Logo Search packages:      
Sourcecode: db3 version File versions  Download package

db.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996, 1997, 1998, 1999, 2000
 *    Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994, 1995, 1996
 *    Keith Bostic.  All rights reserved.
 */
/*
 * Copyright (c) 1990, 1993, 1994, 1995
 *    The Regents of the University of California.  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.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: db.c,v 11.117 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_shash.h"
#include "db_swap.h"
#include "btree.h"
#include "db_am.h"
#include "hash.h"
#include "lock.h"
#include "log.h"
#include "mp.h"
#include "qam.h"
#include "common_ext.h"

/* Actions that __db_master_update can take. */
typedef enum { MU_REMOVE, MU_RENAME, MU_OPEN } mu_action;

/* Flag values that __db_file_setup can return. */
#define     DB_FILE_SETUP_CREATE    0x01
#define     DB_FILE_SETUP_ZERO      0x02

static int __db_file_setup __P((DB *,
             const char *, u_int32_t, int, db_pgno_t, int *));
static int __db_master_update __P((DB *,
             const char *, u_int32_t,
             db_pgno_t *, mu_action, const char *, u_int32_t));
static int __db_refresh __P((DB *));
static int __db_remove_callback __P((DB *, void *));
static int __db_set_pgsize __P((DB *, DB_FH *, char *));
static int __db_subdb_remove __P((DB *, const char *, const char *));
static int __db_subdb_rename __P(( DB *,
            const char *, const char *, const char *));
#if     CONFIG_TEST
static void __db_makecopy __P((const char *, const char *));
static int __db_testdocopy __P((DB *, const char *));
static int __qam_testdocopy __P((DB *, const char *));
#endif

/*
 * __db_open --
 *    Main library interface to the DB access methods.
 *
 * PUBLIC: int __db_open __P((DB *,
 * PUBLIC:     const char *, const char *, DBTYPE, u_int32_t, int));
 */
int
__db_open(dbp, name, subdb, type, flags, mode)
      DB *dbp;
      const char *name, *subdb;
      DBTYPE type;
      u_int32_t flags;
      int mode;
{
      DB_ENV *dbenv;
      DB_LOCK open_lock;
      DB *mdbp;
      db_pgno_t meta_pgno;
      u_int32_t ok_flags;
      int ret, t_ret;

      dbenv = dbp->dbenv;
      mdbp = NULL;

      /* Validate arguments. */
#define     OKFLAGS                                               \
    (DB_CREATE | DB_EXCL | DB_FCNTL_LOCKING |                     \
    DB_NOMMAP | DB_RDONLY | DB_RDWRMASTER | DB_THREAD | DB_TRUNCATE)
      if ((ret = __db_fchk(dbenv, "DB->open", flags, OKFLAGS)) != 0)
            return (ret);
      if (LF_ISSET(DB_EXCL) && !LF_ISSET(DB_CREATE))
            return (__db_ferr(dbenv, "DB->open", 1));
      if (LF_ISSET(DB_RDONLY) && LF_ISSET(DB_CREATE))
            return (__db_ferr(dbenv, "DB->open", 1));
#ifdef      HAVE_VXWORKS
      if (LF_ISSET(DB_TRUNCATE)) {
            __db_err(dbenv, "DB_TRUNCATE unsupported in VxWorks");
            return (__db_eopnotsup(dbenv));
      }
#endif
      switch (type) {
      case DB_UNKNOWN:
            if (LF_ISSET(DB_CREATE|DB_TRUNCATE)) {
                  __db_err(dbenv,
          "%s: DB_UNKNOWN type specified with DB_CREATE or DB_TRUNCATE",
                      name);
                  return (EINVAL);
            }
            ok_flags = 0;
            break;
      case DB_BTREE:
            ok_flags = DB_OK_BTREE;
            break;
      case DB_HASH:
            ok_flags = DB_OK_HASH;
            break;
      case DB_QUEUE:
            ok_flags = DB_OK_QUEUE;
            break;
      case DB_RECNO:
            ok_flags = DB_OK_RECNO;
            break;
      default:
            __db_err(dbenv, "unknown type: %lu", (u_long)type);
            return (EINVAL);
      }
      if (ok_flags)
            DB_ILLEGAL_METHOD(dbp, ok_flags);

      /* The environment may have been created, but never opened. */
      if (!F_ISSET(dbenv, DB_ENV_DBLOCAL | DB_ENV_OPEN_CALLED)) {
            __db_err(dbenv, "environment not yet opened");
            return (EINVAL);
      }

      /*
       * Historically, you could pass in an environment that didn't have a
       * mpool, and DB would create a private one behind the scenes.  This
       * no longer works.
       */
      if (!F_ISSET(dbenv, DB_ENV_DBLOCAL) && !MPOOL_ON(dbenv)) {
            __db_err(dbenv, "environment did not include a memory pool.");
            return (EINVAL);
      }

      /*
       * You can't specify threads during DB->open if subsystems in the
       * environment weren't configured with them.
       */
      if (LF_ISSET(DB_THREAD) &&
          !F_ISSET(dbenv, DB_ENV_DBLOCAL | DB_ENV_THREAD)) {
            __db_err(dbenv, "environment not created using DB_THREAD");
            return (EINVAL);
      }

      /*
       * If the environment was configured with threads, the DB handle
       * must also be free-threaded, so we force the DB_THREAD flag on.
       * (See SR #2033 for why this is a requirement--recovery needs
       * to be able to grab a dbp using __db_fileid_to_dbp, and it has
       * no way of knowing which dbp goes with which thread, so whichever
       * one it finds has to be usable in any of them.)
       */
      if (F_ISSET(dbenv, DB_ENV_THREAD))
            LF_SET(DB_THREAD);

      /* DB_TRUNCATE is not transaction recoverable. */
      if (LF_ISSET(DB_TRUNCATE) && TXN_ON(dbenv)) {
            __db_err(dbenv,
          "DB_TRUNCATE illegal in a transaction protected environment");
            return (EINVAL);
      }

      /* Subdatabase checks. */
      if (subdb != NULL) {
            /* Subdatabases must be created in named files. */
            if (name == NULL) {
                  __db_err(dbenv,
                "multiple databases cannot be created in temporary files");
                  return (EINVAL);
            }

            /* QAM can't be done as a subdatabase. */
            if (type == DB_QUEUE) {
                  __db_err(dbenv, "Queue databases must be one-per-file");
                  return (EINVAL);
            }
      }

      /* Convert any DB->open flags. */
      if (LF_ISSET(DB_RDONLY))
            F_SET(dbp, DB_AM_RDONLY);

      /* Fill in the type. */
      dbp->type = type;

      /*
       * If we're potentially creating a database, wrap the open inside of
       * a transaction.
       */
      if (TXN_ON(dbenv) && LF_ISSET(DB_CREATE))
            if ((ret = __db_metabegin(dbp, &open_lock)) != 0)
                  return (ret);

      /*
       * If we're opening a subdatabase, we have to open (and potentially
       * create) the main database, and then get (and potentially store)
       * our base page number in that database.  Then, we can finally open
       * the subdatabase.
       */
      if (subdb == NULL)
            meta_pgno = PGNO_BASE_MD;
      else {
            /*
             * Open the master database, optionally creating or updating
             * it, and retrieve the metadata page number.
             */
            if ((ret =
                __db_master_open(dbp, name, flags, mode, &mdbp)) != 0)
                  goto err;

            /* Copy the page size and file id from the master. */
            dbp->pgsize = mdbp->pgsize;
            F_SET(dbp, DB_AM_SUBDB);
            memcpy(dbp->fileid, mdbp->fileid, DB_FILE_ID_LEN);

            if ((ret = __db_master_update(mdbp,
                subdb, type, &meta_pgno, MU_OPEN, NULL, flags)) != 0)
                  goto err;

            /*
             * Clear the exclusive open and truncation flags, they only
             * apply to the open of the master database.
             */
            LF_CLR(DB_EXCL | DB_TRUNCATE);
      }

      ret = __db_dbopen(dbp, name, flags, mode, meta_pgno);

      /*
       * You can open the database that describes the subdatabases in the
       * rest of the file read-only.  The content of each key's data is
       * unspecified and applications should never be adding new records
       * or updating existing records.  However, during recovery, we need
       * to open these databases R/W so we can redo/undo changes in them.
       * Likewise, we need to open master databases read/write during
       * rename and remove so we can be sure they're fully sync'ed, so
       * we provide an override flag for the purpose.
       */
      if (subdb == NULL && !IS_RECOVERING(dbenv) && !LF_ISSET(DB_RDONLY) &&
          !LF_ISSET(DB_RDWRMASTER) && F_ISSET(dbp, DB_AM_SUBDB)) {
            __db_err(dbenv,
    "files containing multiple databases may only be opened read-only");
            ret = EINVAL;
            goto err;
      }

err:  /*
       * End any transaction, committing if we were successful, aborting
       * otherwise.
       */
      if (TXN_ON(dbenv) && LF_ISSET(DB_CREATE))
            if ((t_ret = __db_metaend(dbp,
                &open_lock, ret == 0, NULL, NULL)) != 0 && ret == 0)
                  ret = t_ret;

      /* If we were successful, don't discard the file on close. */
      if (ret == 0)
            F_CLR(dbp, DB_AM_DISCARD);

