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mariadb/storage/innobase/trx/trx0undo.cc
Marko Mäkelä 124bae082b MDEV-12289 Keep 128 persistent rollback segments for compatibility and performance 
InnoDB divides the allocation of undo logs into rollback segments.
The DB_ROLL_PTR system column of clustered indexes can address up to
128 rollback segments (TRX_SYS_N_RSEGS). Originally, InnoDB only
created one rollback segment. In MySQL 5.5 or in the InnoDB Plugin
for MySQL 5.1, all 128 rollback segments were created.

MySQL 5.7 hard-codes the rollback segment IDs 1..32 for temporary undo logs.
On upgrade, unless a slow shutdown (innodb_fast_shutdown=0)
was performed on the old server instance, these rollback segments
could be in use by transactions that are in XA PREPARE state or
transactions that were left behind by a server kill followed by a
normal shutdown immediately after restart.

Persistent tables cannot refer to temporary undo logs or vice versa.
Therefore, we should keep two distinct sets of rollback segments:
one for persistent tables and another for temporary tables. In this way,
all 128 rollback segments will be available for both types of tables,
which could improve performance. Also, MariaDB 10.2 will remain more
compatible than MySQL 5.7 with data files from earlier versions of
MySQL or MariaDB.

trx_sys_t::temp_rsegs[TRX_SYS_N_RSEGS]: A new array of temporary
rollback segments. The trx_sys_t::rseg_array[TRX_SYS_N_RSEGS] will
be solely for persistent undo logs.

srv_tmp_undo_logs. Remove. Use the constant TRX_SYS_N_RSEGS.

srv_available_undo_logs: Change the type to ulong.

trx_rseg_get_on_id(): Remove. Instead, let the callers refer to
trx_sys directly.

trx_rseg_create(), trx_sysf_rseg_find_free(): Remove unneeded parameters.
These functions only deal with persistent undo logs.

trx_temp_rseg_create(): New function, to create all temporary rollback
segments at server startup.

trx_rseg_t::is_persistent(): Determine if the rollback segment is for
persistent tables.

trx_sys_is_noredo_rseg_slot(): Remove. The callers must know based on
context (such as table handle) whether the DB_ROLL_PTR is referring to
a persistent undo log.

trx_sys_create_rsegs(): Remove all parameters, which were always passed
as global variables. Instead, modify the global variables directly.

enum trx_rseg_type_t: Remove.

trx_t::get_temp_rseg(): A method to ensure that a temporary
rollback segment has been assigned for the transaction.

trx_t::assign_temp_rseg(): Replaces trx_assign_rseg().

trx_purge_free_segment(), trx_purge_truncate_rseg_history():
Remove the redundant variable noredo=false.
Temporary undo logs are discarded immediately at transaction commit
or rollback, not lazily by purge.

trx_purge_mark_undo_for_truncate(): Remove references to the
temporary rollback segments.

trx_purge_mark_undo_for_truncate(): Remove a check for temporary
rollback segments. Only the dedicated persistent undo log tablespaces
can be truncated.

trx_undo_get_undo_rec_low(), trx_undo_get_undo_rec(): Add the
parameter is_temp.

trx_rseg_mem_restore(): Split from trx_rseg_mem_create().
Initialize the undo log and the rollback segment from the file
data structures.

trx_sysf_get_n_rseg_slots(): Renamed from
trx_sysf_used_slots_for_redo_rseg(). Count the persistent
rollback segment headers that have been initialized.

trx_sys_close(): Also free trx_sys->temp_rsegs[].

get_next_redo_rseg(): Merged to trx_assign_rseg_low().

trx_assign_rseg_low(): Remove the parameters and access the
global variables directly. Revert to simple round-robin, now that
the whole trx_sys->rseg_array[] is for persistent undo log again.

get_next_noredo_rseg(): Moved to trx_t::assign_temp_rseg().

srv_undo_tablespaces_init(): Remove some parameters and use the
global variables directly. Clarify some error messages.

Adjust the test innodb.log_file. Apparently, before these changes,
InnoDB somehow ignored missing dedicated undo tablespace files that
are pointed by the TRX_SYS header page, possibly losing part of
essential transaction system state.
2017-03-31 18:53:04 +03:00

