MDEV-23855: Remove fil_system.LRU and reduce fil_system.mutex contention

Also fixes MDEV-23929: innodb_flush_neighbors is not being ignored
for system tablespace on SSD

When the maximum configured number of file is exceeded, InnoDB will
close data files. We used to maintain a fil_system.LRU list and
a counter fil_node_t::n_pending to achieve this, at the huge cost
of multiple fil_system.mutex operations per I/O operation.

fil_node_open_file_low(): Implement a FIFO replacement policy:
The last opened file will be moved to the end of fil_system.space_list,
and files will be closed from the start of the list. However, we will
not move tablespaces in fil_system.space_list while
i_s_tablespaces_encryption_fill_table() is executing
(producing output for INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION)
because it may cause information of some tablespaces to go missing.
We also avoid this in mariabackup --backup because datafiles_iter_next()
assumes that the ordering is not changed.

IORequest: Fold more parameters to IORequest::type.

fil_space_t::io(): Replaces fil_io().

fil_space_t::flush(): Replaces fil_flush().

OS_AIO_IBUF: Remove. We will always issue synchronous reads of the
change buffer pages in buf_read_page_low().

We will always ignore some errors for background reads.

This should reduce fil_system.mutex contention a little.

fil_node_t::complete_write(): Replaces fil_node_t::complete_io().
On both read and write completion, fil_space_t::release_for_io()
will have to be called.

fil_space_t::io(): Do not acquire fil_system.mutex in the normal
code path.

xb_delta_open_matching_space(): Do not try to open the system tablespace
which was already opened. This fixes a file sharing violation in
mariabackup --prepare --incremental.

Reviewed by: Vladislav Vaintroub

extra/mariabackup/fil_cur.cc

@@ -93,7 +93,6 @@ xb_fil_node_close_file(
 	mutex_enter(&fil_system.mutex);
 
 	ut_ad(node);
-	ut_a(node->n_pending == 0);
 	ut_a(node->n_pending_flushes == 0);
 	ut_a(!node->being_extended);
 
@@ -108,20 +107,10 @@ xb_fil_node_close_file(
 	ut_a(ret);
 
 	node->handle = OS_FILE_CLOSED;
+	mutex_exit(&fil_system.mutex);
 
 	ut_a(fil_system.n_open > 0);
 	fil_system.n_open--;
-
-	if (node->space->purpose == FIL_TYPE_TABLESPACE &&
-	    fil_is_user_tablespace_id(node->space->id)) {
-
-		ut_a(UT_LIST_GET_LEN(fil_system.LRU) > 0);
-
-		/* The node is in the LRU list, remove it */
-		UT_LIST_REMOVE(fil_system.LRU, node);
-	}
-
-	mutex_exit(&fil_system.mutex);
 }
 
 /************************************************************************
@@ -180,18 +169,8 @@ xb_fil_cur_open(
 
 			return(XB_FIL_CUR_SKIP);
 		}
-		mutex_enter(&fil_system.mutex);
 
 		fil_system.n_open++;
-
-		if (node->space->purpose == FIL_TYPE_TABLESPACE &&
-		    fil_is_user_tablespace_id(node->space->id)) {
-
-			/* Put the node to the LRU list */
-			UT_LIST_ADD_FIRST(fil_system.LRU, node);
-		}
-
-		mutex_exit(&fil_system.mutex);
 	}
 
 	ut_ad(node->is_open());
@@ -427,7 +406,7 @@ xb_fil_cur_read(
 	retry_count = 10;
 	ret = XB_FIL_CUR_SUCCESS;
 
-	fil_space_t *space = fil_space_acquire_for_io(cursor->space_id);
+	fil_space_t *space = fil_space_t::get_for_io(cursor->space_id);
 
 	if (!space) {
 		return XB_FIL_CUR_ERROR;

extra/mariabackup/xtrabackup.cc

@@ -3011,6 +3011,7 @@ void
 xb_fil_io_init()
 {
 	fil_system.create(srv_file_per_table ? 50000 : 5000);
+	fil_system.freeze_space_list = 1;
 	fil_system.space_id_reuse_warned = true;
 }
 
