mariadb/log/log0recv.c

/*****************************************************************************

Copyright (c) 1997, 2010, Innobase Oy. 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., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA

*****************************************************************************/

/**************************************************//**
@file log/log0recv.c
Recovery

Created 9/20/1997 Heikki Tuuri
*******************************************************/

#include "log0recv.h"

#ifdef UNIV_NONINL
#include "log0recv.ic"
#endif

#include "mem0mem.h"
#include "buf0buf.h"
#include "buf0flu.h"
#include "mtr0mtr.h"
#include "mtr0log.h"
#include "page0cur.h"
#include "page0zip.h"
#include "btr0btr.h"
#include "btr0cur.h"
#include "ibuf0ibuf.h"
#include "trx0undo.h"
#include "trx0rec.h"
#include "fil0fil.h"
#ifndef UNIV_HOTBACKUP
# include "buf0rea.h"
# include "srv0srv.h"
# include "srv0start.h"
# include "trx0roll.h"
# include "row0merge.h"
# include "sync0sync.h"
#else /* !UNIV_HOTBACKUP */

/** This is set to FALSE if the backup was originally taken with the
ibbackup --include regexp option: then we do not want to create tables in
directories which were not included */
UNIV_INTERN ibool	recv_replay_file_ops	= TRUE;
#endif /* !UNIV_HOTBACKUP */

/** Log records are stored in the hash table in chunks at most of this size;
this must be less than UNIV_PAGE_SIZE as it is stored in the buffer pool */
#define RECV_DATA_BLOCK_SIZE	(MEM_MAX_ALLOC_IN_BUF - sizeof(recv_data_t))

/** Read-ahead area in applying log records to file pages */
#define RECV_READ_AHEAD_AREA	32

/** The recovery system */
UNIV_INTERN recv_sys_t*	recv_sys = NULL;
/** TRUE when applying redo log records during crash recovery; FALSE
otherwise.  Note that this is FALSE while a background thread is
rolling back incomplete transactions. */
UNIV_INTERN ibool	recv_recovery_on;
#ifdef UNIV_LOG_ARCHIVE
/** TRUE when applying redo log records from an archived log file */
UNIV_INTERN ibool	recv_recovery_from_backup_on;
#endif /* UNIV_LOG_ARCHIVE */

#ifndef UNIV_HOTBACKUP
/** TRUE when recv_init_crash_recovery() has been called. */
UNIV_INTERN ibool	recv_needed_recovery;
# ifdef UNIV_DEBUG
/** TRUE if writing to the redo log (mtr_commit) is forbidden.
Protected by log_sys->mutex. */
UNIV_INTERN ibool	recv_no_log_write = FALSE;
# endif /* UNIV_DEBUG */

/** TRUE if buf_page_is_corrupted() should check if the log sequence
number (FIL_PAGE_LSN) is in the future.  Initially FALSE, and set by
recv_recovery_from_checkpoint_start_func(). */
UNIV_INTERN ibool	recv_lsn_checks_on;

/** There are two conditions under which we scan the logs, the first
is normal startup and the second is when we do a recovery from an
archive.
This flag is set if we are doing a scan from the last checkpoint during
startup. If we find log entries that were written after the last checkpoint
we know that the server was not cleanly shutdown. We must then initialize
the crash recovery environment before attempting to store these entries in
the log hash table. */
static ibool		recv_log_scan_is_startup_type;

/** If the following is TRUE, the buffer pool file pages must be invalidated
after recovery and no ibuf operations are allowed; this becomes TRUE if
the log record hash table becomes too full, and log records must be merged
to file pages already before the recovery is finished: in this case no
ibuf operations are allowed, as they could modify the pages read in the
buffer pool before the pages have been recovered to the up-to-date state.

TRUE means that recovery is running and no operations on the log files
are allowed yet: the variable name is misleading. */
UNIV_INTERN ibool	recv_no_ibuf_operations;
/** TRUE when the redo log is being backed up */
# define recv_is_making_a_backup		FALSE
/** TRUE when recovering from a backed up redo log file */
# define recv_is_from_backup			FALSE
#else /* !UNIV_HOTBACKUP */
# define recv_needed_recovery			FALSE
/** TRUE when the redo log is being backed up */
UNIV_INTERN ibool	recv_is_making_a_backup	= FALSE;
/** TRUE when recovering from a backed up redo log file */
UNIV_INTERN ibool	recv_is_from_backup	= FALSE;
# define buf_pool_get_curr_size() (5 * 1024 * 1024)
#endif /* !UNIV_HOTBACKUP */
/** The following counter is used to decide when to print info on
log scan */
static ulint	recv_scan_print_counter;

/** The type of the previous parsed redo log record */
static ulint	recv_previous_parsed_rec_type;
/** The offset of the previous parsed redo log record */
static ulint	recv_previous_parsed_rec_offset;
/** The 'multi' flag of the previous parsed redo log record */
static ulint	recv_previous_parsed_rec_is_multi;

/** Maximum page number encountered in the redo log */
UNIV_INTERN ulint	recv_max_parsed_page_no;

/** This many frames must be left free in the buffer pool when we scan
the log and store the scanned log records in the buffer pool: we will
use these free frames to read in pages when we start applying the
log records to the database.
This is the default value. If the actual size of the buffer pool is
larger than 10 MB we'll set this value to 512. */
UNIV_INTERN ulint	recv_n_pool_free_frames;

/** The maximum lsn we see for a page during the recovery process. If this
is bigger than the lsn we are able to scan up to, that is an indication that
the recovery failed and the database may be corrupt. */
UNIV_INTERN ib_uint64_t	recv_max_page_lsn;

/* prototypes */

#ifndef UNIV_HOTBACKUP
/*******************************************************//**
Initialize crash recovery environment. Can be called iff
recv_needed_recovery == FALSE. */
static
void
recv_init_crash_recovery(void);
/*===========================*/
#endif /* !UNIV_HOTBACKUP */

/********************************************************//**
Creates the recovery system. */
UNIV_INTERN
void
recv_sys_create(void)
/*=================*/
{
	if (recv_sys != NULL) {

		return;
	}

	recv_sys = mem_alloc(sizeof(*recv_sys));
	memset(recv_sys, 0x0, sizeof(*recv_sys));

	mutex_create(&recv_sys->mutex, SYNC_RECV);

	recv_sys->heap = NULL;
	recv_sys->addr_hash = NULL;
}

/********************************************************//**
Release recovery system mutexes. */
UNIV_INTERN
void
recv_sys_close(void)
/*================*/
{
	if (recv_sys != NULL) {
		if (recv_sys->addr_hash != NULL) {
			hash_table_free(recv_sys->addr_hash);
		}

		if (recv_sys->heap != NULL) {
			mem_heap_free(recv_sys->heap);
		}

		if (recv_sys->buf != NULL) {
			ut_free(recv_sys->buf);
		}

		if (recv_sys->last_block_buf_start != NULL) {
			mem_free(recv_sys->last_block_buf_start);
		}

		mutex_free(&recv_sys->mutex);

		mem_free(recv_sys);
		recv_sys = NULL;
	}
}

/********************************************************//**
Frees the recovery system memory. */
UNIV_INTERN
void
recv_sys_mem_free(void)
/*===================*/
{
	if (recv_sys != NULL) {
		if (recv_sys->addr_hash != NULL) {
			hash_table_free(recv_sys->addr_hash);
		}

		if (recv_sys->heap != NULL) {
			mem_heap_free(recv_sys->heap);
		}

		if (recv_sys->buf != NULL) {
			ut_free(recv_sys->buf);
		}

		if (recv_sys->last_block_buf_start != NULL) {
			mem_free(recv_sys->last_block_buf_start);
		}

		mem_free(recv_sys);
		recv_sys = NULL;
	}
}

#ifndef UNIV_HOTBACKUP
/************************************************************
Reset the state of the recovery system variables. */
UNIV_INTERN
void
recv_sys_var_init(void)
/*===================*/
{
	recv_lsn_checks_on = FALSE;

	recv_n_pool_free_frames = 256;

	recv_recovery_on = FALSE;

#ifdef UNIV_LOG_ARCHIVE
	recv_recovery_from_backup_on = FALSE;
#endif /* UNIV_LOG_ARCHIVE */

	recv_needed_recovery = FALSE;

	recv_lsn_checks_on = FALSE;

	recv_log_scan_is_startup_type = FALSE;

	recv_no_ibuf_operations = FALSE;

	recv_scan_print_counter	= 0;

	recv_previous_parsed_rec_type	= 999999;

	recv_previous_parsed_rec_offset	= 0;

	recv_previous_parsed_rec_is_multi = 0;

	recv_max_parsed_page_no	= 0;

	recv_n_pool_free_frames	= 256;

	recv_max_page_lsn = 0;
}
#endif /* !UNIV_HOTBACKUP */

/************************************************************
Inits the recovery system for a recovery operation. */
UNIV_INTERN
void
recv_sys_init(
/*==========*/
	ulint	available_memory)	/*!< in: available memory in bytes */
{
	if (recv_sys->heap != NULL) {

		return;
	}

#ifndef UNIV_HOTBACKUP
	/* Initialize red-black tree for fast insertions into the
	flush_list during recovery process.
	As this initialization is done while holding the buffer pool
	mutex we perform it before acquiring recv_sys->mutex. */
	buf_flush_init_flush_rbt();
#endif /* !UNIV_HOTBACKUP */

	mutex_enter(&(recv_sys->mutex));

#ifndef UNIV_HOTBACKUP
	recv_sys->heap = mem_heap_create_in_buffer(256);
#else /* !UNIV_HOTBACKUP */
	recv_sys->heap = mem_heap_create(256);
	recv_is_from_backup = TRUE;
#endif /* !UNIV_HOTBACKUP */

	/* Set appropriate value of recv_n_pool_free_frames. */
	if (buf_pool_get_curr_size() >= (10 * 1024 * 1024)) {
		/* Buffer pool of size greater than 10 MB. */
		recv_n_pool_free_frames = 512;
	}

	recv_sys->buf = ut_malloc(RECV_PARSING_BUF_SIZE);
	recv_sys->len = 0;
	recv_sys->recovered_offset = 0;

	recv_sys->addr_hash = hash_create(available_memory / 64);
	recv_sys->n_addrs = 0;

	recv_sys->apply_log_recs = FALSE;
	recv_sys->apply_batch_on = FALSE;

	recv_sys->last_block_buf_start = mem_alloc(2 * OS_FILE_LOG_BLOCK_SIZE);

	recv_sys->last_block = ut_align(recv_sys->last_block_buf_start,
					OS_FILE_LOG_BLOCK_SIZE);
	recv_sys->found_corrupt_log = FALSE;

	recv_max_page_lsn = 0;

	mutex_exit(&(recv_sys->mutex));
}

/********************************************************//**
Empties the hash table when it has been fully processed. */
static
void
recv_sys_empty_hash(void)
/*=====================*/
{
	ut_ad(mutex_own(&(recv_sys->mutex)));

	if (recv_sys->n_addrs != 0) {
		fprintf(stderr,
			"InnoDB: Error: %lu pages with log records"
			" were left unprocessed!\n"
			"InnoDB: Maximum page number with"
			" log records on it %lu\n",
			(ulong) recv_sys->n_addrs,
			(ulong) recv_max_parsed_page_no);
		ut_error;
	}

	hash_table_free(recv_sys->addr_hash);
	mem_heap_empty(recv_sys->heap);

	recv_sys->addr_hash = hash_create(buf_pool_get_curr_size() / 256);
}

#ifndef UNIV_HOTBACKUP
# ifndef UNIV_LOG_DEBUG
/********************************************************//**
Frees the recovery system. */
static
void
recv_sys_debug_free(void)
/*=====================*/
{
	mutex_enter(&(recv_sys->mutex));

	hash_table_free(recv_sys->addr_hash);
	mem_heap_free(recv_sys->heap);
	ut_free(recv_sys->buf);
	mem_free(recv_sys->last_block_buf_start);

	recv_sys->buf = NULL;
	recv_sys->heap = NULL;
	recv_sys->addr_hash = NULL;
	recv_sys->last_block_buf_start = NULL;

	mutex_exit(&(recv_sys->mutex));

	/* Free up the flush_rbt. */
	buf_flush_free_flush_rbt();
}
# endif /* UNIV_LOG_DEBUG */

/********************************************************//**
Truncates possible corrupted or extra records from a log group. */
static
void
recv_truncate_group(
/*================*/
	log_group_t*	group,		/*!< in: log group */
	ib_uint64_t	recovered_lsn,	/*!< in: recovery succeeded up to this
					lsn */
	ib_uint64_t	limit_lsn,	/*!< in: this was the limit for
					recovery */
	ib_uint64_t	checkpoint_lsn,	/*!< in: recovery was started from this
					checkpoint */
	ib_uint64_t	archived_lsn)	/*!< in: the log has been archived up to
					this lsn */
{
	ib_uint64_t	start_lsn;
	ib_uint64_t	end_lsn;
	ib_uint64_t	finish_lsn1;
	ib_uint64_t	finish_lsn2;
	ib_uint64_t	finish_lsn;
	ulint		len;
	ulint		i;

	if (archived_lsn == IB_ULONGLONG_MAX) {
		/* Checkpoint was taken in the NOARCHIVELOG mode */
		archived_lsn = checkpoint_lsn;
	}

	finish_lsn1 = ut_uint64_align_down(archived_lsn,
					   OS_FILE_LOG_BLOCK_SIZE)
		+ log_group_get_capacity(group);

	finish_lsn2 = ut_uint64_align_up(recovered_lsn,
					 OS_FILE_LOG_BLOCK_SIZE)
		+ recv_sys->last_log_buf_size;

	if (limit_lsn != IB_ULONGLONG_MAX) {
		/* We do not know how far we should erase log records: erase
		as much as possible */

		finish_lsn = finish_lsn1;
	} else {
		/* It is enough to erase the length of the log buffer */
		finish_lsn = finish_lsn1 < finish_lsn2
			? finish_lsn1 : finish_lsn2;
	}

	ut_a(RECV_SCAN_SIZE <= log_sys->buf_size);

	/* Write the log buffer full of zeros */
	for (i = 0; i < RECV_SCAN_SIZE; i++) {

		*(log_sys->buf + i) = '\0';
	}

	start_lsn = ut_uint64_align_down(recovered_lsn,
					 OS_FILE_LOG_BLOCK_SIZE);

	if (start_lsn != recovered_lsn) {
		/* Copy the last incomplete log block to the log buffer and
		edit its data length: */

		ut_memcpy(log_sys->buf, recv_sys->last_block,
			  OS_FILE_LOG_BLOCK_SIZE);
		log_block_set_data_len(log_sys->buf,
				       (ulint) (recovered_lsn - start_lsn));
	}

	if (start_lsn >= finish_lsn) {

		return;
	}

	for (;;) {
		end_lsn = start_lsn + RECV_SCAN_SIZE;

		if (end_lsn > finish_lsn) {

			end_lsn = finish_lsn;
		}

		len = (ulint) (end_lsn - start_lsn);

		log_group_write_buf(group, log_sys->buf, len, start_lsn, 0);
		if (end_lsn >= finish_lsn) {

			return;
		}

		/* Write the log buffer full of zeros */
		for (i = 0; i < RECV_SCAN_SIZE; i++) {

