MDEV-11254 cleanup: Remove buf_page_t::write_size

commit 6495806 removed all reads of buf_page_t::write_size. Let us remove the field altogether.

Author: dr-m

storage/innobase/buf/buf0buf.cc

@@ -547,13 +547,13 @@ static bool buf_page_decrypt_after_read(buf_page_t* bpage, fil_space_t* space)
 decompress_with_slot:
 ut_d(fil_page_type_validate(dst_frame));
 
-bpage->write_size = fil_page_decompress(slot->crypt_buf,
-dst_frame);
+ulint write_size = fil_page_decompress(slot->crypt_buf,
+ dst_frame);
 slot->release();
 
-ut_ad(!bpage->write_size || fil_page_type_validate(dst_frame));
+ut_ad(!write_size || fil_page_type_validate(dst_frame));
 ut_ad(space->n_pending_ios > 0);
-return bpage->write_size != 0;
+return write_size != 0;
 }
 
 if (space->crypt_data
@@ -1502,7 +1502,6 @@ buf_block_init(
 block->page.io_fix = BUF_IO_NONE;
 block->page.flush_observer = NULL;
 block->page.real_size = 0;
-block->page.write_size = 0;
 block->modify_clock = 0;
 block->page.slot = NULL;
 
@@ -5244,7 +5243,6 @@ buf_page_init_low(
 bpage->access_time = 0;
 bpage->newest_modification = 0;
 bpage->oldest_modification = 0;
-bpage->write_size = 0;
 bpage->real_size = 0;
 bpage->slot = NULL;
 

storage/innobase/include/buf0buf.h

@@ -1,7 +1,7 @@
 /*****************************************************************************
 
 Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
-Copyright (c) 2013, 2020 MariaDB Corporation.
+Copyright (c) 2013, 2020, MariaDB Corporation.
 
 This program is free software; you can redistribute it and/or modify it under
 the terms of the GNU General Public License as published by the Free Software
@@ -1508,11 +1508,6 @@ class buf_page_t {
 zip.data == NULL means an active
 buf_pool->watch */
 
-ulint write_size;/* Write size is set when this
-page is first time written and then
-if written again we check is TRIM
-operation needed. */
-
 ulint real_size;/*!< Real size of the page
 Normal pages == UNIV_PAGE_SIZE
 page compressed pages, payload