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/*****************************************************************************
Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2014, 2017, 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
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 trx/trx0undo.cc
Transaction undo log
Created 3/26/1996 Heikki Tuuri
*******************************************************/
#include "ha_prototypes.h"
#include "trx0undo.h"
#include "fsp0fsp.h"
#include "mach0data.h"
#include "mtr0log.h"
#include "srv0mon.h"
#include "srv0srv.h"
#include "srv0start.h"
#include "trx0purge.h"
#include "trx0rec.h"
#include "trx0rseg.h"
#include "trx0trx.h"
/* How should the old versions in the history list be managed?
----------------------------------------------------------
If each transaction is given a whole page for its update undo log, file
space consumption can be 10 times higher than necessary. Therefore,
partly filled update undo log pages should be reusable. But then there
is no way individual pages can be ordered so that the ordering agrees
with the serialization numbers of the transactions on the pages. Thus,
the history list must be formed of undo logs, not their header pages as
it was in the old implementation.
However, on a single header page the transactions are placed in
the order of their serialization numbers. As old versions are purged, we
may free the page when the last transaction on the page has been purged.
A problem is that the purge has to go through the transactions
in the serialization order. This means that we have to look through all
rollback segments for the one that has the smallest transaction number
in its history list.
When should we do a purge? A purge is necessary when space is
running out in any of the rollback segments. Then we may have to purge
also old version which might be needed by some consistent read. How do
we trigger the start of a purge? When a transaction writes to an undo log,
it may notice that the space is running out. When a read view is closed,
it may make some history superfluous. The server can have an utility which
periodically checks if it can purge some history.
In a parallellized purge we have the problem that a query thread
can remove a delete marked clustered index record before another query
thread has processed an earlier version of the record, which cannot then
be done because the row cannot be constructed from the clustered index
record. To avoid this problem, we will store in the update and delete mark
undo record also the columns necessary to construct the secondary index
entries which are modified.
We can latch the stack of versions of a single clustered index record
by taking a latch on the clustered index page. As long as the latch is held,
no new versions can be added and no versions removed by undo. But, a purge
can still remove old versions from the bottom of the stack. */
/* How to protect rollback segments, undo logs, and history lists with
-------------------------------------------------------------------
latches?
-------
The contention of the trx_sys_t::mutex should be minimized. When a transaction
does its first insert or modify in an index, an undo log is assigned for it.
Then we must have an x-latch to the rollback segment header.
When the transaction does more modifys or rolls back, the undo log is
protected with undo_mutex in the transaction.
When the transaction commits, its insert undo log is either reset and
cached for a fast reuse, or freed. In these cases we must have an x-latch on
the rollback segment page. The update undo log is put to the history list. If
it is not suitable for reuse, its slot in the rollback segment is reset. In
both cases, an x-latch must be acquired on the rollback segment.
The purge operation steps through the history list without modifying
it until a truncate operation occurs, which can remove undo logs from the end
of the list and release undo log segments. In stepping through the list,
s-latches on the undo log pages are enough, but in a truncate, x-latches must
be obtained on the rollback segment and individual pages. */
/********************************************************************//**
Initializes the fields in an undo log segment page. */
static
void
trx_undo_page_init(
/*===============*/
page_t* undo_page, /*!< in: undo log segment page */
ulint type, /*!< in: undo log segment type */
mtr_t* mtr); /*!< in: mtr */
/********************************************************************//**
Creates and initializes an undo log memory object.
@return own: the undo log memory object */
static
trx_undo_t*
trx_undo_mem_create(
/*================*/
trx_rseg_t* rseg, /*!< in: rollback segment memory object */
ulint id, /*!< in: slot index within rseg */
ulint type, /*!< in: type of the log: TRX_UNDO_INSERT or
TRX_UNDO_UPDATE */
trx_id_t trx_id, /*!< in: id of the trx for which the undo log
is created */
const XID* xid, /*!< in: X/Open XA transaction identification*/
ulint page_no,/*!< in: undo log header page number */
ulint offset);/*!< in: undo log header byte offset on page */
/***************************************************************//**
Initializes a cached insert undo log header page for new use. NOTE that this
function has its own log record type MLOG_UNDO_HDR_REUSE. You must NOT change
the operation of this function!
@return undo log header byte offset on page */
static
ulint
trx_undo_insert_header_reuse(
/*=========================*/
page_t* undo_page, /*!< in/out: insert undo log segment
header page, x-latched */
trx_id_t trx_id, /*!< in: transaction id */
mtr_t* mtr); /*!< in: mtr */
/**********************************************************************//**
If an update undo log can be discarded immediately, this function frees the
space, resetting the page to the proper state for caching. */
static
void
trx_undo_discard_latest_update_undo(
/*================================*/
page_t* undo_page, /*!< in: header page of an undo log of size 1 */
mtr_t* mtr); /*!< in: mtr */
/***********************************************************************//**
Gets the previous record in an undo log from the previous page.
@return undo log record, the page s-latched, NULL if none */
static
trx_undo_rec_t*
trx_undo_get_prev_rec_from_prev_page(
/*=================================*/
trx_undo_rec_t* rec, /*!< in: undo record */
ulint page_no,/*!< in: undo log header page number */
ulint offset, /*!< in: undo log header offset on page */
bool shared, /*!< in: true=S-latch, false=X-latch */
mtr_t* mtr) /*!< in: mtr */
{
ulint space;
ulint prev_page_no;
page_t* prev_page;
page_t* undo_page;
undo_page = page_align(rec);
prev_page_no = flst_get_prev_addr(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_NODE, mtr)
.page;
if (prev_page_no == FIL_NULL) {
return(NULL);
}
space = page_get_space_id(undo_page);
buf_block_t* block = buf_page_get(
page_id_t(space, prev_page_no), univ_page_size,
shared ? RW_S_LATCH : RW_X_LATCH, mtr);
buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE);
prev_page = buf_block_get_frame(block);
return(trx_undo_page_get_last_rec(prev_page, page_no, offset));
}
/***********************************************************************//**
Gets the previous record in an undo log.
@return undo log record, the page s-latched, NULL if none */
trx_undo_rec_t*
trx_undo_get_prev_rec(
/*==================*/
trx_undo_rec_t* rec, /*!< in: undo record */
ulint page_no,/*!< in: undo log header page number */
ulint offset, /*!< in: undo log header offset on page */
bool shared, /*!< in: true=S-latch, false=X-latch */
mtr_t* mtr) /*!< in: mtr */
