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db_dispatch.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998, 1999, 2000
 *    Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1995, 1996
 *    The President and Fellows of Harvard University.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Margo Seltzer.
 *
 * 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.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: db_dispatch.c,v 11.41 2001/01/11 18:19:50 bostic Exp $";
#endif /* not lint */

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

#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#endif

#include "db_int.h"
#include "db_page.h"
#include "db_dispatch.h"
#include "db_am.h"
#include "log_auto.h"
#include "txn.h"
#include "txn_auto.h"
#include "log.h"

static int __db_txnlist_find_internal __P((void *, db_txnlist_type,
           u_int32_t, u_int8_t [DB_FILE_ID_LEN], DB_TXNLIST **, int));

/*
 * __db_dispatch --
 *
 * This is the transaction dispatch function used by the db access methods.
 * It is designed to handle the record format used by all the access
 * methods (the one automatically generated by the db_{h,log,read}.sh
 * scripts in the tools directory).  An application using a different
 * recovery paradigm will supply a different dispatch function to txn_open.
 *
 * PUBLIC: int __db_dispatch __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__db_dispatch(dbenv, db, lsnp, redo, info)
      DB_ENV *dbenv;          /* The environment. */
      DBT *db;          /* The log record upon which to dispatch. */
      DB_LSN *lsnp;           /* The lsn of the record being dispatched. */
      db_recops redo;         /* Redo this op (or undo it). */
      void *info;
{
      u_int32_t rectype, txnid;
      int make_call, ret;

      memcpy(&rectype, db->data, sizeof(rectype));
      memcpy(&txnid, (u_int8_t *)db->data + sizeof(rectype), sizeof(txnid));
      make_call = ret = 0;

      /*
       * If we find a record that is in the user's number space and they
       * have specified a recovery routine, let them handle it.  If they
       * didn't specify a recovery routine, then we expect that they've
       * followed all our rules and registered new recovery functions.
       */
      switch (redo) {
      case DB_TXN_ABORT:
            /*
             * XXX
             * db_printlog depends on DB_TXN_ABORT not examining the TXN
             * list.  If that ever changes, fix db_printlog too.
             */
            make_call = 1;
            break;
      case DB_TXN_OPENFILES:
            if (rectype == DB_log_register)
                  return (dbenv->dtab[rectype](dbenv,
                      db, lsnp, redo, info));
            break;
      case DB_TXN_BACKWARD_ROLL:
            /*
             * Running full recovery in the backward pass.  If we've
             * seen this txnid before and added to it our commit list,
             * then we do nothing during this pass, unless this is a child
             * commit record, in which case we need to process it.  If
             * we've never seen it, then we call the appropriate recovery
             * routine.
             *
             * We need to always undo DB_db_noop records, so that we
             * properly handle any aborts before the file was closed.
             */
            if (rectype == DB_log_register ||
                rectype == DB_txn_ckp || rectype == DB_db_noop
                || rectype == DB_txn_child || (txnid != 0 &&
                (ret = __db_txnlist_find(info, txnid)) != 0)) {
                  make_call = 1;
                  if (ret == DB_NOTFOUND && rectype != DB_txn_regop &&
                      rectype != DB_txn_xa_regop && (ret =
                      __db_txnlist_add(dbenv, info, txnid, 1)) != 0)
                        return (ret);
            }
            break;
      case DB_TXN_FORWARD_ROLL:
            /*
             * In the forward pass, if we haven't seen the transaction,
             * do nothing, else recovery it.
             *
             * We need to always redo DB_db_noop records, so that we
             * properly handle any commits after the file was closed.
             */
            if (rectype == DB_log_register ||
                rectype == DB_txn_ckp ||
                rectype == DB_db_noop ||
                __db_txnlist_find(info, txnid) == 0)
                  make_call = 1;
            break;
      default:
            return (__db_unknown_flag(dbenv, "__db_dispatch", redo));
      }