			*(log_sys->buf + i) = '\0';
		}

		start_lsn = end_lsn;
	}
}

/********************************************************//**
Copies the log segment between group->recovered_lsn and recovered_lsn from the
most up-to-date log group to group, so that it contains the latest log data. */
static
void
recv_copy_group(
/*============*/
	log_group_t*	up_to_date_group,	/*!< in: the most up-to-date log
						group */
	log_group_t*	group,			/*!< in: copy to this log
						group */
	ib_uint64_t	recovered_lsn)		/*!< in: recovery succeeded up
						to this lsn */
{
	ib_uint64_t	start_lsn;
	ib_uint64_t	end_lsn;
	ulint		len;

	if (group->scanned_lsn >= recovered_lsn) {

		return;
	}

	ut_a(RECV_SCAN_SIZE <= log_sys->buf_size);

	start_lsn = ut_uint64_align_down(group->scanned_lsn,
					 OS_FILE_LOG_BLOCK_SIZE);
	for (;;) {
		end_lsn = start_lsn + RECV_SCAN_SIZE;

		if (end_lsn > recovered_lsn) {
			end_lsn = ut_uint64_align_up(recovered_lsn,
						     OS_FILE_LOG_BLOCK_SIZE);
		}

		log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
				       up_to_date_group, start_lsn, end_lsn);

		len = (ulint) (end_lsn - start_lsn);

		log_group_write_buf(group, log_sys->buf, len, start_lsn, 0);

		if (end_lsn >= recovered_lsn) {

			return;
		}

		start_lsn = end_lsn;
	}
}

/********************************************************//**
Copies a log segment from the most up-to-date log group to the other log
groups, so that they all contain the latest log data. Also writes the info
about the latest checkpoint to the groups, and inits the fields in the group
memory structs to up-to-date values. */
static
void
recv_synchronize_groups(
/*====================*/
	log_group_t*	up_to_date_group)	/*!< in: the most up-to-date
						log group */
{
	log_group_t*	group;
	ib_uint64_t	start_lsn;
	ib_uint64_t	end_lsn;
	ib_uint64_t	recovered_lsn;
	ib_uint64_t	limit_lsn;

	recovered_lsn = recv_sys->recovered_lsn;
	limit_lsn = recv_sys->limit_lsn;

	/* Read the last recovered log block to the recovery system buffer:
	the block is always incomplete */

	start_lsn = ut_uint64_align_down(recovered_lsn,
					 OS_FILE_LOG_BLOCK_SIZE);
	end_lsn = ut_uint64_align_up(recovered_lsn, OS_FILE_LOG_BLOCK_SIZE);

	ut_a(start_lsn != end_lsn);

	log_group_read_log_seg(LOG_RECOVER, recv_sys->last_block,
			       up_to_date_group, start_lsn, end_lsn);

	group = UT_LIST_GET_FIRST(log_sys->log_groups);

	while (group) {
		if (group != up_to_date_group) {

			/* Copy log data if needed */

			recv_copy_group(group, up_to_date_group,
					recovered_lsn);
		}

		/* Update the fields in the group struct to correspond to
		recovered_lsn */

		log_group_set_fields(group, recovered_lsn);

		group = UT_LIST_GET_NEXT(log_groups, group);
	}

	/* Copy the checkpoint info to the groups; remember that we have
	incremented checkpoint_no by one, and the info will not be written
	over the max checkpoint info, thus making the preservation of max
	checkpoint info on disk certain */

	log_groups_write_checkpoint_info();

	mutex_exit(&(log_sys->mutex));

	/* Wait for the checkpoint write to complete */
	rw_lock_s_lock(&(log_sys->checkpoint_lock));
	rw_lock_s_unlock(&(log_sys->checkpoint_lock));

	mutex_enter(&(log_sys->mutex));
}
#endif /* !UNIV_HOTBACKUP */

/***********************************************************************//**
Checks the consistency of the checkpoint info
@return	TRUE if ok */
static
ibool
recv_check_cp_is_consistent(
/*========================*/
	const byte*	buf)	/*!< in: buffer containing checkpoint info */
{
	ulint	fold;

	fold = ut_fold_binary(buf, LOG_CHECKPOINT_CHECKSUM_1);

	if ((fold & 0xFFFFFFFFUL) != mach_read_from_4(
		    buf + LOG_CHECKPOINT_CHECKSUM_1)) {
		return(FALSE);
	}

	fold = ut_fold_binary(buf + LOG_CHECKPOINT_LSN,
			      LOG_CHECKPOINT_CHECKSUM_2 - LOG_CHECKPOINT_LSN);

	if ((fold & 0xFFFFFFFFUL) != mach_read_from_4(
		    buf + LOG_CHECKPOINT_CHECKSUM_2)) {
		return(FALSE);
	}

	return(TRUE);
}

#ifndef UNIV_HOTBACKUP
/********************************************************//**
Looks for the maximum consistent checkpoint from the log groups.
@return	error code or DB_SUCCESS */
static
ulint
recv_find_max_checkpoint(
/*=====================*/
	log_group_t**	max_group,	/*!< out: max group */
	ulint*		max_field)	/*!< out: LOG_CHECKPOINT_1 or
					LOG_CHECKPOINT_2 */
{
	log_group_t*	group;
	ib_uint64_t	max_no;
	ib_uint64_t	checkpoint_no;
	ulint		field;
	byte*		buf;

	group = UT_LIST_GET_FIRST(log_sys->log_groups);

	max_no = 0;
	*max_group = NULL;
	*max_field = 0;

	buf = log_sys->checkpoint_buf;

	while (group) {
		group->state = LOG_GROUP_CORRUPTED;

		for (field = LOG_CHECKPOINT_1; field <= LOG_CHECKPOINT_2;
		     field += LOG_CHECKPOINT_2 - LOG_CHECKPOINT_1) {

			log_group_read_checkpoint_info(group, field);

			if (!recv_check_cp_is_consistent(buf)) {
#ifdef UNIV_DEBUG
				if (log_debug_writes) {
					fprintf(stderr,
						"InnoDB: Checkpoint in group"
						" %lu at %lu invalid, %lu\n",
						(ulong) group->id,
						(ulong) field,
						(ulong) mach_read_from_4(
							buf
							+ LOG_CHECKPOINT_CHECKSUM_1));

				}
#endif /* UNIV_DEBUG */
				goto not_consistent;
			}

			group->state = LOG_GROUP_OK;

			group->lsn = mach_read_ull(
				buf + LOG_CHECKPOINT_LSN);
			group->lsn_offset = mach_read_from_4(
				buf + LOG_CHECKPOINT_OFFSET);
			checkpoint_no = mach_read_ull(
				buf + LOG_CHECKPOINT_NO);

#ifdef UNIV_DEBUG
			if (log_debug_writes) {
				fprintf(stderr,
					"InnoDB: Checkpoint number %lu"
					" found in group %lu\n",
					(ulong) checkpoint_no,
					(ulong) group->id);
			}
#endif /* UNIV_DEBUG */

			if (checkpoint_no >= max_no) {
				*max_group = group;
				*max_field = field;
				max_no = checkpoint_no;
			}

not_consistent:
			;
		}

		group = UT_LIST_GET_NEXT(log_groups, group);
	}

	if (*max_group == NULL) {

		fprintf(stderr,
			"InnoDB: No valid checkpoint found.\n"
			"InnoDB: If this error appears when you are"
			" creating an InnoDB database,\n"
			"InnoDB: the problem may be that during"
			" an earlier attempt you managed\n"
			"InnoDB: to create the InnoDB data files,"
			" but log file creation failed.\n"
			"InnoDB: If that is the case, please refer to\n"
			"InnoDB: " REFMAN "error-creating-innodb.html\n");
		return(DB_ERROR);
	}

	return(DB_SUCCESS);
}
#else /* !UNIV_HOTBACKUP */
/*******************************************************************//**
Reads the checkpoint info needed in hot backup.
@return	TRUE if success */
UNIV_INTERN
ibool
recv_read_cp_info_for_backup(
/*=========================*/
	const byte*	hdr,	/*!< in: buffer containing the log group
				header */
	ib_uint64_t*	lsn,	/*!< out: checkpoint lsn */
	ulint*		offset,	/*!< out: checkpoint offset in the log group */
	ulint*		fsp_limit,/*!< out: fsp limit of space 0,
				1000000000 if the database is running
				with < version 3.23.50 of InnoDB */
	ib_uint64_t*	cp_no,	/*!< out: checkpoint number */
	ib_uint64_t*	first_header_lsn)
				/*!< out: lsn of of the start of the
				first log file */
{
	ulint		max_cp		= 0;
	ib_uint64_t	max_cp_no	= 0;
	const byte*	cp_buf;

	cp_buf = hdr + LOG_CHECKPOINT_1;

	if (recv_check_cp_is_consistent(cp_buf)) {
		max_cp_no = mach_read_ull(cp_buf + LOG_CHECKPOINT_NO);
		max_cp = LOG_CHECKPOINT_1;
	}

	cp_buf = hdr + LOG_CHECKPOINT_2;

	if (recv_check_cp_is_consistent(cp_buf)) {
		if (mach_read_ull(cp_buf + LOG_CHECKPOINT_NO) > max_cp_no) {
			max_cp = LOG_CHECKPOINT_2;
		}
	}

	if (max_cp == 0) {
		return(FALSE);
	}

	cp_buf = hdr + max_cp;

	*lsn = mach_read_ull(cp_buf + LOG_CHECKPOINT_LSN);
	*offset = mach_read_from_4(cp_buf + LOG_CHECKPOINT_OFFSET);

	/* If the user is running a pre-3.23.50 version of InnoDB, its
	checkpoint data does not contain the fsp limit info */
	if (mach_read_from_4(cp_buf + LOG_CHECKPOINT_FSP_MAGIC_N)
	    == LOG_CHECKPOINT_FSP_MAGIC_N_VAL) {

		*fsp_limit = mach_read_from_4(
			cp_buf + LOG_CHECKPOINT_FSP_FREE_LIMIT);

		if (*fsp_limit == 0) {
			*fsp_limit = 1000000000;
		}
	} else {
		*fsp_limit = 1000000000;
	}

	/*	fprintf(stderr, "fsp limit %lu MB\n", *fsp_limit); */

	*cp_no = mach_read_ull(cp_buf + LOG_CHECKPOINT_NO);

	*first_header_lsn = mach_read_ull(hdr + LOG_FILE_START_LSN);

	return(TRUE);
}
#endif /* !UNIV_HOTBACKUP */

/******************************************************//**
Checks the 4-byte checksum to the trailer checksum field of a log
block.  We also accept a log block in the old format before
InnoDB-3.23.52 where the checksum field contains the log block number.
@return TRUE if ok, or if the log block may be in the format of InnoDB
version predating 3.23.52 */
static
ibool
log_block_checksum_is_ok_or_old_format(
/*===================================*/
	const byte*	block)	/*!< in: pointer to a log block */
{
#ifdef UNIV_LOG_DEBUG
	return(TRUE);
#endif /* UNIV_LOG_DEBUG */
	if (log_block_calc_checksum(block) == log_block_get_checksum(block)) {

		return(TRUE);
	}

	if (log_block_get_hdr_no(block) == log_block_get_checksum(block)) {

		/* We assume the log block is in the format of
		InnoDB version < 3.23.52 and the block is ok */
#if 0
		fprintf(stderr,
			"InnoDB: Scanned old format < InnoDB-3.23.52"
			" log block number %lu\n",
			log_block_get_hdr_no(block));
#endif
		return(TRUE);
	}

	return(FALSE);
}

#ifdef UNIV_HOTBACKUP
/*******************************************************************//**
Scans the log segment and n_bytes_scanned is set to the length of valid
log scanned. */
UNIV_INTERN
void
recv_scan_log_seg_for_backup(
/*=========================*/
	byte*		buf,		/*!< in: buffer containing log data */
	ulint		buf_len,	/*!< in: data length in that buffer */
	ib_uint64_t*	scanned_lsn,	/*!< in/out: lsn of buffer start,
					we return scanned lsn */
	ulint*		scanned_checkpoint_no,
					/*!< in/out: 4 lowest bytes of the
					highest scanned checkpoint number so
					far */
	ulint*		n_bytes_scanned)/*!< out: how much we were able to
					scan, smaller than buf_len if log
					data ended here */
{
	ulint	data_len;
	byte*	log_block;
	ulint	no;

	*n_bytes_scanned = 0;

	for (log_block = buf; log_block < buf + buf_len;
	     log_block += OS_FILE_LOG_BLOCK_SIZE) {

		no = log_block_get_hdr_no(log_block);

#if 0
		fprintf(stderr, "Log block header no %lu\n", no);
#endif

		if (no != log_block_convert_lsn_to_no(*scanned_lsn)
		    || !log_block_checksum_is_ok_or_old_format(log_block)) {
#if 0
			fprintf(stderr,
				"Log block n:o %lu, scanned lsn n:o %lu\n",
				no, log_block_convert_lsn_to_no(*scanned_lsn));
#endif
			/* Garbage or an incompletely written log block */

			log_block += OS_FILE_LOG_BLOCK_SIZE;
#if 0
			fprintf(stderr,
				"Next log block n:o %lu\n",
				log_block_get_hdr_no(log_block));
#endif
			break;
		}

		if (*scanned_checkpoint_no > 0
		    && log_block_get_checkpoint_no(log_block)
		    < *scanned_checkpoint_no
		    && *scanned_checkpoint_no
		    - log_block_get_checkpoint_no(log_block)
		    > 0x80000000UL) {

			/* Garbage from a log buffer flush which was made
			before the most recent database recovery */
#if 0
			fprintf(stderr,
				"Scanned cp n:o %lu, block cp n:o %lu\n",
				*scanned_checkpoint_no,
				log_block_get_checkpoint_no(log_block));
#endif
			break;
		}

		data_len = log_block_get_data_len(log_block);

		*scanned_checkpoint_no
			= log_block_get_checkpoint_no(log_block);
		*scanned_lsn += data_len;

		*n_bytes_scanned += data_len;

		if (data_len < OS_FILE_LOG_BLOCK_SIZE) {
			/* Log data ends here */

#if 0
			fprintf(stderr, "Log block data len %lu\n",
				data_len);
#endif
			break;
		}
	}
}
#endif /* UNIV_HOTBACKUP */

