bt_open.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2005
 *      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.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Olson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: bt_open.c,v 12.5 2005/09/28 17:44:17 margo Exp $
 */

#include "db_config.h"

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

#include <string.h>
#endif

#include "db_int.h"
#include "dbinc/crypto.h"
#include "dbinc/db_page.h"
#include "dbinc/db_swap.h"
#include "dbinc/btree.h"
#include "dbinc/db_shash.h"
#include "dbinc/lock.h"
#include "dbinc/log.h"
#include "dbinc/mp.h"
#include "dbinc/fop.h"

static void __bam_init_meta __P((DB *, BTMETA *, db_pgno_t, DB_LSN *));

/*
 * __bam_open --
 *      Open a btree.
 *
 * PUBLIC: int __bam_open __P((DB *,
 * PUBLIC:      DB_TXN *, const char *, db_pgno_t, u_int32_t));
 */
int
__bam_open(dbp, txn, name, base_pgno, flags)
        DB *dbp;
        DB_TXN *txn;
        const char *name;
        db_pgno_t base_pgno;
        u_int32_t flags;
{
        BTREE *t;

        COMPQUIET(name, NULL);
        t = dbp->bt_internal;

        /*
         * We don't permit the user to specify a prefix routine if they didn't
         * also specify a comparison routine, they can't know enough about our
         * comparison routine to get it right.
         */
        if (t->bt_compare == __bam_defcmp && t->bt_prefix != __bam_defpfx) {
                __db_err(dbp->dbenv,
"prefix comparison may not be specified for default comparison routine");
                return (EINVAL);
        }

        /*
         * Verify that the bt_minkey value specified won't cause the
         * calculation of ovflsize to underflow [#2406] for this pagesize.
         */
        if (B_MINKEY_TO_OVFLSIZE(dbp, t->bt_minkey, dbp->pgsize) >
            B_MINKEY_TO_OVFLSIZE(dbp, DEFMINKEYPAGE, dbp->pgsize)) {
                __db_err(dbp->dbenv,
                    "bt_minkey value of %lu too high for page size of %lu",
                    (u_long)t->bt_minkey, (u_long)dbp->pgsize);
                return (EINVAL);
        }

        /* Start up the tree. */
        return (__bam_read_root(dbp, txn, base_pgno, flags));
}

/*
 * __bam_metachk --
 *
 * PUBLIC: int __bam_metachk __P((DB *, const char *, BTMETA *));
 */
int
__bam_metachk(dbp, name, btm)
        DB *dbp;
        const char *name;
        BTMETA *btm;
{
        DB_ENV *dbenv;
        u_int32_t vers;
        int ret;

        dbenv = dbp->dbenv;

        /*
         * At this point, all we know is that the magic number is for a Btree.
         * Check the version, the database may be out of date.
         */
        vers = btm->dbmeta.version;
        if (F_ISSET(dbp, DB_AM_SWAP))
                M_32_SWAP(vers);
        switch (vers) {
        case 6:
        case 7:
                __db_err(dbenv,
                    "%s: btree version %lu requires a version upgrade",
                    name, (u_long)vers);
                return (DB_OLD_VERSION);
        case 8:
        case 9:
                break;
        default:
                __db_err(dbenv,
                    "%s: unsupported btree version: %lu", name, (u_long)vers);
                return (EINVAL);
        }

        /* Swap the page if we need to. */
        if (F_ISSET(dbp, DB_AM_SWAP) && (ret = __bam_mswap((PAGE *)btm)) != 0)
                return (ret);

        /*
         * Check application info against metadata info, and set info, flags,
         * and type based on metadata info.
         */
        if ((ret =
            __db_fchk(dbenv, "DB->open", btm->dbmeta.flags, BTM_MASK)) != 0)
                return (ret);

        if (F_ISSET(&btm->dbmeta, BTM_RECNO)) {
                if (dbp->type == DB_BTREE)
                        goto wrong_type;
                dbp->type = DB_RECNO;
                DB_ILLEGAL_METHOD(dbp, DB_OK_RECNO);
        } else {
                if (dbp->type == DB_RECNO)
                        goto wrong_type;
                dbp->type = DB_BTREE;
                DB_ILLEGAL_METHOD(dbp, DB_OK_BTREE);
        }

