db_rename.c

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 2001-2005
 *      Sleepycat Software.  All rights reserved.
 *
 * $Id: db_rename.c,v 12.11 2005/10/07 20:21:22 ubell Exp $
 */

#include "db_config.h"

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

#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/db_shash.h"
#include "dbinc/db_am.h"
#include "dbinc/fop.h"
#include "dbinc/lock.h"
#include "dbinc/log.h"
#include "dbinc/mp.h"

static int __db_subdb_rename __P((DB *,
               DB_TXN *, const char *, const char *, const char *));

/*
 * __env_dbrename_pp
 *      DB_ENV->dbrename pre/post processing.
 *
 * PUBLIC: int __env_dbrename_pp __P((DB_ENV *, DB_TXN *,
 * PUBLIC:     const char *, const char *, const char *, u_int32_t));
 */
int
__env_dbrename_pp(dbenv, txn, name, subdb, newname, flags)
        DB_ENV *dbenv;
        DB_TXN *txn;
        const char *name, *subdb, *newname;
        u_int32_t flags;
{
        DB *dbp;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret, txn_local;

        dbp = NULL;
        txn_local = 0;

        PANIC_CHECK(dbenv);
        ENV_ILLEGAL_BEFORE_OPEN(dbenv, "DB_ENV->dbrename");

        /*
         * The actual argument checking is simple, do it inline, outside of
         * the replication block.
         */
        if ((ret = __db_fchk(dbenv, "DB->rename", flags, DB_AUTO_COMMIT)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        /* Check for replication block. */
        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret = __env_rep_enter(dbenv, 1)) != 0) {
                handle_check = 0;
                goto err;
        }

        /*
         * Create local transaction as necessary, check for consistent
         * transaction usage.
         */
        if (IS_ENV_AUTO_COMMIT(dbenv, txn, flags)) {
                if ((ret = __db_txn_auto_init(dbenv, &txn)) != 0)
                        goto err;
                txn_local = 1;
        } else
                if (txn != NULL && !TXN_ON(dbenv)) {
                        ret = __db_not_txn_env(dbenv);
                        goto err;
                }

        LF_CLR(DB_AUTO_COMMIT);

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

        ret = __db_rename_int(dbp, txn, name, subdb, newname);

        if (txn_local) {
                /*
                 * We created the DBP here and when we commit/abort, we'll
                 * release all the transactional locks, including the handle
                 * lock; mark the handle cleared explicitly.
                 */
                LOCK_INIT(dbp->handle_lock);
                dbp->lid = DB_LOCK_INVALIDID;
        } else if (txn != NULL) {
                /*
                 * We created this handle locally so we need to close it
                 * and clean it up.  Unfortunately, it's holding transactional
                 * locks that need to persist until the end of transaction.
                 * If we invalidate the locker id (dbp->lid), then the close
                 * won't free these locks prematurely.
                 */
                 dbp->lid = DB_LOCK_INVALIDID;
        }

err:    if (txn_local && (t_ret =
            __db_txn_auto_resolve(dbenv, txn, 0, ret)) != 0 && ret == 0)
                ret = t_ret;

        /*
         * We never opened this dbp for real, so don't include a transaction
         * handle, and use NOSYNC to avoid calling into mpool.
         *
         * !!!
         * Note we're reversing the order of operations: we started the txn and
         * then opened the DB handle; we're resolving the txn and then closing
         * closing the DB handle -- it's safer.
         */
        if (dbp != NULL &&
            (t_ret = __db_close(dbp, NULL, DB_NOSYNC)) != 0 && ret == 0)
                ret = t_ret;

        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;

        ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_rename_pp
 *      DB->rename pre/post processing.
 *
 * PUBLIC: int __db_rename_pp __P((DB *,
 * PUBLIC:     const char *, const char *, const char *, u_int32_t));
 */
int
__db_rename_pp(dbp, name, subdb, newname, flags)
        DB *dbp;
        const char *name, *subdb, *newname;
        u_int32_t flags;
{
        DB_ENV *dbenv;
        DB_THREAD_INFO *ip;
        int handle_check, ret, t_ret;

        dbenv = dbp->dbenv;
        handle_check = 0;

        PANIC_CHECK(dbenv);

        /*
         * Validate arguments, continuing to destroy the handle on failure.
         *
         * Cannot use DB_ILLEGAL_AFTER_OPEN directly because it returns.
         *
         * !!!
         * We have a serious problem if we're here with a handle used to open
         * a database -- we'll destroy the handle, and the application won't
         * ever be able to close the database.
         */
        if (F_ISSET(dbp, DB_AM_OPEN_CALLED))
                return (__db_mi_open(dbenv, "DB->rename", 1));

        /* Validate arguments. */
        if ((ret = __db_fchk(dbenv, "DB->rename", flags, 0)) != 0)
                return (ret);

        /* Check for consistent transaction usage. */
        if ((ret = __db_check_txn(dbp, NULL, DB_LOCK_INVALIDID, 0)) != 0)
                return (ret);

        ENV_ENTER(dbenv, ip);

        handle_check = IS_ENV_REPLICATED(dbenv);
        if (handle_check && (ret = __db_rep_enter(dbp, 1, 1, 0)) != 0) {
                handle_check = 0;
                goto err;
        }

        /* Rename the file. */
        ret = __db_rename(dbp, NULL, name, subdb, newname);

        if (handle_check && (t_ret = __env_db_rep_exit(dbenv)) != 0 && ret == 0)
                ret = t_ret;
err:    ENV_LEAVE(dbenv, ip);
        return (ret);
}