{
trx_undo_rec_t* prev_rec;
prev_rec = trx_undo_page_get_prev_rec(rec, page_no, offset);
if (prev_rec) {
return(prev_rec);
}
/* We have to go to the previous undo log page to look for the
previous record */
return(trx_undo_get_prev_rec_from_prev_page(rec, page_no, offset,
shared, mtr));
}
/** Gets the next record in an undo log from the next page.
@param[in] space undo log header space
@param[in] undo_page undo log page
@param[in] page_no undo log header page number
@param[in] offset undo log header offset on page
@param[in] mode latch mode: RW_S_LATCH or RW_X_LATCH
@param[in,out] mtr mini-transaction
@return undo log record, the page latched, NULL if none */
static
trx_undo_rec_t*
trx_undo_get_next_rec_from_next_page(
ulint space,
const page_t* undo_page,
ulint page_no,
ulint offset,
ulint mode,
mtr_t* mtr)
{
const trx_ulogf_t* log_hdr;
ulint next_page_no;
page_t* next_page;
ulint next;
if (page_no == page_get_page_no(undo_page)) {
log_hdr = undo_page + offset;
next = mach_read_from_2(log_hdr + TRX_UNDO_NEXT_LOG);
if (next != 0) {
return(NULL);
}
}
next_page_no = flst_get_next_addr(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_NODE, mtr)
.page;
if (next_page_no == FIL_NULL) {
return(NULL);
}
const page_id_t next_page_id(space, next_page_no);
if (mode == RW_S_LATCH) {
next_page = trx_undo_page_get_s_latched(
next_page_id, mtr);
} else {
ut_ad(mode == RW_X_LATCH);
next_page = trx_undo_page_get(next_page_id, mtr);
}
return(trx_undo_page_get_first_rec(next_page, page_no, offset));
}
/***********************************************************************//**
Gets the next record in an undo log.
@return undo log record, the page s-latched, NULL if none */
trx_undo_rec_t*
trx_undo_get_next_rec(
/*==================*/
trx_undo_rec_t* rec, /*!< in: undo record */
ulint page_no,/*!< in: undo log header page number */
ulint offset, /*!< in: undo log header offset on page */
mtr_t* mtr) /*!< in: mtr */
{
ulint space;
trx_undo_rec_t* next_rec;
next_rec = trx_undo_page_get_next_rec(rec, page_no, offset);
if (next_rec) {
return(next_rec);
}
space = page_get_space_id(page_align(rec));
return(trx_undo_get_next_rec_from_next_page(space,
page_align(rec),
page_no, offset,
RW_S_LATCH, mtr));
}
/** Gets the first record in an undo log.
@param[in] space undo log header space
@param[in] page_no undo log header page number
@param[in] offset undo log header offset on page
@param[in] mode latching mode: RW_S_LATCH or RW_X_LATCH
@param[in,out] mtr mini-transaction
@return undo log record, the page latched, NULL if none */
trx_undo_rec_t*
trx_undo_get_first_rec(
ulint space,
ulint page_no,
ulint offset,
ulint mode,
mtr_t* mtr)
{
page_t* undo_page;
trx_undo_rec_t* rec;
const page_id_t page_id(space, page_no);
if (mode == RW_S_LATCH) {
undo_page = trx_undo_page_get_s_latched(page_id, mtr);
} else {
undo_page = trx_undo_page_get(page_id, mtr);
}
rec = trx_undo_page_get_first_rec(undo_page, page_no, offset);
if (rec) {
return(rec);
}
return(trx_undo_get_next_rec_from_next_page(space,
undo_page, page_no, offset,
mode, mtr));
}
/*============== UNDO LOG FILE COPY CREATION AND FREEING ==================*/
/**********************************************************************//**
Writes the mtr log entry of an undo log page initialization. */
UNIV_INLINE
void
trx_undo_page_init_log(
/*===================*/
page_t* undo_page, /*!< in: undo log page */
ulint type, /*!< in: undo log type */
mtr_t* mtr) /*!< in: mtr */
{
mlog_write_initial_log_record(undo_page, MLOG_UNDO_INIT, mtr);
mlog_catenate_ulint_compressed(mtr, type);
}
/***********************************************************//**
Parses the redo log entry of an undo log page initialization.
@return end of log record or NULL */
byte*
trx_undo_parse_page_init(
/*=====================*/
const byte* ptr, /*!< in: buffer */
const byte* end_ptr,/*!< in: buffer end */
page_t* page, /*!< in: page or NULL */
mtr_t* mtr) /*!< in: mtr or NULL */
{
ulint type;
type = mach_parse_compressed(&ptr, end_ptr);
if (ptr == NULL) {
return(NULL);
}
if (page) {
trx_undo_page_init(page, type, mtr);
}
return(const_cast<byte*>(ptr));
}
/********************************************************************//**
Initializes the fields in an undo log segment page. */
static
void
trx_undo_page_init(
/*===============*/
page_t* undo_page, /*!< in: undo log segment page */
ulint type, /*!< in: undo log segment type */
mtr_t* mtr) /*!< in: mtr */
{
trx_upagef_t* page_hdr;
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_TYPE, type);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START,
TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE,
TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE);
fil_page_set_type(undo_page, FIL_PAGE_UNDO_LOG);
trx_undo_page_init_log(undo_page, type, mtr);
}
/***************************************************************//**
Creates a new undo log segment in file.
@return DB_SUCCESS if page creation OK possible error codes are:
DB_TOO_MANY_CONCURRENT_TRXS DB_OUT_OF_FILE_SPACE */
static MY_ATTRIBUTE((warn_unused_result))
dberr_t
trx_undo_seg_create(
/*================*/
trx_rseg_t* rseg MY_ATTRIBUTE((unused)),/*!< in: rollback segment */
trx_rsegf_t* rseg_hdr,/*!< in: rollback segment header, page
x-latched */
ulint type, /*!< in: type of the segment: TRX_UNDO_INSERT or
TRX_UNDO_UPDATE */
ulint* id, /*!< out: slot index within rseg header */
page_t** undo_page,
/*!< out: segment header page x-latched, NULL
if there was an error */
mtr_t* mtr) /*!< in: mtr */
{
ulint slot_no;
ulint space;
buf_block_t* block;
trx_upagef_t* page_hdr;
trx_usegf_t* seg_hdr;
ulint n_reserved;
bool success;
dberr_t err = DB_SUCCESS;
ut_ad(mtr != NULL);
ut_ad(id != NULL);
ut_ad(rseg_hdr != NULL);
ut_ad(mutex_own(&(rseg->mutex)));
/* fputs(type == TRX_UNDO_INSERT
? "Creating insert undo log segment\n"
: "Creating update undo log segment\n", stderr); */
slot_no = trx_rsegf_undo_find_free(rseg_hdr, mtr);
if (slot_no == ULINT_UNDEFINED) {
ib::warn() << "Cannot find a free slot for an undo log. Do"
" you have too many active transactions running"
" concurrently?";
return(DB_TOO_MANY_CONCURRENT_TRXS);
}
space = page_get_space_id(page_align(rseg_hdr));
success = fsp_reserve_free_extents(&n_reserved, space, 2, FSP_UNDO,
mtr);
if (!success) {
return(DB_OUT_OF_FILE_SPACE);
}
/* Allocate a new file segment for the undo log */
block = fseg_create_general(space, 0,
TRX_UNDO_SEG_HDR
+ TRX_UNDO_FSEG_HEADER, TRUE, mtr);
fil_space_release_free_extents(space, n_reserved);
if (block == NULL) {
/* No space left */
return(DB_OUT_OF_FILE_SPACE);
}
buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE);
*undo_page = buf_block_get_frame(block);
page_hdr = *undo_page + TRX_UNDO_PAGE_HDR;
seg_hdr = *undo_page + TRX_UNDO_SEG_HDR;
trx_undo_page_init(*undo_page, type, mtr);
mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_FREE,
TRX_UNDO_SEG_HDR + TRX_UNDO_SEG_HDR_SIZE,
MLOG_2BYTES, mtr);
mlog_write_ulint(seg_hdr + TRX_UNDO_LAST_LOG, 0, MLOG_2BYTES, mtr);
flst_init(seg_hdr + TRX_UNDO_PAGE_LIST, mtr);
flst_add_last(seg_hdr + TRX_UNDO_PAGE_LIST,
page_hdr + TRX_UNDO_PAGE_NODE, mtr);
trx_rsegf_set_nth_undo(rseg_hdr, slot_no,
page_get_page_no(*undo_page), mtr);
*id = slot_no;
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_USED);
return(err);
}
/**********************************************************************//**
Writes the mtr log entry of an undo log header initialization. */
UNIV_INLINE
void
trx_undo_header_create_log(
/*=======================*/
const page_t* undo_page, /*!< in: undo log header page */
trx_id_t trx_id, /*!< in: transaction id */
mtr_t* mtr) /*!< in: mtr */
{
