208 lines
5.5 KiB
C
208 lines
5.5 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996, 1997
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* Sleepycat Software. All rights reserved.
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*/
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#include "config.h"
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#ifndef lint
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static const char copyright[] =
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"@(#) Copyright (c) 1997\n\
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Sleepycat Software Inc. All rights reserved.\n";
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static const char sccsid[] = "@(#)db_apprec.c 10.23 (Sleepycat) 1/17/98";
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#endif
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#ifndef NO_SYSTEM_INCLUDES
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#include <sys/types.h>
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#include <errno.h>
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#include <time.h>
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#include <string.h>
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#include <stdlib.h>
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#endif
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#include "db_int.h"
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#include "shqueue.h"
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#include "db_page.h"
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#include "db_dispatch.h"
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#include "db_am.h"
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#include "log.h"
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#include "txn.h"
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#include "common_ext.h"
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/*
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* __db_apprec --
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* Perform recovery.
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*
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* PUBLIC: int __db_apprec __P((DB_ENV *, int));
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*/
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int
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__db_apprec(dbenv, flags)
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DB_ENV *dbenv;
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int flags;
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{
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DBT data;
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DB_LOG *lp;
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DB_LSN ckp_lsn, first_lsn, lsn;
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time_t now;
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int is_thread, ret;
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void *txninfo;
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lp = dbenv->lg_info;
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/* Initialize the transaction list. */
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if ((ret = __db_txnlist_init(&txninfo)) != 0)
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return (ret);
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/*
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* Save the state of the thread flag -- we don't need it on at the
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* moment because we're single-threaded until recovery is complete.
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*/
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is_thread = F_ISSET(lp, DB_AM_THREAD);
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F_CLR(lp, DB_AM_THREAD);
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/*
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* Recovery is done in three passes:
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* Pass #1:
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* Read forward through the log from the last checkpoint to the
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* end of the log, opening and closing files so that at the end
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* of the log we have the "current" set of files open.
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* Pass #2:
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* Read backward through the log undoing any uncompleted TXNs.
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* If doing catastrophic recovery, we read to the beginning of
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* the log, otherwise, to the most recent checkpoint that occurs
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* before the most recent checkpoint LSN, which is returned by
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* __log_findckp(). During this pass, checkpoint file information
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* is ignored, and file openings and closings are undone.
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* Pass #3:
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* Read forward through the log from the LSN found in pass #2,
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* redoing any committed TXNs. During this pass, checkpoint
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* file information is ignored, and file openings and closings
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* are redone.
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*/
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/*
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* Find the last checkpoint in the log. This is the point from which
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* we want to begin pass #1 (the TXN_OPENFILES pass).
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*/
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memset(&data, 0, sizeof(data));
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if ((ret = log_get(lp, &ckp_lsn, &data, DB_CHECKPOINT)) != 0) {
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/*
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* If we don't find a checkpoint, start from the beginning.
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* If that fails, we're done. Note, we require that there
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* be log records if we're performing recovery, and fail if
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* there aren't.
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*/
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if ((ret = log_get(lp, &ckp_lsn, &data, DB_FIRST)) != 0) {
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__db_err(dbenv, "First log record not found");
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if (ret == DB_NOTFOUND)
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ret = EINVAL;
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goto out;
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}
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}
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/*
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* Now, ckp_lsn is either the lsn of the last checkpoint or the lsn
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* of the first record in the log. Begin the TXN_OPENFILES pass from
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* that lsn, and proceed to the end of the log.
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*/
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lsn = ckp_lsn;
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for (;;) {
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ret = __db_dispatch(lp, &data, &lsn, TXN_OPENFILES, txninfo);
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if (ret != 0 && ret != DB_TXN_CKP)
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goto msgerr;
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if ((ret = log_get(lp, &lsn, &data, DB_NEXT)) != 0) {
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if (ret == DB_NOTFOUND)
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break;
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goto out;
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}
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}
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/*
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* Pass #2.
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*
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* Before we can begin pass #2, backward roll phase, we determine how
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* far back in the log to recover. If we are doing catastrophic
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* recovery, then we go as far back as we have files. If we are
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* doing normal recovery, we go as back to the most recent checkpoint
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* that occurs before the most recent checkpoint LSN.
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*/
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if (LF_ISSET(DB_RECOVER_FATAL)) {
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ZERO_LSN(first_lsn);
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} else
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if ((ret = __log_findckp(lp, &first_lsn)) == DB_NOTFOUND) {
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/*
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* If recovery was specified, there must be log files.
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* If we don't find one, it's an error. (This should
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* have been caught above, when a log_get() of DB_FIRST
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* or DB_CHECKPOINT succeeded, but paranoia is good.)
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*/
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ret = EINVAL;
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goto out;
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}
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for (ret = log_get(lp, &lsn, &data, DB_LAST);
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ret == 0 && log_compare(&lsn, &first_lsn) > 0;
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ret = log_get(lp, &lsn, &data, DB_PREV)) {
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ret = __db_dispatch(lp,
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&data, &lsn, TXN_BACKWARD_ROLL, txninfo);
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if (ret != 0)
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if (ret != DB_TXN_CKP)
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goto msgerr;
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else
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ret = 0;
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}
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if (ret != 0 && ret != DB_NOTFOUND)
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goto out;
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/*
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* Pass #3.
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*/
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for (ret = log_get(lp, &lsn, &data, DB_NEXT);
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ret == 0; ret = log_get(lp, &lsn, &data, DB_NEXT)) {
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ret = __db_dispatch(lp, &data, &lsn, TXN_FORWARD_ROLL, txninfo);
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if (ret != 0)
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if (ret != DB_TXN_CKP)
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goto msgerr;
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else
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ret = 0;
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}
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if (ret != DB_NOTFOUND)
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goto out;
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/* Now close all the db files that are open. */
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__log_close_files(lp);
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/*
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* Now set the maximum transaction id, set the last checkpoint lsn,
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* and the current time. Then take a checkpoint.
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*/
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(void)time(&now);
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dbenv->tx_info->region->last_txnid = ((__db_txnhead *)txninfo)->maxid;
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dbenv->tx_info->region->last_ckp = ckp_lsn;
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dbenv->tx_info->region->time_ckp = (u_int32_t)now;
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if ((ret = txn_checkpoint(dbenv->tx_info, 0, 0)) != 0)
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goto out;
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if (dbenv->db_verbose) {
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__db_err(lp->dbenv, "Recovery complete at %.24s", ctime(&now));
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__db_err(lp->dbenv, "%s %lu %s [%lu][%lu]",
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"Maximum transaction id",
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(u_long)dbenv->tx_info->region->last_txnid,
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"Recovery checkpoint",
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(u_long)dbenv->tx_info->region->last_ckp.file,
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(u_long)dbenv->tx_info->region->last_ckp.offset);
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}
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if (0) {
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msgerr: __db_err(dbenv, "Recovery function for LSN %lu %lu failed",
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(u_long)lsn.file, (u_long)lsn.offset);
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}
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out: F_SET(lp, is_thread);
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__db_txnlist_end(txninfo);
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return (ret);
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}
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