      /* If we were unsuccessful, destroy the DB handle. */
      if (ret != 0) {
            /* In recovery we set log_fileid early. */
            if (IS_RECOVERING(dbenv))
                  dbp->log_fileid = DB_LOGFILEID_INVALID;
            __db_refresh(dbp);
      }

      if (mdbp != NULL) {
            /* If we were successful, don't discard the file on close. */
            if (ret == 0)
                  F_CLR(mdbp, DB_AM_DISCARD);
            if ((t_ret = mdbp->close(mdbp, 0)) != 0 && ret == 0)
                  ret = t_ret;
      }

      return (ret);
}

/*
 * __db_dbopen --
 *    Open a database.
 * PUBLIC: int __db_dbopen __P((DB *, const char *, u_int32_t, int, db_pgno_t));
 */
int
__db_dbopen(dbp, name, flags, mode, meta_pgno)
      DB *dbp;
      const char *name;
      u_int32_t flags;
      int mode;
      db_pgno_t meta_pgno;
{
      DB_ENV *dbenv;
      int ret, retinfo;

      dbenv = dbp->dbenv;

      /* Set up the underlying file. */
      if ((ret = __db_file_setup(dbp,
          name, flags, mode, meta_pgno, &retinfo)) != 0)
            return (ret);

      /*
       * If we created the file, set the truncate flag for the mpool.  This
       * isn't for anything we've done, it's protection against stupid user
       * tricks: if the user deleted a file behind Berkeley DB's back, we
       * may still have pages in the mpool that match the file's "unique" ID.
       */
      if (retinfo & DB_FILE_SETUP_CREATE)
            flags |= DB_TRUNCATE;

      /* Set up the underlying environment. */
      if ((ret = __db_dbenv_setup(dbp, name, flags)) != 0)
            return (ret);

      /*
       * Do access method specific initialization.
       *
       * !!!
       * Set the open flag.  (The underlying access method open functions
       * may want to do things like acquire cursors, so the open flag has
       * to be set before calling them.)
       */
      F_SET(dbp, DB_OPEN_CALLED);

      if (retinfo & DB_FILE_SETUP_ZERO)
            return (0);

      switch (dbp->type) {
      case DB_BTREE:
            ret = __bam_open(dbp, name, meta_pgno, flags);
            break;
      case DB_HASH:
            ret = __ham_open(dbp, name, meta_pgno, flags);
            break;
      case DB_RECNO:
            ret = __ram_open(dbp, name, meta_pgno, flags);
            break;
      case DB_QUEUE:
            ret = __qam_open(dbp, name, meta_pgno, mode, flags);
            break;
      case DB_UNKNOWN:
            return (__db_unknown_type(dbp->dbenv,
                 "__db_dbopen", dbp->type));
            break;
      }
      return (ret);
}

/*
 * __db_master_open --
 *    Open up a handle on a master database.
 *
 * PUBLIC: int __db_master_open __P((DB *,
 * PUBLIC:     const char *, u_int32_t, int, DB **));
 */
int
__db_master_open(subdbp, name, flags, mode, dbpp)
      DB *subdbp;
      const char *name;
      u_int32_t flags;
      int mode;
      DB **dbpp;
{
      DB *dbp;
      int ret;

      /* Open up a handle on the main database. */
      if ((ret = db_create(&dbp, subdbp->dbenv, 0)) != 0)
            return (ret);

      /*
       * It's always a btree.
       * Run in the transaction we've created.
       * Set the pagesize in case we're creating a new database.
       * Flag that we're creating a database with subdatabases.
       */
      dbp->type = DB_BTREE;
      dbp->open_txn = subdbp->open_txn;
      dbp->pgsize = subdbp->pgsize;
      F_SET(dbp, DB_AM_SUBDB);

      if ((ret = __db_dbopen(dbp, name, flags, mode, PGNO_BASE_MD)) != 0) {
            if (!F_ISSET(dbp, DB_AM_DISCARD))
                  dbp->close(dbp, 0);
            return (ret);
      }

      *dbpp = dbp;
      return (0);
}

/*
 * __db_master_update --
 *    Add/Remove a subdatabase from a master database.
 */
static int
__db_master_update(mdbp, subdb, type, meta_pgnop, action, newname, flags)
      DB *mdbp;
      const char *subdb;
      u_int32_t type;
      db_pgno_t *meta_pgnop;        /* may be NULL on MU_RENAME */
      mu_action action;
      const char *newname;
      u_int32_t flags;
{
      DB_ENV *dbenv;
      DBC *dbc, *ndbc;
      DBT key, data, ndata;
      PAGE *p;
      db_pgno_t t_pgno;
      int modify, ret, t_ret;

      dbenv = mdbp->dbenv;
      dbc = ndbc = NULL;
      p = NULL;

      /* Might we modify the master database?  If so, we'll need to lock. */
      modify = (action != MU_OPEN || LF_ISSET(DB_CREATE)) ? 1 : 0;

      memset(&key, 0, sizeof(key));
      memset(&data, 0, sizeof(data));

      /*
       * Open up a cursor.  If this is CDB and we're creating the database,
       * make it an update cursor.
       */
      if ((ret = mdbp->cursor(mdbp, mdbp->open_txn, &dbc,
          (CDB_LOCKING(dbenv) && modify) ? DB_WRITECURSOR : 0)) != 0)
            goto err;

      /*
       * Try to point the cursor at the record.
       *
       * If we're removing or potentially creating an entry, lock the page
       * with DB_RMW.
       *
       * !!!
       * We don't include the name's nul termination in the database.
       */
      key.data = (char *)subdb;
      key.size = strlen(subdb);
      /* In the rename case, we do multiple cursor ops, so MALLOC is safer. */
      F_SET(&data, DB_DBT_MALLOC);
      ret = dbc->c_get(dbc, &key, &data,
          DB_SET | ((STD_LOCKING(dbc) && modify) ? DB_RMW : 0));

      /*
       * What we do next--whether or not we found a record for the
       * specified subdatabase--depends on what the specified action is.
       * Handle ret appropriately as the first statement of each case.
       */
      switch (action) {
      case MU_REMOVE:
            /*
             * We should have found something if we're removing it.  Note
             * that in the common case where the DB we're asking to remove
             * doesn't exist, we won't get this far;  __db_subdb_remove
             * will already have returned an error from __db_open.
             */
            if (ret != 0)
                  goto err;

            /*
             * Delete the subdatabase entry first;  if this fails,
             * we don't want to touch the actual subdb pages.
             */
            if ((ret = dbc->c_del(dbc, 0)) != 0)
                  goto err;

            /*
             * We're handling actual data, not on-page meta-data,
             * so it hasn't been converted to/from opposite
             * endian architectures.  Do it explicitly, now.
             */
            memcpy(meta_pgnop, data.data, sizeof(db_pgno_t));
            DB_NTOHL(meta_pgnop);
            if ((ret = memp_fget(mdbp->mpf, meta_pgnop, 0, &p)) != 0)
                  goto err;

            /* Free and put the page. */
            if ((ret = __db_free(dbc, p)) != 0) {
                  p = NULL;
                  goto err;
            }
            p = NULL;
            break;
      case MU_RENAME:
            /* We should have found something if we're renaming it. */
            if (ret != 0)
                  goto err;

            /*
             * Before we rename, we need to make sure we're not
             * overwriting another subdatabase, or else this operation
             * won't be undoable.  Open a second cursor and check
             * for the existence of newname;  it shouldn't appear under
             * us since we hold the metadata lock.
             */
            if ((ret = mdbp->cursor(mdbp, mdbp->open_txn, &ndbc, 0)) != 0)
                  goto err;
            DB_ASSERT(newname != NULL);
            key.data = (void *) newname;
            key.size = strlen(newname);

            /*
             * We don't actually care what the meta page of the potentially-
             * overwritten DB is;  we just care about existence.
             */
            memset(&ndata, 0, sizeof(ndata));
            F_SET(&ndata, DB_DBT_USERMEM | DB_DBT_PARTIAL);

            if ((ret = ndbc->c_get(ndbc, &key, &ndata, DB_SET)) == 0) {
                  /* A subdb called newname exists.  Bail. */
                  ret = EEXIST;
                  __db_err(dbenv, "rename: database %s exists", newname);
                  goto err;
            } else if (ret != DB_NOTFOUND)
                  goto err;

            /*
             * Now do the put first;  we don't want to lose our
             * sole reference to the subdb.  Use the second cursor
             * so that the first one continues to point to the old record.
             */
            if ((ret = ndbc->c_put(ndbc, &key, &data, DB_KEYFIRST)) != 0)
                  goto err;
            if ((ret = dbc->c_del(dbc, 0)) != 0) {
                  /*
                   * If the delete fails, try to delete the record
                   * we just put, in case we're not txn-protected.
                   */
                  (void)ndbc->c_del(ndbc, 0);
                  goto err;
            }

            break;
      case MU_OPEN:
            /*
             * Get the subdatabase information.  If it already exists,
             * copy out the page number and we're done.
             */
            switch (ret) {
            case 0:
                  memcpy(meta_pgnop, data.data, sizeof(db_pgno_t));
                  DB_NTOHL(meta_pgnop);
                  goto done;
            case DB_NOTFOUND:
                  if (LF_ISSET(DB_CREATE))
                        break;
                  /*
                   * No db_err, it is reasonable to remove a
                   * nonexistent db.
                   */
                  ret = ENOENT;
                  goto err;
            default:
                  goto err;
            }

            if ((ret = __db_new(dbc,
                type == DB_HASH ? P_HASHMETA : P_BTREEMETA, &p)) != 0)
                  goto err;
            *meta_pgnop = PGNO(p);

