Remove traces of multiple InnoDB redo logs

InnoDB never supported more than one copy of a redo log.
There were provisions to do that. For Mariabackup, let us clean up
this code.

log_sys_init(): Renamed from log_init().

log_set_capacity(): Renamed from log_calc_max_ages().

log_init(): Renamed from log_group_init(). Remove the parameters
id, space_id. Let the caller invoke log_set_capacity() when needed.

log_group_t: Remove id, space_id, log_groups.

log_t: Replace log_groups with a single log.

recv_find_max_checkpoint(): Declare globally. Remove the first parameter.

xtrabackup_choose_lsn_offset(): Remove (dead code).

3 files changed, 77 insertions, 233 deletions

diff --git a/extra/mariabackup/xb0xb.h b/extra/mariabackup/xb0xb.h
index c6e4ae22de6..919d1190806 100644
--- a/extra/mariabackup/xb0xb.h
+++ b/extra/mariabackup/xb0xb.h
@@ -66,7 +66,6 @@ void
 innodb_log_checksum_func_update(
 /*============================*/
 ulint	algorithm)	/*!< in: algorithm */;
-dberr_t recv_find_max_checkpoint(log_group_t**	max_group, ulint*		max_field);
 dberr_t
 srv_undo_tablespaces_init(
 /*======================*/
diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index 16a39c58d5c..bb8140718b2 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -564,7 +564,6 @@ enum options_xtrabackup
   OPT_INNODB_LOG_BUFFER_SIZE,
   OPT_INNODB_LOG_FILE_SIZE,
   OPT_INNODB_LOG_FILES_IN_GROUP,
-  OPT_INNODB_MIRRORED_LOG_GROUPS,
   OPT_INNODB_OPEN_FILES,
   OPT_INNODB_SYNC_SPIN_LOOPS,
   OPT_INNODB_THREAD_CONCURRENCY,
@@ -2605,96 +2604,6 @@ skip:
 	return(FALSE);
 }
 
-static
-void
-xtrabackup_choose_lsn_offset(lsn_t start_lsn)
-{
-#if SUPPORT_PERCONA_5_5
-	ulint no, alt_no, expected_no;
-	ulint blocks_in_group;
-	lsn_t tmp_offset, end_lsn;
-	int lsn_chosen = 0;
-	log_group_t *group;
-
-	start_lsn = ut_uint64_align_down(start_lsn, OS_FILE_LOG_BLOCK_SIZE);
-	end_lsn = start_lsn + RECV_SCAN_SIZE;
-
-	group = UT_LIST_GET_FIRST(log_sys->log_groups);
-
-	if (mysql_server_version < 50500 || mysql_server_version > 50600) {
-		/* only make sense for Percona Server 5.5 */
-		return;
-	}
-
-	if (server_flavor == FLAVOR_PERCONA_SERVER) {
-		/* it is Percona Server 5.5 */
-		group->alt_offset_chosen = true;
-		group->lsn_offset = group->lsn_offset_alt;
-		return;
-	}
-
-	if (group->lsn_offset_alt == group->lsn_offset ||
-	    group->lsn_offset_alt == (lsn_t) -1) {
-		/* we have only one option */
-		return;
-	}
-
-	no = alt_no = (ulint) -1;
-	lsn_chosen = 0;
-
-	blocks_in_group = log_block_convert_lsn_to_no(
-		log_group_get_capacity(group)) - 1;
-
-	/* read log block number from usual offset */
-	if (group->lsn_offset < group->file_size * group->n_files &&
-	    (log_group_calc_lsn_offset(start_lsn, group) %
-	     UNIV_PAGE_SIZE) % OS_MIN_LOG_BLOCK_SIZE == 0) {
-		log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
-				       group, start_lsn, end_lsn);
-		no = log_block_get_hdr_no(log_sys->buf);
-	}
-
-	/* read log block number from Percona Server 5.5 offset */
-	tmp_offset = group->lsn_offset;
-	group->lsn_offset = group->lsn_offset_alt;
-
-	if (group->lsn_offset < group->file_size * group->n_files &&
-	    (log_group_calc_lsn_offset(start_lsn, group) %
-	     UNIV_PAGE_SIZE) % OS_MIN_LOG_BLOCK_SIZE == 0) {
-		log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
-				       group, start_lsn, end_lsn);
-		alt_no = log_block_get_hdr_no(log_sys->buf);
-	}
-
-	expected_no = log_block_convert_lsn_to_no(start_lsn);
-
-	ut_a(!(no == expected_no && alt_no == expected_no));
-
-	group->lsn_offset = tmp_offset;
-
-	if ((no <= expected_no &&
-		((expected_no - no) % blocks_in_group) == 0) ||
-	    ((expected_no | 0x40000000UL) - no) % blocks_in_group == 0) {
-		/* default offset looks ok */
-		++lsn_chosen;
-	}
-
-	if ((alt_no <= expected_no &&
-		((expected_no - alt_no) % blocks_in_group) == 0) ||
-	    ((expected_no | 0x40000000UL) - alt_no) % blocks_in_group == 0) {
-		/* PS 5.5 style offset looks ok */
-		++lsn_chosen;
-		group->alt_offset_chosen = true;
-		group->lsn_offset = group->lsn_offset_alt;
-	}
-
-	/* We are in trouble, because we can not make a
-	decision to choose one over the other. Die just
-	like a Buridan's ass */
-	ut_a(lsn_chosen == 1);
-#endif
-}
-
 extern ibool log_block_checksum_is_ok_or_old_format(const byte*	block);
 