        if (F_ISSET(&btm->dbmeta, BTM_DUP))
                F_SET(dbp, DB_AM_DUP);
        else
                if (F_ISSET(dbp, DB_AM_DUP)) {
                        __db_err(dbenv,
                "%s: DB_DUP specified to open method but not set in database",
                            name);
                        return (EINVAL);
                }

        if (F_ISSET(&btm->dbmeta, BTM_RECNUM)) {
                if (dbp->type != DB_BTREE)
                        goto wrong_type;
                F_SET(dbp, DB_AM_RECNUM);

                if ((ret = __db_fcchk(dbenv,
                    "DB->open", dbp->flags, DB_AM_DUP, DB_AM_RECNUM)) != 0)
                        return (ret);
        } else
                if (F_ISSET(dbp, DB_AM_RECNUM)) {
                        __db_err(dbenv,
            "%s: DB_RECNUM specified to open method but not set in database",
                            name);
                        return (EINVAL);
                }

        if (F_ISSET(&btm->dbmeta, BTM_FIXEDLEN)) {
                if (dbp->type != DB_RECNO)
                        goto wrong_type;
                F_SET(dbp, DB_AM_FIXEDLEN);
        } else
                if (F_ISSET(dbp, DB_AM_FIXEDLEN)) {
                        __db_err(dbenv,
        "%s: DB_FIXEDLEN specified to open method but not set in database",
                            name);
                        return (EINVAL);
                }

        if (F_ISSET(&btm->dbmeta, BTM_RENUMBER)) {
                if (dbp->type != DB_RECNO)
                        goto wrong_type;
                F_SET(dbp, DB_AM_RENUMBER);
        } else
                if (F_ISSET(dbp, DB_AM_RENUMBER)) {
                        __db_err(dbenv,
            "%s: DB_RENUMBER specified to open method but not set in database",
                            name);
                        return (EINVAL);
                }

        if (F_ISSET(&btm->dbmeta, BTM_SUBDB))
                F_SET(dbp, DB_AM_SUBDB);
        else
                if (F_ISSET(dbp, DB_AM_SUBDB)) {
                        __db_err(dbenv,
            "%s: multiple databases specified but not supported by file",
                            name);
                        return (EINVAL);
                }

        if (F_ISSET(&btm->dbmeta, BTM_DUPSORT)) {
                if (dbp->dup_compare == NULL)
                        dbp->dup_compare = __bam_defcmp;
                F_SET(dbp, DB_AM_DUPSORT);
        } else
                if (dbp->dup_compare != NULL) {
                        __db_err(dbenv,
                "%s: duplicate sort specified but not supported in database",
                            name);
                        return (EINVAL);
                }

        /* Set the page size. */
        dbp->pgsize = btm->dbmeta.pagesize;

        /* Copy the file's ID. */
        memcpy(dbp->fileid, btm->dbmeta.uid, DB_FILE_ID_LEN);

        return (0);

wrong_type:
        if (dbp->type == DB_BTREE)
                __db_err(dbenv,
                    "open method type is Btree, database type is Recno");
        else
                __db_err(dbenv,
                    "open method type is Recno, database type is Btree");
        return (EINVAL);
}

/*
 * __bam_read_root --
 *      Read the root page and check a tree.
 *
 * PUBLIC: int __bam_read_root __P((DB *, DB_TXN *, db_pgno_t, u_int32_t));
 */
int
__bam_read_root(dbp, txn, base_pgno, flags)
        DB *dbp;
        DB_TXN *txn;
        db_pgno_t base_pgno;
        u_int32_t flags;
{
        BTMETA *meta;
        BTREE *t;
        DBC *dbc;
        DB_LOCK metalock;
        DB_MPOOLFILE *mpf;
        int ret, t_ret;

        COMPQUIET(flags, 0);
        meta = NULL;
        t = dbp->bt_internal;
        LOCK_INIT(metalock);
        mpf = dbp->mpf;
        ret = 0;

        /* Get a cursor.  */
        if ((ret = __db_cursor(dbp, txn, &dbc, 0)) != 0)
                return (ret);