            /*
             * XXX
             * We're handling actual data, not on-page meta-data, so it
             * hasn't been converted to/from opposite endian architectures.
             * Do it explicitly, now.
             */
            t_pgno = PGNO(p);
            DB_HTONL(&t_pgno);
            memset(&ndata, 0, sizeof(ndata));
            ndata.data = &t_pgno;
            ndata.size = sizeof(db_pgno_t);
            if ((ret = dbc->c_put(dbc, &key, &ndata, DB_KEYLAST)) != 0)
                  goto err;
            break;
      }

err:
done: /*
       * If we allocated a page: if we're successful, mark the page dirty
       * and return it to the cache, otherwise, discard/free it.
       */
      if (p != NULL) {
            if (ret == 0) {
                  if ((t_ret =
                      memp_fput(mdbp->mpf, p, DB_MPOOL_DIRTY)) != 0)
                        ret = t_ret;
                  /*
                   * Since we cannot close this file until after
                   * transaction commit, we need to sync the dirty
                   * pages, because we'll read these directly from
                   * disk to open.
                   */
                  if ((t_ret = mdbp->sync(mdbp, 0)) != 0 && ret == 0)
                        ret = t_ret;
            } else
                  (void)__db_free(dbc, p);
      }

      /* Discard the cursor(s) and data. */
      if (data.data != NULL)
            __os_free(data.data, data.size);
      if (dbc != NULL && (t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
            ret = t_ret;
      if (ndbc != NULL && (t_ret = ndbc->c_close(ndbc)) != 0 && ret == 0)
            ret = t_ret;

      return (ret);
}

/*
 * __db_dbenv_setup --
 *    Set up the underlying environment during a db_open.
 *
 * PUBLIC: int __db_dbenv_setup __P((DB *, const char *, u_int32_t));
 */
int
__db_dbenv_setup(dbp, name, flags)
      DB *dbp;
      const char *name;
      u_int32_t flags;
{
      DB *ldbp;
      DB_ENV *dbenv;
      DBT pgcookie;
      DB_MPOOL_FINFO finfo;
      DB_PGINFO pginfo;
      int ret;
      u_int32_t maxid;

      dbenv = dbp->dbenv;

      /* If we don't yet have an environment, it's time to create it. */
      if (!F_ISSET(dbenv, DB_ENV_OPEN_CALLED)) {
            /* Make sure we have at least DB_MINCACHE pages in our cache. */
            if (dbenv->mp_gbytes == 0 &&
                dbenv->mp_bytes < dbp->pgsize * DB_MINPAGECACHE &&
                (ret = dbenv->set_cachesize(
                dbenv, 0, dbp->pgsize * DB_MINPAGECACHE, 0)) != 0)
                  return (ret);

            if ((ret = dbenv->open(dbenv, NULL, DB_CREATE |
                DB_INIT_MPOOL | DB_PRIVATE | LF_ISSET(DB_THREAD), 0)) != 0)
                  return (ret);
      }

      /* Register DB's pgin/pgout functions. */
      if ((ret =
          memp_register(dbenv, DB_FTYPE_SET, __db_pgin, __db_pgout)) != 0)
            return (ret);

      /*
       * Open a backing file in the memory pool.
       *
       * If we need to pre- or post-process a file's pages on I/O, set the
       * file type.  If it's a hash file, always call the pgin and pgout
       * routines.  This means that hash files can never be mapped into
       * process memory.  If it's a btree file and requires swapping, we
       * need to page the file in and out.  This has to be right -- we can't
       * mmap files that are being paged in and out.
       */
      memset(&finfo, 0, sizeof(finfo));
      switch (dbp->type) {
      case DB_BTREE:
      case DB_RECNO:
            finfo.ftype =
                F_ISSET(dbp, DB_AM_SWAP) ? DB_FTYPE_SET : DB_FTYPE_NOTSET;
            finfo.clear_len = DB_PAGE_DB_LEN;
            break;
      case DB_HASH:
            finfo.ftype = DB_FTYPE_SET;
            finfo.clear_len = DB_PAGE_DB_LEN;
            break;
      case DB_QUEUE:
            finfo.ftype =
                F_ISSET(dbp, DB_AM_SWAP) ? DB_FTYPE_SET : DB_FTYPE_NOTSET;
            finfo.clear_len = DB_PAGE_QUEUE_LEN;
            break;
      case DB_UNKNOWN:
            /*
             * If we're running in the verifier, our database might
             * be corrupt and we might not know its type--but we may
             * still want to be able to verify and salvage.
             *
             * If we can't identify the type, it's not going to be safe
             * to call __db_pgin--we pretty much have to give up all
             * hope of salvaging cross-endianness.  Proceed anyway;
             * at worst, the database will just appear more corrupt
             * than it actually is, but at best, we may be able
             * to salvage some data even with no metadata page.
             */
            if (F_ISSET(dbp, DB_AM_VERIFYING)) {
                  finfo.ftype = DB_FTYPE_NOTSET;
                  finfo.clear_len = DB_PAGE_DB_LEN;
                  break;
            }
            return (__db_unknown_type(dbp->dbenv,
                 "__db_dbenv_setup", dbp->type));
      }
      finfo.pgcookie = &pgcookie;
      finfo.fileid = dbp->fileid;
      finfo.lsn_offset = 0;

      pginfo.db_pagesize = dbp->pgsize;
      pginfo.needswap = F_ISSET(dbp, DB_AM_SWAP);
      pgcookie.data = &pginfo;
      pgcookie.size = sizeof(DB_PGINFO);

      if ((ret = memp_fopen(dbenv, name,
          LF_ISSET(DB_RDONLY | DB_NOMMAP | DB_ODDFILESIZE | DB_TRUNCATE),
          0, dbp->pgsize, &finfo, &dbp->mpf)) != 0)
            return (ret);

      /*
       * We may need a per-thread mutex.  Allocate it from the environment
       * region, there's supposed to be extra space there for that purpose.
       */
      if (LF_ISSET(DB_THREAD)) {
            if ((ret = __db_mutex_alloc(
                dbenv, dbenv->reginfo, (MUTEX **)&dbp->mutexp)) != 0)
                  return (ret);
            if ((ret = __db_mutex_init(
                dbenv, dbp->mutexp, 0, MUTEX_THREAD)) != 0) {
                  __db_mutex_free(dbenv, dbenv->reginfo, dbp->mutexp);
                  return (ret);
            }
      }

      /* Get a log file id. */
      if (LOGGING_ON(dbenv) && !IS_RECOVERING(dbenv) &&
#if !defined(DEBUG_ROP)
          !F_ISSET(dbp, DB_AM_RDONLY) &&
#endif
          (ret = log_register(dbenv, dbp, name)) != 0)
            return (ret);

      /*
       * Insert ourselves into the DB_ENV's dblist.  We allocate a
       * unique ID to each {fileid, meta page number} pair, and to
       * each temporary file (since they all have a zero fileid).
       * This ID gives us something to use to tell which DB handles
       * go with which databases in all the cursor adjustment
       * routines, where we don't want to do a lot of ugly and
       * expensive memcmps.
       */
      MUTEX_THREAD_LOCK(dbenv, dbenv->dblist_mutexp);
      for (maxid = 0, ldbp = LIST_FIRST(&dbenv->dblist);
          ldbp != NULL; ldbp = LIST_NEXT(dbp, dblistlinks)) {
            if (name != NULL &&
                memcmp(ldbp->fileid, dbp->fileid, DB_FILE_ID_LEN) == 0 &&
                ldbp->meta_pgno == dbp->meta_pgno)
                  break;
            if (ldbp->adj_fileid > maxid)
                  maxid = ldbp->adj_fileid;
      }

      /*
       * If ldbp is NULL, we didn't find a match, or we weren't
       * really looking because name is NULL.  Assign the dbp an
       * adj_fileid one higher than the largest we found, and
       * insert it at the head of the master dbp list.
       *
       * If ldbp is not NULL, it is a match for our dbp.  Give dbp
       * the same ID that ldbp has, and add it after ldbp so they're
       * together in the list.
       */
      if (ldbp == NULL) {
            dbp->adj_fileid = maxid + 1;
            LIST_INSERT_HEAD(&dbenv->dblist, dbp, dblistlinks);
      } else {
            dbp->adj_fileid = ldbp->adj_fileid;
            LIST_INSERT_AFTER(ldbp, dbp, dblistlinks);
      }
      MUTEX_THREAD_UNLOCK(dbenv, dbenv->dblist_mutexp);

      return (0);
}

/*
 * __db_file_setup --
 *    Setup the file or in-memory data.
 *    Read the database metadata and resolve it with our arguments.
 */
static int
__db_file_setup(dbp, name, flags, mode, meta_pgno, retflags)
      DB *dbp;
      const char *name;
      u_int32_t flags;
      int mode;
      db_pgno_t meta_pgno;
      int *retflags;
{
      DB *mdb;
      DBT namedbt;
      DB_ENV *dbenv;
      DB_FH *fhp, fh;
      DB_LSN lsn;
      DB_TXN *txn;
      size_t nr;
      u_int32_t magic, oflags;
      int ret, retry_cnt, t_ret;
      char *real_name, mbuf[DBMETASIZE];

#define     IS_SUBDB_SETUP    (meta_pgno != PGNO_BASE_MD)

      dbenv = dbp->dbenv;
      dbp->meta_pgno = meta_pgno;
      txn = NULL;
      *retflags = 0;

      /*
       * If we open a file handle and our caller is doing fcntl(2) locking,
       * we can't close it because that would discard the caller's lock.
       * Save it until we close the DB handle.
       */
      if (LF_ISSET(DB_FCNTL_LOCKING)) {
            if ((ret = __os_malloc(dbenv, sizeof(*fhp), NULL, &fhp)) != 0)
                  return (ret);
      } else
            fhp = &fh;
      memset(fhp, 0, sizeof(*fhp));