      if (make_call) {
            if (rectype >= DB_user_BEGIN && dbenv->tx_recover != NULL)
                  return (dbenv->tx_recover(dbenv, db, lsnp, redo));
            else
                  return (dbenv->dtab[rectype](dbenv, db, lsnp, redo, info));
      }

      return (0);
}

/*
 * __db_add_recovery --
 *
 * PUBLIC: int __db_add_recovery __P((DB_ENV *,
 * PUBLIC:    int (*)(DB_ENV *, DBT *, DB_LSN *, db_recops, void *), u_int32_t));
 */
int
__db_add_recovery(dbenv, func, ndx)
      DB_ENV *dbenv;
      int (*func) __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
      u_int32_t ndx;
{
      u_int32_t i, nsize;
      int ret;

      /* Check if we have to grow the table. */
      if (ndx >= dbenv->dtab_size) {
            nsize = ndx + 40;
            if ((ret = __os_realloc(dbenv,
                nsize * sizeof(dbenv->dtab[0]), NULL, &dbenv->dtab)) != 0)
                  return (ret);
            for (i = dbenv->dtab_size; i < nsize; ++i)
                  dbenv->dtab[i] = NULL;
            dbenv->dtab_size = nsize;
      }

      dbenv->dtab[ndx] = func;
      return (0);
}

/*
 * __deprecated_recover --
 *    Stub routine for deprecated recovery functions.
 *
 * PUBLIC: int __deprecated_recover
 * PUBLIC:     __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__deprecated_recover(dbenv, dbtp, lsnp, op, info)
      DB_ENV *dbenv;
      DBT *dbtp;
      DB_LSN *lsnp;
      db_recops op;
      void *info;
{
      COMPQUIET(dbenv, NULL);
      COMPQUIET(dbtp, NULL);
      COMPQUIET(lsnp, NULL);
      COMPQUIET(op, 0);
      COMPQUIET(info, NULL);
      return (EINVAL);
}

/*
 * __db_txnlist_init --
 *    Initialize transaction linked list.
 *
 * PUBLIC: int __db_txnlist_init __P((DB_ENV *, void *));
 */
int
__db_txnlist_init(dbenv, retp)
      DB_ENV *dbenv;
      void *retp;
{
      DB_TXNHEAD *headp;
      int ret;

      if ((ret = __os_malloc(dbenv, sizeof(DB_TXNHEAD), NULL, &headp)) != 0)
            return (ret);

      LIST_INIT(&headp->head);
      headp->maxid = 0;
      headp->generation = 1;

      *(void **)retp = headp;
      return (0);
}

/*
 * __db_txnlist_add --
 *    Add an element to our transaction linked list.
 *
 * PUBLIC: int __db_txnlist_add __P((DB_ENV *, void *, u_int32_t, int32_t));
 */
int
__db_txnlist_add(dbenv, listp, txnid, aborted)
      DB_ENV *dbenv;
      void *listp;
      u_int32_t txnid;
      int32_t aborted;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *elp;
      int ret;

      if ((ret = __os_malloc(dbenv, sizeof(DB_TXNLIST), NULL, &elp)) != 0)
            return (ret);

      hp = (DB_TXNHEAD *)listp;
      LIST_INSERT_HEAD(&hp->head, elp, links);

      elp->type = TXNLIST_TXNID;
      elp->u.t.txnid = txnid;
      elp->u.t.aborted = aborted;
      if (txnid > hp->maxid)
            hp->maxid = txnid;
      elp->u.t.generation = hp->generation;

      return (0);
}
/*
 * __db_txnlist_remove --
 *    Remove an element from our transaction linked list.
 *
 * PUBLIC: int __db_txnlist_remove __P((void *, u_int32_t));
 */
int
__db_txnlist_remove(listp, txnid)
      void *listp;
      u_int32_t txnid;
{
      DB_TXNLIST *entry;

      return (__db_txnlist_find_internal(listp,
           TXNLIST_TXNID, txnid, NULL, &entry, 1));
}