mlog_write_initial_log_record(undo_page, MLOG_UNDO_HDR_CREATE, mtr);
mlog_catenate_ull_compressed(mtr, trx_id);
}
/***************************************************************//**
Creates a new undo log header in file. NOTE that this function has its own
log record type MLOG_UNDO_HDR_CREATE. You must NOT change the operation of
this function!
@return header byte offset on page */
static
ulint
trx_undo_header_create(
/*===================*/
page_t* undo_page, /*!< in/out: undo log segment
header page, x-latched; it is
assumed that there is
TRX_UNDO_LOG_XA_HDR_SIZE bytes
free space on it */
trx_id_t trx_id, /*!< in: transaction id */
mtr_t* mtr) /*!< in: mtr */
{
trx_upagef_t* page_hdr;
trx_usegf_t* seg_hdr;
trx_ulogf_t* log_hdr;
ulint prev_log;
ulint free;
ulint new_free;
ut_ad(mtr && undo_page);
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
free = mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE);
log_hdr = undo_page + free;
new_free = free + TRX_UNDO_LOG_OLD_HDR_SIZE;
ut_a(free + TRX_UNDO_LOG_XA_HDR_SIZE < UNIV_PAGE_SIZE - 100);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START, new_free);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, new_free);
mach_write_to_2(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE);
prev_log = mach_read_from_2(seg_hdr + TRX_UNDO_LAST_LOG);
if (prev_log != 0) {
trx_ulogf_t* prev_log_hdr;
prev_log_hdr = undo_page + prev_log;
mach_write_to_2(prev_log_hdr + TRX_UNDO_NEXT_LOG, free);
}
mach_write_to_2(seg_hdr + TRX_UNDO_LAST_LOG, free);
log_hdr = undo_page + free;
mach_write_to_2(log_hdr + TRX_UNDO_DEL_MARKS, TRUE);
mach_write_to_8(log_hdr + TRX_UNDO_TRX_ID, trx_id);
mach_write_to_2(log_hdr + TRX_UNDO_LOG_START, new_free);
mach_write_to_1(log_hdr + TRX_UNDO_XID_EXISTS, FALSE);
mach_write_to_1(log_hdr + TRX_UNDO_DICT_TRANS, FALSE);
mach_write_to_2(log_hdr + TRX_UNDO_NEXT_LOG, 0);
mach_write_to_2(log_hdr + TRX_UNDO_PREV_LOG, prev_log);
/* Write the log record about the header creation */
trx_undo_header_create_log(undo_page, trx_id, mtr);
return(free);
}
/********************************************************************//**
Write X/Open XA Transaction Identification (XID) to undo log header */
static
void
trx_undo_write_xid(
/*===============*/
trx_ulogf_t* log_hdr,/*!< in: undo log header */
const XID* xid, /*!< in: X/Open XA Transaction Identification */
mtr_t* mtr) /*!< in: mtr */
{
mlog_write_ulint(log_hdr + TRX_UNDO_XA_FORMAT,
static_cast<ulint>(xid->formatID),
MLOG_4BYTES, mtr);
mlog_write_ulint(log_hdr + TRX_UNDO_XA_TRID_LEN,
static_cast<ulint>(xid->gtrid_length),
MLOG_4BYTES, mtr);
mlog_write_ulint(log_hdr + TRX_UNDO_XA_BQUAL_LEN,
static_cast<ulint>(xid->bqual_length),
MLOG_4BYTES, mtr);
mlog_write_string(log_hdr + TRX_UNDO_XA_XID,
reinterpret_cast<const byte*>(xid->data),
XIDDATASIZE, mtr);
}
/********************************************************************//**
Read X/Open XA Transaction Identification (XID) from undo log header */
static
void
trx_undo_read_xid(
/*==============*/
trx_ulogf_t* log_hdr,/*!< in: undo log header */
XID* xid) /*!< out: X/Open XA Transaction Identification */
{
xid->formatID=static_cast<long>(mach_read_from_4(
log_hdr + TRX_UNDO_XA_FORMAT));
xid->gtrid_length=static_cast<long>(mach_read_from_4(
log_hdr + TRX_UNDO_XA_TRID_LEN));
xid->bqual_length=static_cast<long>(mach_read_from_4(
log_hdr + TRX_UNDO_XA_BQUAL_LEN));
memcpy(xid->data, log_hdr + TRX_UNDO_XA_XID, XIDDATASIZE);
}
/***************************************************************//**
Adds space for the XA XID after an undo log old-style header. */
static
void
trx_undo_header_add_space_for_xid(
/*==============================*/
page_t* undo_page,/*!< in: undo log segment header page */
trx_ulogf_t* log_hdr,/*!< in: undo log header */
mtr_t* mtr) /*!< in: mtr */
{
trx_upagef_t* page_hdr;
ulint free;
ulint new_free;
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
free = mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE);
/* free is now the end offset of the old style undo log header */
ut_a(free == (ulint)(log_hdr - undo_page) + TRX_UNDO_LOG_OLD_HDR_SIZE);
new_free = free + (TRX_UNDO_LOG_XA_HDR_SIZE
- TRX_UNDO_LOG_OLD_HDR_SIZE);
/* Add space for a XID after the header, update the free offset
fields on the undo log page and in the undo log header */
mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_START, new_free,
MLOG_2BYTES, mtr);
mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_FREE, new_free,
MLOG_2BYTES, mtr);
mlog_write_ulint(log_hdr + TRX_UNDO_LOG_START, new_free,
MLOG_2BYTES, mtr);
}
/**********************************************************************//**
Writes the mtr log entry of an undo log header reuse. */
UNIV_INLINE
void
trx_undo_insert_header_reuse_log(
/*=============================*/
const page_t* undo_page, /*!< in: undo log header page */
trx_id_t trx_id, /*!< in: transaction id */
mtr_t* mtr) /*!< in: mtr */
{
mlog_write_initial_log_record(undo_page, MLOG_UNDO_HDR_REUSE, mtr);
mlog_catenate_ull_compressed(mtr, trx_id);
}
/** Parse the redo log entry of an undo log page header create or reuse.
@param[in] type MLOG_UNDO_HDR_CREATE or MLOG_UNDO_HDR_REUSE
@param[in] ptr redo log record
@param[in] end_ptr end of log buffer
@param[in,out] page page frame or NULL
@param[in,out] mtr mini-transaction or NULL
@return end of log record or NULL */
byte*
trx_undo_parse_page_header(
mlog_id_t type,
const byte* ptr,
const byte* end_ptr,
page_t* page,
mtr_t* mtr)
{
trx_id_t trx_id = mach_u64_parse_compressed(&ptr, end_ptr);
if (ptr != NULL && page != NULL) {
switch (type) {
case MLOG_UNDO_HDR_CREATE:
trx_undo_header_create(page, trx_id, mtr);
return(const_cast<byte*>(ptr));
case MLOG_UNDO_HDR_REUSE:
trx_undo_insert_header_reuse(page, trx_id, mtr);
return(const_cast<byte*>(ptr));
default:
break;
}
ut_ad(0);
}
return(const_cast<byte*>(ptr));
}
/***************************************************************//**
Initializes a cached insert undo log header page for new use. NOTE that this
function has its own log record type MLOG_UNDO_HDR_REUSE. You must NOT change
the operation of this function!
@return undo log header byte offset on page */
static
ulint
trx_undo_insert_header_reuse(
/*=========================*/
page_t* undo_page, /*!< in/out: insert undo log segment
header page, x-latched */
trx_id_t trx_id, /*!< in: transaction id */
mtr_t* mtr) /*!< in: mtr */
{
trx_upagef_t* page_hdr;
trx_usegf_t* seg_hdr;
trx_ulogf_t* log_hdr;
ulint free;
ulint new_free;
ut_ad(mtr && undo_page);
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
free = TRX_UNDO_SEG_HDR + TRX_UNDO_SEG_HDR_SIZE;
ut_a(free + TRX_UNDO_LOG_XA_HDR_SIZE < UNIV_PAGE_SIZE - 100);
log_hdr = undo_page + free;
new_free = free + TRX_UNDO_LOG_OLD_HDR_SIZE;
/* Insert undo data is not needed after commit: we may free all
the space on the page */
ut_a(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_TYPE)
== TRX_UNDO_INSERT);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START, new_free);
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, new_free);
mach_write_to_2(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE);
log_hdr = undo_page + free;
mach_write_to_8(log_hdr + TRX_UNDO_TRX_ID, trx_id);
mach_write_to_2(log_hdr + TRX_UNDO_LOG_START, new_free);
mach_write_to_1(log_hdr + TRX_UNDO_XID_EXISTS, FALSE);
mach_write_to_1(log_hdr + TRX_UNDO_DICT_TRANS, FALSE);
/* Write the log record MLOG_UNDO_HDR_REUSE */
trx_undo_insert_header_reuse_log(undo_page, trx_id, mtr);
return(free);
}
/**********************************************************************//**
Writes the redo log entry of an update undo log header discard. */
UNIV_INLINE
void
trx_undo_discard_latest_log(