        /* Get the metadata page. */
        if ((ret =
            __db_lget(dbc, 0, base_pgno, DB_LOCK_READ, 0, &metalock)) != 0)
                goto err;
        if ((ret = __memp_fget(mpf, &base_pgno, 0, &meta)) != 0)
                goto err;

        /*
         * If the magic number is set, the tree has been created.  Correct
         * any fields that may not be right.  Note, all of the local flags
         * were set by DB->open.
         *
         * Otherwise, we'd better be in recovery or abort, in which case the
         * metadata page will be created/initialized elsewhere.
         */
        if (meta->dbmeta.magic == DB_BTREEMAGIC) {
                t->bt_minkey = meta->minkey;
                t->re_pad = (int)meta->re_pad;
                t->re_len = meta->re_len;

                t->bt_meta = base_pgno;
                t->bt_root = meta->root;
        } else {
                DB_ASSERT(IS_RECOVERING(dbp->dbenv) ||
                     F_ISSET(dbp, DB_AM_RECOVER));
        }

        /*
         * !!!
         * If creating a subdatabase, we've already done an insert when
         * we put the subdatabase's entry into the master database, so
         * our last-page-inserted value is wrongly initialized for the
         * master database, not the subdatabase we're creating.  I'm not
         * sure where the *right* place to clear this value is, it's not
         * intuitively obvious that it belongs here.
         */
        t->bt_lpgno = PGNO_INVALID;

err:    /* Put the metadata page back. */
        if (meta != NULL &&
            (t_ret = __memp_fput(mpf, meta, 0)) != 0 && ret == 0)
                ret = t_ret;
        if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
                ret = t_ret;

        if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0)
                ret = t_ret;
        return (ret);
}

/*
 * __bam_init_meta --
 *
 * Initialize a btree meta-data page.  The following fields may need
 * to be updated later: last_pgno, root.
 */
static void
__bam_init_meta(dbp, meta, pgno, lsnp)
        DB *dbp;
        BTMETA *meta;
        db_pgno_t pgno;
        DB_LSN *lsnp;
{
        BTREE *t;

        memset(meta, 0, sizeof(BTMETA));
        meta->dbmeta.lsn = *lsnp;
        meta->dbmeta.pgno = pgno;
        meta->dbmeta.magic = DB_BTREEMAGIC;
        meta->dbmeta.version = DB_BTREEVERSION;
        meta->dbmeta.pagesize = dbp->pgsize;
        if (F_ISSET(dbp, DB_AM_CHKSUM))
                FLD_SET(meta->dbmeta.metaflags, DBMETA_CHKSUM);
        if (F_ISSET(dbp, DB_AM_ENCRYPT)) {
                meta->dbmeta.encrypt_alg =
                    ((DB_CIPHER *)dbp->dbenv->crypto_handle)->alg;
                DB_ASSERT(meta->dbmeta.encrypt_alg != 0);
                meta->crypto_magic = meta->dbmeta.magic;
        }
        meta->dbmeta.type = P_BTREEMETA;
        meta->dbmeta.free = PGNO_INVALID;
        meta->dbmeta.last_pgno = pgno;
        if (F_ISSET(dbp, DB_AM_DUP))
                F_SET(&meta->dbmeta, BTM_DUP);
        if (F_ISSET(dbp, DB_AM_FIXEDLEN))
                F_SET(&meta->dbmeta, BTM_FIXEDLEN);
        if (F_ISSET(dbp, DB_AM_RECNUM))
                F_SET(&meta->dbmeta, BTM_RECNUM);
        if (F_ISSET(dbp, DB_AM_RENUMBER))
                F_SET(&meta->dbmeta, BTM_RENUMBER);
        if (F_ISSET(dbp, DB_AM_SUBDB))
                F_SET(&meta->dbmeta, BTM_SUBDB);
        if (dbp->dup_compare != NULL)
                F_SET(&meta->dbmeta, BTM_DUPSORT);
        if (dbp->type == DB_RECNO)
                F_SET(&meta->dbmeta, BTM_RECNO);
        memcpy(meta->dbmeta.uid, dbp->fileid, DB_FILE_ID_LEN);

        t = dbp->bt_internal;
        meta->minkey = t->bt_minkey;
        meta->re_len = t->re_len;
        meta->re_pad = (u_int32_t)t->re_pad;
}

