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mariadb/storage/innobase/buf/buf0dblwr.cc
Jan Lindström 6495806e59 MDEV-11254: innodb-use-trim has no effect in 10.2 
Problem was that implementation merged from 10.1 was incompatible
with InnoDB 5.7.

buf0buf.cc: Add functions to return should we punch hole and
how big.

buf0flu.cc: Add written page to IORequest

fil0fil.cc: Remove unneeded status call and add test is
sparse files and punch hole supported by file system when
tablespace is created. Add call to get file system
block size. Used file node is added to IORequest. Added
functions to check is punch hole supported and setting
punch hole.

ha_innodb.cc: Remove unneeded status variables (trim512-32768)
and trim_op_saved. Deprecate innodb_use_trim and
set it ON by default. Add function to set innodb-use-trim
dynamically.

dberr.h: Add error code DB_IO_NO_PUNCH_HOLE
if punch hole operation fails.

fil0fil.h: Add punch_hole variable to fil_space_t and
block size to fil_node_t.

os0api.h: Header to helper functions on buf0buf.cc and
fil0fil.cc for os0file.h

os0file.h: Remove unneeded m_block_size from IORequest
and add bpage to IORequest to know actual size of
the block and m_fil_node to know tablespace file
system block size and does it support punch hole.

os0file.cc: Add function punch_hole() to IORequest
to do punch_hole operation,
get the file system block size and determine
does file system support sparse files (for punch hole).

page0size.h: remove implicit copy disable and
use this implicit copy to implement copy_from()
function.

buf0dblwr.cc, buf0flu.cc, buf0rea.cc, fil0fil.cc, fil0fil.h,
os0file.h, os0file.cc, log0log.cc, log0recv.cc:
Remove unneeded write_size parameter from fil_io
calls.

srv0mon.h, srv0srv.h, srv0mon.cc: Remove unneeded
trim512-trim32678 status variables. Removed
these from monitor tests.
2017-01-24 14:40:58 +02:00

1316 lines
36 KiB
C++
Raw Blame History

/*****************************************************************************
Copyright (c) 1995, 2015, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2013, 2017, MariaDB Corporation. All Rights Reserved.
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
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file buf/buf0dblwr.cc
Doublwrite buffer module
Created 2011/12/19
*******************************************************/
#include "ha_prototypes.h"
#include "buf0dblwr.h"
#ifdef UNIV_NONINL
#include "buf0buf.ic"
#endif
#include "buf0buf.h"
#include "buf0checksum.h"
#include "srv0start.h"
#include "srv0srv.h"
#include "page0zip.h"
#include "trx0sys.h"
#include "fil0crypt.h"
#include "fil0pagecompress.h"
/** The doublewrite buffer */
buf_dblwr_t* buf_dblwr = NULL;
/** Set to TRUE when the doublewrite buffer is being created */
ibool buf_dblwr_being_created = FALSE;
#define TRX_SYS_DOUBLEWRITE_BLOCKS 2
/****************************************************************//**
Determines if a page number is located inside the doublewrite buffer.
@return TRUE if the location is inside the two blocks of the
doublewrite buffer */
ibool
buf_dblwr_page_inside(
/*==================*/
ulint page_no) /*!< in: page number */
{
if (buf_dblwr == NULL) {
return(FALSE);
}
if (page_no >= buf_dblwr->block1
&& page_no < buf_dblwr->block1
+ TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
return(TRUE);
}
if (page_no >= buf_dblwr->block2
&& page_no < buf_dblwr->block2
+ TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
return(TRUE);
}
return(FALSE);
}
/****************************************************************//**
Calls buf_page_get() on the TRX_SYS_PAGE and returns a pointer to the
doublewrite buffer within it.
@return pointer to the doublewrite buffer within the filespace header
page. */
UNIV_INLINE
byte*
buf_dblwr_get(
/*==========*/
mtr_t* mtr) /*!< in/out: MTR to hold the page latch */
{
buf_block_t* block;
block = buf_page_get(page_id_t(TRX_SYS_SPACE, TRX_SYS_PAGE_NO),
univ_page_size, RW_X_LATCH, mtr);
buf_block_dbg_add_level(block, SYNC_NO_ORDER_CHECK);
return(buf_block_get_frame(block) + TRX_SYS_DOUBLEWRITE);
}
/********************************************************************//**
Flush a batch of writes to the datafiles that have already been
written to the dblwr buffer on disk. */
void
buf_dblwr_sync_datafiles()
/*======================*/
{
/* Wake possible simulated aio thread to actually post the
writes to the operating system */
os_aio_simulated_wake_handler_threads();
/* Wait that all async writes to tablespaces have been posted to
the OS */
os_aio_wait_until_no_pending_writes();
/* Now we flush the data to disk (for example, with fsync) */
fil_flush_file_spaces(FIL_TYPE_TABLESPACE);
}
/****************************************************************//**
Creates or initialializes the doublewrite buffer at a database start. */
static
void
buf_dblwr_init(
/*===========*/
byte* doublewrite) /*!< in: pointer to the doublewrite buf