/*========================*/
page_t* undo_page, /*!< in: undo log header page */
mtr_t* mtr) /*!< in: mtr */
{
mlog_write_initial_log_record(undo_page, MLOG_UNDO_HDR_DISCARD, mtr);
}
/***********************************************************//**
Parses the redo log entry of an undo log page header discard.
@return end of log record or NULL */
byte*
trx_undo_parse_discard_latest(
/*==========================*/
byte* ptr, /*!< in: buffer */
byte* end_ptr MY_ATTRIBUTE((unused)), /*!< in: buffer end */
page_t* page, /*!< in: page or NULL */
mtr_t* mtr) /*!< in: mtr or NULL */
{
ut_ad(end_ptr);
if (page) {
trx_undo_discard_latest_update_undo(page, mtr);
}
return(ptr);
}
/**********************************************************************//**
If an update undo log can be discarded immediately, this function frees the
space, resetting the page to the proper state for caching. */
static
void
trx_undo_discard_latest_update_undo(
/*================================*/
page_t* undo_page, /*!< in: header page of an undo log of size 1 */
mtr_t* mtr) /*!< in: mtr */
{
trx_usegf_t* seg_hdr;
trx_upagef_t* page_hdr;
trx_ulogf_t* log_hdr;
trx_ulogf_t* prev_log_hdr;
ulint free;
ulint prev_hdr_offset;
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
free = mach_read_from_2(seg_hdr + TRX_UNDO_LAST_LOG);
log_hdr = undo_page + free;
prev_hdr_offset = mach_read_from_2(log_hdr + TRX_UNDO_PREV_LOG);
if (prev_hdr_offset != 0) {
prev_log_hdr = undo_page + prev_hdr_offset;
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START,
mach_read_from_2(prev_log_hdr
+ TRX_UNDO_LOG_START));
mach_write_to_2(prev_log_hdr + TRX_UNDO_NEXT_LOG, 0);
}
mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, free);
mach_write_to_2(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_CACHED);
mach_write_to_2(seg_hdr + TRX_UNDO_LAST_LOG, prev_hdr_offset);
trx_undo_discard_latest_log(undo_page, mtr);
}
/** Allocate an undo log page.
@param[in,out] trx transaction
@param[in,out] undo undo log
@param[in,out] mtr mini-transaction that does not hold any page latch
@return X-latched block if success
@retval NULL on failure */
buf_block_t*
trx_undo_add_page(trx_t* trx, trx_undo_t* undo, mtr_t* mtr)
{
ut_ad(mutex_own(&trx->undo_mutex));
trx_rseg_t* rseg = undo->rseg;
buf_block_t* new_block = NULL;
ulint n_reserved;
page_t* header_page;
/* When we add a page to an undo log, this is analogous to
a pessimistic insert in a B-tree, and we must reserve the
counterpart of the tree latch, which is the rseg mutex. */
mutex_enter(&rseg->mutex);
if (rseg->curr_size == rseg->max_size) {
goto func_exit;
}
header_page = trx_undo_page_get(
page_id_t(undo->space, undo->hdr_page_no), mtr);
if (!fsp_reserve_free_extents(&n_reserved, undo->space, 1,
FSP_UNDO, mtr)) {
goto func_exit;
}
new_block = fseg_alloc_free_page_general(
TRX_UNDO_SEG_HDR + TRX_UNDO_FSEG_HEADER
+ header_page,
undo->top_page_no + 1, FSP_UP, TRUE, mtr, mtr);
fil_space_release_free_extents(undo->space, n_reserved);
if (!new_block) {
goto func_exit;
}
ut_ad(rw_lock_get_x_lock_count(&new_block->lock) == 1);
buf_block_dbg_add_level(new_block, SYNC_TRX_UNDO_PAGE);
undo->last_page_no = new_block->page.id.page_no();
trx_undo_page_init(new_block->frame, undo->type, mtr);
flst_add_last(TRX_UNDO_SEG_HDR + TRX_UNDO_PAGE_LIST
+ header_page,
TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE
+ new_block->frame,
mtr);
undo->size++;
rseg->curr_size++;
func_exit:
mutex_exit(&rseg->mutex);
return(new_block);
}
/********************************************************************//**
Frees an undo log page that is not the header page.
@return last page number in remaining log */
static
ulint
trx_undo_free_page(
/*===============*/
trx_rseg_t* rseg, /*!< in: rollback segment */
ibool in_history, /*!< in: TRUE if the undo log is in the history
list */
ulint space, /*!< in: space */
ulint hdr_page_no, /*!< in: header page number */
ulint page_no, /*!< in: page number to free: must not be the
header page */
mtr_t* mtr) /*!< in: mtr which does not have a latch to any
undo log page; the caller must have reserved
the rollback segment mutex */
{
page_t* header_page;
page_t* undo_page;
fil_addr_t last_addr;
trx_rsegf_t* rseg_header;
ulint hist_size;
ut_a(hdr_page_no != page_no);
ut_ad(mutex_own(&(rseg->mutex)));
undo_page = trx_undo_page_get(page_id_t(space, page_no), mtr);
header_page = trx_undo_page_get(page_id_t(space, hdr_page_no), mtr);
flst_remove(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_PAGE_LIST,
undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE, mtr);
fseg_free_page(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_FSEG_HEADER,
space, page_no, false, mtr);
last_addr = flst_get_last(header_page + TRX_UNDO_SEG_HDR
+ TRX_UNDO_PAGE_LIST, mtr);
rseg->curr_size--;
if (in_history) {
rseg_header = trx_rsegf_get(space, rseg->page_no, mtr);
hist_size = mtr_read_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE,
MLOG_4BYTES, mtr);
ut_ad(hist_size > 0);
mlog_write_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE,
hist_size - 1, MLOG_4BYTES, mtr);
}
return(last_addr.page);
}
/** Free the last undo log page. The caller must hold the rseg mutex.
@param[in,out] undo undo log
@param[in,out] mtr mini-transaction that does not hold any undo log page
or that has allocated the undo log page */
void
trx_undo_free_last_page(trx_undo_t* undo, mtr_t* mtr)
{
ut_ad(undo->hdr_page_no != undo->last_page_no);
ut_ad(undo->size > 0);
undo->last_page_no = trx_undo_free_page(
undo->rseg, FALSE, undo->space,
undo->hdr_page_no, undo->last_page_no, mtr);
undo->size--;
}
/** Empties an undo log header page of undo records for that undo log.
Other undo logs may still have records on that page, if it is an update
undo log.
@param[in] space space
@param[in] hdr_page_no header page number
@param[in] hdr_offset header offset
@param[in,out] mtr mini-transaction */
static
void
trx_undo_empty_header_page(
ulint space,
ulint hdr_page_no,
ulint hdr_offset,
mtr_t* mtr)
{
page_t* header_page;
trx_ulogf_t* log_hdr;
ulint end;
header_page = trx_undo_page_get(page_id_t(space, hdr_page_no), mtr);
log_hdr = header_page + hdr_offset;
end = trx_undo_page_get_end(header_page, hdr_page_no, hdr_offset);
mlog_write_ulint(log_hdr + TRX_UNDO_LOG_START, end, MLOG_2BYTES, mtr);
}
/** Truncate the tail of an undo log during rollback.
@param[in,out] undo undo log
@param[in] limit all undo logs after this limit will be discarded
@param[in] is_temp whether this is temporary undo log */
void
trx_undo_truncate_end(trx_undo_t* undo, undo_no_t limit, bool is_temp)
{
ut_ad(mutex_own(&undo->rseg->mutex));
ut_ad(is_temp == !undo->rseg->is_persistent());
for (;;) {
mtr_t mtr;
mtr.start();
if (is_temp) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
trx_undo_rec_t* trunc_here = NULL;
page_t* undo_page = trx_undo_page_get(
page_id_t(undo->space, undo->last_page_no), &mtr);
trx_undo_rec_t* rec = trx_undo_page_get_last_rec(
undo_page, undo->hdr_page_no, undo->hdr_offset);
while (rec) {
if (trx_undo_rec_get_undo_no(rec) >= limit) {
/* Truncate at least this record off, maybe
more */
trunc_here = rec;
} else {
goto function_exit;
}
rec = trx_undo_page_get_prev_rec(rec,
undo->hdr_page_no,
undo->hdr_offset);
}
if (undo->last_page_no == undo->hdr_page_no) {
function_exit:
if (trunc_here) {
mlog_write_ulint(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_FREE,
trunc_here - undo_page,
MLOG_2BYTES, &mtr);
}
mtr.commit();
return;
}
trx_undo_free_last_page(undo, &mtr);
mtr.commit();
}
}
/** Truncate the head of an undo log.
NOTE that only whole pages are freed; the header page is not
freed, but emptied, if all the records there are below the limit.