 /*******************************************************//**
@@ -2862,8 +2771,6 @@ static my_bool
 xtrabackup_copy_logfile(lsn_t from_lsn, my_bool is_last)
 {
 	/* definition from recv_recovery_from_checkpoint_start() */
-	log_group_t*	group;
-	lsn_t		group_scanned_lsn;
 	lsn_t		contiguous_lsn;
 
 	ut_a(dst_log_file != NULL);
@@ -2873,66 +2780,50 @@ xtrabackup_copy_logfile(lsn_t from_lsn, my_bool is_last)
 
 	/* TODO: We must check the contiguous_lsn still exists in log file.. */
 
-	group = UT_LIST_GET_FIRST(log_sys->log_groups);
-
-	while (group) {
-		bool	finished;
-		lsn_t	start_lsn;
-		lsn_t	end_lsn;
-
-		/* reference recv_group_scan_log_recs() */
-		finished = false;
+	bool	finished;
+	lsn_t	start_lsn;
+	lsn_t	end_lsn;
 
-		start_lsn = contiguous_lsn;
+	/* reference recv_group_scan_log_recs() */
 
-		while (!finished) {
+	start_lsn = contiguous_lsn;
 
-			end_lsn = start_lsn + RECV_SCAN_SIZE;
+	do {
+		end_lsn = start_lsn + RECV_SCAN_SIZE;
 
-			xtrabackup_io_throttling();
+		xtrabackup_io_throttling();
 
-			mutex_enter(&log_sys->mutex);
+		log_mutex_enter();
 
-			log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
-					       group, start_lsn, end_lsn, false);
-
-			 if (!xtrabackup_scan_log_recs(group, is_last,
-				start_lsn, &contiguous_lsn, &group_scanned_lsn,
-				&finished)) {
-				goto error;
-			 }
+		log_group_read_log_seg(LOG_RECOVER, log_sys->buf,
+				       &log_sys->log, start_lsn, end_lsn);
 
-			mutex_exit(&log_sys->mutex);
+		bool success = xtrabackup_scan_log_recs(
+			&log_sys->log, is_last,
+			start_lsn, &contiguous_lsn,
+			&log_sys->log.scanned_lsn,
+			&finished);
 
-			start_lsn = end_lsn;
+		log_mutex_exit();
 
+		if (!success) {
+			ds_close(dst_log_file);
+			msg("xtrabackup: Error: xtrabackup_copy_logfile()"
+			    " failed.\n");
+			return(TRUE);
 		}
 