/*******************************************************************//**
Tries to parse a single log record body and also applies it to a page if
specified. File ops are parsed, but not applied in this function.
@return	log record end, NULL if not a complete record */
static
byte*
recv_parse_or_apply_log_rec_body(
/*=============================*/
	byte		type,	/*!< in: type */
	byte*		ptr,	/*!< in: pointer to a buffer */
	byte*		end_ptr,/*!< in: pointer to the buffer end */
	buf_block_t*	block,	/*!< in/out: buffer block or NULL; if
				not NULL, then the log record is
				applied to the page, and the log
				record should be complete then */
	mtr_t*		mtr)	/*!< in: mtr or NULL; should be non-NULL
				if and only if block is non-NULL */
{
	dict_index_t*	index	= NULL;
	page_t*		page;
	page_zip_des_t*	page_zip;
#ifdef UNIV_DEBUG
	ulint		page_type;
#endif /* UNIV_DEBUG */

	ut_ad(!block == !mtr);

	if (block) {
		page = block->frame;
		page_zip = buf_block_get_page_zip(block);
		ut_d(page_type = fil_page_get_type(page));
	} else {
		page = NULL;
		page_zip = NULL;
		ut_d(page_type = FIL_PAGE_TYPE_ALLOCATED);
	}

	switch (type) {
#ifdef UNIV_LOG_LSN_DEBUG
	case MLOG_LSN:
		/* The LSN is checked in recv_parse_log_rec(). */
		break;
#endif /* UNIV_LOG_LSN_DEBUG */
	case MLOG_1BYTE: case MLOG_2BYTES: case MLOG_4BYTES: case MLOG_8BYTES:
#ifdef UNIV_DEBUG
		if (page && page_type == FIL_PAGE_TYPE_ALLOCATED
		    && end_ptr >= ptr + 2) {
			/* It is OK to set FIL_PAGE_TYPE and certain
			list node fields on an empty page.  Any other
			write is not OK. */

			/* NOTE: There may be bogus assertion failures for
			dict_hdr_create(), trx_rseg_header_create(),
			trx_sys_create_doublewrite_buf(), and
			trx_sysf_create().
			These are only called during database creation. */
			ulint	offs = mach_read_from_2(ptr);

			switch (type) {
			default:
				ut_error;
			case MLOG_2BYTES:
				/* Note that this can fail when the
				redo log been written with something
				older than InnoDB Plugin 1.0.4. */
				ut_ad(offs == FIL_PAGE_TYPE
				      || offs == IBUF_TREE_SEG_HEADER
				      + IBUF_HEADER + FSEG_HDR_OFFSET
				      || offs == PAGE_BTR_IBUF_FREE_LIST
				      + PAGE_HEADER + FIL_ADDR_BYTE
				      || offs == PAGE_BTR_IBUF_FREE_LIST
				      + PAGE_HEADER + FIL_ADDR_BYTE
				      + FIL_ADDR_SIZE
				      || offs == PAGE_BTR_SEG_LEAF
				      + PAGE_HEADER + FSEG_HDR_OFFSET
				      || offs == PAGE_BTR_SEG_TOP
				      + PAGE_HEADER + FSEG_HDR_OFFSET
				      || offs == PAGE_BTR_IBUF_FREE_LIST_NODE
				      + PAGE_HEADER + FIL_ADDR_BYTE
				      + 0 /*FLST_PREV*/
				      || offs == PAGE_BTR_IBUF_FREE_LIST_NODE
				      + PAGE_HEADER + FIL_ADDR_BYTE
				      + FIL_ADDR_SIZE /*FLST_NEXT*/);
				break;
			case MLOG_4BYTES:
				/* Note that this can fail when the
				redo log been written with something
				older than InnoDB Plugin 1.0.4. */
				ut_ad(0
				      || offs == IBUF_TREE_SEG_HEADER
				      + IBUF_HEADER + FSEG_HDR_SPACE
				      || offs == IBUF_TREE_SEG_HEADER
				      + IBUF_HEADER + FSEG_HDR_PAGE_NO
				      || offs == PAGE_BTR_IBUF_FREE_LIST
				      + PAGE_HEADER/* flst_init */
				      || offs == PAGE_BTR_IBUF_FREE_LIST
				      + PAGE_HEADER + FIL_ADDR_PAGE
				      || offs == PAGE_BTR_IBUF_FREE_LIST
				      + PAGE_HEADER + FIL_ADDR_PAGE
				      + FIL_ADDR_SIZE
				      || offs == PAGE_BTR_SEG_LEAF
				      + PAGE_HEADER + FSEG_HDR_PAGE_NO
				      || offs == PAGE_BTR_SEG_LEAF
				      + PAGE_HEADER + FSEG_HDR_SPACE
				      || offs == PAGE_BTR_SEG_TOP
				      + PAGE_HEADER + FSEG_HDR_PAGE_NO
				      || offs == PAGE_BTR_SEG_TOP
				      + PAGE_HEADER + FSEG_HDR_SPACE
				      || offs == PAGE_BTR_IBUF_FREE_LIST_NODE
				      + PAGE_HEADER + FIL_ADDR_PAGE
				      + 0 /*FLST_PREV*/
				      || offs == PAGE_BTR_IBUF_FREE_LIST_NODE
				      + PAGE_HEADER + FIL_ADDR_PAGE
				      + FIL_ADDR_SIZE /*FLST_NEXT*/);
				break;
			}
		}
#endif /* UNIV_DEBUG */
		ptr = mlog_parse_nbytes(type, ptr, end_ptr, page, page_zip);
		break;
	case MLOG_REC_INSERT: case MLOG_COMP_REC_INSERT:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_REC_INSERT,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = page_cur_parse_insert_rec(FALSE, ptr, end_ptr,
							block, index, mtr);
		}
		break;
	case MLOG_REC_CLUST_DELETE_MARK: case MLOG_COMP_REC_CLUST_DELETE_MARK:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_REC_CLUST_DELETE_MARK,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = btr_cur_parse_del_mark_set_clust_rec(
				ptr, end_ptr, page, page_zip, index);
		}
		break;
	case MLOG_COMP_REC_SEC_DELETE_MARK:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		/* This log record type is obsolete, but we process it for
		backward compatibility with MySQL 5.0.3 and 5.0.4. */
		ut_a(!page || page_is_comp(page));
		ut_a(!page_zip);
		ptr = mlog_parse_index(ptr, end_ptr, TRUE, &index);
		if (!ptr) {
			break;
		}
		/* Fall through */
	case MLOG_REC_SEC_DELETE_MARK:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		ptr = btr_cur_parse_del_mark_set_sec_rec(ptr, end_ptr,
							 page, page_zip);
		break;
	case MLOG_REC_UPDATE_IN_PLACE: case MLOG_COMP_REC_UPDATE_IN_PLACE:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_REC_UPDATE_IN_PLACE,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = btr_cur_parse_update_in_place(ptr, end_ptr, page,
							    page_zip, index);
		}
		break;
	case MLOG_LIST_END_DELETE: case MLOG_COMP_LIST_END_DELETE:
	case MLOG_LIST_START_DELETE: case MLOG_COMP_LIST_START_DELETE:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_LIST_END_DELETE
				     || type == MLOG_COMP_LIST_START_DELETE,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = page_parse_delete_rec_list(type, ptr, end_ptr,
							 block, index, mtr);
		}
		break;
	case MLOG_LIST_END_COPY_CREATED: case MLOG_COMP_LIST_END_COPY_CREATED:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_LIST_END_COPY_CREATED,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = page_parse_copy_rec_list_to_created_page(
				ptr, end_ptr, block, index, mtr);
		}
		break;
	case MLOG_PAGE_REORGANIZE: case MLOG_COMP_PAGE_REORGANIZE:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_PAGE_REORGANIZE,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = btr_parse_page_reorganize(ptr, end_ptr, index,
							block, mtr);
		}
		break;
	case MLOG_PAGE_CREATE: case MLOG_COMP_PAGE_CREATE:
		/* Allow anything in page_type when creating a page. */
		ut_a(!page_zip);
		ptr = page_parse_create(ptr, end_ptr,
					type == MLOG_COMP_PAGE_CREATE,
					block, mtr);
		break;
	case MLOG_UNDO_INSERT:
		ut_ad(!page || page_type == FIL_PAGE_UNDO_LOG);
		ptr = trx_undo_parse_add_undo_rec(ptr, end_ptr, page);
		break;
	case MLOG_UNDO_ERASE_END:
		ut_ad(!page || page_type == FIL_PAGE_UNDO_LOG);
		ptr = trx_undo_parse_erase_page_end(ptr, end_ptr, page, mtr);
		break;
	case MLOG_UNDO_INIT:
		/* Allow anything in page_type when creating a page. */
		ptr = trx_undo_parse_page_init(ptr, end_ptr, page, mtr);
		break;
	case MLOG_UNDO_HDR_DISCARD:
		ut_ad(!page || page_type == FIL_PAGE_UNDO_LOG);
		ptr = trx_undo_parse_discard_latest(ptr, end_ptr, page, mtr);
		break;
	case MLOG_UNDO_HDR_CREATE:
	case MLOG_UNDO_HDR_REUSE:
		ut_ad(!page || page_type == FIL_PAGE_UNDO_LOG);
		ptr = trx_undo_parse_page_header(type, ptr, end_ptr,
						 page, mtr);
		break;
	case MLOG_REC_MIN_MARK: case MLOG_COMP_REC_MIN_MARK:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		/* On a compressed page, MLOG_COMP_REC_MIN_MARK
		will be followed by MLOG_COMP_REC_DELETE
		or MLOG_ZIP_WRITE_HEADER(FIL_PAGE_PREV, FIL_NULL)
		in the same mini-transaction. */
		ut_a(type == MLOG_COMP_REC_MIN_MARK || !page_zip);
		ptr = btr_parse_set_min_rec_mark(
			ptr, end_ptr, type == MLOG_COMP_REC_MIN_MARK,
			page, mtr);
		break;
	case MLOG_REC_DELETE: case MLOG_COMP_REC_DELETE:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);

		if (NULL != (ptr = mlog_parse_index(
				     ptr, end_ptr,
				     type == MLOG_COMP_REC_DELETE,
				     &index))) {
			ut_a(!page
			     || (ibool)!!page_is_comp(page)
			     == dict_table_is_comp(index->table));
			ptr = page_cur_parse_delete_rec(ptr, end_ptr,
							block, index, mtr);
		}
		break;
	case MLOG_IBUF_BITMAP_INIT:
		/* Allow anything in page_type when creating a page. */
		ptr = ibuf_parse_bitmap_init(ptr, end_ptr, block, mtr);
		break;
	case MLOG_INIT_FILE_PAGE:
		/* Allow anything in page_type when creating a page. */
		ptr = fsp_parse_init_file_page(ptr, end_ptr, block);
		break;
	case MLOG_WRITE_STRING:
		ut_ad(!page || page_type != FIL_PAGE_TYPE_ALLOCATED);
		ptr = mlog_parse_string(ptr, end_ptr, page, page_zip);
		break;
	case MLOG_FILE_CREATE:
	case MLOG_FILE_RENAME:
	case MLOG_FILE_DELETE:
	case MLOG_FILE_CREATE2:
		ptr = fil_op_log_parse_or_replay(ptr, end_ptr, type, 0, 0);
		break;
	case MLOG_ZIP_WRITE_NODE_PTR:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		ptr = page_zip_parse_write_node_ptr(ptr, end_ptr,
						    page, page_zip);
		break;
	case MLOG_ZIP_WRITE_BLOB_PTR:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		ptr = page_zip_parse_write_blob_ptr(ptr, end_ptr,
						    page, page_zip);
		break;
	case MLOG_ZIP_WRITE_HEADER:
		ut_ad(!page || page_type == FIL_PAGE_INDEX);
		ptr = page_zip_parse_write_header(ptr, end_ptr,
						  page, page_zip);
		break;
	case MLOG_ZIP_PAGE_COMPRESS:
		/* Allow anything in page_type when creating a page. */
		ptr = page_zip_parse_compress(ptr, end_ptr,
					      page, page_zip);
		break;
	default:
		ptr = NULL;
		recv_sys->found_corrupt_log = TRUE;
	}

	if (index) {
		dict_table_t*	table = index->table;

		dict_mem_index_free(index);
		dict_mem_table_free(table);
	}

	return(ptr);
}

/*********************************************************************//**
Calculates the fold value of a page file address: used in inserting or
searching for a log record in the hash table.
@return	folded value */
UNIV_INLINE
ulint
recv_fold(
/*======*/
	ulint	space,	/*!< in: space */
	ulint	page_no)/*!< in: page number */
{
	return(ut_fold_ulint_pair(space, page_no));
}

/*********************************************************************//**
Calculates the hash value of a page file address: used in inserting or
searching for a log record in the hash table.
@return	folded value */
UNIV_INLINE
ulint
recv_hash(
/*======*/
	ulint	space,	/*!< in: space */
	ulint	page_no)/*!< in: page number */
{
	return(hash_calc_hash(recv_fold(space, page_no), recv_sys->addr_hash));
}

/*********************************************************************//**
Gets the hashed file address struct for a page.
@return	file address struct, NULL if not found from the hash table */
static
recv_addr_t*
recv_get_fil_addr_struct(
/*=====================*/
	ulint	space,	/*!< in: space id */
	ulint	page_no)/*!< in: page number */
{
	recv_addr_t*	recv_addr;

	recv_addr = HASH_GET_FIRST(recv_sys->addr_hash,
				   recv_hash(space, page_no));
	while (recv_addr) {
		if ((recv_addr->space == space)
		    && (recv_addr->page_no == page_no)) {

			break;
		}

		recv_addr = HASH_GET_NEXT(addr_hash, recv_addr);
	}

	return(recv_addr);
}

/*******************************************************************//**
Adds a new log record to the hash table of log records. */
static
void
recv_add_to_hash_table(
/*===================*/
	byte		type,		/*!< in: log record type */
	ulint		space,		/*!< in: space id */
	ulint		page_no,	/*!< in: page number */
	byte*		body,		/*!< in: log record body */
	byte*		rec_end,	/*!< in: log record end */
	ib_uint64_t	start_lsn,	/*!< in: start lsn of the mtr */
	ib_uint64_t	end_lsn)	/*!< in: end lsn of the mtr */
{
	recv_t*		recv;
	ulint		len;
	recv_data_t*	recv_data;
	recv_data_t**	prev_field;
	recv_addr_t*	recv_addr;

	if (fil_tablespace_deleted_or_being_deleted_in_mem(space, -1)) {
		/* The tablespace does not exist any more: do not store the
		log record */

		return;
	}

	len = rec_end - body;

	recv = mem_heap_alloc(recv_sys->heap, sizeof(recv_t));
	recv->type = type;
	recv->len = rec_end - body;
	recv->start_lsn = start_lsn;
	recv->end_lsn = end_lsn;

	recv_addr = recv_get_fil_addr_struct(space, page_no);

	if (recv_addr == NULL) {
		recv_addr = mem_heap_alloc(recv_sys->heap,
					   sizeof(recv_addr_t));
		recv_addr->space = space;
		recv_addr->page_no = page_no;
		recv_addr->state = RECV_NOT_PROCESSED;

		UT_LIST_INIT(recv_addr->rec_list);