header on trx sys page */
{
ulint buf_size;
buf_dblwr = static_cast<buf_dblwr_t*>(
ut_zalloc_nokey(sizeof(buf_dblwr_t)));
/* There are two blocks of same size in the doublewrite
buffer. */
buf_size = TRX_SYS_DOUBLEWRITE_BLOCKS * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE;
/* There must be atleast one buffer for single page writes
and one buffer for batch writes. */
ut_a(srv_doublewrite_batch_size > 0
&& srv_doublewrite_batch_size < buf_size);
mutex_create(LATCH_ID_BUF_DBLWR, &buf_dblwr->mutex);
buf_dblwr->b_event = os_event_create("dblwr_batch_event");
buf_dblwr->s_event = os_event_create("dblwr_single_event");
buf_dblwr->first_free = 0;
buf_dblwr->s_reserved = 0;
buf_dblwr->b_reserved = 0;
buf_dblwr->block1 = mach_read_from_4(
doublewrite + TRX_SYS_DOUBLEWRITE_BLOCK1);
buf_dblwr->block2 = mach_read_from_4(
doublewrite + TRX_SYS_DOUBLEWRITE_BLOCK2);
buf_dblwr->in_use = static_cast<bool*>(
ut_zalloc_nokey(buf_size * sizeof(bool)));
buf_dblwr->write_buf_unaligned = static_cast<byte*>(
ut_malloc_nokey((1 + buf_size) * UNIV_PAGE_SIZE));
buf_dblwr->write_buf = static_cast<byte*>(
ut_align(buf_dblwr->write_buf_unaligned,
UNIV_PAGE_SIZE));
buf_dblwr->buf_block_arr = static_cast<buf_page_t**>(
ut_zalloc_nokey(buf_size * sizeof(void*)));
}
/****************************************************************//**
Creates the doublewrite buffer to a new InnoDB installation. The header of the
doublewrite buffer is placed on the trx system header page.
@return true if successful, false if not. */
MY_ATTRIBUTE((warn_unused_result))
bool
buf_dblwr_create(void)
/*==================*/
{
buf_block_t* block2;
buf_block_t* new_block;
byte* doublewrite;
byte* fseg_header;
ulint page_no;
ulint prev_page_no;
ulint i;
mtr_t mtr;
if (buf_dblwr) {
/* Already inited */
return(true);
}
start_again:
mtr_start(&mtr);
buf_dblwr_being_created = TRUE;
doublewrite = buf_dblwr_get(&mtr);
if (mach_read_from_4(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC)
== TRX_SYS_DOUBLEWRITE_MAGIC_N) {
/* The doublewrite buffer has already been created:
just read in some numbers */
buf_dblwr_init(doublewrite);
mtr_commit(&mtr);
buf_dblwr_being_created = FALSE;
return(true);
}
ib::info() << "Doublewrite buffer not found: creating new";
ulint min_doublewrite_size =
( ( 2 * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE
+ FSP_EXTENT_SIZE / 2
+ 100)
* UNIV_PAGE_SIZE);
if (buf_pool_get_curr_size() < min_doublewrite_size) {
ib::error() << "Cannot create doublewrite buffer: you must"
" increase your buffer pool size. Cannot continue"
" operation.";
return(false);
}
block2 = fseg_create(TRX_SYS_SPACE, TRX_SYS_PAGE_NO,
TRX_SYS_DOUBLEWRITE
+ TRX_SYS_DOUBLEWRITE_FSEG, &mtr);
/* fseg_create acquires a second latch on the page,
therefore we must declare it: */
buf_block_dbg_add_level(block2, SYNC_NO_ORDER_CHECK);
if (block2 == NULL) {
ib::error() << "Cannot create doublewrite buffer: you must"
" increase your tablespace size."
" Cannot continue operation.";
/* We exit without committing the mtr to prevent
its modifications to the database getting to disk */
return(false);
}
fseg_header = doublewrite + TRX_SYS_DOUBLEWRITE_FSEG;
prev_page_no = 0;
for (i = 0; i < TRX_SYS_DOUBLEWRITE_BLOCKS * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE
+ FSP_EXTENT_SIZE / 2; i++) {
new_block = fseg_alloc_free_page(
fseg_header, prev_page_no + 1, FSP_UP, &mtr);
if (new_block == NULL) {
ib::error() << "Cannot create doublewrite buffer: "
" you must increase your tablespace size."
" Cannot continue operation.";
return(false);
}
/* We read the allocated pages to the buffer pool;
when they are written to disk in a flush, the space
id and page number fields are also written to the
pages. When we at database startup read pages
from the doublewrite buffer, we know that if the
space id and page number in them are the same as
the page position in the tablespace, then the page
has not been written to in doublewrite. */
ut_ad(rw_lock_get_x_lock_count(&new_block->lock) == 1);
page_no = new_block->page.id.page_no();
if (i == FSP_EXTENT_SIZE / 2) {
ut_a(page_no == FSP_EXTENT_SIZE);
mlog_write_ulint(doublewrite
+ TRX_SYS_DOUBLEWRITE_BLOCK1,
page_no, MLOG_4BYTES, &mtr);
mlog_write_ulint(doublewrite
+ TRX_SYS_DOUBLEWRITE_REPEAT
+ TRX_SYS_DOUBLEWRITE_BLOCK1,
page_no, MLOG_4BYTES, &mtr);
} else if (i == FSP_EXTENT_SIZE / 2
+ TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
ut_a(page_no == 2 * FSP_EXTENT_SIZE);
mlog_write_ulint(doublewrite
+ TRX_SYS_DOUBLEWRITE_BLOCK2,
page_no, MLOG_4BYTES, &mtr);
mlog_write_ulint(doublewrite
+ TRX_SYS_DOUBLEWRITE_REPEAT
+ TRX_SYS_DOUBLEWRITE_BLOCK2,
page_no, MLOG_4BYTES, &mtr);
} else if (i > FSP_EXTENT_SIZE / 2) {
ut_a(page_no == prev_page_no + 1);
}
if (((i + 1) & 15) == 0) {
/* rw_locks can only be recursively x-locked
2048 times. (on 32 bit platforms,
(lint) 0 - (X_LOCK_DECR * 2049)
is no longer a negative number, and thus
lock_word becomes like a shared lock).