/* __db_txnlist_close --
 *
 *    Call this when we close a file.  It allows us to reconcile whether
 * we have done any operations on this file with whether the file appears
 * to have been deleted.  If you never do any operations on a file, then
 * we assume it's OK to appear deleted.
 *
 * PUBLIC: int __db_txnlist_close __P((void *, int32_t, u_int32_t));
 */

int
__db_txnlist_close(listp, lid, count)
      void *listp;
      int32_t lid;
      u_int32_t count;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *p;

      hp = (DB_TXNHEAD *)listp;
      for (p = LIST_FIRST(&hp->head); p != NULL; p = LIST_NEXT(p, links)) {
            if (p->type == TXNLIST_DELETE)
                  if (lid == p->u.d.fileid &&
                      !F_ISSET(&p->u.d, TXNLIST_FLAG_CLOSED)) {
                        p->u.d.count += count;
                        return (0);
                  }
      }

      return (0);
}

/*
 * __db_txnlist_delete --
 *
 *    Record that a file was missing or deleted.  If the deleted
 * flag is set, then we've encountered a delete of a file, else we've
 * just encountered a file that is missing.  The lid is the log fileid
 * and is only meaningful if deleted is not equal to 0.
 *
 * PUBLIC: int __db_txnlist_delete __P((DB_ENV *,
 * PUBLIC:     void *, char *, u_int32_t, int));
 */
int
__db_txnlist_delete(dbenv, listp, name, lid, deleted)
      DB_ENV *dbenv;
      void *listp;
      char *name;
      u_int32_t lid;
      int deleted;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *p;
      int ret;

      hp = (DB_TXNHEAD *)listp;
      for (p = LIST_FIRST(&hp->head); p != NULL; p = LIST_NEXT(p, links)) {
            if (p->type == TXNLIST_DELETE)
                  if (strcmp(name, p->u.d.fname) == 0) {
                        if (deleted)
                              F_SET(&p->u.d, TXNLIST_FLAG_DELETED);
                        else
                              F_CLR(&p->u.d, TXNLIST_FLAG_CLOSED);
                        return (0);
                  }
      }

      /* Need to add it. */
      if ((ret = __os_malloc(dbenv, sizeof(DB_TXNLIST), NULL, &p)) != 0)
            return (ret);
      LIST_INSERT_HEAD(&hp->head, p, links);

      p->type = TXNLIST_DELETE;
      p->u.d.flags = 0;
      if (deleted)
            F_SET(&p->u.d, TXNLIST_FLAG_DELETED);
      p->u.d.fileid = lid;
      p->u.d.count = 0;
      ret = __os_strdup(dbenv, name, &p->u.d.fname);

      return (ret);
}

/*
 * __db_txnlist_end --
 *    Discard transaction linked list. Print out any error messages
 * for deleted files.
 *
 * PUBLIC: void __db_txnlist_end __P((DB_ENV *, void *));
 */
void
__db_txnlist_end(dbenv, listp)
      DB_ENV *dbenv;
      void *listp;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *p;
      DB_LOG *lp;

      hp = (DB_TXNHEAD *)listp;
      lp = (DB_LOG *)dbenv->lg_handle;
      while (hp != NULL && (p = LIST_FIRST(&hp->head)) != NULL) {
            LIST_REMOVE(p, links);
            switch (p->type) {
            case TXNLIST_DELETE:
                  /*
                   * If we have a file that is not deleted and has
                   * some operations, we flag the warning.  Since
                   * the file could still be open, we need to check
                   * the actual log table as well.
                   */
                  if ((!F_ISSET(&p->u.d, TXNLIST_FLAG_DELETED) &&
                      p->u.d.count != 0) ||
                      (!F_ISSET(&p->u.d, TXNLIST_FLAG_CLOSED) &&
                      p->u.d.fileid != (int32_t) TXNLIST_INVALID_ID &&
                      p->u.d.fileid < lp->dbentry_cnt &&
                      lp->dbentry[p->u.d.fileid].count != 0))
                        __db_err(dbenv, "warning: %s: %s",
                            p->u.d.fname, db_strerror(ENOENT));
                  __os_freestr(p->u.d.fname);
                  break;
            case TXNLIST_LSN:
                  __os_free(p->u.l.lsn_array,
                      p->u.l.maxn * sizeof(DB_LSN));
                  break;
            default:
                  /* Possibly an incomplete DB_TXNLIST;  just free it. */
                  break;
            }
            __os_free(p, sizeof(DB_TXNLIST));
      }
      __os_free(listp, sizeof(DB_TXNHEAD));
}