		HASH_INSERT(recv_addr_t, addr_hash, recv_sys->addr_hash,
			    recv_fold(space, page_no), recv_addr);
		recv_sys->n_addrs++;
#if 0
		fprintf(stderr, "Inserting log rec for space %lu, page %lu\n",
			space, page_no);
#endif
	}

	UT_LIST_ADD_LAST(rec_list, recv_addr->rec_list, recv);

	prev_field = &(recv->data);

	/* Store the log record body in chunks of less than UNIV_PAGE_SIZE:
	recv_sys->heap grows into the buffer pool, and bigger chunks could not
	be allocated */

	while (rec_end > body) {

		len = rec_end - body;

		if (len > RECV_DATA_BLOCK_SIZE) {
			len = RECV_DATA_BLOCK_SIZE;
		}

		recv_data = mem_heap_alloc(recv_sys->heap,
					   sizeof(recv_data_t) + len);
		*prev_field = recv_data;

		memcpy(recv_data + 1, body, len);

		prev_field = &(recv_data->next);

		body += len;
	}

	*prev_field = NULL;
}

/*********************************************************************//**
Copies the log record body from recv to buf. */
static
void
recv_data_copy_to_buf(
/*==================*/
	byte*	buf,	/*!< in: buffer of length at least recv->len */
	recv_t*	recv)	/*!< in: log record */
{
	recv_data_t*	recv_data;
	ulint		part_len;
	ulint		len;

	len = recv->len;
	recv_data = recv->data;

	while (len > 0) {
		if (len > RECV_DATA_BLOCK_SIZE) {
			part_len = RECV_DATA_BLOCK_SIZE;
		} else {
			part_len = len;
		}

		ut_memcpy(buf, ((byte*)recv_data) + sizeof(recv_data_t),
			  part_len);
		buf += part_len;
		len -= part_len;

		recv_data = recv_data->next;
	}
}

/************************************************************************//**
Applies the hashed log records to the page, if the page lsn is less than the
lsn of a log record. This can be called when a buffer page has just been
read in, or also for a page already in the buffer pool. */
UNIV_INTERN
void
recv_recover_page_func(
/*===================*/
#ifndef UNIV_HOTBACKUP
	ibool		just_read_in,
				/*!< in: TRUE if the i/o handler calls
				this for a freshly read page */
#endif /* !UNIV_HOTBACKUP */
	buf_block_t*	block)	/*!< in/out: buffer block */
{
	page_t*		page;
	page_zip_des_t*	page_zip;
	recv_addr_t*	recv_addr;
	recv_t*		recv;
	byte*		buf;
	ib_uint64_t	start_lsn;
	ib_uint64_t	end_lsn;
	ib_uint64_t	page_lsn;
	ib_uint64_t	page_newest_lsn;
	ibool		modification_to_page;
#ifndef UNIV_HOTBACKUP
	ibool		success;
#endif /* !UNIV_HOTBACKUP */
	mtr_t		mtr;

	mutex_enter(&(recv_sys->mutex));

	if (recv_sys->apply_log_recs == FALSE) {

		/* Log records should not be applied now */

		mutex_exit(&(recv_sys->mutex));

		return;
	}

	recv_addr = recv_get_fil_addr_struct(buf_block_get_space(block),
					     buf_block_get_page_no(block));

	if ((recv_addr == NULL)
	    || (recv_addr->state == RECV_BEING_PROCESSED)
	    || (recv_addr->state == RECV_PROCESSED)) {

		mutex_exit(&(recv_sys->mutex));

		return;
	}

#if 0
	fprintf(stderr, "Recovering space %lu, page %lu\n",
		buf_block_get_space(block), buf_block_get_page_no(block));
#endif

	recv_addr->state = RECV_BEING_PROCESSED;

	mutex_exit(&(recv_sys->mutex));

	mtr_start(&mtr);
	mtr_set_log_mode(&mtr, MTR_LOG_NONE);

	page = block->frame;
	page_zip = buf_block_get_page_zip(block);

#ifndef UNIV_HOTBACKUP
	if (just_read_in) {
		/* Move the ownership of the x-latch on the page to
		this OS thread, so that we can acquire a second
		x-latch on it.  This is needed for the operations to
		the page to pass the debug checks. */

		rw_lock_x_lock_move_ownership(&block->lock);
	}

	success = buf_page_get_known_nowait(RW_X_LATCH, block,
					    BUF_KEEP_OLD,
					    __FILE__, __LINE__,
					    &mtr);
	ut_a(success);

	buf_block_dbg_add_level(block, SYNC_NO_ORDER_CHECK);
#endif /* !UNIV_HOTBACKUP */

	/* Read the newest modification lsn from the page */
	page_lsn = mach_read_ull(page + FIL_PAGE_LSN);

#ifndef UNIV_HOTBACKUP
	/* It may be that the page has been modified in the buffer
	pool: read the newest modification lsn there */

	page_newest_lsn = buf_page_get_newest_modification(&block->page);

	if (page_newest_lsn) {

		page_lsn = page_newest_lsn;
	}
#else /* !UNIV_HOTBACKUP */
	/* In recovery from a backup we do not really use the buffer pool */
	page_newest_lsn = 0;
#endif /* !UNIV_HOTBACKUP */

	modification_to_page = FALSE;
	start_lsn = end_lsn = 0;

	recv = UT_LIST_GET_FIRST(recv_addr->rec_list);

	while (recv) {
		end_lsn = recv->end_lsn;

		if (recv->len > RECV_DATA_BLOCK_SIZE) {
			/* We have to copy the record body to a separate
			buffer */

			buf = mem_alloc(recv->len);

			recv_data_copy_to_buf(buf, recv);
		} else {
			buf = ((byte*)(recv->data)) + sizeof(recv_data_t);
		}

		if (recv->type == MLOG_INIT_FILE_PAGE) {
			page_lsn = page_newest_lsn;

			memset(FIL_PAGE_LSN + page, 0, 8);
			memset(UNIV_PAGE_SIZE - FIL_PAGE_END_LSN_OLD_CHKSUM
			       + page, 0, 8);

			if (page_zip) {
				memset(FIL_PAGE_LSN + page_zip->data, 0, 8);
			}
		}

		if (recv->start_lsn >= page_lsn) {

			ib_uint64_t	end_lsn;

			if (!modification_to_page) {

				modification_to_page = TRUE;
				start_lsn = recv->start_lsn;
			}

#ifdef UNIV_DEBUG
			if (log_debug_writes) {
				fprintf(stderr,
					"InnoDB: Applying log rec"
					" type %lu len %lu"
					" to space %lu page no %lu\n",
					(ulong) recv->type, (ulong) recv->len,
					(ulong) recv_addr->space,
					(ulong) recv_addr->page_no);
			}
#endif /* UNIV_DEBUG */

			recv_parse_or_apply_log_rec_body(recv->type, buf,
							 buf + recv->len,
							 block, &mtr);

			end_lsn = recv->start_lsn + recv->len;
			mach_write_ull(FIL_PAGE_LSN + page, end_lsn);
			mach_write_ull(UNIV_PAGE_SIZE
				       - FIL_PAGE_END_LSN_OLD_CHKSUM
				       + page, end_lsn);

			if (page_zip) {
				mach_write_ull(FIL_PAGE_LSN
					       + page_zip->data, end_lsn);
			}
		}

		if (recv->len > RECV_DATA_BLOCK_SIZE) {
			mem_free(buf);
		}

		recv = UT_LIST_GET_NEXT(rec_list, recv);
	}

#ifdef UNIV_ZIP_DEBUG
	if (fil_page_get_type(page) == FIL_PAGE_INDEX) {
		page_zip_des_t*	page_zip = buf_block_get_page_zip(block);

		if (page_zip) {
			ut_a(page_zip_validate_low(page_zip, page, FALSE));
		}
	}
#endif /* UNIV_ZIP_DEBUG */

	mutex_enter(&(recv_sys->mutex));

	if (recv_max_page_lsn < page_lsn) {
		recv_max_page_lsn = page_lsn;
	}

	recv_addr->state = RECV_PROCESSED;

	ut_a(recv_sys->n_addrs);
	recv_sys->n_addrs--;

	mutex_exit(&(recv_sys->mutex));

#ifndef UNIV_HOTBACKUP
	if (modification_to_page) {
		ut_a(block);

		buf_flush_recv_note_modification(block, start_lsn, end_lsn);
	}
#endif /* !UNIV_HOTBACKUP */

	/* Make sure that committing mtr does not change the modification
	lsn values of page */

	mtr.modifications = FALSE;

	mtr_commit(&mtr);
}

#ifndef UNIV_HOTBACKUP
/*******************************************************************//**
Reads in pages which have hashed log records, from an area around a given
page number.
@return	number of pages found */
static
ulint
recv_read_in_area(
/*==============*/
	ulint	space,	/*!< in: space */
	ulint	zip_size,/*!< in: compressed page size in bytes, or 0 */
	ulint	page_no)/*!< in: page number */
{
	recv_addr_t* recv_addr;
	ulint	page_nos[RECV_READ_AHEAD_AREA];
	ulint	low_limit;
	ulint	n;

	low_limit = page_no - (page_no % RECV_READ_AHEAD_AREA);

	n = 0;

	for (page_no = low_limit; page_no < low_limit + RECV_READ_AHEAD_AREA;
	     page_no++) {
		recv_addr = recv_get_fil_addr_struct(space, page_no);

		if (recv_addr && !buf_page_peek(space, page_no)) {

			mutex_enter(&(recv_sys->mutex));

			if (recv_addr->state == RECV_NOT_PROCESSED) {
				recv_addr->state = RECV_BEING_READ;

				page_nos[n] = page_no;

				n++;
			}

			mutex_exit(&(recv_sys->mutex));
		}
	}

	buf_read_recv_pages(FALSE, space, zip_size, page_nos, n);
	/*
	fprintf(stderr, "Recv pages at %lu n %lu\n", page_nos[0], n);
	*/
	return(n);
}

/*******************************************************************//**
Empties the hash table of stored log records, applying them to appropriate
pages. */
UNIV_INTERN
void
recv_apply_hashed_log_recs(
/*=======================*/
	ibool	allow_ibuf)	/*!< in: if TRUE, also ibuf operations are
				allowed during the application; if FALSE,
				no ibuf operations are allowed, and after
				the application all file pages are flushed to
				disk and invalidated in buffer pool: this
				alternative means that no new log records
				can be generated during the application;
				the caller must in this case own the log
				mutex */
{
	recv_addr_t* recv_addr;
	ulint	i;
	ulint	n_pages;
	ibool	has_printed	= FALSE;
	mtr_t	mtr;
loop:
	mutex_enter(&(recv_sys->mutex));

	if (recv_sys->apply_batch_on) {

		mutex_exit(&(recv_sys->mutex));

		os_thread_sleep(500000);

		goto loop;
	}

	ut_ad(!allow_ibuf == mutex_own(&log_sys->mutex));

	if (!allow_ibuf) {
		recv_no_ibuf_operations = TRUE;
	}

	recv_sys->apply_log_recs = TRUE;
	recv_sys->apply_batch_on = TRUE;

	for (i = 0; i < hash_get_n_cells(recv_sys->addr_hash); i++) {

		recv_addr = HASH_GET_FIRST(recv_sys->addr_hash, i);

		while (recv_addr) {
			ulint	space = recv_addr->space;
			ulint	zip_size = fil_space_get_zip_size(space);
			ulint	page_no = recv_addr->page_no;

			if (recv_addr->state == RECV_NOT_PROCESSED) {
				if (!has_printed) {
					ut_print_timestamp(stderr);
					fputs("  InnoDB: Starting an"
					      " apply batch of log records"
					      " to the database...\n"
					      "InnoDB: Progress in percents: ",
					      stderr);
					has_printed = TRUE;
				}

				mutex_exit(&(recv_sys->mutex));

				if (buf_page_peek(space, page_no)) {
					buf_block_t*	block;

					mtr_start(&mtr);

					block = buf_page_get(
						space, zip_size, page_no,
						RW_X_LATCH, &mtr);
					buf_block_dbg_add_level(
						block, SYNC_NO_ORDER_CHECK);

					recv_recover_page(FALSE, block);
					mtr_commit(&mtr);
				} else {
					recv_read_in_area(space, zip_size,
							  page_no);
				}

				mutex_enter(&(recv_sys->mutex));
			}

			recv_addr = HASH_GET_NEXT(addr_hash, recv_addr);
		}

		if (has_printed
		    && (i * 100) / hash_get_n_cells(recv_sys->addr_hash)
		    != ((i + 1) * 100)
		    / hash_get_n_cells(recv_sys->addr_hash)) {

			fprintf(stderr, "%lu ", (ulong)
				((i * 100)
				 / hash_get_n_cells(recv_sys->addr_hash)));
		}
	}

	/* Wait until all the pages have been processed */

	while (recv_sys->n_addrs != 0) {

		mutex_exit(&(recv_sys->mutex));

		os_thread_sleep(500000);

		mutex_enter(&(recv_sys->mutex));
	}

	if (has_printed) {

		fprintf(stderr, "\n");
	}

	if (!allow_ibuf) {
		/* Flush all the file pages to disk and invalidate them in
		the buffer pool */

		ut_d(recv_no_log_write = TRUE);
		mutex_exit(&(recv_sys->mutex));
		mutex_exit(&(log_sys->mutex));

		n_pages = buf_flush_batch(BUF_FLUSH_LIST, ULINT_MAX,
					  IB_ULONGLONG_MAX);
		ut_a(n_pages != ULINT_UNDEFINED);

		buf_flush_wait_batch_end(BUF_FLUSH_LIST);

		buf_pool_invalidate();

		mutex_enter(&(log_sys->mutex));
		mutex_enter(&(recv_sys->mutex));
		ut_d(recv_no_log_write = FALSE);

		recv_no_ibuf_operations = FALSE;
	}

	recv_sys->apply_log_recs = FALSE;
	recv_sys->apply_batch_on = FALSE;

	recv_sys_empty_hash();

	if (has_printed) {
		fprintf(stderr, "InnoDB: Apply batch completed\n");
	}

	mutex_exit(&(recv_sys->mutex));
}
#else /* !UNIV_HOTBACKUP */
/*******************************************************************//**
Applies log records in the hash table to a backup. */
UNIV_INTERN
void
recv_apply_log_recs_for_backup(void)
/*================================*/
{
	recv_addr_t*	recv_addr;
	ulint		n_hash_cells;
	buf_block_t*	block;
	ulint		actual_size;
	ibool		success;
	ulint		error;
	ulint		i;

	recv_sys->apply_log_recs = TRUE;
	recv_sys->apply_batch_on = TRUE;

	block = back_block1;

	fputs("InnoDB: Starting an apply batch of log records"
	      " to the database...\n"
	      "InnoDB: Progress in percents: ", stderr);

	n_hash_cells = hash_get_n_cells(recv_sys->addr_hash);

	for (i = 0; i < n_hash_cells; i++) {
		/* The address hash table is externally chained */
		recv_addr = hash_get_nth_cell(recv_sys->addr_hash, i)->node;

		while (recv_addr != NULL) {

			ulint	zip_size
				= fil_space_get_zip_size(recv_addr->space);

			if (zip_size == ULINT_UNDEFINED) {
#if 0
				fprintf(stderr,
					"InnoDB: Warning: cannot apply"
					" log record to"
					" tablespace %lu page %lu,\n"
					"InnoDB: because tablespace with"
					" that id does not exist.\n",
					recv_addr->space, recv_addr->page_no);
#endif
				recv_addr->state = RECV_PROCESSED;

				ut_a(recv_sys->n_addrs);
				recv_sys->n_addrs--;

				goto skip_this_recv_addr;
			}

			/* We simulate a page read made by the buffer pool, to
			make sure the recovery apparatus works ok. We must init
			the block. */

			buf_page_init_for_backup_restore(
				recv_addr->space, recv_addr->page_no,
				zip_size, block);