For 4k page size this loop will
lock the fseg header too many times. Since
this code is not done while any other threads
are active, restart the MTR occasionally. */
mtr_commit(&mtr);
mtr_start(&mtr);
doublewrite = buf_dblwr_get(&mtr);
fseg_header = doublewrite
+ TRX_SYS_DOUBLEWRITE_FSEG;
}
prev_page_no = page_no;
}
mlog_write_ulint(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC,
TRX_SYS_DOUBLEWRITE_MAGIC_N,
MLOG_4BYTES, &mtr);
mlog_write_ulint(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC
+ TRX_SYS_DOUBLEWRITE_REPEAT,
TRX_SYS_DOUBLEWRITE_MAGIC_N,
MLOG_4BYTES, &mtr);
mlog_write_ulint(doublewrite
+ TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED,
TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED_N,
MLOG_4BYTES, &mtr);
mtr_commit(&mtr);
/* Flush the modified pages to disk and make a checkpoint */
log_make_checkpoint_at(LSN_MAX, TRUE);
/* Remove doublewrite pages from LRU */
buf_pool_invalidate();
ib::info() << "Doublewrite buffer created";
goto start_again;
}
/**
At database startup initializes the doublewrite buffer memory structure if
we already have a doublewrite buffer created in the data files. If we are
upgrading to an InnoDB version which supports multiple tablespaces, then this
function performs the necessary update operations. If we are in a crash
recovery, this function loads the pages from double write buffer into memory.
@param[in] file File handle
@param[in] path Path name of file
@return DB_SUCCESS or error code */
dberr_t
buf_dblwr_init_or_load_pages(
os_file_t file,
const char* path)
{
byte* buf;
byte* page;
ulint block1;
ulint block2;
ulint space_id;
byte* read_buf;
byte* doublewrite;
byte* unaligned_read_buf;
ibool reset_space_ids = FALSE;
recv_dblwr_t& recv_dblwr = recv_sys->dblwr;
/* We do the file i/o past the buffer pool */
unaligned_read_buf = static_cast<byte*>(
ut_malloc_nokey(3 * UNIV_PAGE_SIZE));
read_buf = static_cast<byte*>(
ut_align(unaligned_read_buf, UNIV_PAGE_SIZE));
/* Read the trx sys header to check if we are using the doublewrite
buffer */
dberr_t err;
IORequest read_request(IORequest::READ);
err = os_file_read(
read_request,
file, read_buf, TRX_SYS_PAGE_NO * UNIV_PAGE_SIZE,
UNIV_PAGE_SIZE);
if (err != DB_SUCCESS) {
ib::error()
<< "Failed to read the system tablespace header page";
ut_free(unaligned_read_buf);
return(err);
}
doublewrite = read_buf + TRX_SYS_DOUBLEWRITE;
if (mach_read_from_4(read_buf + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION) != 0) {
byte* tmp = fil_space_decrypt((ulint)TRX_SYS_SPACE,
read_buf + UNIV_PAGE_SIZE,
univ_page_size, /* page size */
read_buf);
doublewrite = tmp + TRX_SYS_DOUBLEWRITE;
}
if (mach_read_from_4(doublewrite + TRX_SYS_DOUBLEWRITE_MAGIC)
== TRX_SYS_DOUBLEWRITE_MAGIC_N) {
/* The doublewrite buffer has been created */
buf_dblwr_init(doublewrite);
block1 = buf_dblwr->block1;
block2 = buf_dblwr->block2;
buf = buf_dblwr->write_buf;
} else {
ut_free(unaligned_read_buf);
return(DB_SUCCESS);
}
if (mach_read_from_4(doublewrite + TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED)
!= TRX_SYS_DOUBLEWRITE_SPACE_ID_STORED_N) {
/* We are upgrading from a version < 4.1.x to a version where
multiple tablespaces are supported. We must reset the space id
field in the pages in the doublewrite buffer because starting
from this version the space id is stored to
FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID. */
reset_space_ids = TRUE;
ib::info() << "Resetting space id's in the doublewrite buffer";
}
/* Read the pages from the doublewrite buffer to memory */
err = os_file_read(
read_request,
file, buf, block1 * UNIV_PAGE_SIZE,
TRX_SYS_DOUBLEWRITE_BLOCK_SIZE * UNIV_PAGE_SIZE);
if (err != DB_SUCCESS) {
ib::error()
<< "Failed to read the first double write buffer "
"extent";
ut_free(unaligned_read_buf);
return(err);
}
err = os_file_read(
read_request,
file,
buf + TRX_SYS_DOUBLEWRITE_BLOCK_SIZE * UNIV_PAGE_SIZE,
block2 * UNIV_PAGE_SIZE,
TRX_SYS_DOUBLEWRITE_BLOCK_SIZE * UNIV_PAGE_SIZE);
if (err != DB_SUCCESS) {
ib::error()
<< "Failed to read the second double write buffer "
"extent";
ut_free(unaligned_read_buf);
return(err);
}
/* Check if any of these pages is half-written in data files, in the