@param[in,out] rseg rollback segment
@param[in] hdr_page_no header page number
@param[in] hdr_offset header offset on the page
@param[in] limit first undo number to preserve
(everything below the limit will be truncated) */
void
trx_undo_truncate_start(
trx_rseg_t* rseg,
ulint hdr_page_no,
ulint hdr_offset,
undo_no_t limit)
{
page_t* undo_page;
trx_undo_rec_t* rec;
trx_undo_rec_t* last_rec;
ulint page_no;
mtr_t mtr;
ut_ad(mutex_own(&(rseg->mutex)));
if (!limit) {
return;
}
loop:
mtr_start(&mtr);
if (!rseg->is_persistent()) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
rec = trx_undo_get_first_rec(rseg->space, hdr_page_no, hdr_offset,
RW_X_LATCH, &mtr);
if (rec == NULL) {
/* Already empty */
mtr_commit(&mtr);
return;
}
undo_page = page_align(rec);
last_rec = trx_undo_page_get_last_rec(undo_page, hdr_page_no,
hdr_offset);
if (trx_undo_rec_get_undo_no(last_rec) >= limit) {
mtr_commit(&mtr);
return;
}
page_no = page_get_page_no(undo_page);
if (page_no == hdr_page_no) {
trx_undo_empty_header_page(rseg->space,
hdr_page_no, hdr_offset,
&mtr);
} else {
trx_undo_free_page(rseg, TRUE, rseg->space, hdr_page_no,
page_no, &mtr);
}
mtr_commit(&mtr);
goto loop;
}
/** Frees an undo log segment which is not in the history list.
@param[in] undo undo log
@param[in] noredo whether the undo tablespace is redo logged */
static
void
trx_undo_seg_free(
const trx_undo_t* undo,
bool noredo)
{
trx_rseg_t* rseg;
fseg_header_t* file_seg;
trx_rsegf_t* rseg_header;
trx_usegf_t* seg_header;
ibool finished;
mtr_t mtr;
rseg = undo->rseg;
do {
mtr_start(&mtr);
if (noredo) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
}
mutex_enter(&(rseg->mutex));
seg_header = trx_undo_page_get(page_id_t(undo->space,
undo->hdr_page_no),
&mtr)
+ TRX_UNDO_SEG_HDR;
file_seg = seg_header + TRX_UNDO_FSEG_HEADER;
finished = fseg_free_step(file_seg, false, &mtr);
if (finished) {
/* Update the rseg header */
rseg_header = trx_rsegf_get(
rseg->space, rseg->page_no, &mtr);
trx_rsegf_set_nth_undo(rseg_header, undo->id, FIL_NULL,
&mtr);
MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_USED);
}
mutex_exit(&(rseg->mutex));
mtr_commit(&mtr);
} while (!finished);
}
/*========== UNDO LOG MEMORY COPY INITIALIZATION =====================*/
/********************************************************************//**
Creates and initializes an undo log memory object according to the values
in the header in file, when the database is started. The memory object is
inserted in the appropriate list of rseg.
@return own: the undo log memory object */
static
trx_undo_t*
trx_undo_mem_create_at_db_start(
/*============================*/
trx_rseg_t* rseg, /*!< in: rollback segment memory object */
ulint id, /*!< in: slot index within rseg */
ulint page_no,/*!< in: undo log segment page number */
mtr_t* mtr) /*!< in: mtr */
{
page_t* undo_page;
trx_upagef_t* page_header;
trx_usegf_t* seg_header;
trx_ulogf_t* undo_header;
trx_undo_t* undo;
ulint type;
ulint state;
trx_id_t trx_id;
ulint offset;
fil_addr_t last_addr;
page_t* last_page;
trx_undo_rec_t* rec;
XID xid;
ibool xid_exists = FALSE;
ut_a(id < TRX_RSEG_N_SLOTS);
undo_page = trx_undo_page_get(page_id_t(rseg->space, page_no), mtr);
page_header = undo_page + TRX_UNDO_PAGE_HDR;
type = mtr_read_ulint(page_header + TRX_UNDO_PAGE_TYPE, MLOG_2BYTES,
mtr);
seg_header = undo_page + TRX_UNDO_SEG_HDR;
state = mach_read_from_2(seg_header + TRX_UNDO_STATE);
offset = mach_read_from_2(seg_header + TRX_UNDO_LAST_LOG);
undo_header = undo_page + offset;
trx_id = mach_read_from_8(undo_header + TRX_UNDO_TRX_ID);
xid_exists = mtr_read_ulint(undo_header + TRX_UNDO_XID_EXISTS,
MLOG_1BYTE, mtr);
/* Read X/Open XA transaction identification if it exists, or
set it to NULL. */
xid.null();
if (xid_exists == TRUE) {
trx_undo_read_xid(undo_header, &xid);
}
mutex_enter(&(rseg->mutex));
undo = trx_undo_mem_create(rseg, id, type, trx_id, &xid,
page_no, offset);
mutex_exit(&(rseg->mutex));
undo->dict_operation = mtr_read_ulint(
undo_header + TRX_UNDO_DICT_TRANS, MLOG_1BYTE, mtr);
undo->table_id = mach_read_from_8(undo_header + TRX_UNDO_TABLE_ID);
undo->state = state;
undo->size = flst_get_len(seg_header + TRX_UNDO_PAGE_LIST);
/* If the log segment is being freed, the page list is inconsistent! */
if (state == TRX_UNDO_TO_FREE) {
goto add_to_list;
}
last_addr = flst_get_last(seg_header + TRX_UNDO_PAGE_LIST, mtr);
undo->last_page_no = last_addr.page;
undo->top_page_no = last_addr.page;
last_page = trx_undo_page_get(
page_id_t(rseg->space, undo->last_page_no), mtr);
rec = trx_undo_page_get_last_rec(last_page, page_no, offset);
if (rec == NULL) {
undo->empty = TRUE;
} else {
undo->empty = FALSE;
undo->top_offset = rec - last_page;
undo->top_undo_no = trx_undo_rec_get_undo_no(rec);
}
add_to_list:
if (type == TRX_UNDO_INSERT) {
if (state != TRX_UNDO_CACHED) {
UT_LIST_ADD_LAST(rseg->insert_undo_list, undo);
} else {
UT_LIST_ADD_LAST(rseg->insert_undo_cached, undo);
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED);
}
} else {
ut_ad(type == TRX_UNDO_UPDATE);
if (state != TRX_UNDO_CACHED) {
UT_LIST_ADD_LAST(rseg->update_undo_list, undo);
} else {
UT_LIST_ADD_LAST(rseg->update_undo_cached, undo);
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED);
}
}
return(undo);
}
/********************************************************************//**
Initializes the undo log lists for a rollback segment memory copy. This
function is only called when the database is started or a new rollback
segment is created.
@return the combined size of undo log segments in pages */
ulint
trx_undo_lists_init(
/*================*/
trx_rseg_t* rseg) /*!< in: rollback segment memory object */
{
ulint size = 0;
trx_rsegf_t* rseg_header;
ulint i;
mtr_t mtr;
mtr_start(&mtr);
rseg_header = trx_rsegf_get_new(rseg->space, rseg->page_no, &mtr);
for (i = 0; i < TRX_RSEG_N_SLOTS; i++) {
ulint page_no;
page_no = trx_rsegf_get_nth_undo(rseg_header, i, &mtr);
/* In forced recovery: try to avoid operations which look
at database pages; undo logs are rapidly changing data, and
the probability that they are in an inconsistent state is
high */
if (page_no != FIL_NULL
&& srv_force_recovery < SRV_FORCE_NO_UNDO_LOG_SCAN) {
trx_undo_t* undo;
undo = trx_undo_mem_create_at_db_start(
rseg, i, page_no, &mtr);
size += undo->size;
mtr_commit(&mtr);
mtr_start(&mtr);
rseg_header = trx_rsegf_get(
rseg->space, rseg->page_no, &mtr);
/* Found a used slot */
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_USED);
}
}
mtr_commit(&mtr);
return(size);
}
/********************************************************************//**
Creates and initializes an undo log memory object.
@return own: the undo log memory object */
static
trx_undo_t*
trx_undo_mem_create(
/*================*/
trx_rseg_t* rseg, /*!< in: rollback segment memory object */
ulint id, /*!< in: slot index within rseg */
ulint type, /*!< in: type of the log: TRX_UNDO_INSERT or
TRX_UNDO_UPDATE */
trx_id_t trx_id, /*!< in: id of the trx for which the undo log
is created */
const XID* xid, /*!< in: X/Open transaction identification */
ulint page_no,/*!< in: undo log header page number */
ulint offset) /*!< in: undo log header byte offset on page */
{
trx_undo_t* undo;
ut_ad(mutex_own(&(rseg->mutex)));
ut_a(id < TRX_RSEG_N_SLOTS);
undo = static_cast<trx_undo_t*>(ut_malloc_nokey(sizeof(*undo)));
if (undo == NULL) {
return(NULL);
}
undo->id = id;
undo->type = type;
undo->state = TRX_UNDO_ACTIVE;
undo->del_marks = FALSE;
undo->trx_id = trx_id;
undo->xid = *xid;
undo->dict_operation = FALSE;
undo->rseg = rseg;
undo->space = rseg->space;
undo->hdr_page_no = page_no;
undo->hdr_offset = offset;
undo->last_page_no = page_no;
undo->size = 1;