			/* Extend the tablespace's last file if the page_no
			does not fall inside its bounds; we assume the last
			file is auto-extending, and ibbackup copied the file
			when it still was smaller */

			success = fil_extend_space_to_desired_size(
				&actual_size,
				recv_addr->space, recv_addr->page_no + 1);
			if (!success) {
				fprintf(stderr,
					"InnoDB: Fatal error: cannot extend"
					" tablespace %lu to hold %lu pages\n",
					recv_addr->space, recv_addr->page_no);

				exit(1);
			}

			/* Read the page from the tablespace file using the
			fil0fil.c routines */

			if (zip_size) {
				error = fil_io(OS_FILE_READ, TRUE,
					       recv_addr->space, zip_size,
					       recv_addr->page_no, 0, zip_size,
					       block->page.zip.data, NULL);
				if (error == DB_SUCCESS
				    && !buf_zip_decompress(block, TRUE)) {
					exit(1);
				}
			} else {
				error = fil_io(OS_FILE_READ, TRUE,
					       recv_addr->space, 0,
					       recv_addr->page_no, 0,
					       UNIV_PAGE_SIZE,
					       block->frame, NULL);
			}

			if (error != DB_SUCCESS) {
				fprintf(stderr,
					"InnoDB: Fatal error: cannot read"
					" from tablespace"
					" %lu page number %lu\n",
					(ulong) recv_addr->space,
					(ulong) recv_addr->page_no);

				exit(1);
			}

			/* Apply the log records to this page */
			recv_recover_page(FALSE, block);

			/* Write the page back to the tablespace file using the
			fil0fil.c routines */

			buf_flush_init_for_writing(
				block->frame, buf_block_get_page_zip(block),
				mach_read_ull(block->frame + FIL_PAGE_LSN));

			if (zip_size) {
				error = fil_io(OS_FILE_WRITE, TRUE,
					       recv_addr->space, zip_size,
					       recv_addr->page_no, 0,
					       zip_size,
					       block->page.zip.data, NULL);
			} else {
				error = fil_io(OS_FILE_WRITE, TRUE,
					       recv_addr->space, 0,
					       recv_addr->page_no, 0,
					       UNIV_PAGE_SIZE,
					       block->frame, NULL);
			}
skip_this_recv_addr:
			recv_addr = HASH_GET_NEXT(addr_hash, recv_addr);
		}

		if ((100 * i) / n_hash_cells
		    != (100 * (i + 1)) / n_hash_cells) {
			fprintf(stderr, "%lu ",
				(ulong) ((100 * i) / n_hash_cells));
			fflush(stderr);
		}
	}

	recv_sys_empty_hash();
}
#endif /* !UNIV_HOTBACKUP */

/*******************************************************************//**
Tries to parse a single log record and returns its length.
@return	length of the record, or 0 if the record was not complete */
static
ulint
recv_parse_log_rec(
/*===============*/
	byte*	ptr,	/*!< in: pointer to a buffer */
	byte*	end_ptr,/*!< in: pointer to the buffer end */
	byte*	type,	/*!< out: type */
	ulint*	space,	/*!< out: space id */
	ulint*	page_no,/*!< out: page number */
	byte**	body)	/*!< out: log record body start */
{
	byte*	new_ptr;

	*body = NULL;

	if (ptr == end_ptr) {

		return(0);
	}

	if (*ptr == MLOG_MULTI_REC_END) {

		*type = *ptr;

		return(1);
	}

	if (*ptr == MLOG_DUMMY_RECORD) {
		*type = *ptr;

		*space = ULINT_UNDEFINED - 1; /* For debugging */

		return(1);
	}

	new_ptr = mlog_parse_initial_log_record(ptr, end_ptr, type, space,
						page_no);
	*body = new_ptr;

	if (UNIV_UNLIKELY(!new_ptr)) {

		return(0);
	}

#ifdef UNIV_LOG_LSN_DEBUG
	if (*type == MLOG_LSN) {
		ib_uint64_t	lsn = (ib_uint64_t) *space << 32 | *page_no;
# ifdef UNIV_LOG_DEBUG
		ut_a(lsn == log_sys->old_lsn);
# else /* UNIV_LOG_DEBUG */
		ut_a(lsn == recv_sys->recovered_lsn);
# endif /* UNIV_LOG_DEBUG */
	}
#endif /* UNIV_LOG_LSN_DEBUG */

	new_ptr = recv_parse_or_apply_log_rec_body(*type, new_ptr, end_ptr,
						   NULL, NULL);
	if (UNIV_UNLIKELY(new_ptr == NULL)) {

		return(0);
	}

	if (*page_no > recv_max_parsed_page_no) {
		recv_max_parsed_page_no = *page_no;
	}

	return(new_ptr - ptr);
}

/*******************************************************//**
Calculates the new value for lsn when more data is added to the log. */
static
ib_uint64_t
recv_calc_lsn_on_data_add(
/*======================*/
	ib_uint64_t	lsn,	/*!< in: old lsn */
	ib_uint64_t	len)	/*!< in: this many bytes of data is
				added, log block headers not included */
{
	ulint	frag_len;
	ulint	lsn_len;

	frag_len = (((ulint) lsn) % OS_FILE_LOG_BLOCK_SIZE)
		- LOG_BLOCK_HDR_SIZE;
	ut_ad(frag_len < OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_HDR_SIZE
	      - LOG_BLOCK_TRL_SIZE);
	lsn_len = (ulint) len;
	lsn_len += (lsn_len + frag_len)
		/ (OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_HDR_SIZE
		   - LOG_BLOCK_TRL_SIZE)
		* (LOG_BLOCK_HDR_SIZE + LOG_BLOCK_TRL_SIZE);

	return(lsn + lsn_len);
}

#ifdef UNIV_LOG_DEBUG
/*******************************************************//**
Checks that the parser recognizes incomplete initial segments of a log
record as incomplete. */
static
void
recv_check_incomplete_log_recs(
/*===========================*/
	byte*	ptr,	/*!< in: pointer to a complete log record */
	ulint	len)	/*!< in: length of the log record */
{
	ulint	i;
	byte	type;
	ulint	space;
	ulint	page_no;
	byte*	body;

	for (i = 0; i < len; i++) {
		ut_a(0 == recv_parse_log_rec(ptr, ptr + i, &type, &space,
					     &page_no, &body));
	}
}
#endif /* UNIV_LOG_DEBUG */

/*******************************************************//**
Prints diagnostic info of corrupt log. */
static
void
recv_report_corrupt_log(
/*====================*/
	byte*	ptr,	/*!< in: pointer to corrupt log record */
	byte	type,	/*!< in: type of the record */
	ulint	space,	/*!< in: space id, this may also be garbage */
	ulint	page_no)/*!< in: page number, this may also be garbage */
{
	fprintf(stderr,
		"InnoDB: ############### CORRUPT LOG RECORD FOUND\n"
		"InnoDB: Log record type %lu, space id %lu, page number %lu\n"
		"InnoDB: Log parsing proceeded successfully up to %llu\n"
		"InnoDB: Previous log record type %lu, is multi %lu\n"
		"InnoDB: Recv offset %lu, prev %lu\n",
		(ulong) type, (ulong) space, (ulong) page_no,
		recv_sys->recovered_lsn,
		(ulong) recv_previous_parsed_rec_type,
		(ulong) recv_previous_parsed_rec_is_multi,
		(ulong) (ptr - recv_sys->buf),
		(ulong) recv_previous_parsed_rec_offset);

	if ((ulint)(ptr - recv_sys->buf + 100)
	    > recv_previous_parsed_rec_offset
	    && (ulint)(ptr - recv_sys->buf + 100
		       - recv_previous_parsed_rec_offset)
	    < 200000) {
		fputs("InnoDB: Hex dump of corrupt log starting"
		      " 100 bytes before the start\n"
		      "InnoDB: of the previous log rec,\n"
		      "InnoDB: and ending 100 bytes after the start"
		      " of the corrupt rec:\n",
		      stderr);

		ut_print_buf(stderr,
			     recv_sys->buf
			     + recv_previous_parsed_rec_offset - 100,
			     ptr - recv_sys->buf + 200
			     - recv_previous_parsed_rec_offset);
		putc('\n', stderr);
	}

#ifndef UNIV_HOTBACKUP
	if (!srv_force_recovery) {
		fputs("InnoDB: Set innodb_force_recovery"
		      " to ignore this error.\n", stderr);
		ut_error;
	}
#endif /* !UNIV_HOTBACKUP */

	fputs("InnoDB: WARNING: the log file may have been corrupt and it\n"
	      "InnoDB: is possible that the log scan did not proceed\n"
	      "InnoDB: far enough in recovery! Please run CHECK TABLE\n"
	      "InnoDB: on your InnoDB tables to check that they are ok!\n"
	      "InnoDB: If mysqld crashes after this recovery, look at\n"
	      "InnoDB: " REFMAN "forcing-recovery.html\n"
	      "InnoDB: about forcing recovery.\n", stderr);

	fflush(stderr);
}

/*******************************************************//**
Parses log records from a buffer and stores them to a hash table to wait
merging to file pages.
@return	currently always returns FALSE */
static
ibool
recv_parse_log_recs(
/*================*/
	ibool	store_to_hash)	/*!< in: TRUE if the records should be stored
				to the hash table; this is set to FALSE if just
				debug checking is needed */
{
	byte*		ptr;
	byte*		end_ptr;
	ulint		single_rec;
	ulint		len;
	ulint		total_len;
	ib_uint64_t	new_recovered_lsn;
	ib_uint64_t	old_lsn;
	byte		type;
	ulint		space;
	ulint		page_no;
	byte*		body;
	ulint		n_recs;

	ut_ad(mutex_own(&(log_sys->mutex)));
	ut_ad(recv_sys->parse_start_lsn != 0);
loop:
	ptr = recv_sys->buf + recv_sys->recovered_offset;

	end_ptr = recv_sys->buf + recv_sys->len;

	if (ptr == end_ptr) {

		return(FALSE);
	}

	single_rec = (ulint)*ptr & MLOG_SINGLE_REC_FLAG;

	if (single_rec || *ptr == MLOG_DUMMY_RECORD) {
		/* The mtr only modified a single page, or this is a file op */

		old_lsn = recv_sys->recovered_lsn;

		/* Try to parse a log record, fetching its type, space id,
		page no, and a pointer to the body of the log record */

		len = recv_parse_log_rec(ptr, end_ptr, &type, &space,
					 &page_no, &body);

		if (len == 0 || recv_sys->found_corrupt_log) {
			if (recv_sys->found_corrupt_log) {

				recv_report_corrupt_log(ptr,
							type, space, page_no);
			}

			return(FALSE);
		}

		new_recovered_lsn = recv_calc_lsn_on_data_add(old_lsn, len);

		if (new_recovered_lsn > recv_sys->scanned_lsn) {
			/* The log record filled a log block, and we require
			that also the next log block should have been scanned
			in */

			return(FALSE);
		}

		recv_previous_parsed_rec_type = (ulint)type;
		recv_previous_parsed_rec_offset = recv_sys->recovered_offset;
		recv_previous_parsed_rec_is_multi = 0;

		recv_sys->recovered_offset += len;
		recv_sys->recovered_lsn = new_recovered_lsn;

#ifdef UNIV_DEBUG
		if (log_debug_writes) {
			fprintf(stderr,
				"InnoDB: Parsed a single log rec"
				" type %lu len %lu space %lu page no %lu\n",
				(ulong) type, (ulong) len, (ulong) space,
				(ulong) page_no);
		}
#endif /* UNIV_DEBUG */

		if (type == MLOG_DUMMY_RECORD) {
			/* Do nothing */

		} else if (!store_to_hash) {
			/* In debug checking, update a replicate page
			according to the log record, and check that it
			becomes identical with the original page */
#ifdef UNIV_LOG_DEBUG
			recv_check_incomplete_log_recs(ptr, len);
#endif/* UNIV_LOG_DEBUG */

		} else if (type == MLOG_FILE_CREATE
			   || type == MLOG_FILE_CREATE2
			   || type == MLOG_FILE_RENAME
			   || type == MLOG_FILE_DELETE) {
			ut_a(space);
#ifdef UNIV_HOTBACKUP
			if (recv_replay_file_ops) {

				/* In ibbackup --apply-log, replay an .ibd file
				operation, if possible; note that
				fil_path_to_mysql_datadir is set in ibbackup to
				point to the datadir we should use there */

				if (NULL == fil_op_log_parse_or_replay(
					    body, end_ptr, type,
					    space, page_no)) {
					fprintf(stderr,
						"InnoDB: Error: file op"
						" log record of type %lu"
						" space %lu not complete in\n"
						"InnoDB: the replay phase."
						" Path %s\n",
						(ulint)type, space,
						(char*)(body + 2));

					ut_error;
				}
			}
#endif
			/* In normal mysqld crash recovery we do not try to
			replay file operations */
#ifdef UNIV_LOG_LSN_DEBUG
		} else if (type == MLOG_LSN) {
			/* Do not add these records to the hash table.
			The page number and space id fields are misused
			for something else. */
#endif /* UNIV_LOG_LSN_DEBUG */
		} else {
			recv_add_to_hash_table(type, space, page_no, body,
					       ptr + len, old_lsn,
					       recv_sys->recovered_lsn);
		}
	} else {
		/* Check that all the records associated with the single mtr
		are included within the buffer */

		total_len = 0;
		n_recs = 0;

		for (;;) {
			len = recv_parse_log_rec(ptr, end_ptr, &type, &space,
						 &page_no, &body);
			if (len == 0 || recv_sys->found_corrupt_log) {

				if (recv_sys->found_corrupt_log) {

					recv_report_corrupt_log(
						ptr, type, space, page_no);
				}

				return(FALSE);
			}

			recv_previous_parsed_rec_type = (ulint)type;
			recv_previous_parsed_rec_offset
				= recv_sys->recovered_offset + total_len;
			recv_previous_parsed_rec_is_multi = 1;

#ifdef UNIV_LOG_DEBUG
			if ((!store_to_hash) && (type != MLOG_MULTI_REC_END)) {
				recv_check_incomplete_log_recs(ptr, len);
			}
#endif /* UNIV_LOG_DEBUG */