intended position */
page = buf;
for (ulint i = 0; i < TRX_SYS_DOUBLEWRITE_BLOCK_SIZE * 2; i++) {
if (reset_space_ids) {
ulint source_page_no;
space_id = 0;
mach_write_to_4(page + FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID,
space_id);
/* We do not need to calculate new checksums for the
pages because the field .._SPACE_ID does not affect
them. Write the page back to where we read it from. */
if (i < TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
source_page_no = block1 + i;
} else {
source_page_no = block2
+ i - TRX_SYS_DOUBLEWRITE_BLOCK_SIZE;
}
IORequest write_request(IORequest::WRITE);
err = os_file_write(
write_request, path, file, page,
source_page_no * UNIV_PAGE_SIZE,
UNIV_PAGE_SIZE);
if (err != DB_SUCCESS) {
ib::error()
<< "Failed to write to the double write"
" buffer";
ut_free(unaligned_read_buf);
return(err);
}
} else if (memcmp(field_ref_zero, page + FIL_PAGE_LSN, 8)) {
/* Each valid page header must contain
a nonzero FIL_PAGE_LSN field. */
recv_dblwr.add(page);
}
page += univ_page_size.physical();
}
if (reset_space_ids) {
os_file_flush(file);
}
ut_free(unaligned_read_buf);
return(DB_SUCCESS);
}
/** Process and remove the double write buffer pages for all tablespaces. */
void
buf_dblwr_process(void)
{
ulint page_no_dblwr = 0;
byte* read_buf;
byte* unaligned_read_buf;
recv_dblwr_t& recv_dblwr = recv_sys->dblwr;
unaligned_read_buf = static_cast<byte*>(
ut_malloc_nokey(2 * UNIV_PAGE_SIZE));
read_buf = static_cast<byte*>(
ut_align(unaligned_read_buf, UNIV_PAGE_SIZE));
for (recv_dblwr_t::list::iterator i = recv_dblwr.pages.begin();
i != recv_dblwr.pages.end();
++i, ++page_no_dblwr) {
byte* page = *i;
ulint page_no = page_get_page_no(page);
ulint space_id = page_get_space_id(page);
fil_space_t* space = fil_space_get(space_id);
if (space == NULL) {
/* Maybe we have dropped the tablespace
and this page once belonged to it: do nothing */
continue;
}
fil_space_open_if_needed(space);
const page_id_t page_id(space_id, page_no);
if (page_no >= space->size) {
/* Do not report the warning if the tablespace
is scheduled for truncation or was truncated
and we have parsed an MLOG_TRUNCATE record. */
if (!srv_is_tablespace_truncated(space_id)
&& !srv_was_tablespace_truncated(space)) {
ib::warn() << "A copy of page " << page_id
<< " in the doublewrite buffer slot "
<< page_no_dblwr
<< " is not within space bounds";
}
continue;
}
const page_size_t page_size(space->flags);
ut_ad(!buf_page_is_zeroes(page, page_size));
/* We want to ensure that for partial reads the
unread portion of the page is NUL. */
memset(read_buf, 0x0, page_size.physical());
IORequest request;
request.dblwr_recover();
/* Read in the actual page from the file */
dberr_t err = fil_io(
request, true,
page_id, page_size,
0, page_size.physical(), read_buf, NULL);
if (err != DB_SUCCESS) {
ib::warn()
<< "Double write buffer recovery: "
<< page_id << " read failed with "
<< "error: " << ut_strerr(err);
}
const bool is_all_zero = buf_page_is_zeroes(
read_buf, page_size);
if (is_all_zero) {
/* We will check if the copy in the
doublewrite buffer is valid. If not, we will
ignore this page (there should be redo log
records to initialize it). */
} else {
if (fil_page_is_compressed_encrypted(read_buf) ||
fil_page_is_compressed(read_buf)) {
/* Decompress the page before
validating the checksum. */
fil_decompress_page(
NULL, read_buf, UNIV_PAGE_SIZE,
NULL, true);
}
if (fil_space_verify_crypt_checksum(
read_buf, page_size)
|| !buf_page_is_corrupted(
true, read_buf, page_size, false)) {
/* The page is good; there is no need
to consult the doublewrite buffer. */
continue;
}
/* We intentionally skip this message for
is_all_zero pages. */
ib::info()
<< "Trying to recover page " << page_id
<< " from the doublewrite buffer.";
}
/* Next, validate the doublewrite page. */
if (fil_page_is_compressed_encrypted(page) ||
fil_page_is_compressed(page)) {
/* Decompress the page before
validating the checksum. */
fil_decompress_page(
NULL, page, UNIV_PAGE_SIZE, NULL, true);
}
if (!fil_space_verify_crypt_checksum(page, page_size)
&& buf_page_is_corrupted(true, page, page_size, false)) {
if (!is_all_zero) {
ib::warn() << "A doublewrite copy of page "