      /*
       * If the file is in-memory, set up is simple.  Otherwise, do the
       * hard work of opening and reading the file.
       *
       * If we have a file name, try and read the first page, figure out
       * what type of file it is, and initialize everything we can based
       * on that file's meta-data page.
       *
       * !!!
       * There's a reason we don't push this code down into the buffer cache.
       * The problem is that there's no information external to the file that
       * we can use as a unique ID.  UNIX has dev/inode pairs, but they are
       * not necessarily unique after reboot, if the file was mounted via NFS.
       * Windows has similar problems, as the FAT filesystem doesn't maintain
       * dev/inode numbers across reboot.  So, we must get something from the
       * file we can use to ensure that, even after a reboot, the file we're
       * joining in the cache is the right file for us to join.  The solution
       * we use is to maintain a file ID that's stored in the database, and
       * that's why we have to open and read the file before calling into the
       * buffer cache.
       *
       * The secondary reason is that there's additional information that
       * we want to have before instantiating a file in the buffer cache:
       * the page size, file type (btree/hash), if swapping is required,
       * and flags (DB_RDONLY, DB_CREATE, DB_TRUNCATE).  We could handle
       * needing this information by allowing it to be set for a file in
       * the buffer cache even after the file has been opened, and, of
       * course, supporting the ability to flush a file from the cache as
       * necessary, e.g., if we guessed wrongly about the page size.  Given
       * that we have to read the file anyway to get the file ID, we might
       * as well get the rest, too.
       *
       * Get the real file name.
       */
      if (name == NULL) {
            F_SET(dbp, DB_AM_INMEM);

            if (dbp->type == DB_UNKNOWN) {
                  __db_err(dbenv,
                      "DBTYPE of unknown without existing file");
                  return (EINVAL);
            }
            real_name = NULL;

            /* Set the page size if we don't have one yet. */
            if (dbp->pgsize == 0)
                  dbp->pgsize = DB_DEF_IOSIZE;

            /*
             * If the file is a temporary file and we're doing locking,
             * then we have to create a unique file ID.  We can't use our
             * normal dev/inode pair (or whatever this OS uses in place of
             * dev/inode pairs) because no backing file will be created
             * until the mpool cache is filled forcing the buffers to disk.
             * Grab a random locker ID to use as a file ID.  The created
             * ID must never match a potential real file ID -- we know it
             * won't because real file IDs contain a time stamp after the
             * dev/inode pair, and we're simply storing a 4-byte value.
             *
             * !!!
             * Store the locker in the file id structure -- we can get it
             * from there as necessary, and it saves having two copies.
             */
            if (LOCKING_ON(dbenv) &&
                (ret = lock_id(dbenv, (u_int32_t *)dbp->fileid)) != 0)
                  return (ret);

            return (0);
      }

      /* Get the real backing file name. */
      if ((ret = __db_appname(dbenv,
          DB_APP_DATA, NULL, name, 0, NULL, &real_name)) != 0)
            return (ret);

      /*
       * Open the backing file.  We need to make sure that multiple processes
       * attempting to create the file at the same time are properly ordered
       * so that only one of them creates the "unique" file ID, so we open it
       * O_EXCL and O_CREAT so two simultaneous attempts to create the region
       * will return failure in one of the attempts.  If we're the one that
       * fails, simply retry without the O_CREAT flag, which will require the
       * meta-data page exist.
       */

      /* Fill in the default file mode. */
      if (mode == 0)
            mode = __db_omode("rwrw--");

      oflags = 0;
      if (LF_ISSET(DB_RDONLY))
            oflags |= DB_OSO_RDONLY;
      if (LF_ISSET(DB_TRUNCATE))
            oflags |= DB_OSO_TRUNC;

      retry_cnt = 0;
open_retry:
      *retflags = 0;
      ret = 0;
      if (!IS_SUBDB_SETUP && LF_ISSET(DB_CREATE)) {
            if (dbp->open_txn != NULL) {
                  /*
                   * Start a child transaction to wrap this individual
                   * create.
                   */
                  if ((ret =
                      txn_begin(dbenv, dbp->open_txn, &txn, 0)) != 0)
                        goto err_msg;

                  memset(&namedbt, 0, sizeof(namedbt));
                  namedbt.data = (char *)name;
                  namedbt.size = strlen(name) + 1;
                  if ((ret = __crdel_fileopen_log(dbenv, txn,
                      &lsn, DB_FLUSH, &namedbt, mode)) != 0)
                        goto err_msg;
            }
            DB_TEST_RECOVERY(dbp, DB_TEST_PREOPEN, ret, name);
            if ((ret = __os_open(dbenv, real_name,
                oflags | DB_OSO_CREATE | DB_OSO_EXCL, mode, fhp)) == 0) {
                  DB_TEST_RECOVERY(dbp, DB_TEST_POSTOPEN, ret, name);

                  /* Commit the file create. */
                  if (dbp->open_txn != NULL) {
                        if ((ret = txn_commit(txn, DB_TXN_SYNC)) != 0)
                              goto err_msg;
                        txn = NULL;
                  }

                  /*
                   * We created the file.  This means that if we later
                   * fail, we need to delete the file and if we're going
                   * to do that, we need to trash any pages in the
                   * memory pool.  Since we only know here that we
                   * created the file, we're going to set the flag here
                   * and clear it later if we commit successfully.
                   */
                  F_SET(dbp, DB_AM_DISCARD);
                  *retflags |= DB_FILE_SETUP_CREATE;
            } else {
                  /*
                   * Abort the file create.  If the abort fails, report
                   * the error returned by txn_abort(), rather than the
                   * open error, for no particular reason.
                   */
                  if (dbp->open_txn != NULL) {
                        if ((t_ret = txn_abort(txn)) != 0) {
                              ret = t_ret;
                              goto err_msg;
                        }
                        txn = NULL;
                  }

                  /*
                   * If we were not doing an exclusive open, try again
                   * without the create flag.
                   */
                  if (ret == EEXIST && !LF_ISSET(DB_EXCL)) {
                        LF_CLR(DB_CREATE);
                        DB_TEST_RECOVERY(dbp,
                            DB_TEST_POSTOPEN, ret, name);
                        goto open_retry;
                  }
            }
      } else
            ret = __os_open(dbenv, real_name, oflags, mode, fhp);

      /*
       * Be quiet if we couldn't open the file because it didn't exist
       * or we did not have permission,
       * the customers don't like those messages appearing in the logs.
       * Otherwise, complain loudly.
       */
      if (ret != 0) {
            if (ret == EACCES || ret == ENOENT)
                  goto err;
            goto err_msg;
      }

      /* Set the page size if we don't have one yet. */
      if (dbp->pgsize == 0) {
            if (IS_SUBDB_SETUP) {
                  if ((ret = __db_master_open(dbp,
                      name, flags, mode, &mdb)) != 0)
                        goto err;
                  dbp->pgsize = mdb->pgsize;
                  (void)mdb->close(mdb, 0);
            } else if ((ret = __db_set_pgsize(dbp, fhp, real_name)) != 0)
                  goto err;
      }

      /*
       * Seek to the metadata offset; if it's a master database open or a
       * database without subdatabases, we're seeking to 0, but that's OK.
       */
      if ((ret = __os_seek(dbenv, fhp,
          dbp->pgsize, meta_pgno, 0, 0, DB_OS_SEEK_SET)) != 0)
            goto err_msg;

      /*
       * Read the metadata page.  We read DBMETASIZE bytes, which is larger
       * than any access method's metadata page and smaller than any disk
       * sector.
       */
      if ((ret = __os_read(dbenv, fhp, mbuf, sizeof(mbuf), &nr)) != 0)
            goto err_msg;

      if (nr == sizeof(mbuf)) {
            /*
             * Figure out what access method we're dealing with, and then
             * call access method specific code to check error conditions
             * based on conflicts between the found file and application
             * arguments.  A found file overrides some user information --
             * we don't consider it an error, for example, if the user set
             * an expected byte order and the found file doesn't match it.
             */
            F_CLR(dbp, DB_AM_SWAP);
            magic = ((DBMETA *)mbuf)->magic;

swap_retry: switch (magic) {
            case DB_BTREEMAGIC:
                  if ((ret =
                      __bam_metachk(dbp, name, (BTMETA *)mbuf)) != 0)
                        goto err;
                  break;
            case DB_HASHMAGIC:
                  if ((ret =
                      __ham_metachk(dbp, name, (HMETA *)mbuf)) != 0)
                        goto err;
                  break;
            case DB_QAMMAGIC:
                  if ((ret =
                      __qam_metachk(dbp, name, (QMETA *)mbuf)) != 0)
                        goto err;
                  break;
            case 0:
                  /*
                   * There are two ways we can get a 0 magic number.
                   * If we're creating a subdatabase, then the magic
                   * number will be 0.  We allocate a page as part of
                   * finding out what the base page number will be for
                   * the new subdatabase, but it's not initialized in
                   * any way.
                   *
                   * The second case happens if we are in recovery
                   * and we are going to recreate a database, it's
                   * possible that it's page was created (on systems
                   * where pages must be created explicitly to avoid
                   * holes in files) but is still 0.
                   */
                  if (IS_SUBDB_SETUP) {         /* Case 1 */
                        if ((IS_RECOVERING(dbenv)
                            && F_ISSET((DB_LOG *)
                            dbenv->lg_handle, DBLOG_FORCE_OPEN))
                            || ((DBMETA *)mbuf)->pgno != PGNO_INVALID)
                              goto empty;

                        ret = EINVAL;
                        goto err;
                  }
                                          /* Case 2 */
                  if (IS_RECOVERING(dbenv)) {
                        *retflags |= DB_FILE_SETUP_ZERO;
                        goto empty;
                  }
                  goto bad_format;
            default:
                  if (F_ISSET(dbp, DB_AM_SWAP))
                        goto bad_format;