#ifdef UNIV_DEBUG
			if (log_debug_writes) {
				fprintf(stderr,
					"InnoDB: Parsed a multi log rec"
					" type %lu len %lu"
					" space %lu page no %lu\n",
					(ulong) type, (ulong) len,
					(ulong) space, (ulong) page_no);
			}
#endif /* UNIV_DEBUG */

			total_len += len;
			n_recs++;

			ptr += len;

			if (type == MLOG_MULTI_REC_END) {

				/* Found the end mark for the records */

				break;
			}
		}

		new_recovered_lsn = recv_calc_lsn_on_data_add(
			recv_sys->recovered_lsn, total_len);

		if (new_recovered_lsn > recv_sys->scanned_lsn) {
			/* The log record filled a log block, and we require
			that also the next log block should have been scanned
			in */

			return(FALSE);
		}

		/* Add all the records to the hash table */

		ptr = recv_sys->buf + recv_sys->recovered_offset;

		for (;;) {
			old_lsn = recv_sys->recovered_lsn;
			len = recv_parse_log_rec(ptr, end_ptr, &type, &space,
						 &page_no, &body);
			if (recv_sys->found_corrupt_log) {

				recv_report_corrupt_log(ptr,
							type, space, page_no);
			}

			ut_a(len != 0);
			ut_a(0 == ((ulint)*ptr & MLOG_SINGLE_REC_FLAG));

			recv_sys->recovered_offset += len;
			recv_sys->recovered_lsn
				= recv_calc_lsn_on_data_add(old_lsn, len);
			if (type == MLOG_MULTI_REC_END) {

				/* Found the end mark for the records */

				break;
			}

			if (store_to_hash
#ifdef UNIV_LOG_LSN_DEBUG
			    && type != MLOG_LSN
#endif /* UNIV_LOG_LSN_DEBUG */
			    ) {
				recv_add_to_hash_table(type, space, page_no,
						       body, ptr + len,
						       old_lsn,
						       new_recovered_lsn);
			}

			ptr += len;
		}
	}

	goto loop;
}

/*******************************************************//**
Adds data from a new log block to the parsing buffer of recv_sys if
recv_sys->parse_start_lsn is non-zero.
@return	TRUE if more data added */
static
ibool
recv_sys_add_to_parsing_buf(
/*========================*/
	const byte*	log_block,	/*!< in: log block */
	ib_uint64_t	scanned_lsn)	/*!< in: lsn of how far we were able
					to find data in this log block */
{
	ulint	more_len;
	ulint	data_len;
	ulint	start_offset;
	ulint	end_offset;

	ut_ad(scanned_lsn >= recv_sys->scanned_lsn);

	if (!recv_sys->parse_start_lsn) {
		/* Cannot start parsing yet because no start point for
		it found */

		return(FALSE);
	}

	data_len = log_block_get_data_len(log_block);

	if (recv_sys->parse_start_lsn >= scanned_lsn) {

		return(FALSE);

	} else if (recv_sys->scanned_lsn >= scanned_lsn) {

		return(FALSE);

	} else if (recv_sys->parse_start_lsn > recv_sys->scanned_lsn) {
		more_len = (ulint) (scanned_lsn - recv_sys->parse_start_lsn);
	} else {
		more_len = (ulint) (scanned_lsn - recv_sys->scanned_lsn);
	}

	if (more_len == 0) {

		return(FALSE);
	}

	ut_ad(data_len >= more_len);

	start_offset = data_len - more_len;

	if (start_offset < LOG_BLOCK_HDR_SIZE) {
		start_offset = LOG_BLOCK_HDR_SIZE;
	}

	end_offset = data_len;

	if (end_offset > OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE) {
		end_offset = OS_FILE_LOG_BLOCK_SIZE - LOG_BLOCK_TRL_SIZE;
	}

	ut_ad(start_offset <= end_offset);

	if (start_offset < end_offset) {
		ut_memcpy(recv_sys->buf + recv_sys->len,
			  log_block + start_offset, end_offset - start_offset);

		recv_sys->len += end_offset - start_offset;

		ut_a(recv_sys->len <= RECV_PARSING_BUF_SIZE);
	}

	return(TRUE);
}

/*******************************************************//**
Moves the parsing buffer data left to the buffer start. */
static
void
recv_sys_justify_left_parsing_buf(void)
/*===================================*/
{
	ut_memmove(recv_sys->buf, recv_sys->buf + recv_sys->recovered_offset,
		   recv_sys->len - recv_sys->recovered_offset);

	recv_sys->len -= recv_sys->recovered_offset;

	recv_sys->recovered_offset = 0;
}

/*******************************************************//**
Scans log from a buffer and stores new log data to the parsing buffer.
Parses and hashes the log records if new data found.  Unless
UNIV_HOTBACKUP is defined, this function will apply log records
automatically when the hash table becomes full.
@return TRUE if limit_lsn has been reached, or not able to scan any
more in this log group */
UNIV_INTERN
ibool
recv_scan_log_recs(
/*===============*/
	ulint		available_memory,/*!< in: we let the hash table of recs
					to grow to this size, at the maximum */
	ibool		store_to_hash,	/*!< in: TRUE if the records should be
					stored to the hash table; this is set
					to FALSE if just debug checking is
					needed */
	const byte*	buf,		/*!< in: buffer containing a log
					segment or garbage */
	ulint		len,		/*!< in: buffer length */
	ib_uint64_t	start_lsn,	/*!< in: buffer start lsn */
	ib_uint64_t*	contiguous_lsn,	/*!< in/out: it is known that all log
					groups contain contiguous log data up
					to this lsn */
	ib_uint64_t*	group_scanned_lsn)/*!< out: scanning succeeded up to
					this lsn */
{
	const byte*	log_block;
	ulint		no;
	ib_uint64_t	scanned_lsn;
	ibool		finished;
	ulint		data_len;
	ibool		more_data;

	ut_ad(start_lsn % OS_FILE_LOG_BLOCK_SIZE == 0);
	ut_ad(len % OS_FILE_LOG_BLOCK_SIZE == 0);
	ut_ad(len >= OS_FILE_LOG_BLOCK_SIZE);
	ut_a(store_to_hash <= TRUE);

	finished = FALSE;

	log_block = buf;
	scanned_lsn = start_lsn;
	more_data = FALSE;

	do {
		no = log_block_get_hdr_no(log_block);
		/*
		fprintf(stderr, "Log block header no %lu\n", no);

		fprintf(stderr, "Scanned lsn no %lu\n",
		log_block_convert_lsn_to_no(scanned_lsn));
		*/
		if (no != log_block_convert_lsn_to_no(scanned_lsn)
		    || !log_block_checksum_is_ok_or_old_format(log_block)) {

			if (no == log_block_convert_lsn_to_no(scanned_lsn)
			    && !log_block_checksum_is_ok_or_old_format(
				    log_block)) {
				fprintf(stderr,
					"InnoDB: Log block no %lu at"
					" lsn %llu has\n"
					"InnoDB: ok header, but checksum field"
					" contains %lu, should be %lu\n",
					(ulong) no,
					scanned_lsn,
					(ulong) log_block_get_checksum(
						log_block),
					(ulong) log_block_calc_checksum(
						log_block));
			}

			/* Garbage or an incompletely written log block */

			finished = TRUE;

			break;
		}

		if (log_block_get_flush_bit(log_block)) {
			/* This block was a start of a log flush operation:
			we know that the previous flush operation must have
			been completed for all log groups before this block
			can have been flushed to any of the groups. Therefore,
			we know that log data is contiguous up to scanned_lsn
			in all non-corrupt log groups. */

			if (scanned_lsn > *contiguous_lsn) {
				*contiguous_lsn = scanned_lsn;
			}
		}

		data_len = log_block_get_data_len(log_block);

		if ((store_to_hash || (data_len == OS_FILE_LOG_BLOCK_SIZE))
		    && scanned_lsn + data_len > recv_sys->scanned_lsn
		    && (recv_sys->scanned_checkpoint_no > 0)
		    && (log_block_get_checkpoint_no(log_block)
			< recv_sys->scanned_checkpoint_no)
		    && (recv_sys->scanned_checkpoint_no
			- log_block_get_checkpoint_no(log_block)
			> 0x80000000UL)) {

			/* Garbage from a log buffer flush which was made
			before the most recent database recovery */

			finished = TRUE;
#ifdef UNIV_LOG_DEBUG
			/* This is not really an error, but currently
			we stop here in the debug version: */

			ut_error;
#endif
			break;
		}

		if (!recv_sys->parse_start_lsn
		    && (log_block_get_first_rec_group(log_block) > 0)) {

			/* We found a point from which to start the parsing
			of log records */

			recv_sys->parse_start_lsn = scanned_lsn
				+ log_block_get_first_rec_group(log_block);
			recv_sys->scanned_lsn = recv_sys->parse_start_lsn;
			recv_sys->recovered_lsn = recv_sys->parse_start_lsn;
		}

		scanned_lsn += data_len;

		if (scanned_lsn > recv_sys->scanned_lsn) {

			/* We have found more entries. If this scan is
 			of startup type, we must initiate crash recovery
			environment before parsing these log records. */

#ifndef UNIV_HOTBACKUP
			if (recv_log_scan_is_startup_type
			    && !recv_needed_recovery) {

				fprintf(stderr,
					"InnoDB: Log scan progressed"
					" past the checkpoint lsn %llu\n",
					recv_sys->scanned_lsn);
				recv_init_crash_recovery();
			}
#endif /* !UNIV_HOTBACKUP */

			/* We were able to find more log data: add it to the
			parsing buffer if parse_start_lsn is already
			non-zero */

			if (recv_sys->len + 4 * OS_FILE_LOG_BLOCK_SIZE
			    >= RECV_PARSING_BUF_SIZE) {
				fprintf(stderr,
					"InnoDB: Error: log parsing"
					" buffer overflow."
					" Recovery may have failed!\n");

				recv_sys->found_corrupt_log = TRUE;

#ifndef UNIV_HOTBACKUP
				if (!srv_force_recovery) {
					fputs("InnoDB: Set"
					      " innodb_force_recovery"
					      " to ignore this error.\n",
					      stderr);
					ut_error;
				}
#endif /* !UNIV_HOTBACKUP */

			} else if (!recv_sys->found_corrupt_log) {
				more_data = recv_sys_add_to_parsing_buf(
					log_block, scanned_lsn);
			}

			recv_sys->scanned_lsn = scanned_lsn;
			recv_sys->scanned_checkpoint_no
				= log_block_get_checkpoint_no(log_block);
		}

		if (data_len < OS_FILE_LOG_BLOCK_SIZE) {
			/* Log data for this group ends here */

			finished = TRUE;
			break;
		} else {
			log_block += OS_FILE_LOG_BLOCK_SIZE;
		}
	} while (log_block < buf + len && !finished);

	*group_scanned_lsn = scanned_lsn;

	if (recv_needed_recovery
	    || (recv_is_from_backup && !recv_is_making_a_backup)) {
		recv_scan_print_counter++;

		if (finished || (recv_scan_print_counter % 80 == 0)) {

			fprintf(stderr,
				"InnoDB: Doing recovery: scanned up to"
				" log sequence number %llu\n",
				*group_scanned_lsn);
		}
	}

	if (more_data && !recv_sys->found_corrupt_log) {
		/* Try to parse more log records */

		recv_parse_log_recs(store_to_hash);

#ifndef UNIV_HOTBACKUP
		if (store_to_hash && mem_heap_get_size(recv_sys->heap)
		    > available_memory) {

			/* Hash table of log records has grown too big:
			empty it; FALSE means no ibuf operations
			allowed, as we cannot add new records to the
			log yet: they would be produced by ibuf
			operations */

			recv_apply_hashed_log_recs(FALSE);
		}
#endif /* !UNIV_HOTBACKUP */

		if (recv_sys->recovered_offset > RECV_PARSING_BUF_SIZE / 4) {
			/* Move parsing buffer data to the buffer start */

			recv_sys_justify_left_parsing_buf();
		}
	}

	return(finished);
}

#ifndef UNIV_HOTBACKUP
/*******************************************************//**
Scans log from a buffer and stores new log data to the parsing buffer. Parses
and hashes the log records if new data found. */
static
void
recv_group_scan_log_recs(
/*=====================*/
	log_group_t*	group,		/*!< in: log group */
	ib_uint64_t*	contiguous_lsn,	/*!< in/out: it is known that all log
					groups contain contiguous log data up
					to this lsn */
	ib_uint64_t*	group_scanned_lsn)/*!< out: scanning succeeded up to
					this lsn */
{
	ibool		finished;
	ib_uint64_t	start_lsn;
	ib_uint64_t	end_lsn;

	finished = FALSE;

	start_lsn = *contiguous_lsn;

	while (!finished) {
		end_lsn = start_lsn + RECV_SCAN_SIZE;

		log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
				       group, start_lsn, end_lsn);

		finished = recv_scan_log_recs(
			(buf_pool->curr_size - recv_n_pool_free_frames)
			* UNIV_PAGE_SIZE, TRUE, log_sys->buf, RECV_SCAN_SIZE,
			start_lsn, contiguous_lsn, group_scanned_lsn);
		start_lsn = end_lsn;
	}

#ifdef UNIV_DEBUG
	if (log_debug_writes) {
		fprintf(stderr,
			"InnoDB: Scanned group %lu up to"
			" log sequence number %llu\n",
			(ulong) group->id,
			*group_scanned_lsn);
	}
#endif /* UNIV_DEBUG */
}

/*******************************************************//**
Initialize crash recovery environment. Can be called iff
recv_needed_recovery == FALSE. */
static
void
recv_init_crash_recovery(void)
/*==========================*/
{
	ut_a(!recv_needed_recovery);

	recv_needed_recovery = TRUE;

	ut_print_timestamp(stderr);

	fprintf(stderr,
		"  InnoDB: Database was not"
		" shut down normally!\n"
		"InnoDB: Starting crash recovery.\n");

	fprintf(stderr,
		"InnoDB: Reading tablespace information"
		" from the .ibd files...\n");

	fil_load_single_table_tablespaces();

	/* If we are using the doublewrite method, we will
	check if there are half-written pages in data files,
	and restore them from the doublewrite buffer if
	possible */

	if (srv_force_recovery < SRV_FORCE_NO_LOG_REDO) {

		fprintf(stderr,
			"InnoDB: Restoring possible"
			" half-written data pages from"
			" the doublewrite\n"
			"InnoDB: buffer...\n");
		trx_sys_doublewrite_init_or_restore_pages(TRUE);
	}
}