/*
 * __db_txnlist_find --
 *    Checks to see if a txnid with the current generation is in the
 *    txnid list.  This returns DB_NOTFOUND if the item isn't in the
 *    list otherwise it returns (like __db_txnlist_find_internal) a
 *    1 or 0 indicating if the transaction is aborted or not.  A txnid
 *    of 0 means the record was generated while not in a transaction.
 *
 * PUBLIC: int __db_txnlist_find __P((void *, u_int32_t));
 */
int
__db_txnlist_find(listp, txnid)
      void *listp;
      u_int32_t txnid;
{
      DB_TXNLIST *entry;

      if (txnid == 0)
            return (DB_NOTFOUND);
      return (__db_txnlist_find_internal(listp,
           TXNLIST_TXNID, txnid, NULL, &entry, 0));
}

/*
 * __db_txnlist_find_internal --
 *    Find an entry on the transaction list.
 * If the entry is not there or the list pointeris not initialized
 * we return DB_NOTFOUND.  If the item is found, we return the aborted
 * status (1 for aborted, 0 for not aborted).  Currently we always call
 * this with an initialized list pointer but checking for NULL keeps it general.
 */
static int
__db_txnlist_find_internal(listp, type, txnid, uid, txnlistp, delete)
      void *listp;
      db_txnlist_type type;
      u_int32_t txnid;
      u_int8_t uid[DB_FILE_ID_LEN];
      DB_TXNLIST **txnlistp;
      int delete;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *p;
      int ret;

      if ((hp = (DB_TXNHEAD *)listp) == NULL)
            return (DB_NOTFOUND);

      for (p = LIST_FIRST(&hp->head); p != NULL; p = LIST_NEXT(p, links)) {
            if (p->type != type)
                  continue;
            switch (type) {
            case TXNLIST_TXNID:
                  if (p->u.t.txnid != txnid ||
                      hp->generation != p->u.t.generation)
                        continue;
                  ret = p->u.t.aborted;
                  break;

            case TXNLIST_PGNO:
                  if (memcmp(uid, p->u.p.uid, DB_FILE_ID_LEN) != 0)
                        continue;

                  ret = 0;
                  break;
            default:
                  DB_ASSERT(0);
                  ret = EINVAL;
            }
            if (delete == 1) {
                  LIST_REMOVE(p, links);
                  __os_free(p, sizeof(DB_TXNLIST));
            } else if (p != LIST_FIRST(&hp->head)) {
                  /* Move it to head of list. */
                  LIST_REMOVE(p, links);
                  LIST_INSERT_HEAD(&hp->head, p, links);
            }
            *txnlistp = p;
            return (ret);
      }

      return (DB_NOTFOUND);
}

/*
 * __db_txnlist_gen --
 *    Change the current generation number.
 *
 * PUBLIC: void __db_txnlist_gen __P((void *, int));
 */
void
__db_txnlist_gen(listp, incr)
      void *listp;
      int incr;
{
      DB_TXNHEAD *hp;