@@ -3087,24 +3088,16 @@ xb_load_single_table_tablespace(
 	bool is_empty_file = file->exists() && file->is_empty_file();
 
 	if (err == DB_SUCCESS && file->space_id() != SRV_TMP_SPACE_ID) {
-		os_offset_t	node_size = os_file_get_size(file->handle());
-		os_offset_t	n_pages;
-
-		ut_a(node_size != (os_offset_t) -1);
-
-		n_pages = node_size / fil_space_t::physical_size(file->flags());
-
-		space = fil_space_create(
+		space = fil_space_t::create(
 			name, file->space_id(), file->flags(),
 			FIL_TYPE_TABLESPACE, NULL/* TODO: crypt_data */);
 
 		ut_a(space != NULL);
 
-		space->add(file->filepath(), OS_FILE_CLOSED, uint32_t(n_pages),
-			   false, false);
+		space->add(file->filepath(), OS_FILE_CLOSED, 0, false, false);
 		/* by opening the tablespace we forcing node and space objects
 		in the cache to be populated with fields from space header */
-		space->open();
+		space->get_size();
 
 		if (srv_operation == SRV_OPERATION_RESTORE_DELTA
 		    || xb_close_files) {
@@ -3406,19 +3399,6 @@ xb_load_tablespaces()
 	return(DB_SUCCESS);
 }
 
-/************************************************************************
-Initialize the tablespace memory cache and populate it by scanning for and
-opening data files.
-@returns DB_SUCCESS or error code.*/
-static
-dberr_t
-xb_data_files_init()
-{
-	xb_fil_io_init();
-
-	return(xb_load_tablespaces());
-}
-
 /** Destroy the tablespace memory cache. */
 static void xb_data_files_close()
 {
@@ -4607,6 +4587,22 @@ xb_delta_open_matching_space(
 		return file;
 	}
 
+	if (!info.space_id && fil_system.sys_space) {
+		fil_node_t *node
+			= UT_LIST_GET_FIRST(fil_system.sys_space->chain);
+		for (; node; node = UT_LIST_GET_NEXT(chain, node)) {
+			if (!strcmp(node->name, real_name)) {
+				break;
+			}
+		}
+		if (node && node->handle != OS_FILE_CLOSED) {
+			*success = true;
+			return node->handle;
+		}
+		msg("mariabackup: Cannot find file %s\n", real_name);
+		return OS_FILE_CLOSED;
+	}
+
 	log_mutex_enter();
 	if (!fil_is_user_tablespace_id(info.space_id)) {
 found:
@@ -4704,8 +4700,8 @@ xb_delta_open_matching_space(
 	ut_ad(fil_space_t::zip_size(flags) == info.zip_size);
 	ut_ad(fil_space_t::physical_size(flags) == info.page_size);
 
-	if (fil_space_create(dest_space_name, info.space_id, flags,
-			      FIL_TYPE_TABLESPACE, 0)) {
+	if (fil_space_t::create(dest_space_name, info.space_id, flags,
+				FIL_TYPE_TABLESPACE, 0)) {
 		*success = xb_space_create_file(real_name, info.space_id,
 						flags, &file);
 	} else {
@@ -4925,15 +4921,15 @@ xtrabackup_apply_delta(
 		os_file_close(src_file);
 		os_file_delete(0,src_path);
 	}
-	if (dst_file != OS_FILE_CLOSED)
+	if (dst_file != OS_FILE_CLOSED && info.space_id)
 		os_file_close(dst_file);
 	return TRUE;
 
 error:
 	aligned_free(incremental_buffer);
 	if (src_file != OS_FILE_CLOSED)
 		os_file_close(src_file);
-	if (dst_file != OS_FILE_CLOSED)
+	if (dst_file != OS_FILE_CLOSED && info.space_id)
 		os_file_close(dst_file);
 	msg("Error: xtrabackup_apply_delta(): "
 	    "failed to apply %s to %s.\n", src_path, dst_path);
@@ -5387,16 +5383,17 @@ static bool xtrabackup_prepare_func(char** argv)
 		srv_allow_writes_event = os_event_create(0);
 		os_event_set(srv_allow_writes_event);
 #endif
-		dberr_t err = xb_data_files_init();
-		if (err != DB_SUCCESS) {
+		xb_fil_io_init();
+		if (dberr_t err = xb_load_tablespaces()) {
 			msg("mariabackup: error: xb_data_files_init() failed "
 			    "with error %s\n", ut_strerr(err));
 			goto error_cleanup;
 		}
 
 		inc_dir_tables_hash.create(1000);
 