                  M_32_SWAP(magic);
                  F_SET(dbp, DB_AM_SWAP);
                  goto swap_retry;
            }
      } else {
            /*
             * Only newly created files are permitted to fail magic
             * number tests.
             */
            if (nr != 0 || (!IS_RECOVERING(dbenv) && IS_SUBDB_SETUP))
                  goto bad_format;

            /* Let the caller know that we had a 0-length file. */
            if (!LF_ISSET(DB_CREATE | DB_TRUNCATE))
                  *retflags |= DB_FILE_SETUP_ZERO;

            /*
             * The only way we can reach here with the DB_CREATE flag set
             * is if we created the file.  If that's not the case, then
             * either (a) someone else created the file but has not yet
             * written out the metadata page, or (b) we truncated the file
             * (DB_TRUNCATE) leaving it zero-length.  In the case of (a),
             * we want to sleep and give the file creator time to write
             * the metadata page.  In the case of (b), we want to continue.
             *
             * !!!
             * There's a race in the case of two processes opening the file
             * with the DB_TRUNCATE flag set at roughly the same time, and
             * they could theoretically hurt each other.  Sure hope that's
             * unlikely.
             */
            if (!LF_ISSET(DB_CREATE | DB_TRUNCATE) &&
                !IS_RECOVERING(dbenv)) {
                  if (retry_cnt++ < 3) {
                        __os_sleep(dbenv, 1, 0);
                        goto open_retry;
                  }
bad_format:       if (!IS_RECOVERING(dbenv))
                        __db_err(dbenv,
                            "%s: unexpected file type or format", name);
                  ret = EINVAL;
                  goto err;
            }

            DB_ASSERT (dbp->type != DB_UNKNOWN);

empty:            /*
             * The file is empty, and that's OK.  If it's not a subdatabase,
             * though, we do need to generate a unique file ID for it.  The
             * unique file ID includes a timestamp so that we can't collide
             * with any other files, even when the file IDs (dev/inode pair)
             * are reused.
             */
            if (!IS_SUBDB_SETUP) {
                  if (*retflags & DB_FILE_SETUP_ZERO)
                        memset(dbp->fileid, 0, DB_FILE_ID_LEN);
                  else if ((ret = __os_fileid(dbenv,
                      real_name, 1, dbp->fileid)) != 0)
                        goto err_msg;
            }
      }

      if (0) {
err_msg:    __db_err(dbenv, "%s: %s", name, db_strerror(ret));
      }

      /*
       * Abort any running transaction -- it can only exist if something
       * went wrong.
       */
err:
DB_TEST_RECOVERY_LABEL

      /*
       * If we opened a file handle and our caller is doing fcntl(2) locking,
       * then we can't close it because that would discard the caller's lock.
       * Otherwise, close the handle.
       */
      if (F_ISSET(fhp, DB_FH_VALID)) {
            if (ret == 0 && LF_ISSET(DB_FCNTL_LOCKING))
                  dbp->saved_open_fhp = fhp;
            else
                  if ((t_ret = __os_closehandle(fhp)) != 0 && ret == 0)
                        ret = t_ret;
      }

      /*
       * This must be done after the file is closed, since
       * txn_abort() may remove the file, and an open file
       * cannot be removed on a Windows platforms.
       */
      if (txn != NULL)
            (void)txn_abort(txn);

      if (real_name != NULL)
            __os_freestr(real_name);

      return (ret);
}

/*
 * __db_set_pgsize --
 *    Set the page size based on file information.
 */
static int
__db_set_pgsize(dbp, fhp, name)
      DB *dbp;
      DB_FH *fhp;
      char *name;
{
      DB_ENV *dbenv;
      u_int32_t iopsize;
      int ret;

      dbenv = dbp->dbenv;

      /*
       * Use the filesystem's optimum I/O size as the pagesize if a pagesize
       * not specified.  Some filesystems have 64K as their optimum I/O size,
       * but as that results in fairly large default caches, we limit the
       * default pagesize to 16K.
       */
      if ((ret = __os_ioinfo(dbenv, name, fhp, NULL, NULL, &iopsize)) != 0) {
            __db_err(dbenv, "%s: %s", name, db_strerror(ret));
            return (ret);
      }
      if (iopsize < 512)
            iopsize = 512;
      if (iopsize > 16 * 1024)
            iopsize = 16 * 1024;

      /*
       * Sheer paranoia, but we don't want anything that's not a power-of-2
       * (we rely on that for alignment of various types on the pages), and
       * we want a multiple of the sector size as well.
       */
      OS_ROUNDOFF(iopsize, 512);

      dbp->pgsize = iopsize;
      F_SET(dbp, DB_AM_PGDEF);

      return (0);
}

/*
 * __db_close --
 *    DB destructor.
 *
 * PUBLIC: int __db_close __P((DB *, u_int32_t));
 */
int
__db_close(dbp, flags)
      DB *dbp;
      u_int32_t flags;
{
      DB_ENV *dbenv;
      DBC *dbc;
      int ret, t_ret;

      ret = 0;

      dbenv = dbp->dbenv;
      PANIC_CHECK(dbenv);

      /* Validate arguments. */
      if ((ret = __db_closechk(dbp, flags)) != 0)
            goto err;

      /* If never opened, or not currently open, it's easy. */
      if (!F_ISSET(dbp, DB_OPEN_CALLED))
            goto never_opened;

      /* Sync the underlying access method. */
      if (!LF_ISSET(DB_NOSYNC) && !F_ISSET(dbp, DB_AM_DISCARD) &&
          (t_ret = dbp->sync(dbp, 0)) != 0 && ret == 0)
            ret = t_ret;

      /*
       * Go through the active cursors and call the cursor recycle routine,
       * which resolves pending operations and moves the cursors onto the
       * free list.  Then, walk the free list and call the cursor destroy
       * routine.
       */
      while ((dbc = TAILQ_FIRST(&dbp->active_queue)) != NULL)
            if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
                  ret = t_ret;
      while ((dbc = TAILQ_FIRST(&dbp->free_queue)) != NULL)
            if ((t_ret = __db_c_destroy(dbc)) != 0 && ret == 0)
                  ret = t_ret;

      /*
       * Close any outstanding join cursors.  Join cursors destroy
       * themselves on close and have no separate destroy routine.
       */
      while ((dbc = TAILQ_FIRST(&dbp->join_queue)) != NULL)
            if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
                  ret = t_ret;

      /* Remove this DB handle from the DB_ENV's dblist. */
      MUTEX_THREAD_LOCK(dbenv, dbenv->dblist_mutexp);
      LIST_REMOVE(dbp, dblistlinks);
      MUTEX_THREAD_UNLOCK(dbenv, dbenv->dblist_mutexp);

      /* Sync the memory pool. */
      if (!LF_ISSET(DB_NOSYNC) && !F_ISSET(dbp, DB_AM_DISCARD) &&
          (t_ret = memp_fsync(dbp->mpf)) != 0 &&
          t_ret != DB_INCOMPLETE && ret == 0)
            ret = t_ret;

      /* Close any handle we've been holding since the open.  */
      if (dbp->saved_open_fhp != NULL &&
          F_ISSET(dbp->saved_open_fhp, DB_FH_VALID) &&
          (t_ret = __os_closehandle(dbp->saved_open_fhp)) != 0 && ret == 0)
            ret = t_ret;

never_opened:
      /*
       * Call the access specific close function.
       *
       * !!!
       * Because of where the function is called in the close process,
       * these routines can't do anything that would dirty pages or
       * otherwise affect closing down the database.
       */
      if ((t_ret = __ham_db_close(dbp)) != 0 && ret == 0)
            ret = t_ret;
      if ((t_ret = __bam_db_close(dbp)) != 0 && ret == 0)
            ret = t_ret;
      if ((t_ret = __qam_db_close(dbp)) != 0 && ret == 0)
            ret = t_ret;

err:
      /* Refresh the structure and close any local environment. */
      if ((t_ret = __db_refresh(dbp)) != 0 && ret == 0)
            ret = t_ret;
      if (F_ISSET(dbenv, DB_ENV_DBLOCAL) &&
          --dbenv->dblocal_ref == 0 &&
          (t_ret = dbenv->close(dbenv, 0)) != 0 && ret == 0)
            ret = t_ret;

      memset(dbp, CLEAR_BYTE, sizeof(*dbp));
      __os_free(dbp, sizeof(*dbp));

      return (ret);
}

/*
 * __db_refresh --
 *    Refresh the DB structure, releasing any allocated resources.
 */
static int
__db_refresh(dbp)
      DB *dbp;
{
      DB_ENV *dbenv;
      DBC *dbc;
      int ret, t_ret;

      ret = 0;

      dbenv = dbp->dbenv;

      /*
       * Go through the active cursors and call the cursor recycle routine,
       * which resolves pending operations and moves the cursors onto the
       * free list.  Then, walk the free list and call the cursor destroy
       * routine.
       */
      while ((dbc = TAILQ_FIRST(&dbp->active_queue)) != NULL)
            if ((t_ret = dbc->c_close(dbc)) != 0 && ret == 0)
                  ret = t_ret;
      while ((dbc = TAILQ_FIRST(&dbp->free_queue)) != NULL)
            if ((t_ret = __db_c_destroy(dbc)) != 0 && ret == 0)
                  ret = t_ret;

      dbp->type = 0;

      /* Close the memory pool file handle. */
      if (dbp->mpf != NULL) {
            if (F_ISSET(dbp, DB_AM_DISCARD))
                  (void)__memp_fremove(dbp->mpf);
            if ((t_ret = memp_fclose(dbp->mpf)) != 0 && ret == 0)
                  ret = t_ret;
            dbp->mpf = NULL;
      }

