga.cpp:9189:44: warning: use of logical '&&' with constant operand [-Wconstant-logical-operand]
storage/mroonga/vendor/groonga/lib/expr.c:4987:22: warning: comparison of constant -1 with expression of type 'grn_operator' is always false [-Wtautological-constant-out-of-range-compare]
storage/xtradb/btr/btr0scrub.cc:151:17: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/buf/buf0buf.cc:5047:8: warning: nonnull parameter 'bpage' will evaluate to 'true' on first encounter [-Wpointer-bool-conversion]
storage/xtradb/fil/fil0crypt.cc:2454:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/row/row0mysql.cc:3324:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
storage/xtradb/row/row0mysql.cc:3332:5: warning: format specifies type 'long' but the argument has type 'int' [-Wformat]
unittest/sql/mf_iocache-t.cc:120:35: warning: format specifies type 'unsigned long' but the argument has type 'int' [-Wformat]
unittest/sql/mf_iocache-t.cc:96:35: note: expanded from macro 'INFO_TAIL'