-		group->scanned_lsn = group_scanned_lsn;
-
-		msg_ts(">> log scanned up to (" LSN_PF ")\n",
-		       group->scanned_lsn);
-
-		group = UT_LIST_GET_NEXT(log_groups, group);
-
-		/* update global variable*/
-		log_copy_scanned_lsn = group_scanned_lsn;
+		start_lsn = end_lsn;
+	} while (!finished);
 
-		/* innodb_mirrored_log_groups must be 1, no other groups */
-		ut_a(group == NULL);
-
-		debug_sync_point("xtrabackup_copy_logfile_pause");
-
-	}
+	msg_ts(">> log scanned up to (" LSN_PF ")\n",
+	       log_sys->log.scanned_lsn);
 
+	/* update global variable*/
+	log_copy_scanned_lsn = log_sys->log.scanned_lsn;
 
+	debug_sync_point("xtrabackup_copy_logfile_pause");
 	return(FALSE);
-
-error:
-	mutex_exit(&log_sys->mutex);
-	ds_close(dst_log_file);
-	msg("xtrabackup: Error: xtrabackup_copy_logfile() failed.\n");
-	return(TRUE);
 }
 
 static
@@ -3244,13 +3135,12 @@ xb_fil_io_init(void)
 Populates the tablespace memory cache by scanning for and opening data files.
 @returns DB_SUCCESS or error code.*/
 static
-ulint
-xb_load_tablespaces(void)
-/*=====================*/
+dberr_t
+xb_load_tablespaces()
 {
 	ulint	i;
 	ibool	create_new_db;
-	ulint	err;
+	dberr_t	err;
 	ulint   sum_of_new_sizes;
 	lsn_t min_arch_logno, max_arch_logno;
 
@@ -3321,9 +3211,9 @@ xb_load_tablespaces(void)
 Initialize the tablespace memory cache and populate it by scanning for and
 opening data files.
 @returns DB_SUCCESS or error code.*/
-ulint
-xb_data_files_init(void)
-/*====================*/
+static
+dberr_t
+xb_data_files_init()
 {
 	xb_fil_io_init();
 
@@ -3332,9 +3222,9 @@ xb_data_files_init(void)
 
 /************************************************************************
 Destroy the tablespace memory cache. */
+static
 void
-xb_data_files_close(void)
-/*====================*/
+xb_data_files_close()
 {
 	ulint	i;
 
@@ -3745,7 +3635,6 @@ open_or_create_log_file(
 	ibool	log_file_has_been_opened,/*!< in: TRUE if a log file has been
 					opened before: then it is an error
 					to try to create another log file */
-	ulint	k,			/*!< in: log group number */
 	ulint	i)			/*!< in: log file number in group */
 {
 	ibool	ret;
@@ -3755,8 +3644,6 @@ open_or_create_log_file(
 
 	UT_NOT_USED(create_new_db);
 	UT_NOT_USED(log_file_has_been_opened);
-	UT_NOT_USED(k);
-	ut_ad(k == 0);
 
 	*log_file_created = FALSE;
 
@@ -3804,20 +3691,14 @@ open_or_create_log_file(
 		which is for this log group */
 
 		fil_space_create(name,
-				 2 * k + SRV_LOG_SPACE_FIRST_ID, 0, FIL_LOG, 0, 0);
+				 SRV_LOG_SPACE_FIRST_ID, 0, FIL_TYPE_LOG, 0, 0);
+		log_init(srv_n_log_files, srv_log_file_size * UNIV_PAGE_SIZE);
 	}
 
 	ut_a(fil_validate());
 
 	ut_a(fil_node_create(name, (ulint)srv_log_file_size,
-			     2 * k + SRV_LOG_SPACE_FIRST_ID, FALSE));
-	if (i == 0) {
-		log_group_init(k, srv_n_log_files,
-			       srv_log_file_size * UNIV_PAGE_SIZE,
-			       2 * k + SRV_LOG_SPACE_FIRST_ID,
-			       SRV_LOG_SPACE_FIRST_ID + 1); /* dummy arch
-							    space id */
-	}
+			     SRV_LOG_SPACE_FIRST_ID, FALSE));
 
 	return(DB_SUCCESS);
 }
@@ -3911,7 +3792,7 @@ xtrabackup_backup_func(void)
 	lsn_t			 latest_cp;
 	uint			 i;
 	uint			 count;
-	os_ib_mutex_t		 count_mutex;
+	pthread_mutex_t		 count_mutex;
 	data_thread_ctxt_t 	*data_threads;
 