      /* Discard the thread mutex. */
      if (dbp->mutexp != NULL) {
            __db_mutex_free(dbenv, dbenv->reginfo, dbp->mutexp);
            dbp->mutexp = NULL;
      }

      /* Discard the log file id. */
      if (!IS_RECOVERING(dbenv)
          && dbp->log_fileid != DB_LOGFILEID_INVALID)
            (void)log_unregister(dbenv, dbp);

      F_CLR(dbp, DB_AM_DISCARD);
      F_CLR(dbp, DB_AM_INMEM);
      F_CLR(dbp, DB_AM_RDONLY);
      F_CLR(dbp, DB_AM_SWAP);
      F_CLR(dbp, DB_DBM_ERROR);
      F_CLR(dbp, DB_OPEN_CALLED);

      return (ret);
}

/*
 * __db_remove
 *    Remove method for DB.
 *
 * PUBLIC: int __db_remove __P((DB *, const char *, const char *, u_int32_t));
 */
int
__db_remove(dbp, name, subdb, flags)
      DB *dbp;
      const char *name, *subdb;
      u_int32_t flags;
{
      DBT namedbt;
      DB_ENV *dbenv;
      DB_LOCK remove_lock;
      DB_LSN newlsn;
      int ret, t_ret, (*callback_func) __P((DB *, void *));
      char *backup, *real_back, *real_name;
      void *cookie;

      dbenv = dbp->dbenv;
      ret = 0;
      backup = real_back = real_name = NULL;

      PANIC_CHECK(dbenv);
      /*
       * Cannot use DB_ILLEGAL_AFTER_OPEN here because that returns
       * and we cannot return, but must deal with the error and destroy
       * the handle anyway.
       */
      if (F_ISSET(dbp, DB_OPEN_CALLED)) {
            ret = __db_mi_open(dbp->dbenv, "remove", 1);
            goto err_close;
      }

      /* Validate arguments. */
      if ((ret = __db_removechk(dbp, flags)) != 0)
            goto err_close;

      /*
       * Subdatabases.
       */
      if (subdb != NULL) {
            /* Subdatabases must be created in named files. */
            if (name == NULL) {
                  __db_err(dbenv,
                "multiple databases cannot be created in temporary files");
                  goto err_close;
            }
            return (__db_subdb_remove(dbp, name, subdb));
      }

      if ((ret = dbp->open(dbp,
          name, NULL, DB_UNKNOWN, DB_RDWRMASTER, 0)) != 0)
            goto err_close;

      if (LOGGING_ON(dbenv) && (ret = __log_file_lock(dbp)) != 0)
            goto err_close;

      if ((ret = dbp->sync(dbp, 0)) != 0)
            goto err_close;

      /* Start the transaction and log the delete. */
      if (TXN_ON(dbenv) && (ret = __db_metabegin(dbp, &remove_lock)) != 0)
            goto err_close;

      if (LOGGING_ON(dbenv)) {
            memset(&namedbt, 0, sizeof(namedbt));
            namedbt.data = (char *)name;
            namedbt.size = strlen(name) + 1;

            if ((ret = __crdel_delete_log(dbenv,
                dbp->open_txn, &newlsn, DB_FLUSH,
                dbp->log_fileid, &namedbt)) != 0) {
                  __db_err(dbenv,
                      "%s: %s", name, db_strerror(ret));
                  goto err;
            }
      }

      /* Find the real name of the file. */
      if ((ret = __db_appname(dbenv,
          DB_APP_DATA, NULL, name, 0, NULL, &real_name)) != 0)
            goto err;

      /*
       * XXX
       * We don't bother to open the file and call __memp_fremove on the mpf.
       * There is a potential race here.  It is at least possible that, if
       * the unique filesystem ID (dev/inode pair on UNIX) is reallocated
       * within a second (the granularity of the fileID timestamp), a new
       * file open will get the same fileID as the file being "removed".
       * We may actually want to open the file and call __memp_fremove on
       * the mpf to get around this.
       */

      /* Create name for backup file. */
      if (TXN_ON(dbenv)) {
            if ((ret =
                __db_backup_name(dbenv, name, &backup, &newlsn)) != 0)
                  goto err;
            if ((ret = __db_appname(dbenv,
                DB_APP_DATA, NULL, backup, 0, NULL, &real_back)) != 0)
                  goto err;
      }

      callback_func = __db_remove_callback;
      cookie = real_back;
      DB_TEST_RECOVERY(dbp, DB_TEST_PRERENAME, ret, name);
      if (dbp->db_am_remove != NULL &&
          (ret = dbp->db_am_remove(dbp,
          name, subdb, &newlsn, &callback_func, &cookie)) != 0)
            goto err;
      /*
       * On Windows, the underlying file must be closed to perform a remove.
       * Nothing later in __db_remove requires that it be open, and the
       * dbp->close closes it anyway, so we just close it early.
       */
      (void)__memp_fremove(dbp->mpf);
      if ((ret = memp_fclose(dbp->mpf)) != 0)
            goto err;
      dbp->mpf = NULL;

      if (TXN_ON(dbenv))
            ret = __os_rename(dbenv, real_name, real_back);
      else
            ret = __os_unlink(dbenv, real_name);

      DB_TEST_RECOVERY(dbp, DB_TEST_POSTRENAME, ret, name);

err:
DB_TEST_RECOVERY_LABEL
      /*
       * End the transaction, committing the transaction if we were
       * successful, aborting otherwise.
       */
      if (dbp->open_txn != NULL && (t_ret = __db_metaend(dbp, &remove_lock,
         ret == 0, callback_func, cookie)) != 0 && ret == 0)
            ret = t_ret;

      /* FALLTHROUGH */

err_close:
      if (real_back != NULL)
            __os_freestr(real_back);
      if (real_name != NULL)
            __os_freestr(real_name);
      if (backup != NULL)
            __os_freestr(backup);

      /* We no longer have an mpool, so syncing would be disastrous. */
      if ((t_ret = dbp->close(dbp, DB_NOSYNC)) != 0 && ret == 0)
            ret = t_ret;

      return (ret);
}

/*
 * __db_subdb_remove --
 *    Remove a subdatabase.
 */
static int
__db_subdb_remove(dbp, name, subdb)
      DB *dbp;
      const char *name, *subdb;
{
      DB *mdbp;
      DBC *dbc;
      DB_ENV *dbenv;
      DB_LOCK remove_lock;
      db_pgno_t meta_pgno;
      int ret, t_ret;

      mdbp = NULL;
      dbc = NULL;
      dbenv = dbp->dbenv;

      /* Start the transaction. */
      if (TXN_ON(dbenv) && (ret = __db_metabegin(dbp, &remove_lock)) != 0)
            goto err_close;

      /*
       * Open the subdatabase.  We can use the user's DB handle for this
       * purpose, I think.
       */
      if ((ret = __db_open(dbp, name, subdb, DB_UNKNOWN, 0, 0)) != 0)
            goto err;

      /* Free up the pages in the subdatabase. */
      switch (dbp->type) {
            case DB_BTREE:
            case DB_RECNO:
                  if ((ret = __bam_reclaim(dbp, dbp->open_txn)) != 0)
                        goto err;
                  break;
            case DB_HASH:
                  if ((ret = __ham_reclaim(dbp, dbp->open_txn)) != 0)
                        goto err;
                  break;
            default:
                  ret = __db_unknown_type(dbp->dbenv,
                       "__db_subdb_remove", dbp->type);
                  goto err;
      }

      /*
       * Remove the entry from the main database and free the subdatabase
       * metadata page.
       */
      if ((ret = __db_master_open(dbp, name, 0, 0, &mdbp)) != 0)
            goto err;

      if ((ret = __db_master_update(mdbp,
           subdb, dbp->type, &meta_pgno, MU_REMOVE, NULL, 0)) != 0)
            goto err;

err:  /*
       * End the transaction, committing the transaction if we were
       * successful, aborting otherwise.
       */
      if (dbp->open_txn != NULL && (t_ret = __db_metaend(dbp,
          &remove_lock, ret == 0, NULL, NULL)) != 0 && ret == 0)
            ret = t_ret;

err_close:
      /*
       * Close the user's DB handle -- do this LAST to avoid smashing the
       * the transaction information.
       */
      if ((t_ret = dbp->close(dbp, 0)) != 0 && ret == 0)
            ret = t_ret;

      if (mdbp != NULL && (t_ret = mdbp->close(mdbp, 0)) != 0 && ret == 0)
            ret = t_ret;

      return (ret);
}

/*
 * __db_rename
 *    Rename method for DB.
 *
 * PUBLIC: int __db_rename __P((DB *,
 * PUBLIC:     const char *, const char *, const char *, u_int32_t));
 */
int
__db_rename(dbp, filename, subdb, newname, flags)
      DB *dbp;
      const char *filename, *subdb, *newname;
      u_int32_t flags;
{
      DBT namedbt, newnamedbt;
      DB_ENV *dbenv;
      DB_LOCK remove_lock;
      DB_LSN newlsn;
      char *real_name, *real_newname;
      int ret, t_ret;

      dbenv = dbp->dbenv;
      ret = 0;
      real_name = real_newname = NULL;

      PANIC_CHECK(dbenv);
      /*
       * Cannot use DB_ILLEGAL_AFTER_OPEN here because that returns
       * and we cannot return, but must deal with the error and destroy
       * the handle anyway.
       */
      if (F_ISSET(dbp, DB_OPEN_CALLED)) {
            ret = __db_mi_open(dbp->dbenv, "rename", 1);
            goto err_close;
      }

      /* Validate arguments -- has same rules as remove. */
      if ((ret = __db_removechk(dbp, flags)) != 0)
            goto err_close;

