txn_rec.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1996
 *      The President and Fellows of Harvard University.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: txn_rec.c,v 12.4 2005/10/19 15:10:45 bostic Exp $
 */

#include "db_config.h"

#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>

#include <string.h>
#endif

#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/txn.h"
#include "dbinc/db_am.h"

/*
 * PUBLIC: int __txn_regop_recover
 * PUBLIC:    __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 *
 * These records are only ever written for commits.  Normally, we redo any
 * committed transaction, however if we are doing recovery to a timestamp, then
 * we may treat transactions that committed after the timestamp as aborted.
 */
int
__txn_regop_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        DB_TXNHEAD *headp;
        __txn_regop_args *argp;
        int ret;
        u_int32_t status;

#ifdef DEBUG_RECOVER
        (void)__txn_regop_print(dbenv, dbtp, lsnp, op, info);
#endif

        if ((ret = __txn_regop_read(dbenv, dbtp->data, &argp)) != 0)
                return (ret);

        headp = info;
        /*
         * We are only ever called during FORWARD_ROLL or BACKWARD_ROLL.
         * We check for the former explicitly and the last two clauses
         * apply to the BACKWARD_ROLL case.
         */

        if (op == DB_TXN_FORWARD_ROLL) {
                /*
                 * If this was a 2-phase-commit transaction, then it
                 * might already have been removed from the list, and
                 * that's OK.  Ignore the return code from remove.
                 */
                if ((ret = __db_txnlist_remove(dbenv,
                    info, argp->txnid->txnid)) != DB_NOTFOUND && ret != 0)
                        goto err;
        } else if ((dbenv->tx_timestamp != 0 &&
            argp->timestamp > (int32_t)dbenv->tx_timestamp) ||
            (!IS_ZERO_LSN(headp->trunc_lsn) &&
            log_compare(&headp->trunc_lsn, lsnp) < 0)) {
                /*
                 * We failed either the timestamp check or the trunc_lsn check,
                 * so we treat this as an abort even if it was a commit record.
                 */
                if ((ret = __db_txnlist_update(dbenv, info,
                    argp->txnid->txnid, TXN_ABORT, NULL, &status, 1)) != 0)
                        goto err;
                else if (status != TXN_IGNORE && status != TXN_OK)
                        goto err;
        } else {
                /* This is a normal commit; mark it appropriately. */
                if ((ret = __db_txnlist_update(dbenv,
                    info, argp->txnid->txnid, argp->opcode, lsnp,
                    &status, 0)) == DB_NOTFOUND) {
                        if ((ret = __db_txnlist_add(dbenv,
                            info, argp->txnid->txnid,
                            argp->opcode == TXN_ABORT ?
                            TXN_IGNORE : argp->opcode, lsnp)) != 0)
                                goto err;
                } else if (ret != 0 ||
                    (status != TXN_IGNORE && status != TXN_OK))
                        goto err;
        }

        if (ret == 0)
                *lsnp = argp->prev_lsn;

        if (0) {
err:            __db_err(dbenv,
                    "txnid %lx commit record found, already on commit list",
                    (u_long)argp->txnid->txnid);
                ret = EINVAL;
        }
        __os_free(dbenv, argp);

        return (ret);
}

/*
 * PUBLIC: int __txn_xa_regop_recover
 * PUBLIC:    __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 *
 * These records are only ever written for prepares.
 */
int
__txn_xa_regop_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __txn_xa_regop_args *argp;
        int ret;
        u_int32_t status;

#ifdef DEBUG_RECOVER
        (void)__txn_xa_regop_print(dbenv, dbtp, lsnp, op, info);
#endif

        if ((ret = __txn_xa_regop_read(dbenv, dbtp->data, &argp)) != 0)
                return (ret);

        if (argp->opcode != TXN_PREPARE && argp->opcode != TXN_ABORT) {
                ret = EINVAL;
                goto err;
        }

        /*
         * The return value here is either a DB_NOTFOUND or it is
         * the transaction status from the list.  It is not a normal
         * error return, so we must make sure that in each of the
         * cases below, we overwrite the ret value so we return
         * appropriately.
         */
        ret = __db_txnlist_find(dbenv, info, argp->txnid->txnid, &status);

        /*
         * If we are rolling forward, then an aborted prepare
         * indicates that this may the last record we'll see for
         * this transaction ID, so we should remove it from the
         * list.
         */