 #ifdef USE_POSIX_FADVISE
@@ -4031,13 +3912,13 @@ xtrabackup_backup_func(void)
 
 	xb_fil_io_init();
 
-	log_init();
+	log_sys_init();
 
 	lock_sys_create(srv_lock_table_size);
 
 	for (i = 0; i < srv_n_log_files; i++) {
 		err = open_or_create_log_file(FALSE, &log_file_created,
-					      log_opened, 0, i);
+					      log_opened, i);
 		if (err != DB_SUCCESS) {
 
 			//return((int) err);
@@ -4092,72 +3973,60 @@ xtrabackup_backup_func(void)
         fil_system_t*   f_system = fil_system;
 
 	/* definition from recv_recovery_from_checkpoint_start() */
-	log_group_t*	max_cp_group;
 	ulint		max_cp_field;
-	byte*		buf;
-	byte*		log_hdr_buf_;
-	byte*		log_hdr_buf;
-	ulint		err;
 
 	/* start back ground thread to copy newer log */
 	os_thread_id_t log_copying_thread_id;
 	datafiles_iter_t *it;
 
-	log_hdr_buf_ = static_cast<byte *>
-		(ut_malloc(LOG_FILE_HDR_SIZE + UNIV_PAGE_SIZE_MAX));
-	log_hdr_buf = static_cast<byte *>
-		(ut_align(log_hdr_buf_, UNIV_PAGE_SIZE_MAX));
-
 	/* get current checkpoint_lsn */
 	/* Look for the latest checkpoint from any of the log groups */
 
-	mutex_enter(&log_sys->mutex);
+	log_mutex_enter();
 
-	err = recv_find_max_checkpoint(&max_cp_group, &max_cp_field);
+	dberr_t err = recv_find_max_checkpoint(&max_cp_field);
 
 	if (err != DB_SUCCESS) {
+		exit(EXIT_FAILURE);
+	}
 
-		ut_free(log_hdr_buf_);
+	if (log_sys->log.format == 0) {
+old_format:
+		msg("xtrabackup: Error: cannot process redo log"
+		    " before MariaDB 10.2.2\n");
 		exit(EXIT_FAILURE);
 	}
 
-	log_group_read_checkpoint_info(max_cp_group, max_cp_field);
-	buf = log_sys->checkpoint_buf;
+	ut_ad(!((log_sys->log.format ^ LOG_HEADER_FORMAT_CURRENT)
+		& ~LOG_HEADER_FORMAT_ENCRYPTED));
+
+	const byte* buf = log_sys->checkpoint_buf;
 
 	checkpoint_lsn_start = mach_read_from_8(buf + LOG_CHECKPOINT_LSN);
 	checkpoint_no_start = mach_read_from_8(buf + LOG_CHECKPOINT_NO);
 
-	mutex_exit(&log_sys->mutex);
-
 reread_log_header:
-	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, NULL);
-
-	/* check consistency of log file header to copy */
-	mutex_enter(&log_sys->mutex);
+	err = recv_find_max_checkpoint(&max_cp_field);
 
-	err = recv_find_max_checkpoint(&max_cp_group, &max_cp_field);
-
-        if (err != DB_SUCCESS) {
+	if (err != DB_SUCCESS) {
+		exit(EXIT_FAILURE);
+	}
 
-		ut_free(log_hdr_buf_);
-                exit(EXIT_FAILURE);
-        }
+	if (log_sys->log.format == 0) {
+		goto old_format;
+	}
 