      /*
       * During recovery generation numbers keep track of how many "restart"
       * checkpoints we've seen.  Restart checkpoints occur whenever we take
       * a checkpoint and there are no outstanding transactions.  When that
       * happens, we can reset transaction IDs back to 1.  It always happens
       * at recovery and it prevents us from exhausting the transaction IDs
       * name space.
       */
      hp = (DB_TXNHEAD *)listp;
      hp->generation += incr;
}

#define     TXN_BUBBLE(AP, MAX) {                                 \
      int __j;                                        \
      DB_LSN __tmp;                                         \
                                                      \
      for (__j = 0; __j < MAX - 1; __j++)                   \
            if (log_compare(&AP[__j], &AP[__j + 1]) < 0) {        \
                  __tmp = AP[__j];                    \
                  AP[__j] = AP[__j + 1];                    \
                  AP[__j + 1] = __tmp;                      \
            }                                         \
}

/*
 * __db_txnlist_lsnadd --
 *    Add to or re-sort the transaction list lsn entry.
 * Note that since this is used during an abort, the __txn_undo
 * code calls into the "recovery" subsystem explicitly, and there
 * is only a single TXNLIST_LSN entry on the list.
 *
 * PUBLIC: int __db_txnlist_lsnadd __P((DB_ENV *, void *, DB_LSN *, u_int32_t));
 */
int
__db_txnlist_lsnadd(dbenv, listp, lsnp, flags)
      DB_ENV *dbenv;
      void *listp;
      DB_LSN *lsnp;
      u_int32_t flags;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *elp;
      int i, ret;

      hp = (DB_TXNHEAD *)listp;

      for (elp = LIST_FIRST(&hp->head);
          elp != NULL; elp = LIST_NEXT(elp, links))
            if (elp->type == TXNLIST_LSN)
                  break;

      if (elp == NULL)
            return (EINVAL);

      if (LF_ISSET(TXNLIST_NEW)) {
            if (elp->u.l.ntxns >= elp->u.l.maxn) {
                  if ((ret = __os_realloc(dbenv,
                      2 * elp->u.l.maxn * sizeof(DB_LSN),
                      NULL, &elp->u.l.lsn_array)) != 0)
                        return (ret);
                  elp->u.l.maxn *= 2;
            }
            elp->u.l.lsn_array[elp->u.l.ntxns++] = *lsnp;
      } else
            /* Simply replace the 0th element. */
            elp->u.l.lsn_array[0] = *lsnp;

      /*
       * If we just added a new entry and there may be NULL
       * entries, so we have to do a complete bubble sort,
       * not just trickle a changed entry around.
       */
      for (i = 0; i < (!LF_ISSET(TXNLIST_NEW) ? 1 : elp->u.l.ntxns); i++)
            TXN_BUBBLE(elp->u.l.lsn_array, elp->u.l.ntxns);

      *lsnp = elp->u.l.lsn_array[0];

      return (0);
}

/*
 * __db_txnlist_lsnhead --
 *    Return a pointer to the beginning of the lsn_array.
 *
 * PUBLIC: int __db_txnlist_lsnhead __P((void *, DB_LSN **));
 */
int
__db_txnlist_lsnhead(listp, lsnpp)
      void *listp;
      DB_LSN **lsnpp;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *elp;

      hp = (DB_TXNHEAD *)listp;

      for (elp = LIST_FIRST(&hp->head);
          elp != NULL; elp = LIST_NEXT(elp, links))
            if (elp->type == TXNLIST_LSN)
                  break;

      if (elp == NULL)
            return (EINVAL);