      /*
       * Subdatabases.
       */
      if (subdb != NULL) {
            if (filename == NULL) {
                  __db_err(dbenv,
                "multiple databases cannot be created in temporary files");
                  goto err_close;
            }
            return (__db_subdb_rename(dbp, filename, subdb, newname));
      }

      if ((ret = dbp->open(dbp,
          filename, NULL, DB_UNKNOWN, DB_RDWRMASTER, 0)) != 0)
            goto err_close;

      if (LOGGING_ON(dbenv) && (ret = __log_file_lock(dbp)) != 0)
            goto err_close;

      if ((ret = dbp->sync(dbp, 0)) != 0)
            goto err_close;

      /* Start the transaction and log the rename. */
      if (TXN_ON(dbenv) && (ret = __db_metabegin(dbp, &remove_lock)) != 0)
            goto err_close;

      if (LOGGING_ON(dbenv)) {
            memset(&namedbt, 0, sizeof(namedbt));
            namedbt.data = (char *)filename;
            namedbt.size = strlen(filename) + 1;

            memset(&newnamedbt, 0, sizeof(namedbt));
            newnamedbt.data = (char *)newname;
            newnamedbt.size = strlen(newname) + 1;

            if ((ret = __crdel_rename_log(dbenv, dbp->open_txn,
                &newlsn, 0, dbp->log_fileid, &namedbt, &newnamedbt)) != 0) {
                  __db_err(dbenv, "%s: %s", filename, db_strerror(ret));
                  goto err;
            }

            if ((ret = __log_filelist_update(dbenv, dbp,
                dbp->log_fileid, newname, NULL)) != 0)
                  goto err;
      }

      /* Find the real name of the file. */
      if ((ret = __db_appname(dbenv,
          DB_APP_DATA, NULL, filename, 0, NULL, &real_name)) != 0)
            goto err;

      /* Find the real newname of the file. */
      if ((ret = __db_appname(dbenv,
          DB_APP_DATA, NULL, newname, 0, NULL, &real_newname)) != 0)
            goto err;

      /*
       * It is an error to rename a file over one that already exists,
       * as that wouldn't be transaction-safe.
       */
      if (__os_exists(real_newname, NULL) == 0) {
            ret = EEXIST;
            __db_err(dbenv, "rename: file %s exists", real_newname);
            goto err;
      }

      DB_TEST_RECOVERY(dbp, DB_TEST_PRERENAME, ret, filename);
      if (dbp->db_am_rename != NULL &&
          (ret = dbp->db_am_rename(dbp, filename, subdb, newname)) != 0)
            goto err;
      /*
       * We have to flush the cache for a couple of reasons.  First, the
       * underlying MPOOLFILE maintains a "name" that unrelated processes
       * can use to open the file in order to flush pages, and that name
       * is about to be wrong.  Second, on Windows the unique file ID is
       * generated from the file's name, not other file information as is
       * the case on UNIX, and so a subsequent open of the old file name
       * could conceivably result in a matching "unique" file ID.
       */
      if ((ret = __memp_fremove(dbp->mpf)) != 0)
            goto err;

      /*
       * On Windows, the underlying file must be closed to perform a rename.
       * Nothing later in __db_rename requires that it be open, and the call
       * to dbp->close closes it anyway, so we just close it early.
       */
      if ((ret = memp_fclose(dbp->mpf)) != 0)
            goto err;
      dbp->mpf = NULL;

      ret = __os_rename(dbenv, real_name, real_newname);
      DB_TEST_RECOVERY(dbp, DB_TEST_POSTRENAME, ret, newname);

DB_TEST_RECOVERY_LABEL
err:  if (dbp->open_txn != NULL && (t_ret = __db_metaend(dbp,
          &remove_lock, ret == 0, NULL, NULL)) != 0 && ret == 0)
            ret = t_ret;

err_close:
      /* We no longer have an mpool, so syncing would be disastrous. */
      dbp->close(dbp, DB_NOSYNC);
      if (real_name != NULL)
            __os_freestr(real_name);
      if (real_newname != NULL)
            __os_freestr(real_newname);

      return (ret);
}

/*
 * __db_subdb_rename --
 *    Rename a subdatabase.
 */
static int
__db_subdb_rename(dbp, name, subdb, newname)
      DB *dbp;
      const char *name, *subdb, *newname;
{
      DB *mdbp;
      DBC *dbc;
      DB_ENV *dbenv;
      DB_LOCK remove_lock;
      int ret, t_ret;

      mdbp = NULL;
      dbc = NULL;
      dbenv = dbp->dbenv;

      /* Start the transaction. */
      if (TXN_ON(dbenv) && (ret = __db_metabegin(dbp, &remove_lock)) != 0)
            goto err_close;

      /*
       * Open the subdatabase.  We can use the user's DB handle for this
       * purpose, I think.
       */
      if ((ret = __db_open(dbp, name, subdb, DB_UNKNOWN, 0, 0)) != 0)
            goto err;

      /*
       * Rename the entry in the main database.
       */
      if ((ret = __db_master_open(dbp, name, 0, 0, &mdbp)) != 0)
            goto err;

      if ((ret = __db_master_update(mdbp,
           subdb, dbp->type, NULL, MU_RENAME, newname, 0)) != 0)
            goto err;

err:  /*
       * End the transaction, committing the transaction if we were
       * successful, aborting otherwise.
       */
      if (dbp->open_txn != NULL && (t_ret = __db_metaend(dbp,
          &remove_lock, ret == 0, NULL, NULL)) != 0 && ret == 0)
            ret = t_ret;

err_close:
      /*
       * Close the user's DB handle -- do this LAST to avoid smashing the
       * the transaction information.
       */
      if ((t_ret = dbp->close(dbp, 0)) != 0 && ret == 0)
            ret = t_ret;

      if (mdbp != NULL && (t_ret = mdbp->close(mdbp, 0)) != 0 && ret == 0)
            ret = t_ret;

      return (ret);
}

/*
 * __db_metabegin --
 *
 * Begin a meta-data operation.  This involves doing any required locking,
 * potentially beginning a transaction and then telling the caller if you
 * did or did not begin the transaction.
 *
 * The writing flag indicates if the caller is actually allowing creates
 * or doing deletes (i.e., if the caller is opening and not creating, then
 * we don't need to do any of this).
 * PUBLIC: int __db_metabegin __P((DB *, DB_LOCK *));
 */
int
__db_metabegin(dbp, lockp)
      DB *dbp;
      DB_LOCK *lockp;
{
      DB_ENV *dbenv;
      DBT dbplock;
      u_int32_t locker, lockval;
      int ret;

      dbenv = dbp->dbenv;

      lockp->off = LOCK_INVALID;

      /*
       * There is no single place where we can know that we are or are not
       * going to be creating any files and/or subdatabases, so we will
       * always begin a tranasaction when we start creating one.  If we later
       * discover that this was unnecessary, we will abort the transaction.
       * Recovery is written so that if we log a file create, but then
       * discover that we didn't have to do it, we recover correctly.  The
       * file recovery design document has details.
       *
       * We need to single thread all create and delete operations, so if we
       * are running with locking, we must obtain a lock. We use lock_id to
       * generate a unique locker id and use a handcrafted DBT as the object
       * on which we are locking.
       */
      if (LOCKING_ON(dbenv)) {
            if ((ret = lock_id(dbenv, &locker)) != 0)
                  return (ret);
            lockval = 0;
            dbplock.data = &lockval;
            dbplock.size = sizeof(lockval);
            if ((ret = lock_get(dbenv,
                locker, 0, &dbplock, DB_LOCK_WRITE, lockp)) != 0)
                  return (ret);
      }

      return (txn_begin(dbenv, NULL, &dbp->open_txn, 0));
}

/*
 * __db_metaend --
 *    End a meta-data operation.
 * PUBLIC: int __db_metaend __P((DB *,
 * PUBLIC:       DB_LOCK *, int, int (*)(DB *, void *), void *));
 */
int
__db_metaend(dbp, lockp, commit, callback, cookie)
      DB *dbp;
      DB_LOCK *lockp;
      int commit, (*callback) __P((DB *, void *));
      void *cookie;
{
      DB_ENV *dbenv;
      int ret, t_ret;

      ret = 0;
      dbenv = dbp->dbenv;

      /* End the transaction. */
      if (commit) {
            if ((ret = txn_commit(dbp->open_txn, DB_TXN_SYNC)) == 0) {
                  /*
                   * Unlink any underlying file, we've committed the
                   * transaction.
                   */
                  if (callback != NULL)
                        ret = callback(dbp, cookie);
            }
      } else if ((t_ret = txn_abort(dbp->open_txn)) && ret == 0)
            ret = t_ret;

      /* Release our lock. */
      if (lockp->off != LOCK_INVALID &&
          (t_ret = lock_put(dbenv, lockp)) != 0 && ret == 0)
            ret = t_ret;

      return (ret);
}

/*
 * __db_log_page
 *    Log a meta-data or root page during a create operation.
 *
 * PUBLIC: int __db_log_page __P((DB *,
 * PUBLIC:     const char *, DB_LSN *, db_pgno_t, PAGE *));
 */
int
__db_log_page(dbp, name, lsn, pgno, page)
      DB *dbp;
      const char *name;
      DB_LSN *lsn;
      db_pgno_t pgno;
      PAGE *page;
{
      DBT name_dbt, page_dbt;
      DB_LSN new_lsn;
      int ret;

      if (dbp->open_txn == NULL)
            return (0);

      memset(&page_dbt, 0, sizeof(page_dbt));
      page_dbt.size = dbp->pgsize;
      page_dbt.data = page;
      if (pgno == PGNO_BASE_MD) {
            /*
             * !!!
             * Make sure that we properly handle a null name.  The old
             * Tcl sent us pathnames of the form ""; it may be the case
             * that the new Tcl doesn't do that, so we can get rid of
             * the second check here.
             */
            memset(&name_dbt, 0, sizeof(name_dbt));
            name_dbt.data = (char *)name;
            if (name == NULL || *name == '\0')
                  name_dbt.size = 0;
            else
                  name_dbt.size = strlen(name) + 1;

            ret = __crdel_metapage_log(dbp->dbenv,
                dbp->open_txn, &new_lsn, DB_FLUSH,
                dbp->log_fileid, &name_dbt, pgno, &page_dbt);
      } else
            ret = __crdel_metasub_log(dbp->dbenv, dbp->open_txn,
                &new_lsn, 0, dbp->log_fileid, pgno, &page_dbt, lsn);

      if (ret == 0)
            page->lsn = new_lsn;
      return (ret);
}

/*
 * __db_backup_name
 *    Create the backup file name for a given file.
 *
 * PUBLIC: int __db_backup_name __P((DB_ENV *,
 * PUBLIC:     const char *, char **, DB_LSN *));
 */
#undef      BACKUP_PREFIX
#define     BACKUP_PREFIX     "__db."