-		ok = xtrabackup_apply_deltas();
+		ok = fil_system.sys_space->open(false)
+			&& xtrabackup_apply_deltas();
 
 		xb_data_files_close();
 
@@ -5426,6 +5423,8 @@ static bool xtrabackup_prepare_func(char** argv)
 		goto error_cleanup;
 	}
 
+	fil_system.freeze_space_list = 0;
+
 	/* increase IO threads */
 	if (srv_n_file_io_threads < 10) {
 		srv_n_read_io_threads = 4;
@@ -5447,6 +5446,8 @@ static bool xtrabackup_prepare_func(char** argv)
 		goto error_cleanup;
 	}
 
+	ut_ad(!fil_system.freeze_space_list);
+
 	if (ok) {
 		msg("Last binlog file %s, position %lld",
 		    trx_sys.recovered_binlog_filename,

mysql-test/suite/encryption/t/innodb-remove-encryption.test

@@ -29,6 +29,7 @@ create table t1(a int not null primary key, b char(200)) engine=innodb;
 --source include/wait_condition.inc
 
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 
 --echo # Success!
@@ -41,6 +42,7 @@ SET GLOBAL innodb_encrypt_tables = off;
 --let $wait_condition=SELECT COUNT(*) = $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0 AND ROTATING_OR_FLUSHING = 0;
 --source include/wait_condition.inc
 
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 
@@ -51,6 +53,7 @@ SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_
 --let $restart_parameters=--skip-file-key-management --innodb-encrypt-tables=OFF --innodb-encryption-threads=0 --innodb-tablespaces-encryption
 -- source include/restart_mysqld.inc
 
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 

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

@@ -26,6 +26,7 @@ let $restart_parameters= --innodb_encryption_threads=5 --innodb_encryption_rotat
 --source include/wait_condition.inc
 
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 
 --echo # Restart the server with innodb_encryption_rotate_key_age= 0
@@ -45,6 +46,7 @@ create table t4 (f1 int not null)engine=innodb encrypted=NO;
 
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 
 --echo # Disable encryption when innodb_encryption_rotate_key_age is 0
@@ -57,6 +59,7 @@ set global innodb_encrypt_tables = OFF;
 --let $wait_condition=SELECT COUNT(*) >= $tables_count FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0 AND ROTATING_OR_FLUSHING = 0;
 --source include/wait_condition.inc
 
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 --echo # Display only encrypted create tables (t3)
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
@@ -73,11 +76,13 @@ set global innodb_encrypt_tables = ON;
 
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
 --echo # Display only unencrypted create tables (t4)
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 
 --let $restart_parameters=
 -- source include/restart_mysqld.inc
 
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION = 0;
+--sorted_result
 SELECT NAME FROM INFORMATION_SCHEMA.INNODB_TABLESPACES_ENCRYPTION WHERE MIN_KEY_VERSION <> 0;
 DROP TABLE t4, t3, t2, t1;

mysql-test/suite/innodb/r/table_definition_cache_debug.result

@@ -1,4 +1,4 @@
-call mtr.add_suppression("InnoDB: innodb_open_files=13 is exceeded");
+call mtr.add_suppression("InnoDB: innodb_open_files=.* is exceeded");
 SET @save_tdc= @@GLOBAL.table_definition_cache;
 SET @save_toc= @@GLOBAL.table_open_cache;
 SET GLOBAL table_definition_cache= 400;

mysql-test/suite/innodb/t/innodb-trim.test

@@ -32,18 +32,6 @@ commit;
 set autocommit=1;
 
 
-let $success= `SELECT variable_value FROM information_schema.global_status WHERE variable_name = 'innodb_num_page_compressed_trim_op'`;
-
-if (!$success) {
---disable_query_log
---disable_result_log
-    DROP PROCEDURE innodb_insert_proc;
-    DROP TABLE innodb_page_compressed;
---enable_query_log
---enable_result_log
-    --skip "Test requires TRIM";
-}
-
 DROP PROCEDURE innodb_insert_proc;
 DROP TABLE innodb_page_compressed;
 

mysql-test/suite/innodb/t/table_definition_cache_debug.test

@@ -4,7 +4,7 @@
 # This test is slow on buildbot.
 --source include/big_test.inc
 
-call mtr.add_suppression("InnoDB: innodb_open_files=13 is exceeded");
+call mtr.add_suppression("InnoDB: innodb_open_files=.* is exceeded");
 