/*
 * __bam_new_file --
 * Create the necessary pages to begin a new database file.
 *
 * This code appears more complex than it is because of the two cases (named
 * and unnamed).  The way to read the code is that for each page being created,
 * there are three parts: 1) a "get page" chunk (which either uses malloc'd
 * memory or calls __memp_fget), 2) the initialization, and 3) the "put page"
 * chunk which either does a fop write or an __memp_fput.
 *
 * PUBLIC: int __bam_new_file __P((DB *, DB_TXN *, DB_FH *, const char *));
 */
int
__bam_new_file(dbp, txn, fhp, name)
        DB *dbp;
        DB_TXN *txn;
        DB_FH *fhp;
        const char *name;
{
        BTMETA *meta;
        DB_ENV *dbenv;
        DB_LSN lsn;
        DB_MPOOLFILE *mpf;
        DB_PGINFO pginfo;
        DBT pdbt;
        PAGE *root;
        db_pgno_t pgno;
        int ret, t_ret;
        void *buf;

        dbenv = dbp->dbenv;
        mpf = dbp->mpf;
        root = NULL;
        meta = NULL;
        buf = NULL;

        if (F_ISSET(dbp, DB_AM_INMEM)) {
                /* Build the meta-data page. */
                pgno = PGNO_BASE_MD;
                if ((ret =
                    __memp_fget(mpf, &pgno, DB_MPOOL_CREATE, &meta)) != 0)
                        return (ret);
                LSN_NOT_LOGGED(lsn);
                __bam_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
                meta->root = 1;
                meta->dbmeta.last_pgno = 1;
                if ((ret =
                    __db_log_page(dbp, txn, &lsn, pgno, (PAGE *)meta)) != 0)
                        goto err;
                ret = __memp_fput(mpf, meta, DB_MPOOL_DIRTY);
                meta = NULL;
                if (ret != 0)
                        goto err;

                /* Build the root page. */
                pgno = 1;
                if ((ret =
                    __memp_fget(mpf, &pgno, DB_MPOOL_CREATE, &root)) != 0)
                        goto err;
                P_INIT(root, dbp->pgsize, 1, PGNO_INVALID, PGNO_INVALID,
                    LEAFLEVEL, dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE);
                LSN_NOT_LOGGED(root->lsn);
                if ((ret =
                    __db_log_page(dbp, txn, &root->lsn, pgno, root)) != 0)
                        goto err;
                ret = __memp_fput(mpf, root, DB_MPOOL_DIRTY);
                root = NULL;
                if (ret != 0)
                        goto err;
        } else {
                memset(&pdbt, 0, sizeof(pdbt));

                /* Build the meta-data page. */
                pginfo.db_pagesize = dbp->pgsize;
                pginfo.flags =
                    F_ISSET(dbp, (DB_AM_CHKSUM | DB_AM_ENCRYPT | DB_AM_SWAP));
                pginfo.type = dbp->type;
                pdbt.data = &pginfo;
                pdbt.size = sizeof(pginfo);
                if ((ret = __os_calloc(dbenv, 1, dbp->pgsize, &buf)) != 0)
                        return (ret);
                meta = (BTMETA *)buf;
                LSN_NOT_LOGGED(lsn);
                __bam_init_meta(dbp, meta, PGNO_BASE_MD, &lsn);
                meta->root = 1;
                meta->dbmeta.last_pgno = 1;
                if ((ret = __db_pgout(dbenv, PGNO_BASE_MD, meta, &pdbt)) != 0)
                        goto err;
                if ((ret = __fop_write(dbenv, txn, name, DB_APP_DATA, fhp,
                    dbp->pgsize, 0, 0, buf, dbp->pgsize, 1, F_ISSET(
                    dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0)) != 0)
                        goto err;
                meta = NULL;