<< page_id << " is corrupted.";
}
/* Theoretically we could have another good
copy for this page in the doublewrite
buffer. If not, we will report a fatal error
for a corrupted page somewhere else if that
page was truly needed. */
continue;
}
if (page_no == 0) {
/* Check the FSP_SPACE_FLAGS. */
ulint flags = fsp_header_get_flags(page);
if (!fsp_flags_is_valid(flags)
&& fsp_flags_convert_from_101(flags)
== ULINT_UNDEFINED) {
ib::warn() << "Ignoring a doublewrite copy"
" of page " << page_id
<< " due to invalid flags "
<< ib::hex(flags);
continue;
}
/* The flags on the page should be converted later. */
}
/* Write the good page from the doublewrite buffer to
the intended position. */
IORequest write_request(IORequest::WRITE);
fil_io(write_request, true, page_id, page_size,
0, page_size.physical(),
const_cast<byte*>(page), NULL);
ib::info() << "Recovered page " << page_id
<< " from the doublewrite buffer.";
}
recv_dblwr.pages.clear();
fil_flush_file_spaces(FIL_TYPE_TABLESPACE);
ut_free(unaligned_read_buf);
}
/****************************************************************//**
Frees doublewrite buffer. */
void
buf_dblwr_free(void)
/*================*/
{
/* Free the double write data structures. */
ut_a(buf_dblwr != NULL);
ut_ad(buf_dblwr->s_reserved == 0);
ut_ad(buf_dblwr->b_reserved == 0);
os_event_destroy(buf_dblwr->b_event);
os_event_destroy(buf_dblwr->s_event);
ut_free(buf_dblwr->write_buf_unaligned);
buf_dblwr->write_buf_unaligned = NULL;
ut_free(buf_dblwr->buf_block_arr);
buf_dblwr->buf_block_arr = NULL;
ut_free(buf_dblwr->in_use);
buf_dblwr->in_use = NULL;
mutex_free(&buf_dblwr->mutex);
ut_free(buf_dblwr);
buf_dblwr = NULL;
}
/********************************************************************//**
Updates the doublewrite buffer when an IO request is completed. */
void
buf_dblwr_update(
/*=============*/
const buf_page_t* bpage, /*!< in: buffer block descriptor */
buf_flush_t flush_type)/*!< in: flush type */
{
if (!srv_use_doublewrite_buf
|| buf_dblwr == NULL
|| fsp_is_system_temporary(bpage->id.space())) {
return;
}
ut_ad(!srv_read_only_mode);
switch (flush_type) {
case BUF_FLUSH_LIST:
case BUF_FLUSH_LRU:
mutex_enter(&buf_dblwr->mutex);
ut_ad(buf_dblwr->batch_running);
ut_ad(buf_dblwr->b_reserved > 0);
ut_ad(buf_dblwr->b_reserved <= buf_dblwr->first_free);
buf_dblwr->b_reserved--;
if (buf_dblwr->b_reserved == 0) {
mutex_exit(&buf_dblwr->mutex);
/* This will finish the batch. Sync data files
to the disk. */
fil_flush_file_spaces(FIL_TYPE_TABLESPACE);
mutex_enter(&buf_dblwr->mutex);
/* We can now reuse the doublewrite memory buffer: */
buf_dblwr->first_free = 0;
buf_dblwr->batch_running = false;
os_event_set(buf_dblwr->b_event);
}
mutex_exit(&buf_dblwr->mutex);
break;
case BUF_FLUSH_SINGLE_PAGE:
{
const ulint size = TRX_SYS_DOUBLEWRITE_BLOCKS * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE;
ulint i;
mutex_enter(&buf_dblwr->mutex);
for (i = srv_doublewrite_batch_size; i < size; ++i) {
if (buf_dblwr->buf_block_arr[i] == bpage) {
buf_dblwr->s_reserved--;
buf_dblwr->buf_block_arr[i] = NULL;
buf_dblwr->in_use[i] = false;
break;
}
}
/* The block we are looking for must exist as a
reserved block. */
ut_a(i < size);
}
os_event_set(buf_dblwr->s_event);
mutex_exit(&buf_dblwr->mutex);
break;
case BUF_FLUSH_N_TYPES:
ut_error;
}
}
/********************************************************************//**
Check the LSN values on the page. */
static
void
buf_dblwr_check_page_lsn(
/*=====================*/
const page_t* page) /*!< in: page to check */
{
ibool page_compressed = (mach_read_from_2(page+FIL_PAGE_TYPE) == FIL_PAGE_PAGE_COMPRESSED);
uint key_version = mach_read_from_4(page + FIL_PAGE_FILE_FLUSH_LSN_OR_KEY_VERSION);
/* Ignore page compressed or encrypted pages */
if (page_compressed || key_version) {
return;
}
if (memcmp(page + (FIL_PAGE_LSN + 4),
page + (UNIV_PAGE_SIZE
- FIL_PAGE_END_LSN_OLD_CHKSUM + 4),
4)) {
const ulint lsn1 = mach_read_from_4(
page + FIL_PAGE_LSN + 4);
const ulint lsn2 = mach_read_from_4(
page + UNIV_PAGE_SIZE - FIL_PAGE_END_LSN_OLD_CHKSUM
+ 4);
ib::error() << "The page to be written seems corrupt!"
" The low 4 bytes of LSN fields do not match"
" (" << lsn1 << " != " << lsn2 << ")!"