      *lsnpp = &elp->u.l.lsn_array[0];

      return (0);
}

/*
 * __db_txnlist_lsninit --
 *    Initialize a transaction list with an lsn array entry.
 *
 * PUBLIC: int __db_txnlist_lsninit __P((DB_ENV *, DB_TXNHEAD *, DB_LSN *));
 */
int
__db_txnlist_lsninit(dbenv, hp, lsnp)
      DB_ENV *dbenv;
      DB_TXNHEAD *hp;
      DB_LSN *lsnp;
{
      DB_TXNLIST *elp;
      int ret;

      elp = NULL;

      if ((ret = __os_malloc(dbenv, sizeof(DB_TXNLIST), NULL, &elp)) != 0)
            goto err;
      LIST_INSERT_HEAD(&hp->head, elp, links);

      if ((ret = __os_malloc(dbenv,
          12 * sizeof(DB_LSN), NULL, &elp->u.l.lsn_array)) != 0)
            goto err;
      elp->type = TXNLIST_LSN;
      elp->u.l.maxn = 12;
      elp->u.l.ntxns = 1;
      elp->u.l.lsn_array[0] = *lsnp;

      return (0);

err:  __db_txnlist_end(dbenv, hp);
      return (ret);
}

/*
 * __db_add_limbo -- add pages to the limbo list.
 *    Get the file information and call pgnoadd
 * for each page.
 *
 * PUBLIC: int __db_add_limbo __P((DB_ENV *,
 * PUBLIC:      void *, int32_t, db_pgno_t, int32_t));
 */
int
__db_add_limbo(dbenv, info, fileid, pgno, count)
      DB_ENV *dbenv;
      void *info;
      int32_t fileid;
      db_pgno_t pgno;
      int32_t count;
{
      DB_LOG *dblp;
      FNAME *fnp;
      int ret;

      dblp = dbenv->lg_handle;
      if ((ret = __log_lid_to_fname(dblp, fileid, &fnp)) != 0)
            return (ret);

      do {
            if ((ret =
                __db_txnlist_pgnoadd(dbenv, info, fileid, fnp->ufid,
                R_ADDR(&dblp->reginfo, fnp->name_off), pgno)) != 0)
                  return (ret);
            pgno++;
      } while (--count != 0);

      return (0);
}

/*
 * __db_do_the_limbo -- move pages from limbo to free.
 *
 * If we are in recovery we add things to the free list without
 * logging becasue we want to incrementaly apply logs that
 * may be generated on another copy of this environment.
 * Otherwise we just call __db_free to put the pages on
 * the free list and log the activity.
 *
 * PUBLIC: int __db_do_the_limbo __P((DB_ENV *, DB_TXNHEAD *));
 */
int
__db_do_the_limbo(dbenv, hp)
      DB_ENV *dbenv;
      DB_TXNHEAD *hp;
{
      DB *dbp;
      DBC *dbc;
      DBMETA *meta;
      DB_TXN *txn;
      DB_TXNLIST *elp;
      PAGE *pagep;
      db_pgno_t last_pgno, pgno;
      int i, in_recover, put_page, ret, t_ret;

      dbp = NULL;
      dbc = NULL;
      txn = NULL;
      ret = 0;

      /* Are we in recovery? */
      in_recover = F_ISSET((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER);

      for (elp = LIST_FIRST(&hp->head);
          elp != NULL; elp = LIST_NEXT(elp, links)) {
            if (elp->type != TXNLIST_PGNO)
                  continue;

            if (in_recover) {
                  if ((ret = db_create(&dbp, dbenv, 0)) != 0)
                        goto err;

