Analysis: When pages in doublewrite buffer are analyzed compressed
pages do not have correct checksum.
Fix: Decompress page before checksum is compared. If decompression
fails we still check checksum and corrupted pages are found.
If decompression succeeds, page now contains the original
checksum.
There was two problems. Firstly, if page in ibuf is encrypted but
decrypt failed we should not allow InnoDB to start because
this means that system tablespace is encrypted and not usable.
Secondly, if page decrypt is detected we should return false
from buf_page_decrypt_after_read.
Backport pull request #125 from grooverdan/MDEV-8923_innodb_buffer_pool_dump_pct to 10.0
WL#6504 InnoDB buffer pool dump/load enchantments
This patch consists of two parts:
1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load
From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e
Add testcases for innodb_buffer_pool_dump_pct_basic.
Part of the code authored by Daniel Black
WL#6504 InnoDB buffer pool dump/load enchantments
This patch consists of two parts:
1. Dump only the hottest N% of the buffer pool(s)
2. Prevent hogging the server duing BP load
From MySQL - commit b409342c43ce2edb68807100a77001367c7e6b8e
Analysis: When a page is read from encrypted table and page can't be
decrypted because of bad key (or incorrect encryption algorithm or
method) page was incorrectly left on buffer pool.
Fix: Remove page from buffer pool and from pending IO.
Analysis: Problem was that in fil_read_first_page we do find that
table has encryption information and that encryption service
or used key_id is not available. But, then we just printed
fatal error message that causes above assertion.
Fix: When we open single table tablespace if it has encryption
information (crypt_data) store this crypt data to the table
structure. When we open a table and we find out that tablespace
is not available, check has table a encryption information
and from there is encryption service or used key_id is not available.
If it is, add additional warning for SQL-layer.
MDEV-8409: Changing file-key-management-encryption-algorithm causes crash and no real info why
Analysis: Both bugs has two different error cases. Firstly, at startup
when server reads latest checkpoint but requested key_version,
key management plugin or encryption algorithm or method is not found
leading corrupted log entry. Secondly, similarly when reading system
tablespace if requested key_version, key management plugin or encryption
algorithm or method is not found leading buffer pool page corruption.
Fix: Firsly, when reading checkpoint at startup check if the log record
may be encrypted and if we find that it could be encrypted, print error
message and do not start server. Secondly, if page is buffer pool seems
corrupted but we find out that there is crypt_info, print additional
error message before asserting.
Added new dynamic configuration variable innodb_buf_dump_status_frequency
to configure how often buffer pool dump status is printed in the logs.
A number between [0, 100] that tells how oftern buffer pool dump status
in percentages should be printed. E.g. 10 means that buffer pool dump
status is printed when every 10% of number of buffer pool pages are
dumped. Default is 0 (only start and end status is printed).
Analysis: Problem was that actual payload size (page size) after compression
was handled incorrectly on encryption. Additionally, some of the variables
were not initialized.
Fixed by encrypting/decrypting only the actual compressed page size.
Analysis: Problem is that there is not enough temporary buffer slots
for pending IO requests.
Fixed by allocating same amount of temporary buffer slots as there
are max pending IO requests.
Analysis: Problem is that both encrypted tables and compressed tables use
FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION to store
required metadata. Furhermore, for only compressed tables currently
code skips compression.
Fixes:
- Only encrypted pages store key_version to FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION,
no need to fix
- Only compressed pages store compression algorithm to FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION,
no need to fix as they have different page type FIL_PAGE_PAGE_COMPRESSED
- Compressed and encrypted pages now use a new page type FIL_PAGE_PAGE_COMPRESSED_ENCRYPTED and
key_version is stored on FIL header offset FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION and compression
method is stored after FIL header similar way as compressed size, so that first
FIL_PAGE_COMPRESSED_SIZE is stored followed by FIL_PAGE_COMPRESSION_METHOD
- Fix buf_page_encrypt_before_write function to really compress pages if compression is enabled
- Fix buf_page_decrypt_after_read function to really decompress pages if compression is used
- Small style fixes
Make sure that when we publish the crypt_data we access the
memory cache of the tablespace crypt_data. Make sure that
crypt_data is stored whenever it is really needed.
All this is not yet enough in my opinion because:
sql/encryption.cc has DBUG_ASSERT(scheme->type == 1) i.e.
crypt_data->type == CRYPT_SCHEME_1
However, for InnoDB point of view we have global crypt_data
for every tablespace. When we change variables on crypt_data
we take mutex. However, when we use crypt_data for
encryption/decryption we use pointer to this global
structure and no mutex to protect against changes on
crypt_data.
Tablespace encryption starts in fil_crypt_start_encrypting_space
from crypt_data that has crypt_data->type = CRYPT_SCHEME_UNENCRYPTED
and later we write page 0 CRYPT_SCHEME_1 and finally whe publish
that to memory cache.
Analysis: Problem was that tablespaces not encrypted might not have
crypt_data stored on disk.
Fixed by always creating crypt_data to memory cache of the tablespace.
MDEV-8138: strange results from encrypt-and-grep test
Analysis: crypt_data->type is not updated correctly on memory
cache. This caused problem with state tranfer on
encrypted => unencrypted => encrypted.
Fixed by updating memory cache of crypt_data->type correctly based on
current srv_encrypt_tables value to either CRYPT_SCHEME_1 or
CRYPT_SCHEME_UNENCRYPTED.
Analysis: Problem was that we did create crypt data for encrypted table but
this new crypt data was not written to page 0. Instead a default crypt data
was written to page 0 at table creation.
Fixed by explicitly writing new crypt data to page 0 after successfull
table creation.