" Noticed in the buffer pool.";
}
}
/********************************************************************//**
Asserts when a corrupt block is find during writing out data to the
disk. */
static
void
buf_dblwr_assert_on_corrupt_block(
/*==============================*/
const buf_block_t* block) /*!< in: block to check */
{
buf_page_print(block->frame, univ_page_size, BUF_PAGE_PRINT_NO_CRASH);
ib::fatal() << "Apparent corruption of an index page "
<< block->page.id
<< " to be written to data file. We intentionally crash"
" the server to prevent corrupt data from ending up in"
" data files.";
}
/********************************************************************//**
Check the LSN values on the page with which this block is associated.
Also validate the page if the option is set. */
static
void
buf_dblwr_check_block(
/*==================*/
const buf_block_t* block) /*!< in: block to check */
{
ut_ad(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE);
if (block->skip_flush_check) {
return;
}
switch (fil_page_get_type(block->frame)) {
case FIL_PAGE_INDEX:
case FIL_PAGE_RTREE:
if (page_is_comp(block->frame)) {
if (page_simple_validate_new(block->frame)) {
return;
}
} else if (page_simple_validate_old(block->frame)) {
return;
}
/* While it is possible that this is not an index page
but just happens to have wrongly set FIL_PAGE_TYPE,
such pages should never be modified to without also
adjusting the page type during page allocation or
buf_flush_init_for_writing() or fil_page_reset_type(). */
break;
case FIL_PAGE_TYPE_FSP_HDR:
case FIL_PAGE_IBUF_BITMAP:
case FIL_PAGE_TYPE_UNKNOWN:
/* Do not complain again, we already reset this field. */
case FIL_PAGE_UNDO_LOG:
case FIL_PAGE_INODE:
case FIL_PAGE_IBUF_FREE_LIST:
case FIL_PAGE_TYPE_SYS:
case FIL_PAGE_TYPE_TRX_SYS:
case FIL_PAGE_TYPE_XDES:
case FIL_PAGE_TYPE_BLOB:
case FIL_PAGE_TYPE_ZBLOB:
case FIL_PAGE_TYPE_ZBLOB2:
/* TODO: validate also non-index pages */
return;
case FIL_PAGE_TYPE_ALLOCATED:
/* empty pages should never be flushed */
return;
break;
}
buf_dblwr_assert_on_corrupt_block(block);
}
/********************************************************************//**
Writes a page that has already been written to the doublewrite buffer
to the datafile. It is the job of the caller to sync the datafile. */
static
void
buf_dblwr_write_block_to_datafile(
/*==============================*/
const buf_page_t* bpage, /*!< in: page to write */
bool sync) /*!< in: true if sync IO
is requested */
{
ut_a(buf_page_in_file(bpage));
ulint type = IORequest::WRITE;
if (sync) {
type |= IORequest::DO_NOT_WAKE;
}
IORequest request(type, const_cast<buf_page_t*>(bpage));
/* We request frame here to get correct buffer in case of
encryption and/or page compression */
void * frame = buf_page_get_frame(bpage);
if (bpage->zip.data != NULL) {
ut_ad(bpage->size.is_compressed());
fil_io(request, sync, bpage->id, bpage->size, 0,
bpage->size.physical(),
(void*) frame,
(void*) bpage);
} else {
ut_ad(!bpage->size.is_compressed());
/* Our IO API is common for both reads and writes and is
therefore geared towards a non-const parameter. */
buf_block_t* block = reinterpret_cast<buf_block_t*>(
const_cast<buf_page_t*>(bpage));
ut_a(buf_block_get_state(block) == BUF_BLOCK_FILE_PAGE);
buf_dblwr_check_page_lsn(block->frame);
fil_io(request,
sync, bpage->id, bpage->size, 0, bpage->real_size,
frame, block);
}
}
/********************************************************************//**
Flushes possible buffered writes from the doublewrite memory buffer to disk,
and also wakes up the aio thread if simulated aio is used. It is very
important to call this function after a batch of writes has been posted,
and also when we may have to wait for a page latch! Otherwise a deadlock
of threads can occur. */
void
buf_dblwr_flush_buffered_writes(void)
/*=================================*/
{
byte* write_buf;
ulint first_free;
ulint len;
if (!srv_use_doublewrite_buf || buf_dblwr == NULL) {
/* Sync the writes to the disk. */
buf_dblwr_sync_datafiles();
return;
}
ut_ad(!srv_read_only_mode);
try_again:
mutex_enter(&buf_dblwr->mutex);
/* Write first to doublewrite buffer blocks. We use synchronous
aio and thus know that file write has been completed when the
control returns. */
if (buf_dblwr->first_free == 0) {
mutex_exit(&buf_dblwr->mutex);
/* Wake possible simulated aio thread as there could be
system temporary tablespace pages active for flushing.