/********************************************************//**
Recovers from a checkpoint. When this function returns, the database is able
to start processing of new user transactions, but the function
recv_recovery_from_checkpoint_finish should be called later to complete
the recovery and free the resources used in it.
@return	error code or DB_SUCCESS */
UNIV_INTERN
ulint
recv_recovery_from_checkpoint_start_func(
/*=====================================*/
#ifdef UNIV_LOG_ARCHIVE
	ulint		type,		/*!< in: LOG_CHECKPOINT or
					LOG_ARCHIVE */
	ib_uint64_t	limit_lsn,	/*!< in: recover up to this lsn
					if possible */
#endif /* UNIV_LOG_ARCHIVE */
	ib_uint64_t	min_flushed_lsn,/*!< in: min flushed lsn from
					data files */
	ib_uint64_t	max_flushed_lsn)/*!< in: max flushed lsn from
					data files */
{
	log_group_t*	group;
	log_group_t*	max_cp_group;
	log_group_t*	up_to_date_group;
	ulint		max_cp_field;
	ib_uint64_t	checkpoint_lsn;
	ib_uint64_t	checkpoint_no;
	ib_uint64_t	old_scanned_lsn;
	ib_uint64_t	group_scanned_lsn;
	ib_uint64_t	contiguous_lsn;
	ib_uint64_t	archived_lsn;
	byte*		buf;
	byte		log_hdr_buf[LOG_FILE_HDR_SIZE];
	ulint		err;

#ifdef UNIV_LOG_ARCHIVE
	ut_ad(type != LOG_CHECKPOINT || limit_lsn == IB_ULONGLONG_MAX);
/** TRUE when recovering from a checkpoint */
# define TYPE_CHECKPOINT	(type == LOG_CHECKPOINT)
/** Recover up to this log sequence number */
# define LIMIT_LSN		limit_lsn
#else /* UNIV_LOG_ARCHIVE */
/** TRUE when recovering from a checkpoint */
# define TYPE_CHECKPOINT	1
/** Recover up to this log sequence number */
# define LIMIT_LSN		IB_ULONGLONG_MAX
#endif /* UNIV_LOG_ARCHIVE */

	if (TYPE_CHECKPOINT) {
		recv_sys_create();
		recv_sys_init(buf_pool_get_curr_size());
	}

	if (srv_force_recovery >= SRV_FORCE_NO_LOG_REDO) {
		fprintf(stderr,
			"InnoDB: The user has set SRV_FORCE_NO_LOG_REDO on\n");
		fprintf(stderr,
			"InnoDB: Skipping log redo\n");

		return(DB_SUCCESS);
	}

	recv_recovery_on = TRUE;

	recv_sys->limit_lsn = LIMIT_LSN;

	mutex_enter(&(log_sys->mutex));

	/* Look for the latest checkpoint from any of the log groups */

	err = recv_find_max_checkpoint(&max_cp_group, &max_cp_field);

	if (err != DB_SUCCESS) {

		mutex_exit(&(log_sys->mutex));

		return(err);
	}

	log_group_read_checkpoint_info(max_cp_group, max_cp_field);

	buf = log_sys->checkpoint_buf;

	checkpoint_lsn = mach_read_ull(buf + LOG_CHECKPOINT_LSN);
	checkpoint_no = mach_read_ull(buf + LOG_CHECKPOINT_NO);
	archived_lsn = mach_read_ull(buf + LOG_CHECKPOINT_ARCHIVED_LSN);

	/* Read the first log file header to print a note if this is
	a recovery from a restored InnoDB Hot Backup */

	fil_io(OS_FILE_READ | OS_FILE_LOG, TRUE, max_cp_group->space_id, 0,
	       0, 0, LOG_FILE_HDR_SIZE,
	       log_hdr_buf, max_cp_group);

	if (0 == ut_memcmp(log_hdr_buf + LOG_FILE_WAS_CREATED_BY_HOT_BACKUP,
			   (byte*)"ibbackup", (sizeof "ibbackup") - 1)) {
		/* This log file was created by ibbackup --restore: print
		a note to the user about it */

		fprintf(stderr,
			"InnoDB: The log file was created by"
			" ibbackup --apply-log at\n"
			"InnoDB: %s\n",
			log_hdr_buf + LOG_FILE_WAS_CREATED_BY_HOT_BACKUP);
		fprintf(stderr,
			"InnoDB: NOTE: the following crash recovery"
			" is part of a normal restore.\n");

		/* Wipe over the label now */

		memset(log_hdr_buf + LOG_FILE_WAS_CREATED_BY_HOT_BACKUP,
		       ' ', 4);
		/* Write to the log file to wipe over the label */
		fil_io(OS_FILE_WRITE | OS_FILE_LOG, TRUE,
		       max_cp_group->space_id, 0,
		       0, 0, OS_FILE_LOG_BLOCK_SIZE,
		       log_hdr_buf, max_cp_group);
	}

#ifdef UNIV_LOG_ARCHIVE
	group = UT_LIST_GET_FIRST(log_sys->log_groups);

	while (group) {
		log_checkpoint_get_nth_group_info(buf, group->id,
						  &(group->archived_file_no),
						  &(group->archived_offset));

		group = UT_LIST_GET_NEXT(log_groups, group);
	}
#endif /* UNIV_LOG_ARCHIVE */

	if (TYPE_CHECKPOINT) {
		/* Start reading the log groups from the checkpoint lsn up. The
		variable contiguous_lsn contains an lsn up to which the log is
		known to be contiguously written to all log groups. */

		recv_sys->parse_start_lsn = checkpoint_lsn;
		recv_sys->scanned_lsn = checkpoint_lsn;
		recv_sys->scanned_checkpoint_no = 0;
		recv_sys->recovered_lsn = checkpoint_lsn;

		srv_start_lsn = checkpoint_lsn;
	}

	contiguous_lsn = ut_uint64_align_down(recv_sys->scanned_lsn,
					      OS_FILE_LOG_BLOCK_SIZE);
	if (TYPE_CHECKPOINT) {
		up_to_date_group = max_cp_group;
#ifdef UNIV_LOG_ARCHIVE
	} else {
		ulint	capacity;

		/* Try to recover the remaining part from logs: first from
		the logs of the archived group */

		group = recv_sys->archive_group;
		capacity = log_group_get_capacity(group);

		if (recv_sys->scanned_lsn > checkpoint_lsn + capacity
		    || checkpoint_lsn > recv_sys->scanned_lsn + capacity) {

			mutex_exit(&(log_sys->mutex));

			/* The group does not contain enough log: probably
			an archived log file was missing or corrupt */

			return(DB_ERROR);
		}

		recv_group_scan_log_recs(group, &contiguous_lsn,
					 &group_scanned_lsn);
		if (recv_sys->scanned_lsn < checkpoint_lsn) {

			mutex_exit(&(log_sys->mutex));

			/* The group did not contain enough log: an archived
			log file was missing or invalid, or the log group
			was corrupt */

			return(DB_ERROR);
		}

		group->scanned_lsn = group_scanned_lsn;
		up_to_date_group = group;
#endif /* UNIV_LOG_ARCHIVE */
	}

	ut_ad(RECV_SCAN_SIZE <= log_sys->buf_size);

	group = UT_LIST_GET_FIRST(log_sys->log_groups);

#ifdef UNIV_LOG_ARCHIVE
	if ((type == LOG_ARCHIVE) && (group == recv_sys->archive_group)) {
		group = UT_LIST_GET_NEXT(log_groups, group);
	}
#endif /* UNIV_LOG_ARCHIVE */

	/* Set the flag to publish that we are doing startup scan. */
	recv_log_scan_is_startup_type = TYPE_CHECKPOINT;
	while (group) {
		old_scanned_lsn = recv_sys->scanned_lsn;

		recv_group_scan_log_recs(group, &contiguous_lsn,
					 &group_scanned_lsn);
		group->scanned_lsn = group_scanned_lsn;

		if (old_scanned_lsn < group_scanned_lsn) {
			/* We found a more up-to-date group */

			up_to_date_group = group;
		}

#ifdef UNIV_LOG_ARCHIVE
		if ((type == LOG_ARCHIVE)
		    && (group == recv_sys->archive_group)) {
			group = UT_LIST_GET_NEXT(log_groups, group);
		}
#endif /* UNIV_LOG_ARCHIVE */

		group = UT_LIST_GET_NEXT(log_groups, group);
	}

	/* Done with startup scan. Clear the flag. */
	recv_log_scan_is_startup_type = FALSE;
	if (TYPE_CHECKPOINT) {
		/* NOTE: we always do a 'recovery' at startup, but only if
		there is something wrong we will print a message to the
		user about recovery: */

		if (checkpoint_lsn != max_flushed_lsn
		    || checkpoint_lsn != min_flushed_lsn) {

			if (checkpoint_lsn < max_flushed_lsn) {
				fprintf(stderr,
					"InnoDB: #########################"
					"#################################\n"
					"InnoDB:                          "
					"WARNING!\n"
					"InnoDB: The log sequence number"
					" in ibdata files is higher\n"
					"InnoDB: than the log sequence number"
					" in the ib_logfiles! Are you sure\n"
					"InnoDB: you are using the right"
					" ib_logfiles to start up"
					" the database?\n"
					"InnoDB: Log sequence number in"
					" ib_logfiles is %llu, log\n"
					"InnoDB: sequence numbers stamped"
					" to ibdata file headers are between\n"
					"InnoDB: %llu and %llu.\n"
					"InnoDB: #########################"
					"#################################\n",
					checkpoint_lsn,
					min_flushed_lsn,
					max_flushed_lsn);
			}

			if (!recv_needed_recovery) {
				fprintf(stderr,
					"InnoDB: The log sequence number"
					" in ibdata files does not match\n"
					"InnoDB: the log sequence number"
					" in the ib_logfiles!\n");
				recv_init_crash_recovery();
			}
		}

		if (!recv_needed_recovery) {
			/* Init the doublewrite buffer memory structure */
			trx_sys_doublewrite_init_or_restore_pages(FALSE);
		}
	}

	/* We currently have only one log group */
	if (group_scanned_lsn < checkpoint_lsn) {
		ut_print_timestamp(stderr);
		fprintf(stderr,
			"  InnoDB: ERROR: We were only able to scan the log"
			" up to\n"
			"InnoDB: %llu, but a checkpoint was at %llu.\n"
			"InnoDB: It is possible that"
			" the database is now corrupt!\n",
			group_scanned_lsn,
			checkpoint_lsn);
	}

	if (group_scanned_lsn < recv_max_page_lsn) {
		ut_print_timestamp(stderr);
		fprintf(stderr,
			"  InnoDB: ERROR: We were only able to scan the log"
			" up to %llu\n"
			"InnoDB: but a database page a had an lsn %llu."
			" It is possible that the\n"
			"InnoDB: database is now corrupt!\n",
			group_scanned_lsn,
			recv_max_page_lsn);
	}

	if (recv_sys->recovered_lsn < checkpoint_lsn) {

		mutex_exit(&(log_sys->mutex));

		if (recv_sys->recovered_lsn >= LIMIT_LSN) {

			return(DB_SUCCESS);
		}

		ut_error;

		return(DB_ERROR);
	}

	/* Synchronize the uncorrupted log groups to the most up-to-date log
	group; we also copy checkpoint info to groups */

	log_sys->next_checkpoint_lsn = checkpoint_lsn;
	log_sys->next_checkpoint_no = checkpoint_no + 1;

#ifdef UNIV_LOG_ARCHIVE
	log_sys->archived_lsn = archived_lsn;
#endif /* UNIV_LOG_ARCHIVE */

	recv_synchronize_groups(up_to_date_group);

	if (!recv_needed_recovery) {
		ut_a(checkpoint_lsn == recv_sys->recovered_lsn);
	} else {
		srv_start_lsn = recv_sys->recovered_lsn;
	}

	log_sys->lsn = recv_sys->recovered_lsn;

	ut_memcpy(log_sys->buf, recv_sys->last_block, OS_FILE_LOG_BLOCK_SIZE);

	log_sys->buf_free = (ulint) log_sys->lsn % OS_FILE_LOG_BLOCK_SIZE;
	log_sys->buf_next_to_write = log_sys->buf_free;
	log_sys->written_to_some_lsn = log_sys->lsn;
	log_sys->written_to_all_lsn = log_sys->lsn;

	log_sys->last_checkpoint_lsn = checkpoint_lsn;

	log_sys->next_checkpoint_no = checkpoint_no + 1;

#ifdef UNIV_LOG_ARCHIVE
	if (archived_lsn == IB_ULONGLONG_MAX) {

		log_sys->archiving_state = LOG_ARCH_OFF;
	}
#endif /* UNIV_LOG_ARCHIVE */

	mutex_enter(&(recv_sys->mutex));

	recv_sys->apply_log_recs = TRUE;

	mutex_exit(&(recv_sys->mutex));

	mutex_exit(&(log_sys->mutex));

	recv_lsn_checks_on = TRUE;

	/* The database is now ready to start almost normal processing of user
	transactions: transaction rollbacks and the application of the log
	records in the hash table can be run in background. */

	return(DB_SUCCESS);

#undef TYPE_CHECKPOINT
#undef LIMIT_LSN
}

/********************************************************//**
Completes recovery from a checkpoint. */
UNIV_INTERN
void
recv_recovery_from_checkpoint_finish(void)
/*======================================*/
{
	/* Apply the hashed log records to the respective file pages */

	if (srv_force_recovery < SRV_FORCE_NO_LOG_REDO) {

		recv_apply_hashed_log_recs(TRUE);
	}

#ifdef UNIV_DEBUG
	if (log_debug_writes) {
		fprintf(stderr,
			"InnoDB: Log records applied to the database\n");
	}
#endif /* UNIV_DEBUG */

	if (recv_needed_recovery) {
		trx_sys_print_mysql_master_log_pos();
		trx_sys_print_mysql_binlog_offset();
	}

	if (recv_sys->found_corrupt_log) {

		fprintf(stderr,
			"InnoDB: WARNING: the log file may have been"
			" corrupt and it\n"
			"InnoDB: is possible that the log scan or parsing"
			" did not proceed\n"
			"InnoDB: far enough in recovery. Please run"
			" CHECK TABLE\n"
			"InnoDB: on your InnoDB tables to check that"
			" they are ok!\n"
			"InnoDB: It may be safest to recover your"
			" InnoDB database from\n"
			"InnoDB: a backup!\n");
	}

	/* Free the resources of the recovery system */

	recv_recovery_on = FALSE;

#ifndef UNIV_LOG_DEBUG
	recv_sys_debug_free();
#endif
	/* Roll back any recovered data dictionary transactions, so
	that the data dictionary tables will be free of any locks.
	The data dictionary latch should guarantee that there is at
	most one data dictionary transaction active at a time. */
	trx_rollback_or_clean_recovered(FALSE);
}

/********************************************************//**
Initiates the rollback of active transactions. */
UNIV_INTERN
void
recv_recovery_rollback_active(void)
/*===============================*/
{
	int		i;

#ifdef UNIV_SYNC_DEBUG
	/* Wait for a while so that created threads have time to suspend
	themselves before we switch the latching order checks on */
	os_thread_sleep(1000000);