 SET @save_tdc= @@GLOBAL.table_definition_cache;
 SET @save_toc= @@GLOBAL.table_open_cache;

storage/innobase/CMakeLists.txt

@@ -1,3 +1,4 @@
+
 # Copyright (c) 2006, 2017, Oracle and/or its affiliates. All rights reserved.
 # Copyright (c) 2014, 2020, MariaDB Corporation.
 #
@@ -186,7 +187,6 @@ SET(INNOBASE_SOURCES
 	include/mtr0mtr.h
 	include/mtr0mtr.ic
 	include/mtr0types.h
-	include/os0api.h
 	include/os0event.h
 	include/os0file.h
 	include/os0file.ic

storage/innobase/btr/btr0cur.cc

@@ -3304,21 +3304,34 @@ btr_cur_ins_lock_and_undo(
 
 /**
 Prefetch siblings of the leaf for the pessimistic operation.
-@param block	leaf page */
-static void btr_cur_prefetch_siblings(const buf_block_t* block)
+@param block	leaf page
+@param index    index of the page */
+static void btr_cur_prefetch_siblings(const buf_block_t *block,
+                                      const dict_index_t *index)
 {
-  const page_t *page= block->frame;
-  ut_ad(page_is_leaf(page));
+  ut_ad(page_is_leaf(block->frame));
+
+  if (index->is_ibuf())
+    return;
 
+  const page_t *page= block->frame;
   uint32_t prev= mach_read_from_4(my_assume_aligned<4>(page + FIL_PAGE_PREV));
   uint32_t next= mach_read_from_4(my_assume_aligned<4>(page + FIL_PAGE_NEXT));
 
   if (prev != FIL_NULL)
-    buf_read_page_background(page_id_t(block->page.id().space(), prev),
+  {
+    ut_a(index->table->space->acquire_for_io());
+    buf_read_page_background(index->table->space,
+                             page_id_t(block->page.id().space(), prev),
                              block->zip_size(), false);
+  }
   if (next != FIL_NULL)
-    buf_read_page_background(page_id_t(block->page.id().space(), next),
+  {
+    ut_a(index->table->space->acquire_for_io());
+    buf_read_page_background(index->table->space,
+                             page_id_t(block->page.id().space(), next),
                              block->zip_size(), false);
+  }
 }
 
 /*************************************************************//**
@@ -3436,8 +3449,8 @@ btr_cur_optimistic_insert(
 
 		/* prefetch siblings of the leaf for the pessimistic
 		operation, if the page is leaf. */
-		if (page_is_leaf(page) && !index->is_ibuf()) {
-			btr_cur_prefetch_siblings(block);
+		if (page_is_leaf(page)) {
+			btr_cur_prefetch_siblings(block, index);
 		}
 fail_err:
 
@@ -4575,7 +4588,7 @@ btr_cur_optimistic_update(
 
 		/* prefetch siblings of the leaf for the pessimistic
 		operation. */
-		btr_cur_prefetch_siblings(block);
+		btr_cur_prefetch_siblings(block, index);
 
 		return(DB_OVERFLOW);
 	}
@@ -4766,10 +4779,10 @@ btr_cur_optimistic_update(
 		}
 	}
 
-	if (err != DB_SUCCESS && !index->is_ibuf()) {
+	if (err != DB_SUCCESS) {
 		/* prefetch siblings of the leaf for the pessimistic
 		operation. */
-		btr_cur_prefetch_siblings(block);
+		btr_cur_prefetch_siblings(block, index);
 	}
 
 	return(err);
@@ -5481,7 +5494,7 @@ btr_cur_optimistic_delete_func(
 	if (!no_compress_needed) {
 		/* prefetch siblings of the leaf for the pessimistic
 		operation. */
-		btr_cur_prefetch_siblings(block);
+		btr_cur_prefetch_siblings(block, cursor->index);
 		goto func_exit;
 	}