undo->empty = TRUE;
undo->top_page_no = page_no;
undo->guess_block = NULL;
undo->withdraw_clock = 0;
return(undo);
}
/********************************************************************//**
Initializes a cached undo log object for new use. */
static
void
trx_undo_mem_init_for_reuse(
/*========================*/
trx_undo_t* undo, /*!< in: undo log to init */
trx_id_t trx_id, /*!< in: id of the trx for which the undo log
is created */
const XID* xid, /*!< in: X/Open XA transaction identification*/
ulint offset) /*!< in: undo log header byte offset on page */
{
ut_ad(mutex_own(&((undo->rseg)->mutex)));
ut_a(undo->id < TRX_RSEG_N_SLOTS);
undo->state = TRX_UNDO_ACTIVE;
undo->del_marks = FALSE;
undo->trx_id = trx_id;
undo->xid = *xid;
undo->dict_operation = FALSE;
undo->hdr_offset = offset;
undo->empty = TRUE;
}
/********************************************************************//**
Frees an undo log memory copy. */
void
trx_undo_mem_free(
/*==============*/
trx_undo_t* undo) /*!< in: the undo object to be freed */
{
ut_a(undo->id < TRX_RSEG_N_SLOTS);
ut_free(undo);
}
/**********************************************************************//**
Creates a new undo log.
@return DB_SUCCESS if successful in creating the new undo lob object,
possible error codes are: DB_TOO_MANY_CONCURRENT_TRXS
DB_OUT_OF_FILE_SPACE DB_OUT_OF_MEMORY */
static MY_ATTRIBUTE((nonnull, warn_unused_result))
dberr_t
trx_undo_create(
/*============*/
trx_t* trx, /*!< in: transaction */
trx_rseg_t* rseg, /*!< in: rollback segment memory copy */
ulint type, /*!< in: type of the log: TRX_UNDO_INSERT or
TRX_UNDO_UPDATE */
trx_id_t trx_id, /*!< in: id of the trx for which the undo log
is created */
const XID* xid, /*!< in: X/Open transaction identification*/
trx_undo_t** undo, /*!< out: the new undo log object, undefined
* if did not succeed */
mtr_t* mtr) /*!< in: mtr */
{
trx_rsegf_t* rseg_header;
ulint page_no;
ulint offset;
ulint id;
page_t* undo_page;
dberr_t err;
ut_ad(mutex_own(&(rseg->mutex)));
if (rseg->curr_size == rseg->max_size) {
return(DB_OUT_OF_FILE_SPACE);
}
rseg->curr_size++;
rseg_header = trx_rsegf_get(rseg->space, rseg->page_no, mtr);
err = trx_undo_seg_create(rseg, rseg_header, type, &id,
&undo_page, mtr);
if (err != DB_SUCCESS) {
/* Did not succeed */
rseg->curr_size--;
return(err);
}
page_no = page_get_page_no(undo_page);
offset = trx_undo_header_create(undo_page, trx_id, mtr);
trx_undo_header_add_space_for_xid(undo_page, undo_page + offset, mtr);
*undo = trx_undo_mem_create(rseg, id, type, trx_id, xid,
page_no, offset);
if (*undo == NULL) {
err = DB_OUT_OF_MEMORY;
}
return(err);
}
/*================ UNDO LOG ASSIGNMENT AND CLEANUP =====================*/
/********************************************************************//**
Reuses a cached undo log.
@return the undo log memory object, NULL if none cached */
static
trx_undo_t*
trx_undo_reuse_cached(
/*==================*/
trx_t* trx, /*!< in: transaction */
trx_rseg_t* rseg, /*!< in: rollback segment memory object */
ulint type, /*!< in: type of the log: TRX_UNDO_INSERT or
TRX_UNDO_UPDATE */
trx_id_t trx_id, /*!< in: id of the trx for which the undo log
is used */
const XID* xid, /*!< in: X/Open XA transaction identification */
mtr_t* mtr) /*!< in: mtr */
{
trx_undo_t* undo;
page_t* undo_page;
ulint offset;
ut_ad(mutex_own(&(rseg->mutex)));
if (type == TRX_UNDO_INSERT) {
undo = UT_LIST_GET_FIRST(rseg->insert_undo_cached);
if (undo == NULL) {
return(NULL);
}
UT_LIST_REMOVE(rseg->insert_undo_cached, undo);
MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED);
} else {
ut_ad(type == TRX_UNDO_UPDATE);
undo = UT_LIST_GET_FIRST(rseg->update_undo_cached);
if (undo == NULL) {
return(NULL);
}
UT_LIST_REMOVE(rseg->update_undo_cached, undo);
MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED);
}
ut_ad(undo->size == 1);
ut_a(undo->id < TRX_RSEG_N_SLOTS);
undo_page = trx_undo_page_get(
page_id_t(undo->space, undo->hdr_page_no), mtr);
if (type == TRX_UNDO_INSERT) {
offset = trx_undo_insert_header_reuse(undo_page, trx_id, mtr);
trx_undo_header_add_space_for_xid(
undo_page, undo_page + offset, mtr);
} else {
ut_a(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR
+ TRX_UNDO_PAGE_TYPE)
== TRX_UNDO_UPDATE);
offset = trx_undo_header_create(undo_page, trx_id, mtr);
trx_undo_header_add_space_for_xid(
undo_page, undo_page + offset, mtr);
}
trx_undo_mem_init_for_reuse(undo, trx_id, xid, offset);
return(undo);
}
/**********************************************************************//**
Marks an undo log header as a header of a data dictionary operation
transaction. */
static
void
trx_undo_mark_as_dict_operation(
/*============================*/
trx_t* trx, /*!< in: dict op transaction */
trx_undo_t* undo, /*!< in: assigned undo log */
mtr_t* mtr) /*!< in: mtr */
{
page_t* hdr_page;
hdr_page = trx_undo_page_get(
page_id_t(undo->space, undo->hdr_page_no), mtr);
switch (trx_get_dict_operation(trx)) {
case TRX_DICT_OP_NONE:
ut_error;
case TRX_DICT_OP_INDEX:
/* Do not discard the table on recovery. */
undo->table_id = 0;
break;
case TRX_DICT_OP_TABLE:
undo->table_id = trx->table_id;
break;
}
mlog_write_ulint(hdr_page + undo->hdr_offset
+ TRX_UNDO_DICT_TRANS,
TRUE, MLOG_1BYTE, mtr);
mlog_write_ull(hdr_page + undo->hdr_offset + TRX_UNDO_TABLE_ID,
undo->table_id, mtr);
undo->dict_operation = TRUE;
}
/** Assign an undo log for a transaction.
A new undo log is created or a cached undo log reused.
@param[in,out] trx transaction
@param[in] rseg rollback segment
@param[out] undo the undo log
@param[in] type TRX_UNDO_INSERT or TRX_UNDO_UPDATE
@retval DB_SUCCESS on success
@retval DB_TOO_MANY_CONCURRENT_TRXS
@retval DB_OUT_OF_FILE_SPACE
@retval DB_READ_ONLY
@retval DB_OUT_OF_MEMORY */
dberr_t
trx_undo_assign_undo(
trx_t* trx,
trx_rseg_t* rseg,
trx_undo_t** undo,
ulint type)
{
const bool is_temp = rseg == trx->rsegs.m_noredo.rseg;
mtr_t mtr;
dberr_t err = DB_SUCCESS;
ut_ad(mutex_own(&trx->undo_mutex));
ut_ad(rseg == trx->rsegs.m_redo.rseg
|| rseg == trx->rsegs.m_noredo.rseg);
ut_ad(type == TRX_UNDO_INSERT || type == TRX_UNDO_UPDATE);
mtr.start(trx);
if (is_temp) {
mtr.set_log_mode(MTR_LOG_NO_REDO);
ut_ad(undo == &trx->rsegs.m_noredo.undo);
} else {
ut_ad(undo == (type == TRX_UNDO_INSERT
? &trx->rsegs.m_redo.insert_undo
: &trx->rsegs.m_redo.update_undo));
}
mutex_enter(&rseg->mutex);
*undo = trx_undo_reuse_cached(trx, rseg, type, trx->id, trx->xid,
&mtr);
if (*undo == NULL) {
err = trx_undo_create(trx, rseg, type, trx->id, trx->xid,
undo, &mtr);
if (err != DB_SUCCESS) {
goto func_exit;
}
}
if (is_temp) {
UT_LIST_ADD_FIRST(rseg->insert_undo_list, *undo);
} else {
UT_LIST_ADD_FIRST(type == TRX_UNDO_INSERT
? rseg->insert_undo_list
: rseg->update_undo_list, *undo);
if (trx_get_dict_operation(trx) != TRX_DICT_OP_NONE) {
trx_undo_mark_as_dict_operation(trx, *undo, &mtr);
}
}
func_exit:
mutex_exit(&rseg->mutex);
mtr.commit();
return(err);
}
/******************************************************************//**
Sets the state of the undo log segment at a transaction finish.
@return undo log segment header page, x-latched */
page_t*
trx_undo_set_state_at_finish(
/*=========================*/
trx_undo_t* undo, /*!< in: undo log memory copy */
mtr_t* mtr) /*!< in: mtr */
{
trx_usegf_t* seg_hdr;
trx_upagef_t* page_hdr;
page_t* undo_page;
ulint state;
ut_a(undo->id < TRX_RSEG_N_SLOTS);
undo_page = trx_undo_page_get(
page_id_t(undo->space, undo->hdr_page_no), mtr);
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
page_hdr = undo_page + TRX_UNDO_PAGE_HDR;
if (undo->size == 1
&& mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE)
< TRX_UNDO_PAGE_REUSE_LIMIT) {
state = TRX_UNDO_CACHED;