/*
 * __db_rename
 *      DB->rename method.
 *
 * PUBLIC: int __db_rename
 * PUBLIC:     __P((DB *, DB_TXN *, const char *, const char *, const char *));
 */
int
__db_rename(dbp, txn, name, subdb, newname)
        DB *dbp;
        DB_TXN *txn;
        const char *name, *subdb, *newname;
{
        int ret, t_ret;

        ret = __db_rename_int(dbp, txn, name, subdb, newname);

        if ((t_ret = __db_close(dbp, txn, DB_NOSYNC)) != 0 && ret == 0)
                ret = t_ret;

        return (ret);
}

/*
 * __db_rename_int
 *      Worker function for DB->rename method; the close of the dbp is
 * left in the wrapper routine.
 *
 * PUBLIC: int __db_rename_int
 * PUBLIC:     __P((DB *, DB_TXN *, const char *, const char *, const char *));
 */
int
__db_rename_int(dbp, txn, name, subdb, newname)
        DB *dbp;
        DB_TXN *txn;
        const char *name, *subdb, *newname;
{
        DB_ENV *dbenv;
        int ret;
        char *old, *real_name;

        dbenv = dbp->dbenv;
        real_name = NULL;

        DB_TEST_RECOVERY(dbp, DB_TEST_PREDESTROY, ret, name);

        if (name == NULL && subdb == NULL) {
                __db_err(dbenv, "Rename on temporary files invalid");
                ret = EINVAL;
                goto err;
        }

        if (name == NULL)
                MAKE_INMEM(dbp);
        else if (subdb != NULL) {
                ret = __db_subdb_rename(dbp, txn, name, subdb, newname);
                goto err;
        }

        /*
         * From here on down, this pertains to files or in-memory databases.
         *
         * Find the real name of the file.
         */
        if (F_ISSET(dbp, DB_AM_INMEM)) {
                old = (char *)subdb;
                real_name = (char *)subdb;
        } else {
                if ((ret = __db_appname(dbenv,
                    DB_APP_DATA, name, 0, NULL, &real_name)) != 0)
                        goto err;
                old = (char *)name;
        }

        if ((ret = __fop_remove_setup(dbp, txn, real_name, 0)) != 0)
                goto err;

        if (dbp->db_am_rename != NULL &&
            (ret = dbp->db_am_rename(dbp, txn, name, subdb, newname)) != 0)
                goto err;

        /*
         * The transactional case and non-transactional case are
         * quite different.  In the non-transactional case, we simply
         * do the rename.  In the transactional case, since we need
         * the ability to back out and maintain locking, we have to
         * create a temporary object as a placeholder.  This is all
         * taken care of in the fop layer.
         */
        if (txn != NULL) {
                if ((ret = __fop_dummy(dbp, txn, old, newname, 0)) != 0)
                        goto err;
        } else {
                if ((ret = __fop_dbrename(dbp, old, newname)) != 0)
                        goto err;
        }

        /*
         * I am pretty sure that we haven't gotten a dbreg id, so calling
         * dbreg_filelist_update is not necessary.
         */
        DB_ASSERT(dbp->log_filename == NULL ||
            dbp->log_filename->id == DB_LOGFILEID_INVALID);

        DB_TEST_RECOVERY(dbp, DB_TEST_POSTDESTROY, ret, newname);

DB_TEST_RECOVERY_LABEL
err:    if (!F_ISSET(dbp, DB_AM_INMEM) && real_name != NULL)
                __os_free(dbenv, real_name);

        return (ret);
}

/*
 * __db_subdb_rename --
 *      Rename a subdatabase.
 */
static int
__db_subdb_rename(dbp, txn, name, subdb, newname)
        DB *dbp;
        DB_TXN *txn;
        const char *name, *subdb, *newname;
{
        DB *mdbp;
        DB_ENV *dbenv;
        PAGE *meta;
        int ret, t_ret;

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

        /*
         * We have not opened this dbp so it isn't marked as a subdb,
         * but it ought to be.
         */
        F_SET(dbp, DB_AM_SUBDB);

        /*
         * Rename the entry in the main database.  We need to first
         * get the meta-data page number (via MU_OPEN) so that we can
         * read the meta-data page and obtain a handle lock.  Once we've
         * done that, we can proceed to do the rename in the master.
         */
        if ((ret = __db_master_open(dbp, txn, name, 0, 0, &mdbp)) != 0)
                goto err;

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

        if ((ret = __memp_fget(mdbp->mpf, &dbp->meta_pgno, 0, &meta)) != 0)
                goto err;
        memcpy(dbp->fileid, ((DBMETA *)meta)->uid, DB_FILE_ID_LEN);
        if ((ret = __fop_lock_handle(dbenv,
            dbp, mdbp->lid, DB_LOCK_WRITE, NULL, NOWAIT_FLAG(txn))) != 0)
                goto err;

        ret = __memp_fput(mdbp->mpf, meta, 0);
        meta = NULL;
        if (ret != 0)
                goto err;

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

        DB_TEST_RECOVERY(dbp, DB_TEST_POSTDESTROY, ret, name);

DB_TEST_RECOVERY_LABEL
err:
        if (meta != NULL &&
            (t_ret = __memp_fput(mdbp->mpf, meta, 0)) != 0 && ret == 0)
                ret = t_ret;

        if (mdbp != NULL &&
            (t_ret = __db_close(mdbp, txn, DB_NOSYNC)) != 0 && ret == 0)
                ret = t_ret;

        return (ret);
}

---