#undef      MAX_LSN_TO_TEXT
#define     MAX_LSN_TO_TEXT   21
int
__db_backup_name(dbenv, name, backup, lsn)
      DB_ENV *dbenv;
      const char *name;
      char **backup;
      DB_LSN *lsn;
{
      size_t len;
      int plen, ret;
      char *p, *retp;

      len = strlen(name) + strlen(BACKUP_PREFIX) + MAX_LSN_TO_TEXT + 1;

      if ((ret = __os_malloc(dbenv, len, NULL, &retp)) != 0)
            return (ret);

      /*
       * Create the name.  Backup file names are of the form:
       *
       *    __db.name.0x[lsn-file].0x[lsn-offset]
       *
       * which guarantees uniqueness.
       *
       * However, name may contain an env-relative path in it.
       * In that case, put the __db. after the last portion of
       * the pathname.
       */
      if ((p = __db_rpath(name)) == NULL)
            snprintf(retp, len,
                "%s%s.0x%x0x%x", BACKUP_PREFIX, name,
                lsn->file, lsn->offset);
      else {
            plen = p - name + 1;
            p++;
            snprintf(retp, len,
                "%.*s%s%s.0x%x0x%x", plen, name, BACKUP_PREFIX, p,
                lsn->file, lsn->offset);
      }

      *backup = retp;
      return (0);
}

/*
 * __db_remove_callback --
 *    Callback function -- on file remove commit, it unlinks the backing
 *    file.
 */
static int
__db_remove_callback(dbp, cookie)
      DB *dbp;
      void *cookie;
{
      return (__os_unlink(dbp->dbenv, cookie));
}

/*
 * __dblist_get --
 *    Get the first element of dbenv->dblist with
 *    dbp->adj_fileid matching adjid.
 *
 * PUBLIC: DB *__dblist_get __P((DB_ENV *, u_int32_t));
 */
DB *
__dblist_get(dbenv, adjid)
      DB_ENV *dbenv;
      u_int32_t adjid;
{
      DB *dbp;

      for (dbp = LIST_FIRST(&dbenv->dblist);
          dbp != NULL && dbp->adj_fileid != adjid;
          dbp = LIST_NEXT(dbp, dblistlinks))
            ;

      return (dbp);
}

#if   CONFIG_TEST
/*
 * __db_testcopy
 *    Create a copy of all backup files and our "main" DB.
 *
 * PUBLIC: int __db_testcopy __P((DB *, const char *));
 */
int
__db_testcopy(dbp, name)
      DB *dbp;
      const char *name;
{
      if (dbp->type == DB_QUEUE)
            return (__qam_testdocopy(dbp, name));
      else
            return (__db_testdocopy(dbp, name));
}

static int
__qam_testdocopy(dbp, name)
      DB *dbp;
      const char *name;
{
      QUEUE_FILELIST *filelist, *fp;
      char buf[256], *dir;
      int ret;

      filelist = NULL;
      if ((ret = __db_testdocopy(dbp, name)) != 0)
            return (ret);
      if (dbp->mpf != NULL &&
          (ret = __qam_gen_filelist(dbp, &filelist)) != 0)
            return (ret);

      if (filelist == NULL)
            return (0);
      dir = ((QUEUE *)dbp->q_internal)->dir;
      for (fp = filelist; fp->mpf != NULL; fp++) {
            snprintf(buf, sizeof(buf), QUEUE_EXTENT, dir, name, fp->id);
            if ((ret = __db_testdocopy(dbp, buf)) != 0)
                  return (ret);
      }

      __os_free(filelist, 0);
      return (0);
}

/*
 * __db_testdocopy
 *    Create a copy of all backup files and our "main" DB.
 *
 */
static int
__db_testdocopy(dbp, name)
      DB *dbp;
      const char *name;
{
      size_t len;
      int dircnt, i, ret;
      char **namesp, *backup, *copy, *dir, *p, *real_name;
      real_name = NULL;
      /* Get the real backing file name. */
      if ((ret = __db_appname(dbp->dbenv,
          DB_APP_DATA, NULL, name, 0, NULL, &real_name)) != 0)
            return (ret);

      copy = backup = NULL;
      namesp = NULL;

      /*
       * Maximum size of file, including adding a ".afterop".
       */
      len = strlen(real_name) + strlen(BACKUP_PREFIX) + MAX_LSN_TO_TEXT + 9;

      if ((ret = __os_malloc(dbp->dbenv, len, NULL, &copy)) != 0)
            goto out;

      if ((ret = __os_malloc(dbp->dbenv, len, NULL, &backup)) != 0)
            goto out;

      /*
       * First copy the file itself.
       */
      snprintf(copy, len, "%s.afterop", real_name);
      __db_makecopy(real_name, copy);

      if ((ret = __os_strdup(dbp->dbenv, real_name, &dir)) != 0)
            goto out;
      __os_freestr(real_name);
      real_name = NULL;
      /*
       * Create the name.  Backup file names are of the form:
       *
       *    __db.name.0x[lsn-file].0x[lsn-offset]
       *
       * which guarantees uniqueness.  We want to look for the
       * backup name, followed by a '.0x' (so that if they have
       * files named, say, 'a' and 'abc' we won't match 'abc' when
       * looking for 'a'.
       */
      snprintf(backup, len, "%s%s.0x", BACKUP_PREFIX, name);

      /*
       * We need the directory path to do the __os_dirlist.
       */
      p = __db_rpath(dir);
      if (p != NULL)
            *p = '\0';
      ret = __os_dirlist(dbp->dbenv, dir, &namesp, &dircnt);
#if DIAGNOSTIC
      /*
       * XXX
       * To get the memory guard code to work because it uses strlen and we
       * just moved the end of the string somewhere sooner.  This causes the
       * guard code to fail because it looks at one byte past the end of the
       * string.
       */
      *p = '/';
#endif
      __os_freestr(dir);
      if (ret != 0)
            goto out;
      for (i = 0; i < dircnt; i++) {
            /*
             * Need to check if it is a backup file for this.
             * No idea what namesp[i] may be or how long, so
             * must use strncmp and not memcmp.  We don't want
             * to use strcmp either because we are only matching
             * the first part of the real file's name.  We don't
             * know its LSN's.
             */
            if (strncmp(namesp[i], backup, strlen(backup)) == 0) {
                  if ((ret = __db_appname(dbp->dbenv, DB_APP_DATA,
                      NULL, namesp[i], 0, NULL, &real_name)) != 0)
                        goto out;

                  /*
                   * This should not happen.  Check that old
                   * .afterop files aren't around.
                   * If so, just move on.
                   */
                  if (strstr(real_name, ".afterop") != NULL) {
                        __os_freestr(real_name);
                        real_name = NULL;
                        continue;
                  }
                  snprintf(copy, len, "%s.afterop", real_name);
                  __db_makecopy(real_name, copy);
                  __os_freestr(real_name);
                  real_name = NULL;
            }
      }
out:
      if (backup != NULL)
            __os_freestr(backup);
      if (copy != NULL)
            __os_freestr(copy);
      if (namesp != NULL)
            __os_dirfree(namesp, dircnt);
      if (real_name != NULL)
            __os_freestr(real_name);
      return (ret);
}

static void
__db_makecopy(src, dest)
      const char *src, *dest;
{
      DB_FH rfh, wfh;
      size_t rcnt, wcnt;
      char *buf;

      memset(&rfh, 0, sizeof(rfh));
      memset(&wfh, 0, sizeof(wfh));

      if (__os_malloc(NULL, 1024, NULL, &buf) != 0)
            return;

      if (__os_open(NULL,
          src, DB_OSO_RDONLY, __db_omode("rw----"), &rfh) != 0)
            goto err;
      if (__os_open(NULL, dest,
          DB_OSO_CREATE | DB_OSO_TRUNC, __db_omode("rw----"), &wfh) != 0)
            goto err;

      for (;;)
            if (__os_read(NULL, &rfh, buf, 1024, &rcnt) < 0 || rcnt == 0 ||
                __os_write(NULL, &wfh, buf, rcnt, &wcnt) < 0 || wcnt != rcnt)
                  break;

err:  __os_free(buf, 1024);
      if (F_ISSET(&rfh, DB_FH_VALID))
            __os_closehandle(&rfh);
      if (F_ISSET(&wfh, DB_FH_VALID))
            __os_closehandle(&wfh);
}
#endif

Generated by  Doxygen 1.6.0   Back to index