	/* Switch latching order checks on in sync0sync.c */
	sync_order_checks_on = TRUE;
#endif
	/* Drop partially created indexes. */
	row_merge_drop_temp_indexes();
	/* Drop temporary tables. */
	row_mysql_drop_temp_tables();

	if (srv_force_recovery < SRV_FORCE_NO_TRX_UNDO) {
		/* Rollback the uncommitted transactions which have no user
		session */

		os_thread_create(trx_rollback_or_clean_all_recovered,
				 (void *)&i, NULL);
	}
}

/******************************************************//**
Resets the logs. The contents of log files will be lost! */
UNIV_INTERN
void
recv_reset_logs(
/*============*/
	ib_uint64_t	lsn,		/*!< in: reset to this lsn
					rounded up to be divisible by
					OS_FILE_LOG_BLOCK_SIZE, after
					which we add
					LOG_BLOCK_HDR_SIZE */
#ifdef UNIV_LOG_ARCHIVE
	ulint		arch_log_no,	/*!< in: next archived log file number */
#endif /* UNIV_LOG_ARCHIVE */
	ibool		new_logs_created)/*!< in: TRUE if resetting logs
					is done at the log creation;
					FALSE if it is done after
					archive recovery */
{
	log_group_t*	group;

	ut_ad(mutex_own(&(log_sys->mutex)));

	log_sys->lsn = ut_uint64_align_up(lsn, OS_FILE_LOG_BLOCK_SIZE);

	group = UT_LIST_GET_FIRST(log_sys->log_groups);

	while (group) {
		group->lsn = log_sys->lsn;
		group->lsn_offset = LOG_FILE_HDR_SIZE;
#ifdef UNIV_LOG_ARCHIVE
		group->archived_file_no = arch_log_no;
		group->archived_offset = 0;
#endif /* UNIV_LOG_ARCHIVE */

		if (!new_logs_created) {
			recv_truncate_group(group, group->lsn, group->lsn,
					    group->lsn, group->lsn);
		}

		group = UT_LIST_GET_NEXT(log_groups, group);
	}

	log_sys->buf_next_to_write = 0;
	log_sys->written_to_some_lsn = log_sys->lsn;
	log_sys->written_to_all_lsn = log_sys->lsn;

	log_sys->next_checkpoint_no = 0;
	log_sys->last_checkpoint_lsn = 0;

#ifdef UNIV_LOG_ARCHIVE
	log_sys->archived_lsn = log_sys->lsn;
#endif /* UNIV_LOG_ARCHIVE */

	log_block_init(log_sys->buf, log_sys->lsn);
	log_block_set_first_rec_group(log_sys->buf, LOG_BLOCK_HDR_SIZE);

	log_sys->buf_free = LOG_BLOCK_HDR_SIZE;
	log_sys->lsn += LOG_BLOCK_HDR_SIZE;

	mutex_exit(&(log_sys->mutex));

	/* Reset the checkpoint fields in logs */

	log_make_checkpoint_at(IB_ULONGLONG_MAX, TRUE);
	log_make_checkpoint_at(IB_ULONGLONG_MAX, TRUE);

	mutex_enter(&(log_sys->mutex));
}
#endif /* !UNIV_HOTBACKUP */

#ifdef UNIV_HOTBACKUP
/******************************************************//**
Creates new log files after a backup has been restored. */
UNIV_INTERN
void
recv_reset_log_files_for_backup(
/*============================*/
	const char*	log_dir,	/*!< in: log file directory path */
	ulint		n_log_files,	/*!< in: number of log files */
	ulint		log_file_size,	/*!< in: log file size */
	ib_uint64_t	lsn)		/*!< in: new start lsn, must be
					divisible by OS_FILE_LOG_BLOCK_SIZE */
{
	os_file_t	log_file;
	ibool		success;
	byte*		buf;
	ulint		i;
	ulint		log_dir_len;
	char		name[5000];
	static const char ib_logfile_basename[] = "ib_logfile";

	log_dir_len = strlen(log_dir);
	/* full path name of ib_logfile consists of log dir path + basename
	+ number. This must fit in the name buffer.
	*/
	ut_a(log_dir_len + strlen(ib_logfile_basename) + 11  < sizeof(name));

	buf = ut_malloc(LOG_FILE_HDR_SIZE + OS_FILE_LOG_BLOCK_SIZE);
	memset(buf, '\0', LOG_FILE_HDR_SIZE + OS_FILE_LOG_BLOCK_SIZE);

	for (i = 0; i < n_log_files; i++) {

		sprintf(name, "%s%s%lu", log_dir,
			ib_logfile_basename, (ulong)i);

		log_file = os_file_create_simple(name, OS_FILE_CREATE,
						 OS_FILE_READ_WRITE, &success);
		if (!success) {
			fprintf(stderr,
				"InnoDB: Cannot create %s. Check that"
				" the file does not exist yet.\n", name);

			exit(1);
		}

		fprintf(stderr,
			"Setting log file size to %lu %lu\n",
			(ulong) ut_get_high32(log_file_size),
			(ulong) log_file_size & 0xFFFFFFFFUL);

		success = os_file_set_size(name, log_file,
					   log_file_size & 0xFFFFFFFFUL,
					   ut_get_high32(log_file_size));

		if (!success) {
			fprintf(stderr,
				"InnoDB: Cannot set %s size to %lu %lu\n",
				name, (ulong) ut_get_high32(log_file_size),
				(ulong) (log_file_size & 0xFFFFFFFFUL));
			exit(1);
		}

		os_file_flush(log_file);
		os_file_close(log_file);
	}

	/* We pretend there is a checkpoint at lsn + LOG_BLOCK_HDR_SIZE */

	log_reset_first_header_and_checkpoint(buf, lsn);

	log_block_init_in_old_format(buf + LOG_FILE_HDR_SIZE, lsn);
	log_block_set_first_rec_group(buf + LOG_FILE_HDR_SIZE,
				      LOG_BLOCK_HDR_SIZE);
	sprintf(name, "%s%s%lu", log_dir, ib_logfile_basename, (ulong)0);

	log_file = os_file_create_simple(name, OS_FILE_OPEN,
					 OS_FILE_READ_WRITE, &success);
	if (!success) {
		fprintf(stderr, "InnoDB: Cannot open %s.\n", name);

		exit(1);
	}

	os_file_write(name, log_file, buf, 0, 0,
		      LOG_FILE_HDR_SIZE + OS_FILE_LOG_BLOCK_SIZE);
	os_file_flush(log_file);
	os_file_close(log_file);

	ut_free(buf);
}
#endif /* UNIV_HOTBACKUP */

#ifdef UNIV_LOG_ARCHIVE
/******************************************************//**
Reads from the archive of a log group and performs recovery.
@return	TRUE if no more complete consistent archive files */
static
ibool
log_group_recover_from_archive_file(
/*================================*/
	log_group_t*	group)		/*!< in: log group */
{
	os_file_t	file_handle;
	ib_uint64_t	start_lsn;
	ib_uint64_t	file_end_lsn;
	ib_uint64_t	dummy_lsn;
	ib_uint64_t	scanned_lsn;
	ulint		len;
	ibool		ret;
	byte*		buf;
	ulint		read_offset;
	ulint		file_size;
	ulint		file_size_high;
	int		input_char;
	char		name[10000];

	ut_a(0);

try_open_again:
	buf = log_sys->buf;

	/* Add the file to the archive file space; open the file */

	log_archived_file_name_gen(name, group->id, group->archived_file_no);

	file_handle = os_file_create(name, OS_FILE_OPEN,
				     OS_FILE_LOG, OS_FILE_AIO, &ret);

	if (ret == FALSE) {
ask_again:
		fprintf(stderr,
			"InnoDB: Do you want to copy additional"
			" archived log files\n"
			"InnoDB: to the directory\n");
		fprintf(stderr,
			"InnoDB: or were these all the files needed"
			" in recovery?\n");
		fprintf(stderr,
			"InnoDB: (Y == copy more files; N == this is all)?");

		input_char = getchar();

		if (input_char == (int) 'N') {

			return(TRUE);
		} else if (input_char == (int) 'Y') {

			goto try_open_again;
		} else {
			goto ask_again;
		}
	}

	ret = os_file_get_size(file_handle, &file_size, &file_size_high);
	ut_a(ret);

	ut_a(file_size_high == 0);

	fprintf(stderr, "InnoDB: Opened archived log file %s\n", name);

	ret = os_file_close(file_handle);

	if (file_size < LOG_FILE_HDR_SIZE) {
		fprintf(stderr,
			"InnoDB: Archive file header incomplete %s\n", name);

		return(TRUE);
	}

	ut_a(ret);

	/* Add the archive file as a node to the space */

	fil_node_create(name, 1 + file_size / UNIV_PAGE_SIZE,
			group->archive_space_id, FALSE);
#if RECV_SCAN_SIZE < LOG_FILE_HDR_SIZE
# error "RECV_SCAN_SIZE < LOG_FILE_HDR_SIZE"
#endif

	/* Read the archive file header */
	fil_io(OS_FILE_READ | OS_FILE_LOG, TRUE, group->archive_space_id, 0, 0,
	       LOG_FILE_HDR_SIZE, buf, NULL);

	/* Check if the archive file header is consistent */

	if (mach_read_from_4(buf + LOG_GROUP_ID) != group->id
	    || mach_read_from_4(buf + LOG_FILE_NO)
	    != group->archived_file_no) {
		fprintf(stderr,
			"InnoDB: Archive file header inconsistent %s\n", name);

		return(TRUE);
	}

	if (!mach_read_from_4(buf + LOG_FILE_ARCH_COMPLETED)) {
		fprintf(stderr,
			"InnoDB: Archive file not completely written %s\n",
			name);

		return(TRUE);
	}

	start_lsn = mach_read_ull(buf + LOG_FILE_START_LSN);
	file_end_lsn = mach_read_ull(buf + LOG_FILE_END_LSN);

	if (!recv_sys->scanned_lsn) {

		if (recv_sys->parse_start_lsn < start_lsn) {
			fprintf(stderr,
				"InnoDB: Archive log file %s"
				" starts from too big a lsn\n",
				name);
			return(TRUE);
		}

		recv_sys->scanned_lsn = start_lsn;
	}

	if (recv_sys->scanned_lsn != start_lsn) {

		fprintf(stderr,
			"InnoDB: Archive log file %s starts from"
			" a wrong lsn\n",
			name);
		return(TRUE);
	}

	read_offset = LOG_FILE_HDR_SIZE;

	for (;;) {
		len = RECV_SCAN_SIZE;

		if (read_offset + len > file_size) {
			len = ut_calc_align_down(file_size - read_offset,
						 OS_FILE_LOG_BLOCK_SIZE);
		}

		if (len == 0) {

			break;
		}

#ifdef UNIV_DEBUG
		if (log_debug_writes) {
			fprintf(stderr,
				"InnoDB: Archive read starting at"
				" lsn %llu, len %lu from file %s\n",
				start_lsn,
				(ulong) len, name);
		}
#endif /* UNIV_DEBUG */

		fil_io(OS_FILE_READ | OS_FILE_LOG, TRUE,
		       group->archive_space_id, read_offset / UNIV_PAGE_SIZE,
		       read_offset % UNIV_PAGE_SIZE, len, buf, NULL);

		ret = recv_scan_log_recs(
			(buf_pool->n_frames - recv_n_pool_free_frames)
			* UNIV_PAGE_SIZE, TRUE, buf, len, start_lsn,
			&dummy_lsn, &scanned_lsn);

		if (scanned_lsn == file_end_lsn) {

			return(FALSE);
		}

		if (ret) {
			fprintf(stderr,
				"InnoDB: Archive log file %s"
				" does not scan right\n",
				name);
			return(TRUE);
		}

		read_offset += len;
		start_lsn += len;

		ut_ad(start_lsn == scanned_lsn);
	}

	return(FALSE);
}

/********************************************************//**
Recovers from archived log files, and also from log files, if they exist.
@return	error code or DB_SUCCESS */
UNIV_INTERN
ulint
recv_recovery_from_archive_start(
/*=============================*/
	ib_uint64_t	min_flushed_lsn,/*!< in: min flushed lsn field from the
					data files */
	ib_uint64_t	limit_lsn,	/*!< in: recover up to this lsn if
					possible */
	ulint		first_log_no)	/*!< in: number of the first archived
					log file to use in the recovery; the
					file will be searched from
					INNOBASE_LOG_ARCH_DIR specified in
					server config file */
{
	log_group_t*	group;
	ulint		group_id;
	ulint		trunc_len;
	ibool		ret;
	ulint		err;

	ut_a(0);

	recv_sys_create();
	recv_sys_init(buf_pool_get_curr_size());

	recv_recovery_on = TRUE;
	recv_recovery_from_backup_on = TRUE;

	recv_sys->limit_lsn = limit_lsn;

	group_id = 0;

	group = UT_LIST_GET_FIRST(log_sys->log_groups);

	while (group) {
		if (group->id == group_id) {

			break;
		}

		group = UT_LIST_GET_NEXT(log_groups, group);
	}

	if (!group) {
		fprintf(stderr,
			"InnoDB: There is no log group defined with id %lu!\n",
			(ulong) group_id);
		return(DB_ERROR);
	}

	group->archived_file_no = first_log_no;

	recv_sys->parse_start_lsn = min_flushed_lsn;

	recv_sys->scanned_lsn = 0;
	recv_sys->scanned_checkpoint_no = 0;
	recv_sys->recovered_lsn = recv_sys->parse_start_lsn;

	recv_sys->archive_group = group;

	ret = FALSE;

	mutex_enter(&(log_sys->mutex));

	while (!ret) {
		ret = log_group_recover_from_archive_file(group);

		/* Close and truncate a possible processed archive file
		from the file space */

		trunc_len = UNIV_PAGE_SIZE
			* fil_space_get_size(group->archive_space_id);
		if (trunc_len > 0) {
			fil_space_truncate_start(group->archive_space_id,
						 trunc_len);
		}

		group->archived_file_no++;
	}

	if (recv_sys->recovered_lsn < limit_lsn) {

		if (!recv_sys->scanned_lsn) {

			recv_sys->scanned_lsn = recv_sys->parse_start_lsn;
		}

		mutex_exit(&(log_sys->mutex));

		err = recv_recovery_from_checkpoint_start(LOG_ARCHIVE,
							  limit_lsn,
							  IB_ULONGLONG_MAX,
							  IB_ULONGLONG_MAX);
		if (err != DB_SUCCESS) {

			return(err);
		}

		mutex_enter(&(log_sys->mutex));
	}

	if (limit_lsn != IB_ULONGLONG_MAX) {

		recv_apply_hashed_log_recs(FALSE);

		recv_reset_logs(recv_sys->recovered_lsn, 0, FALSE);
	}

	mutex_exit(&(log_sys->mutex));

	return(DB_SUCCESS);
}

/********************************************************//**
Completes recovery from archive. */
UNIV_INTERN
void
recv_recovery_from_archive_finish(void)
/*===================================*/
{
	recv_recovery_from_checkpoint_finish();

	recv_recovery_from_backup_on = FALSE;
}
#endif /* UNIV_LOG_ARCHIVE */