} else if (undo->type == TRX_UNDO_INSERT) {
state = TRX_UNDO_TO_FREE;
} else {
state = TRX_UNDO_TO_PURGE;
}
undo->state = state;
mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, state, MLOG_2BYTES, mtr);
return(undo_page);
}
/** Set the state of the undo log segment at a XA PREPARE or XA ROLLBACK.
@param[in,out] trx transaction
@param[in,out] undo insert_undo or update_undo log
@param[in] rollback false=XA PREPARE, true=XA ROLLBACK
@param[in,out] mtr mini-transaction
@return undo log segment header page, x-latched */
page_t*
trx_undo_set_state_at_prepare(
trx_t* trx,
trx_undo_t* undo,
bool rollback,
mtr_t* mtr)
{
trx_usegf_t* seg_hdr;
trx_ulogf_t* undo_header;
page_t* undo_page;
ulint offset;
ut_ad(trx && undo && mtr);
ut_a(undo->id < TRX_RSEG_N_SLOTS);
undo_page = trx_undo_page_get(
page_id_t(undo->space, undo->hdr_page_no), mtr);
seg_hdr = undo_page + TRX_UNDO_SEG_HDR;
if (rollback) {
ut_ad(undo->state == TRX_UNDO_PREPARED);
mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE,
MLOG_2BYTES, mtr);
return(undo_page);
}
/*------------------------------*/
ut_ad(undo->state == TRX_UNDO_ACTIVE);
undo->state = TRX_UNDO_PREPARED;
undo->xid = *trx->xid;
/*------------------------------*/
mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, undo->state,
MLOG_2BYTES, mtr);
offset = mach_read_from_2(seg_hdr + TRX_UNDO_LAST_LOG);
undo_header = undo_page + offset;
mlog_write_ulint(undo_header + TRX_UNDO_XID_EXISTS,
TRUE, MLOG_1BYTE, mtr);
trx_undo_write_xid(undo_header, &undo->xid, mtr);
return(undo_page);
}
/**********************************************************************//**
Adds the update undo log header as the first in the history list, and
frees the memory object, or puts it to the list of cached update undo log
segments. */
void
trx_undo_update_cleanup(
/*====================*/
trx_t* trx, /*!< in: trx owning the update
undo log */
page_t* undo_page, /*!< in: update undo log header page,
x-latched */
mtr_t* mtr) /*!< in: mtr */
{
trx_undo_t* undo = trx->rsegs.m_redo.update_undo;
trx_rseg_t* rseg = undo->rseg;
ut_ad(mutex_own(&rseg->mutex));
trx_purge_add_update_undo_to_history(trx, undo_page, mtr);
UT_LIST_REMOVE(rseg->update_undo_list, undo);
trx->rsegs.m_redo.update_undo = NULL;
if (undo->state == TRX_UNDO_CACHED) {
UT_LIST_ADD_FIRST(rseg->update_undo_cached, undo);
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED);
} else {
ut_ad(undo->state == TRX_UNDO_TO_PURGE);
trx_undo_mem_free(undo);
}
}
/** Free an insert or temporary undo log after commit or rollback.
The information is not needed after a commit or rollback, therefore
the data can be discarded.
@param[in,out] undo undo log
@param[in] is_temp whether this is temporary undo log */
void
trx_undo_commit_cleanup(trx_undo_t* undo, bool is_temp)
{
trx_rseg_t* rseg = undo->rseg;
ut_ad(is_temp == !rseg->is_persistent());
mutex_enter(&rseg->mutex);
UT_LIST_REMOVE(rseg->insert_undo_list, undo);
if (undo->state == TRX_UNDO_CACHED) {
UT_LIST_ADD_FIRST(rseg->insert_undo_cached, undo);
MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED);
} else {
ut_ad(undo->state == TRX_UNDO_TO_FREE);
/* Delete first the undo log segment in the file */
mutex_exit(&rseg->mutex);
trx_undo_seg_free(undo, is_temp);
mutex_enter(&rseg->mutex);
ut_ad(rseg->curr_size > undo->size);
rseg->curr_size -= undo->size;
trx_undo_mem_free(undo);
}
mutex_exit(&rseg->mutex);
}
/********************************************************************//**
At shutdown, frees the undo logs of a PREPARED transaction. */
void
trx_undo_free_prepared(
/*===================*/
trx_t* trx) /*!< in/out: PREPARED transaction */
{
ut_ad(srv_shutdown_state == SRV_SHUTDOWN_EXIT_THREADS);
if (trx->rsegs.m_redo.update_undo) {
switch (trx->rsegs.m_redo.update_undo->state) {
case TRX_UNDO_PREPARED:
break;
case TRX_UNDO_ACTIVE:
/* lock_trx_release_locks() assigns
trx->is_recovered=false */
ut_a(!srv_was_started
|| srv_read_only_mode
|| srv_force_recovery >= SRV_FORCE_NO_TRX_UNDO);
break;
default:
ut_error;
}
UT_LIST_REMOVE(trx->rsegs.m_redo.rseg->update_undo_list,
trx->rsegs.m_redo.update_undo);
trx_undo_mem_free(trx->rsegs.m_redo.update_undo);
trx->rsegs.m_redo.update_undo = NULL;
}
if (trx->rsegs.m_redo.insert_undo) {
switch (trx->rsegs.m_redo.insert_undo->state) {
case TRX_UNDO_PREPARED:
break;
case TRX_UNDO_ACTIVE:
/* lock_trx_release_locks() assigns
trx->is_recovered=false */
ut_a(!srv_was_started
|| srv_read_only_mode
|| srv_force_recovery >= SRV_FORCE_NO_TRX_UNDO);
break;
default:
ut_error;
}
UT_LIST_REMOVE(trx->rsegs.m_redo.rseg->insert_undo_list,
trx->rsegs.m_redo.insert_undo);
trx_undo_mem_free(trx->rsegs.m_redo.insert_undo);
trx->rsegs.m_redo.insert_undo = NULL;
}
if (trx_undo_t*& undo = trx->rsegs.m_noredo.undo) {
ut_a(undo->state == TRX_UNDO_PREPARED);
UT_LIST_REMOVE(trx->rsegs.m_noredo.rseg->insert_undo_list,
undo);
trx_undo_mem_free(undo);
undo = NULL;
}
}
/** Truncate UNDO tablespace, reinitialize header and rseg.
@param[in] undo_trunc UNDO tablespace handler
@return true if success else false. */
bool
trx_undo_truncate_tablespace(
undo::Truncate* undo_trunc)
{
bool success = true;
ulint space_id = undo_trunc->get_marked_space_id();
/* Step-1: Truncate tablespace. */
success = fil_truncate_tablespace(
space_id, SRV_UNDO_TABLESPACE_SIZE_IN_PAGES);
if (!success) {
return(success);
}
/* Step-2: Re-initialize tablespace header.
Avoid REDO logging as we don't want to apply the action if server
crashes. For fix-up we have UNDO-truncate-ddl-log. */
mtr_t mtr;
mtr_start(&mtr);
mtr_set_log_mode(&mtr, MTR_LOG_NO_REDO);
fsp_header_init(space_id, SRV_UNDO_TABLESPACE_SIZE_IN_PAGES, &mtr);
mtr_commit(&mtr);
/* Step-3: Re-initialize rollback segment header that resides
in truncated tablespaced. */
mtr_start(&mtr);
mtr_set_log_mode(&mtr, MTR_LOG_NO_REDO);
mtr_x_lock(fil_space_get_latch(space_id, NULL), &mtr);
for (ulint i = 0; i < undo_trunc->rsegs_size(); ++i) {
trx_rsegf_t* rseg_header;
trx_rseg_t* rseg = undo_trunc->get_ith_rseg(i);
rseg->page_no = trx_rseg_header_create(
space_id, ULINT_MAX, rseg->id, &mtr);
rseg_header = trx_rsegf_get_new(space_id, rseg->page_no, &mtr);
/* Before re-initialization ensure that we free the existing
structure. There can't be any active transactions. */
ut_a(UT_LIST_GET_LEN(rseg->update_undo_list) == 0);
ut_a(UT_LIST_GET_LEN(rseg->insert_undo_list) == 0);
trx_undo_t* next_undo;
for (trx_undo_t* undo =
UT_LIST_GET_FIRST(rseg->update_undo_cached);
undo != NULL;
undo = next_undo) {
next_undo = UT_LIST_GET_NEXT(undo_list, undo);
UT_LIST_REMOVE(rseg->update_undo_cached, undo);
MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED);
trx_undo_mem_free(undo);
}
for (trx_undo_t* undo =
UT_LIST_GET_FIRST(rseg->insert_undo_cached);
undo != NULL;
undo = next_undo) {
next_undo = UT_LIST_GET_NEXT(undo_list, undo);
UT_LIST_REMOVE(rseg->insert_undo_cached, undo);
MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED);
trx_undo_mem_free(undo);
}
UT_LIST_INIT(rseg->update_undo_list, &trx_undo_t::undo_list);
UT_LIST_INIT(rseg->update_undo_cached, &trx_undo_t::undo_list);
UT_LIST_INIT(rseg->insert_undo_list, &trx_undo_t::undo_list);
UT_LIST_INIT(rseg->insert_undo_cached, &trx_undo_t::undo_list);
rseg->max_size = mtr_read_ulint(
rseg_header + TRX_RSEG_MAX_SIZE, MLOG_4BYTES, &mtr);
/* Initialize the undo log lists according to the rseg header */
rseg->curr_size = mtr_read_ulint(
rseg_header + TRX_RSEG_HISTORY_SIZE, MLOG_4BYTES, &mtr)
+ 1;
ut_ad(rseg->curr_size == 1);
rseg->trx_ref_count = 0;
rseg->last_page_no = FIL_NULL;
rseg->last_offset = 0;
rseg->last_trx_no = 0;
rseg->last_del_marks = FALSE;
}
mtr_commit(&mtr);
return(success);
}
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