Note: system temporary tablespace pages are not scheduled
for doublewrite. */
os_aio_simulated_wake_handler_threads();
return;
}
if (buf_dblwr->batch_running) {
/* Another thread is running the batch right now. Wait
for it to finish. */
int64_t sig_count = os_event_reset(buf_dblwr->b_event);
mutex_exit(&buf_dblwr->mutex);
os_event_wait_low(buf_dblwr->b_event, sig_count);
goto try_again;
}
ut_a(!buf_dblwr->batch_running);
ut_ad(buf_dblwr->first_free == buf_dblwr->b_reserved);
/* Disallow anyone else to post to doublewrite buffer or to
start another batch of flushing. */
buf_dblwr->batch_running = true;
first_free = buf_dblwr->first_free;
/* Now safe to release the mutex. Note that though no other
thread is allowed to post to the doublewrite batch flushing
but any threads working on single page flushes are allowed
to proceed. */
mutex_exit(&buf_dblwr->mutex);
write_buf = buf_dblwr->write_buf;
for (ulint len2 = 0, i = 0;
i < buf_dblwr->first_free;
len2 += UNIV_PAGE_SIZE, i++) {
const buf_block_t* block;
block = (buf_block_t*) buf_dblwr->buf_block_arr[i];
if (buf_block_get_state(block) != BUF_BLOCK_FILE_PAGE
|| block->page.zip.data) {
/* No simple validate for compressed
pages exists. */
continue;
}
/* Check that the actual page in the buffer pool is
not corrupt and the LSN values are sane. */
buf_dblwr_check_block(block);
/* Check that the page as written to the doublewrite
buffer has sane LSN values. */
buf_dblwr_check_page_lsn(write_buf + len2);
}
/* Write out the first block of the doublewrite buffer */
len = ut_min(TRX_SYS_DOUBLEWRITE_BLOCK_SIZE,
buf_dblwr->first_free) * UNIV_PAGE_SIZE;
fil_io(IORequestWrite, true,
page_id_t(TRX_SYS_SPACE, buf_dblwr->block1), univ_page_size,
0, len, (void*) write_buf, NULL);
if (buf_dblwr->first_free <= TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
/* No unwritten pages in the second block. */
goto flush;
}
/* Write out the second block of the doublewrite buffer. */
len = (buf_dblwr->first_free - TRX_SYS_DOUBLEWRITE_BLOCK_SIZE)
* UNIV_PAGE_SIZE;
write_buf = buf_dblwr->write_buf
+ TRX_SYS_DOUBLEWRITE_BLOCK_SIZE * UNIV_PAGE_SIZE;
fil_io(IORequestWrite, true,
page_id_t(TRX_SYS_SPACE, buf_dblwr->block2), univ_page_size,
0, len, (void*) write_buf, NULL);
flush:
/* increment the doublewrite flushed pages counter */
srv_stats.dblwr_pages_written.add(buf_dblwr->first_free);
srv_stats.dblwr_writes.inc();
/* Now flush the doublewrite buffer data to disk */
fil_flush(TRX_SYS_SPACE);
/* We know that the writes have been flushed to disk now
and in recovery we will find them in the doublewrite buffer
blocks. Next do the writes to the intended positions. */
/* Up to this point first_free and buf_dblwr->first_free are
same because we have set the buf_dblwr->batch_running flag
disallowing any other thread to post any request but we
can't safely access buf_dblwr->first_free in the loop below.
This is so because it is possible that after we are done with
the last iteration and before we terminate the loop, the batch
gets finished in the IO helper thread and another thread posts
a new batch setting buf_dblwr->first_free to a higher value.
If this happens and we are using buf_dblwr->first_free in the
loop termination condition then we'll end up dispatching
the same block twice from two different threads. */
ut_ad(first_free == buf_dblwr->first_free);
for (ulint i = 0; i < first_free; i++) {
buf_dblwr_write_block_to_datafile(
buf_dblwr->buf_block_arr[i], false);
}
/* Wake possible simulated aio thread to actually post the
writes to the operating system. We don't flush the files
at this point. We leave it to the IO helper thread to flush
datafiles when the whole batch has been processed. */
os_aio_simulated_wake_handler_threads();
}
/********************************************************************//**
Posts a buffer page for writing. If the doublewrite memory buffer is
full, calls buf_dblwr_flush_buffered_writes and waits for for free
space to appear. */
void
buf_dblwr_add_to_batch(
/*====================*/
buf_page_t* bpage) /*!< in: buffer block to write */
{
ut_a(buf_page_in_file(bpage));
try_again:
mutex_enter(&buf_dblwr->mutex);
ut_a(buf_dblwr->first_free <= srv_doublewrite_batch_size);
if (buf_dblwr->batch_running) {
/* This not nearly as bad as it looks. There is only
page_cleaner thread which does background flushing
in batches therefore it is unlikely to be a contention
point. The only exception is when a user thread is
forced to do a flush batch because of a sync
checkpoint. */
int64_t sig_count = os_event_reset(buf_dblwr->b_event);
mutex_exit(&buf_dblwr->mutex);
os_event_wait_low(buf_dblwr->b_event, sig_count);
goto try_again;
}
if (buf_dblwr->first_free == srv_doublewrite_batch_size) {
mutex_exit(&(buf_dblwr->mutex));
buf_dblwr_flush_buffered_writes();
goto try_again;
}
byte* p = buf_dblwr->write_buf
+ univ_page_size.physical() * buf_dblwr->first_free;
/* We request frame here to get correct buffer in case of
encryption and/or page compression */
