The function fsp_flags_try_adjust(), which is called on startup,
is incrementing the Innodb_pages0_read counts for every affected file.
Adjust the result of encryption.innodb_lotoftables accordingly.
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.