                  /*
                   * It is ok if the file is nolonger there.
                   */
                  dbp->type = DB_UNKNOWN;
                  ret = __db_dbopen(dbp,
                      elp->u.p.fname, 0, __db_omode("rw----"), 0);
            } else {
                  /*
                   * If we are in transaction undo, then we know
                   * the fileid is still correct.
                   */
                  if ((ret =
                      __db_fileid_to_db(dbenv, &dbp,
                      elp->u.p.fileid, 0)) != 0 && ret != DB_DELETED)
                        goto err;
                  /* File is being destroyed. */
                  if (F_ISSET(dbp, DB_AM_DISCARD))
                        ret = DB_DELETED;
            }
            /*
             * Verify that we are opening the same file that we were
             * referring to when we wrote this log record.
             */
            if (ret == 0 &&
                memcmp(elp->u.p.uid, dbp->fileid, DB_FILE_ID_LEN) == 0) {
                  last_pgno = PGNO_INVALID;
                  if (in_recover) {
                        pgno = PGNO_BASE_MD;
                        if ((ret = memp_fget(dbp->mpf,
                            &pgno, 0, (PAGE **)&meta)) != 0)
                              goto err;
                        last_pgno = meta->free;
                        /*
                         * Check to see if the head of the free
                         * list is any of the pages we are about
                         * to link in.  We could have crashed
                         * after linking them in and before writing
                         * a checkpoint.
                         * It may not be the last one since
                         * any page may get reallocated before here.
                         */
                        if (last_pgno != PGNO_INVALID)
                              for (i = 0; i < elp->u.p.nentries; i++)
                                    if (last_pgno
                                         == elp->u.p.pgno_array[i])
                                          goto done_it;
                  }

                  for (i = 0; i < elp->u.p.nentries; i++) {
                        pgno = elp->u.p.pgno_array[i];
                        if ((ret = memp_fget(dbp->mpf,
                            &pgno, DB_MPOOL_CREATE, &pagep)) != 0)
                              goto err;

                        put_page = 1;
                        if (IS_ZERO_LSN(LSN(pagep))) {
                              P_INIT(pagep, dbp->pgsize,
                                  pgno, PGNO_INVALID,
                                  last_pgno, 0, P_INVALID);

                              if (in_recover) {
                                    LSN(pagep) = LSN(meta);
                                    last_pgno = pgno;
                              } else {
                                    /*
                                     * Starting the transaction
                                     * is postponed until we know
                                     * we have something to do.
                                     */
                                    if (txn == NULL &&
                                        (ret = txn_begin(dbenv,
                                        NULL, &txn, 0)) != 0)
                                          goto err;

                                    if (dbc == NULL &&
                                        (ret = dbp->cursor(dbp,
                                        txn, &dbc, 0)) != 0)
                                          goto err;
                                    /* Turn off locking. */
                                    F_SET(dbc, DBC_COMPENSATE);

                                    /* __db_free puts the page. */
                                    if ((ret =
                                        __db_free(dbc, pagep)) != 0)
                                          goto err;
                                    put_page = 0;
                              }
                        }

                        if (put_page == 1 &&
                            (ret = memp_fput(dbp->mpf,
                            pagep, DB_MPOOL_DIRTY)) != 0)
                              goto err;
                  }
                  if (in_recover) {
                        if (last_pgno == meta->free) {
done_it:
                              if ((ret =
                                  memp_fput(dbp->mpf, meta, 0)) != 0)
                                    goto err;
                        } else {
                              /*
                               * Flush the new free list then
                               * update the metapage.  This is
                               * unlogged so we cannot have the
                               * metapage pointing at pages that
                               * are not on disk.
                               */
                              dbp->sync(dbp, 0);
                              meta->free = last_pgno;
                              if ((ret = memp_fput(dbp->mpf,
                                  meta, DB_MPOOL_DIRTY)) != 0)
                                    goto err;
                        }
                  }
                  if (dbc != NULL && (ret = dbc->c_close(dbc)) != 0)
                        goto err;
                  dbc = NULL;
            }
            if (in_recover && (t_ret = dbp->close(dbp, 0)) != 0 && ret == 0)
                  ret = t_ret;
            dbp = NULL;
            __os_free(elp->u.p.fname, 0);
            __os_free(elp->u.p.pgno_array, 0);
            if (ret == ENOENT)
                  ret = 0;
            else if (ret != 0)
                  goto err;
      }

      if (txn != NULL) {
            ret = txn_commit(txn, 0);
            txn = NULL;
      }
err:
      if (dbc != NULL)
            (void)dbc->c_close(dbc);
      if (in_recover && dbp != NULL)
            (void)dbp->close(dbp, 0);
      if (txn != NULL)
            (void)txn_abort(txn);
      return (ret);