void * frame = buf_page_get_frame(bpage);
if (bpage->size.is_compressed()) {
UNIV_MEM_ASSERT_RW(bpage->zip.data, bpage->size.physical());
/* Copy the compressed page and clear the rest. */
memcpy(p, frame, bpage->size.physical());
memset(p + bpage->size.physical(), 0x0,
univ_page_size.physical() - bpage->size.physical());
} else {
ut_a(buf_page_get_state(bpage) == BUF_BLOCK_FILE_PAGE);
UNIV_MEM_ASSERT_RW(frame,
bpage->size.logical());
memcpy(p, frame, bpage->size.logical());
}
buf_dblwr->buf_block_arr[buf_dblwr->first_free] = bpage;
buf_dblwr->first_free++;
buf_dblwr->b_reserved++;
ut_ad(!buf_dblwr->batch_running);
ut_ad(buf_dblwr->first_free == buf_dblwr->b_reserved);
ut_ad(buf_dblwr->b_reserved <= srv_doublewrite_batch_size);
if (buf_dblwr->first_free == srv_doublewrite_batch_size) {
mutex_exit(&(buf_dblwr->mutex));
buf_dblwr_flush_buffered_writes();
return;
}
mutex_exit(&(buf_dblwr->mutex));
}
/********************************************************************//**
Writes a page to the doublewrite buffer on disk, sync it, then write
the page to the datafile and sync the datafile. This function is used
for single page flushes. If all the buffers allocated for single page
flushes in the doublewrite buffer are in use we wait here for one to
become free. We are guaranteed that a slot will become free because any
thread that is using a slot must also release the slot before leaving
this function. */
void
buf_dblwr_write_single_page(
/*========================*/
buf_page_t* bpage, /*!< in: buffer block to write */
bool sync) /*!< in: true if sync IO requested */
{
ulint n_slots;
ulint size;
ulint offset;
ulint i;
ut_a(buf_page_in_file(bpage));
ut_a(srv_use_doublewrite_buf);
ut_a(buf_dblwr != NULL);
/* total number of slots available for single page flushes
starts from srv_doublewrite_batch_size to the end of the
buffer. */
size = TRX_SYS_DOUBLEWRITE_BLOCKS * TRX_SYS_DOUBLEWRITE_BLOCK_SIZE;
ut_a(size > srv_doublewrite_batch_size);
n_slots = size - srv_doublewrite_batch_size;
if (buf_page_get_state(bpage) == BUF_BLOCK_FILE_PAGE) {
/* Check that the actual page in the buffer pool is
not corrupt and the LSN values are sane. */
buf_dblwr_check_block((buf_block_t*) bpage);
/* Check that the page as written to the doublewrite
buffer has sane LSN values. */
if (!bpage->zip.data) {
buf_dblwr_check_page_lsn(
((buf_block_t*) bpage)->frame);
}
}
retry:
mutex_enter(&buf_dblwr->mutex);
if (buf_dblwr->s_reserved == n_slots) {
/* All slots are reserved. */
int64_t sig_count = os_event_reset(buf_dblwr->s_event);
mutex_exit(&buf_dblwr->mutex);
os_event_wait_low(buf_dblwr->s_event, sig_count);
goto retry;
}
for (i = srv_doublewrite_batch_size; i < size; ++i) {
if (!buf_dblwr->in_use[i]) {
break;
}
}
/* We are guaranteed to find a slot. */
ut_a(i < size);
buf_dblwr->in_use[i] = true;
buf_dblwr->s_reserved++;
buf_dblwr->buf_block_arr[i] = bpage;
/* increment the doublewrite flushed pages counter */
srv_stats.dblwr_pages_written.inc();
srv_stats.dblwr_writes.inc();
mutex_exit(&buf_dblwr->mutex);
/* Lets see if we are going to write in the first or second
block of the doublewrite buffer. */
if (i < TRX_SYS_DOUBLEWRITE_BLOCK_SIZE) {
offset = buf_dblwr->block1 + i;
} else {
offset = buf_dblwr->block2 + i
- TRX_SYS_DOUBLEWRITE_BLOCK_SIZE;
}
/* We deal with compressed and uncompressed pages a little
differently here. In case of uncompressed pages we can
directly write the block to the allocated slot in the
doublewrite buffer in the system tablespace and then after
syncing the system table space we can proceed to write the page
in the datafile.
In case of compressed page we first do a memcpy of the block
to the in-memory buffer of doublewrite before proceeding to
write it. This is so because we want to pad the remaining
bytes in the doublewrite page with zeros. */
/* We request frame here to get correct buffer in case of
encryption and/or page compression */
void * frame = buf_page_get_frame(bpage);
if (bpage->size.is_compressed()) {
memcpy(buf_dblwr->write_buf + univ_page_size.physical() * i,
frame, bpage->size.physical());
memset(buf_dblwr->write_buf + univ_page_size.physical() * i
+ bpage->size.physical(), 0x0,
univ_page_size.physical() - bpage->size.physical());
fil_io(IORequestWrite,
true,
page_id_t(TRX_SYS_SPACE, offset),
univ_page_size,
0,
univ_page_size.physical(),
(void *)(buf_dblwr->write_buf + univ_page_size.physical() * i),
NULL);
} else {
/* It is a regular page. Write it directly to the
doublewrite buffer */
fil_io(IORequestWrite,
true,
page_id_t(TRX_SYS_SPACE, offset),
univ_page_size,
0,
univ_page_size.physical(),
(void*) frame,
NULL);
}
/* Now flush the doublewrite buffer data to disk */
fil_flush(TRX_SYS_SPACE);
/* We know that the write has been flushed to disk now
and during recovery we will find it in the doublewrite buffer
blocks. Next do the write to the intended position. */
buf_dblwr_write_block_to_datafile(bpage, sync);
}
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