        if (op == DB_TXN_FORWARD_ROLL) {
                if ((ret = __db_txnlist_remove(dbenv,
                    info, argp->txnid->txnid)) != 0)
                        goto txn_err;
        } else if (op == DB_TXN_BACKWARD_ROLL && status == TXN_PREPARE) {
                /*
                 * On the backward pass, we have four possibilities:
                 * 1. The transaction is already committed, no-op.
                 * 2. The transaction is already aborted, no-op.
                 * 3. The prepare failed and was aborted, mark as abort.
                 * 4. The transaction is neither committed nor aborted.
                 *       Treat this like a commit and roll forward so that
                 *       the transaction can be resurrected in the region.
                 * We handle cases 3 and 4 here; cases 1 and 2
                 * are the final clause below.
                 */
                if (argp->opcode == TXN_ABORT) {
                        if ((ret = __db_txnlist_update(dbenv,
                             info, argp->txnid->txnid,
                             TXN_ABORT, NULL, &status, 0)) != 0 &&
                             status != TXN_PREPARE)
                                goto txn_err;
                        ret = 0;
                }
                /*
                 * This is prepared, but not yet committed transaction.  We
                 * need to add it to the transaction list, so that it gets
                 * rolled forward. We also have to add it to the region's
                 * internal state so it can be properly aborted or committed
                 * after recovery (see txn_recover).
                 */
                else if ((ret = __db_txnlist_remove(dbenv,
                    info, argp->txnid->txnid)) != 0) {
txn_err:                __db_err(dbenv,
                            "Transaction not in list %x", argp->txnid->txnid);
                        ret = DB_NOTFOUND;
                } else if ((ret = __db_txnlist_add(dbenv,
                   info, argp->txnid->txnid, TXN_COMMIT, lsnp)) == 0)
                        ret = __txn_restore_txn(dbenv, lsnp, argp);
        } else
                ret = 0;

        if (ret == 0)
                *lsnp = argp->prev_lsn;

err:    __os_free(dbenv, argp);

        return (ret);
}

/*
 * PUBLIC: int __txn_ckp_recover
 * PUBLIC: __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__txn_ckp_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        DB_REP *db_rep;
        REP *rep;
        __txn_ckp_args *argp;
        int ret;

#ifdef DEBUG_RECOVER
        __txn_ckp_print(dbenv, dbtp, lsnp, op, info);
#endif
        if ((ret = __txn_ckp_read(dbenv, dbtp->data, &argp)) != 0)
                return (ret);

        if (op == DB_TXN_BACKWARD_ROLL)
                __db_txnlist_ckp(dbenv, info, lsnp);

        if (op == DB_TXN_FORWARD_ROLL) {
                /* Record the max generation number that we've seen. */
                if (REP_ON(dbenv)) {
                        db_rep = dbenv->rep_handle;
                        rep = db_rep->region;
                        if (argp->rep_gen > rep->recover_gen)
                                rep->recover_gen = argp->rep_gen;
                }
        }

        *lsnp = argp->last_ckp;
        __os_free(dbenv, argp);
        return (DB_TXN_CKP);
}

/*
 * __txn_child_recover
 *      Recover a commit record for a child transaction.
 *
 * PUBLIC: int __txn_child_recover
 * PUBLIC:    __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__txn_child_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __txn_child_args *argp;
        int ret, t_ret;
        u_int32_t c_stat, p_stat, tmpstat;

#ifdef DEBUG_RECOVER
        (void)__txn_child_print(dbenv, dbtp, lsnp, op, info);
#endif
        if ((ret = __txn_child_read(dbenv, dbtp->data, &argp)) != 0)
                return (ret);

        /*
         * This is a record in a PARENT's log trail indicating that a
         * child committed.  If we are aborting, return the childs last
         * record's LSN.  If we are in recovery, then if the
         * parent is committing, we set ourselves up to commit, else
         * we do nothing.
         */
        if (op == DB_TXN_ABORT) {
                *lsnp = argp->c_lsn;
                ret = __db_txnlist_lsnadd(dbenv, info, &argp->prev_lsn);
                goto out;
        } else if (op == DB_TXN_BACKWARD_ROLL) {
                /* Child might exist -- look for it. */
                ret = __db_txnlist_find(dbenv, info, argp->child, &c_stat);
                t_ret =
                    __db_txnlist_find(dbenv, info, argp->txnid->txnid, &p_stat);
                if (ret != 0 && ret != DB_NOTFOUND)
                        goto out;
                if (t_ret != 0 && t_ret != DB_NOTFOUND) {
                        ret = t_ret;
                        goto out;
                }
                /*
                 * If the parent is in state COMMIT or IGNORE, then we apply
                 * that to the child, else we need to abort the child.
                 */

                if (ret == DB_NOTFOUND  ||
                    c_stat == TXN_OK || c_stat == TXN_COMMIT) {
                        if (t_ret == DB_NOTFOUND ||
                             (p_stat != TXN_COMMIT  && p_stat != TXN_IGNORE))
                                c_stat = TXN_ABORT;
                        else
                                c_stat = p_stat;

