MDEV-27058: Reduce the size of buf_block_t and buf_page_t

buf_page_t::frame: Moved from buf_block_t::frame.
All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED
pages will have frame=nullptr, while all 'fat' buf_block_t
will have a non-null frame pointing to aligned innodb_page_size bytes.
This eliminates the need for separate states for
BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE.

buf_page_t::lock: Moved from buf_block_t::lock. That is, all block
descriptors will have a page latch. The IO_PIN state that was used
for discarding or creating the uncompressed page frame of a
ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix
and page X-latch.

page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status
of buf_page_t with a single std::atomic<uint32_t>. All modifications
will use store(), fetch_add(), fetch_sub(). This space was previously
wasted to alignment on 64-bit systems. We will use the following encoding
that combines a state (partly read-fix or write-fix) and a buffer-fix
count:

buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED)
buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY)
buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH)
buf_page_t::FREED=3 + fix: pages marked as freed in the file
buf_page_t::UNFIXED=1U<<29 + fix: normal pages
buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge
buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite)
buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched)
buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched)
buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf
buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite)

buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to
UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch.

buf_page_t::read_complete(): Renamed from buf_page_read_complete().
Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch.

buf_page_t::can_relocate(): If the page latch is being held or waited for,
or the block is buffer-fixed or io-fixed, return false. (The condition
on the page latch is new.)

Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we
will acquire the page latch before fix(), and unfix() before unlocking.

buf_page_t::flush(): Replaces buf_flush_page(). Optimize the
handling of FREED pages.

buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held
by the caller.

buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates.

buf_page_get_low(): Ignore guesses that are read-fixed because they
may not yet be registered in buf_pool.page_hash and buf_pool.LRU.

buf_page_optimistic_get(): Acquire latch before buffer-fixing.

buf_page_make_young(): Leave read-fixed blocks alone, because they
might not be registered in buf_pool.LRU yet.

recv_sys_t::recover_deferred(), recv_sys_t::recover_low():
Possibly fix MDEV-26326, by holding a page X-latch instead of
only buffer-fixing the page.

mysql-test/suite/encryption/r/innodb_encrypt_key_rotation_age.result

@@ -67,13 +67,13 @@ test/t2
 test/t3
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 NAME
-test/t4
-SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
-NAME
 innodb_system
-mysql/innodb_index_stats
 mysql/innodb_table_stats
+mysql/innodb_index_stats
 mysql/transaction_registry
+test/t4
+SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
+NAME
 test/t1
 test/t2
 test/t3

mysql-test/suite/encryption/r/innodb_encryption.result

@@ -66,7 +66,7 @@ innodb_encryption_threads	0
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0
 AND NAME NOT LIKE 'innodb_undo%' AND NAME NOT LIKE 'mysql/innodb_%_stats' AND NAME NOT LIKE 'mysql/transaction_registry';
 NAME
-innodb_system
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0
 AND NAME NOT LIKE 'innodb_undo%' AND NAME NOT LIKE 'mysql/innodb_%_stats' AND NAME NOT LIKE 'mysql/transaction_registry';
 NAME
+innodb_system

mysql-test/suite/encryption/t/innodb_encryption.test

@@ -90,6 +90,9 @@ AND NAME NOT LIKE 'innodb_undo%' AND NAME NOT LIKE 'mysql/innodb_%_stats' AND NA
 
 SHOW VARIABLES LIKE 'innodb_encrypt%';
 
+--let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--source include/wait_condition.inc
+
 --sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0
 AND NAME NOT LIKE 'innodb_undo%' AND NAME NOT LIKE 'mysql/innodb_%_stats' AND NAME NOT LIKE 'mysql/transaction_registry';

mysql-test/suite/innodb_i_s/innodb_buffer_page.result

@@ -18,7 +18,7 @@ INNODB_BUFFER_PAGE	CREATE TEMPORARY TABLE `INNODB_BUFFER_PAGE` (
   `DATA_SIZE` bigint(21) unsigned NOT NULL DEFAULT 0,
   `COMPRESSED_SIZE` bigint(21) unsigned NOT NULL DEFAULT 0,
   `PAGE_STATE` enum('NOT_USED','MEMORY','REMOVE_HASH','FILE_PAGE') NOT NULL,
-  `IO_FIX` enum('IO_NONE','IO_READ','IO_WRITE','IO_PIN') NOT NULL,
+  `IO_FIX` enum('IO_NONE','IO_READ','IO_WRITE') NOT NULL,
   `IS_OLD` int(1) NOT NULL DEFAULT 0,
   `FREE_PAGE_CLOCK` bigint(21) unsigned NOT NULL DEFAULT 0
 ) ENGINE=MEMORY DEFAULT CHARSET=utf8mb3

mysql-test/suite/innodb_i_s/innodb_buffer_page_lru.result

@@ -18,7 +18,7 @@ INNODB_BUFFER_PAGE_LRU	CREATE TEMPORARY TABLE `INNODB_BUFFER_PAGE_LRU` (
   `DATA_SIZE` bigint(21) unsigned NOT NULL DEFAULT 0,
   `COMPRESSED_SIZE` bigint(21) unsigned NOT NULL DEFAULT 0,
   `COMPRESSED` int(1) NOT NULL DEFAULT 0,
-  `IO_FIX` enum('IO_NONE','IO_READ','IO_WRITE','IO_PIN') NOT NULL,
+  `IO_FIX` enum('IO_NONE','IO_READ','IO_WRITE') NOT NULL,
   `IS_OLD` int(1) DEFAULT NULL,
   `FREE_PAGE_CLOCK` bigint(21) unsigned NOT NULL DEFAULT 0
 ) ENGINE=MEMORY DEFAULT CHARSET=utf8mb3

storage/innobase/CMakeLists.txt

@@ -95,7 +95,6 @@ SET(INNOBASE_SOURCES
 	include/buf0dblwr.h
 	include/buf0dump.h
 	include/buf0flu.h
-	include/buf0flu.ic
 	include/buf0lru.h
 	include/buf0rea.h
 	include/buf0types.h