-        log_group_read_checkpoint_info(max_cp_group, max_cp_field);
-        buf = log_sys->checkpoint_buf;
+	ut_ad(!((log_sys->log.format ^ LOG_HEADER_FORMAT_CURRENT)
+		& ~LOG_HEADER_FORMAT_ENCRYPTED));
 
 	if(checkpoint_no_start != mach_read_from_8(buf + LOG_CHECKPOINT_NO)) {
 
 		checkpoint_lsn_start = mach_read_from_8(buf + LOG_CHECKPOINT_LSN);
 		checkpoint_no_start = mach_read_from_8(buf + LOG_CHECKPOINT_NO);
-		mutex_exit(&log_sys->mutex);
 		goto reread_log_header;
 	}
 
-	mutex_exit(&log_sys->mutex);
+	log_mutex_exit();
 
 	xtrabackup_init_datasinks();
 
@@ -4204,10 +4073,6 @@ reread_log_header:
 				 &io_watching_thread_id);
 	}
 
-	mutex_enter(&log_sys->mutex);
-	xtrabackup_choose_lsn_offset(checkpoint_lsn_start);
-	mutex_exit(&log_sys->mutex);
-
 	/* copy log file by current position */
 	if(xtrabackup_copy_logfile(checkpoint_lsn_start, FALSE))
 		exit(EXIT_FAILURE);
@@ -4220,7 +4085,7 @@ reread_log_header:
 	err = xb_load_tablespaces();
 	if (err != DB_SUCCESS) {
 		msg("xtrabackup: error: xb_load_tablespaces() failed with"
-		    "error code %lu\n", err);
+		    "error code %u\n", err);
 		exit(EXIT_FAILURE);
 	}
 
@@ -4297,35 +4162,24 @@ reread_log_header:
 	}
 
 	/* read the latest checkpoint lsn */
-	latest_cp = 0;
 	{
-		log_group_t*	max_cp_group;
 		ulint	max_cp_field;
-		ulint	err;
-
-		mutex_enter(&log_sys->mutex);
 
-		err = recv_find_max_checkpoint(&max_cp_group, &max_cp_field);
+		log_mutex_enter();
 
-		if (err != DB_SUCCESS) {
+		if (recv_find_max_checkpoint(&max_cp_field) == DB_SUCCESS
+		    && log_sys->log.format != 0) {
+			latest_cp = mach_read_from_8(log_sys->checkpoint_buf +
+						     LOG_CHECKPOINT_LSN);
+			msg("xtrabackup: The latest check point"
+			    " (for incremental): '" LSN_PF "'\n", latest_cp);
+		} else {
+			latest_cp = 0;
 			msg("xtrabackup: Error: recv_find_max_checkpoint() failed.\n");
-			mutex_exit(&log_sys->mutex);
-			goto skip_last_cp;
 		}
-
-		log_group_read_checkpoint_info(max_cp_group, max_cp_field);
-
-		xtrabackup_choose_lsn_offset(checkpoint_lsn_start);
-
-		latest_cp = mach_read_from_8(log_sys->checkpoint_buf +
-					     LOG_CHECKPOINT_LSN);
-
-		mutex_exit(&log_sys->mutex);
-
-		msg("xtrabackup: The latest check point (for incremental): "
-		    "'" LSN_PF "'\n", latest_cp);
+		log_mutex_exit();
 	}
-skip_last_cp:
+
 	/* stop log_copying_thread */
 	log_copying = FALSE;
 	os_event_set(log_copying_stop);
diff --git a/extra/mariabackup/xtrabackup.h b/extra/mariabackup/xtrabackup.h
index d3c4c486d9f..371466aad2c 100644
--- a/extra/mariabackup/xtrabackup.h
+++ b/extra/mariabackup/xtrabackup.h
@@ -182,15 +182,6 @@ datafiles_iter_t *datafiles_iter_new(fil_system_t *f_system);
 fil_node_t *datafiles_iter_next(datafiles_iter_t *it);
 void datafiles_iter_free(datafiles_iter_t *it);
 
-/************************************************************************
-Initialize the tablespace memory cache and populate it by scanning for and
-opening data files */
-ulint xb_data_files_init(void);
-
-/************************************************************************
-Destroy the tablespace memory cache. */
-void xb_data_files_close(void);
-
 /***********************************************************************
 Reads the space flags from a given data file and returns the compressed
 page size, or 0 if the space is not compressed. */