                /* Build the root page. */
#ifdef DIAGNOSTIC
                memset(buf, CLEAR_BYTE, dbp->pgsize);
#endif
                root = (PAGE *)buf;
                P_INIT(root, dbp->pgsize, 1, PGNO_INVALID, PGNO_INVALID,
                    LEAFLEVEL, dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE);
                LSN_NOT_LOGGED(root->lsn);
                if ((ret = __db_pgout(dbenv, root->pgno, root, &pdbt)) != 0)
                        goto err;
                if ((ret = __fop_write(dbenv, txn, name, DB_APP_DATA, fhp,
                    dbp->pgsize, 1, 0, buf, dbp->pgsize, 1, F_ISSET(
                    dbp, DB_AM_NOT_DURABLE) ? DB_LOG_NOT_DURABLE : 0)) != 0)
                        goto err;
                root = NULL;
        }

err:    if (buf != NULL)
                __os_free(dbenv, buf);
        else {
                if (meta != NULL &&
                    (t_ret = __memp_fput(mpf, meta, 0)) != 0 && ret == 0)
                        ret = t_ret;
                if (root != NULL &&
                    (t_ret = __memp_fput(mpf, root, 0)) != 0 && ret == 0)
                        ret = t_ret;
        }
        return (ret);
}

/*
 * __bam_new_subdb --
 *      Create a metadata page and a root page for a new btree.
 *
 * PUBLIC: int __bam_new_subdb __P((DB *, DB *, DB_TXN *));
 */
int
__bam_new_subdb(mdbp, dbp, txn)
        DB *mdbp, *dbp;
        DB_TXN *txn;
{
        BTMETA *meta;
        DBC *dbc;
        DB_ENV *dbenv;
        DB_LOCK metalock;
        DB_LSN lsn;
        DB_MPOOLFILE *mpf;
        PAGE *root;
        int ret, t_ret;

        dbenv = mdbp->dbenv;
        mpf = mdbp->mpf;
        dbc = NULL;
        meta = NULL;
        root = NULL;

        if ((ret = __db_cursor(mdbp, txn,
            &dbc, CDB_LOCKING(dbenv) ?  DB_WRITECURSOR : 0)) != 0)
                return (ret);

        /* Get, and optionally create the metadata page. */
        if ((ret = __db_lget(dbc,
            0, dbp->meta_pgno, DB_LOCK_WRITE, 0, &metalock)) != 0)
                goto err;
        if ((ret =
            __memp_fget(mpf, &dbp->meta_pgno, DB_MPOOL_CREATE, &meta)) != 0)
                goto err;

        /* Build meta-data page. */
        lsn = meta->dbmeta.lsn;
        __bam_init_meta(dbp, meta, dbp->meta_pgno, &lsn);
        if ((ret = __db_log_page(mdbp,
            txn, &meta->dbmeta.lsn, dbp->meta_pgno, (PAGE *)meta)) != 0)
                goto err;

        /* Create and initialize a root page. */
        if ((ret = __db_new(dbc,
            dbp->type == DB_RECNO ? P_LRECNO : P_LBTREE, &root)) != 0)
                goto err;
        root->level = LEAFLEVEL;

        if (DBENV_LOGGING(dbenv) &&
            (ret = __bam_root_log(mdbp, txn, &meta->dbmeta.lsn, 0,
            meta->dbmeta.pgno, root->pgno, &meta->dbmeta.lsn)) != 0)
                goto err;

        meta->root = root->pgno;
        if ((ret =
            __db_log_page(mdbp, txn, &root->lsn, root->pgno, root)) != 0)
                goto err;

        /* Release the metadata and root pages. */
        if ((ret = __memp_fput(mpf, meta, DB_MPOOL_DIRTY)) != 0)
                goto err;
        meta = NULL;
        if ((ret = __memp_fput(mpf, root, DB_MPOOL_DIRTY)) != 0)
                goto err;
        root = NULL;
err:
        if (meta != NULL)
                if ((t_ret = __memp_fput(mpf, meta, 0)) != 0 && ret == 0)
                        ret = t_ret;
        if (root != NULL)
                if ((t_ret = __memp_fput(mpf, root, 0)) != 0 && ret == 0)
                        ret = t_ret;
        if ((t_ret = __LPUT(dbc, metalock)) != 0 && ret == 0)
                ret = t_ret;
        if (dbc != NULL)
                if ((t_ret = __db_c_close(dbc)) != 0 && ret == 0)
                        ret = t_ret;
        return (ret);
}

---