}

#define     DB_TXNLIST_MAX_PGNO     8 /* A nice even number. */

/*
 * __db_txnlist_pgnoadd --
 *    Find the txnlist entry for a file and add this pgno,
 * or add the list entry for the file and then add the pgno.
 *
 * PUBLIC: int __db_txnlist_pgnoadd __P((DB_ENV *, DB_TXNHEAD *,
 * PUBLIC:      int32_t, u_int8_t [DB_FILE_ID_LEN], char *, db_pgno_t));
 */
int
__db_txnlist_pgnoadd(dbenv, hp, fileid, uid, fname, pgno)
      DB_ENV *dbenv;
      DB_TXNHEAD *hp;
      int32_t fileid;
      u_int8_t uid[DB_FILE_ID_LEN];
      char *fname;
      db_pgno_t pgno;
{
      DB_TXNLIST *elp;
      int len, ret;

      elp = NULL;

      if (__db_txnlist_find_internal(hp, TXNLIST_PGNO, 0, uid, &elp, 0) != 0) {
            if ((ret =
                __os_malloc(dbenv, sizeof(DB_TXNLIST), NULL, &elp)) != 0)
                  goto err;
            LIST_INSERT_HEAD(&hp->head, elp, links);
            elp->u.p.fileid = fileid;
            memcpy(elp->u.p.uid, uid, DB_FILE_ID_LEN);

            len = strlen(fname) + 1;
            if ((ret = __os_malloc(dbenv, len, NULL, &elp->u.p.fname)) != 0)
                  goto err;
            memcpy(elp->u.p.fname, fname, len);

            elp->u.p.maxentry = 0;
            elp->type = TXNLIST_PGNO;
            if ((ret = __os_malloc(dbenv,
                8 * sizeof(db_pgno_t), NULL, &elp->u.p.pgno_array)) != 0)
                  goto err;
            elp->u.p.maxentry = DB_TXNLIST_MAX_PGNO;
            elp->u.p.nentries = 0;
      } else if (elp->u.p.nentries == elp->u.p.maxentry) {
            elp->u.p.maxentry <<= 1;
            if ((ret = __os_realloc(dbenv, elp->u.p.maxentry *
                sizeof(db_pgno_t), NULL, &elp->u.p.pgno_array)) != 0)
                  goto err;
      }

      elp->u.p.pgno_array[elp->u.p.nentries++] = pgno;

      return (0);

err:  __db_txnlist_end(dbenv, hp);
      return (ret);
}

#ifdef DEBUG
/*
 * __db_txnlist_print --
 *    Print out the transaction list.
 *
 * PUBLIC: void __db_txnlist_print __P((void *));
 */
void
__db_txnlist_print(listp)
      void *listp;
{
      DB_TXNHEAD *hp;
      DB_TXNLIST *p;

      hp = (DB_TXNHEAD *)listp;

      printf("Maxid: %lu Generation: %lu\n",
          (u_long)hp->maxid, (u_long)hp->generation);
      for (p = LIST_FIRST(&hp->head); p != NULL; p = LIST_NEXT(p, links)) {
            switch (p->type) {
            case TXNLIST_TXNID:
                  printf("TXNID: %lu(%lu)\n",
                      (u_long)p->u.t.txnid, (u_long)p->u.t.generation);
                  break;
            case TXNLIST_DELETE:
                  printf("FILE: %s id=%d ops=%d %s %s\n",
                      p->u.d.fname, p->u.d.fileid, p->u.d.count,
                      F_ISSET(&p->u.d, TXNLIST_FLAG_DELETED) ?
                      "(deleted)" : "(missing)",
                      F_ISSET(&p->u.d, TXNLIST_FLAG_CLOSED) ?
                      "(closed)" : "(open)");

                  break;
            default:
                  printf("Unrecognized type: %d\n", p->type);
                  break;
            }
      }
}
#endif

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