                        if (ret == DB_NOTFOUND)
                                ret = __db_txnlist_add(dbenv,
                                     info, argp->child, c_stat, NULL);
                        else
                                ret = __db_txnlist_update(dbenv, info,
                                     argp->child, c_stat, NULL, &tmpstat, 0);
                } else if (c_stat == TXN_EXPECTED) {
                        /*
                         * The open after this create succeeded.  If the
                         * parent succeeded, we don't want to redo; if the
                         * parent aborted, we do want to undo.
                         */
                        switch (p_stat) {
                        case TXN_COMMIT:
                        case TXN_IGNORE:
                                c_stat = TXN_IGNORE;
                                break;
                        default:
                                c_stat = TXN_ABORT;
                        }
                        ret = __db_txnlist_update(dbenv,
                            info, argp->child, c_stat, NULL, &tmpstat, 0);
                } else if (c_stat == TXN_UNEXPECTED) {
                        /*
                         * The open after this create failed.  If the parent
                         * is rolling forward, we need to roll forward.  If
                         * the parent failed, then we do not want to abort
                         * (because the file may not be the one in which we
                         * are interested).
                         */
                        ret = __db_txnlist_update(dbenv, info, argp->child,
                            p_stat == TXN_COMMIT ? TXN_COMMIT : TXN_IGNORE,
                            NULL, &tmpstat, 0);
                }
        } else if (op == DB_TXN_OPENFILES) {
                /*
                 * If we have a partial subtransaction, then the whole
                 * transaction should be ignored.
                 */
                if ((ret = __db_txnlist_find(dbenv,
                    info, argp->child, &c_stat)) == DB_NOTFOUND)
                        ret = __db_txnlist_update(dbenv, info,
                             argp->txnid->txnid, TXN_IGNORE,
                             NULL, &p_stat, 1);
        } else if (DB_REDO(op)) {
                /* Forward Roll */
                if ((ret =
                    __db_txnlist_remove(dbenv, info, argp->child)) != 0)
                        __db_err(dbenv,
                            "Transaction not in list %x", argp->child);
        }

        if (ret == 0)
                *lsnp = argp->prev_lsn;

out:    __os_free(dbenv, argp);

        return (ret);
}

/*
 * __txn_restore_txn --
 *      Using only during XA recovery.  If we find any transactions that are
 * prepared, but not yet committed, then we need to restore the transaction's
 * state into the shared region, because the TM is going to issue an abort
 * or commit and we need to respond correctly.
 *
 * lsnp is the LSN of the returned LSN
 * argp is the prepare record (in an appropriate structure)
 *
 * PUBLIC: int __txn_restore_txn __P((DB_ENV *,
 * PUBLIC:     DB_LSN *, __txn_xa_regop_args *));
 */
int
__txn_restore_txn(dbenv, lsnp, argp)
        DB_ENV *dbenv;
        DB_LSN *lsnp;
        __txn_xa_regop_args *argp;
{
        DB_TXNMGR *mgr;
        TXN_DETAIL *td;
        DB_TXNREGION *region;
        int ret;

        if (argp->xid.size == 0)
                return (0);

        mgr = dbenv->tx_handle;
        region = mgr->reginfo.primary;
        TXN_SYSTEM_LOCK(dbenv);

        /* Allocate a new transaction detail structure. */
        if ((ret =
            __db_shalloc(&mgr->reginfo, sizeof(TXN_DETAIL), 0, &td)) != 0) {
                TXN_SYSTEM_UNLOCK(dbenv);
                return (ret);
        }

        /* Place transaction on active transaction list. */
        SH_TAILQ_INSERT_HEAD(&region->active_txn, td, links, __txn_detail);

        td->txnid = argp->txnid->txnid;
        td->begin_lsn = argp->begin_lsn;
        td->last_lsn = *lsnp;
        td->parent = 0;
        td->status = TXN_PREPARED;
        td->xa_status = TXN_XA_PREPARED;
        memcpy(td->xid, argp->xid.data, argp->xid.size);
        td->bqual = argp->bqual;
        td->gtrid = argp->gtrid;
        td->format = argp->formatID;
        td->flags = 0;
        F_SET(td, TXN_DTL_RESTORED);

        region->stat.st_nrestores++;
        region->stat.st_nactive++;
        if (region->stat.st_nactive > region->stat.st_maxnactive)
                region->stat.st_maxnactive = region->stat.st_nactive;
        TXN_SYSTEM_UNLOCK(dbenv);
        return (0);
}

/*
 * __txn_recycle_recover --
 *      Recovery function for recycle.
 *
 * PUBLIC: int __txn_recycle_recover
 * PUBLIC:   __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__txn_recycle_recover(dbenv, dbtp, lsnp, op, info)
        DB_ENV *dbenv;
        DBT *dbtp;
        DB_LSN *lsnp;
        db_recops op;
        void *info;
{
        __txn_recycle_args *argp;
        int ret;

#ifdef DEBUG_RECOVER
        (void)__txn_child_print(dbenv, dbtp, lsnp, op, info);
#endif
        if ((ret = __txn_recycle_read(dbenv, dbtp->data, &argp)) != 0)
                return (ret);

        COMPQUIET(lsnp, NULL);

        if ((ret = __db_txnlist_gen(dbenv, info,
            DB_UNDO(op) ? -1 : 1, argp->min, argp->max)) != 0)
                return (ret);

        __os_free(dbenv, argp);

        return (0);
}

---