Fixes also MDEV-13488: InnoDB writes CRYPT_INFO even though
encryption is not enabled.
Problem was that we created encryption metadata (crypt_data) for
system tablespace even when no encryption was enabled and too early.
System tablespace can be encrypted only using key rotation.
Test innodb-key-rotation-disable, innodb_encryption, innodb_lotoftables
require adjustment because INFORMATION_SCHEMA INNODB_TABLESPACES_ENCRYPTION
contain row only if tablespace really has encryption metadata.
fil_crypt_set_thread_cnt: Send message to background encryption threads
if they exits when they are ready. This is required to find tablespaces
requiring key rotation if no other changes happen.
fil_crypt_find_space_to_rotate: Decrease the amount of time waiting
when nothing happens to better enable key rotation on startup.
fsp_header_init: Write encryption metadata to page 0 only if tablespace is
encrypted or encryption is disabled by table option.
i_s_dict_fill_tablespaces_encryption : Skip tablespaces that do not
contain encryption metadata. This is required to avoid too early
wait condition trigger in encrypted -> unencrypted state transfer.
open_or_create_data_files: Do not create encryption metadata
by default to system tablespace.
Perform a slow shutdown at the start of the test, and create all
InnoDB tables with STATS_PERSISTENT=0, so that any I/O related to
background tasks (change buffer merge, purge, persistent statistics)
should be eliminated.
Analysis: By design InnoDB was reading first page of every .ibd file
at startup to find out is tablespace encrypted or not. This is
because tablespace could have been encrypted always, not
encrypted newer or encrypted based on configuration and this
information can be find realible only from first page of .ibd file.
Fix: Do not read first page of every .ibd file at startup. Instead
whenever tablespace is first time accedded we will read the first
page to find necessary information about tablespace encryption
status.
TODO: Add support for SYS_TABLEOPTIONS where all table options
encryption information included will be stored.
