mariadb/extra/mariabackup/fil_cur.h
Marko Mäkelä 8c71c6aa8b MDEV-12548 Initial implementation of Mariabackup for MariaDB 10.2
InnoDB I/O and buffer pool interfaces and the redo log format
have been changed between MariaDB 10.1 and 10.2, and the backup
code has to be adjusted accordingly.

The code has been simplified, and many memory leaks have been fixed.
Instead of the file name xtrabackup_logfile, the file name ib_logfile0
is being used for the copy of the redo log. Unnecessary InnoDB startup and
shutdown and some unnecessary threads have been removed.

Some help was provided by Vladislav Vaintroub.

Parameters have been cleaned up and aligned with those of MariaDB 10.2.

The --dbug option has been added, so that in debug builds,
--dbug=d,ib_log can be specified to enable diagnostic messages
for processing redo log entries.

By default, innodb_doublewrite=OFF, so that --prepare works faster.
If more crash-safety for --prepare is needed, double buffering
can be enabled.

The parameter innodb_log_checksums=OFF can be used to ignore redo log
checksums in --backup.

Some messages have been cleaned up.
Unless --export is specified, Mariabackup will not deal with undo log.
The InnoDB mini-transaction redo log is not only about user-level
transactions; it is actually about mini-transactions. To avoid confusion,
call it the redo log, not transaction log.

We disable any undo log processing in --prepare.

Because MariaDB 10.2 supports indexed virtual columns, the
undo log processing would need to be able to evaluate virtual column
expressions. To reduce the amount of code dependencies, we will not
process any undo log in prepare.

This means that the --export option must be disabled for now.

This also means that the following options are redundant
and have been removed:
	xtrabackup --apply-log-only
	innobackupex --redo-only

In addition to disabling any undo log processing, we will disable any
further changes to data pages during --prepare, including the change
buffer merge. This means that restoring incremental backups should
reliably work even when change buffering is being used on the server.
Because of this, preparing a backup will not generate any further
redo log, and the redo log file can be safely deleted. (If the
--export option is enabled in the future, it must generate redo log
when processing undo logs and buffered changes.)

In --prepare, we cannot easily know if a partial backup was used,
especially when restoring a series of incremental backups. So, we
simply warn about any missing files, and ignore the redo log for them.

FIXME: Enable the --export option.

FIXME: Improve the handling of the MLOG_INDEX_LOAD record, and write
a test that initiates a backup while an ALGORITHM=INPLACE operation
is creating indexes or rebuilding a table. An error should be detected
when preparing the backup.

FIXME: In --incremental --prepare, xtrabackup_apply_delta() should
ensure that if FSP_SIZE is modified, the file size will be adjusted
accordingly.
2017-07-05 11:43:28 +03:00

128 lines
4.5 KiB
C

/******************************************************
XtraBackup: hot backup tool for InnoDB
(c) 2009-2013 Percona LLC and/or its affiliates.
Originally Created 3/3/2009 Yasufumi Kinoshita
Written by Alexey Kopytov, Aleksandr Kuzminsky, Stewart Smith, Vadim Tkachenko,
Yasufumi Kinoshita, Ignacio Nin and Baron Schwartz.
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, Fifth Floor, Boston, MA 02110-1301, USA
*******************************************************/
/* Source file cursor interface */
#ifndef FIL_CUR_H
#define FIL_CUR_H
#include <my_dir.h>
#include "read_filt.h"
#include "srv0start.h"
struct xb_fil_cur_t {
pfs_os_file_t file; /*!< source file handle */
fil_node_t* node; /*!< source tablespace node */
char rel_path[FN_REFLEN];
/*!< normalized file path */
char abs_path[FN_REFLEN];
/*!< absolute file path */
MY_STAT statinfo; /*!< information about the file */
page_size_t page_size; /*!< page size */
xb_read_filt_t* read_filter; /*!< read filter */
xb_read_filt_ctxt_t read_filter_ctxt;
/*!< read filter context */
byte* orig_buf; /*!< read buffer */
byte* buf; /*!< aligned pointer for orig_buf */
size_t buf_size; /*!< buffer size in bytes */
size_t buf_read; /*!< number of read bytes in buffer
after the last cursor read */
size_t buf_npages; /*!< number of pages in buffer after the
last cursor read */
ib_int64_t buf_offset; /*!< file offset of the first page in
buffer */
ulint buf_page_no; /*!< number of the first page in
buffer */
uint thread_n; /*!< thread number for diagnostics */
ulint space_id; /*!< ID of tablespace */
ulint space_size; /*!< space size in pages */
/** TODO: remove this default constructor */
xb_fil_cur_t() : page_size(0), read_filter_ctxt() {}
/** @return whether this is not a file-per-table tablespace */
bool is_system() const
{
ut_ad(space_id != SRV_TMP_SPACE_ID);
return(space_id == TRX_SYS_SPACE
|| srv_is_undo_tablespace(space_id));
}
};
typedef enum {
XB_FIL_CUR_SUCCESS,
XB_FIL_CUR_SKIP,
XB_FIL_CUR_ERROR,
XB_FIL_CUR_EOF
} xb_fil_cur_result_t;
/************************************************************************
Open a source file cursor and initialize the associated read filter.
@return XB_FIL_CUR_SUCCESS on success, XB_FIL_CUR_SKIP if the source file must
be skipped and XB_FIL_CUR_ERROR on error. */
xb_fil_cur_result_t
xb_fil_cur_open(
/*============*/
xb_fil_cur_t* cursor, /*!< out: source file cursor */
xb_read_filt_t* read_filter, /*!< in/out: the read filter */
fil_node_t* node, /*!< in: source tablespace node */
uint thread_n); /*!< thread number for diagnostics */
/************************************************************************
Reads and verifies the next block of pages from the source
file. Positions the cursor after the last read non-corrupted page.
@return XB_FIL_CUR_SUCCESS if some have been read successfully, XB_FIL_CUR_EOF
if there are no more pages to read and XB_FIL_CUR_ERROR on error. */
xb_fil_cur_result_t
xb_fil_cur_read(
/*============*/
xb_fil_cur_t* cursor); /*!< in/out: source file cursor */
/************************************************************************
Close the source file cursor opened with xb_fil_cur_open() and its
associated read filter. */
void
xb_fil_cur_close(
/*=============*/
xb_fil_cur_t *cursor); /*!< in/out: source file cursor */
/***********************************************************************
Extracts the relative path ("database/table.ibd") of a tablespace from a
specified possibly absolute path.
For user tablespaces both "./database/table.ibd" and
"/remote/dir/database/table.ibd" result in "database/table.ibd".
For system tablepsaces (i.e. When is_system is TRUE) both "/remote/dir/ibdata1"
and "./ibdata1" yield "ibdata1" in the output. */
const char *
xb_get_relative_path(
/*=================*/
const char* path, /*!< in: tablespace path (either
relative or absolute) */
ibool is_system); /*!< in: TRUE for system tablespaces,
i.e. when only the filename must be
returned. */
#endif