dbreg_rec.c

这是linux下运行的mysql软件包,可用于linux 下安装 php + mysql + apach 的网络配置

/*-
 * See the file LICENSE for redistribution information.
 *
 * Copyright (c) 1996-2002
 *	Sleepycat Software.  All rights reserved.
 */
/*
 * Copyright (c) 1995, 1996
 *	The President and Fellows of Harvard University.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "db_config.h"

#ifndef lint
static const char revid[] = "$Id: dbreg_rec.c,v 11.108 2002/08/14 20:04:25 bostic Exp $";
#endif /* not lint */

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

#include <string.h>
#endif

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

static int __dbreg_open_file __P((DB_ENV *,
    DB_TXN *, __dbreg_register_args *, void *));

/*
 * PUBLIC: int __dbreg_register_recover
 * PUBLIC:     __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *));
 */
int
__dbreg_register_recover(dbenv, dbtp, lsnp, op, info)
	DB_ENV *dbenv;
	DBT *dbtp;
	DB_LSN *lsnp;
	db_recops op;
	void *info;
{
	DB_ENTRY *dbe;
	DB_LOG *dblp;
	DB *dbp;
	__dbreg_register_args *argp;
	int do_close, do_open, do_rem, ret, t_ret;

	dblp = dbenv->lg_handle;
	dbp = NULL;

#ifdef DEBUG_RECOVER
	REC_PRINT(__dbreg_register_print);
#endif
	do_open = do_close = 0;
	if ((ret = __dbreg_register_read(dbenv, dbtp->data, &argp)) != 0)
		goto out;

	switch (argp->opcode) {
	case LOG_OPEN:
		if ((DB_REDO(op) ||
		    op == DB_TXN_OPENFILES || op == DB_TXN_POPENFILES))
			do_open = 1;
		else
			do_close = 1;
		break;

	case LOG_CLOSE:
		if (DB_UNDO(op))
			do_open = 1;
		else
			do_close = 1;
		break;
	case LOG_RCLOSE:
		/*
		 * LOG_RCLOSE was generated by recover because a file
		 * was left open.  The POPENFILES pass, which is run
		 * to open files to abort prepared transactions,
		 * may not include the open for this file so we
		 * open it here.  Note that a normal CLOSE is
		 * not legal before the prepared transaction is
		 * committed or aborted.
		 */
		if (DB_UNDO(op) || op == DB_TXN_POPENFILES)
			do_open = 1;
		else
			do_close = 1;
		break;

	case LOG_CHECKPOINT:
		if (DB_UNDO(op) ||
		    op == DB_TXN_OPENFILES || op == DB_TXN_POPENFILES)
			do_open = 1;
		break;
	}

	if (do_open) {
		/*
		 * We must open the db even if the meta page is not
		 * yet written as we may be creating subdatabase.
		 */
		if (op == DB_TXN_OPENFILES && argp->opcode != LOG_CHECKPOINT)
			F_SET(dblp, DBLOG_FORCE_OPEN);

		/*
		 * During an abort or an open pass to recover prepared txns,
		 * we need to make sure that we use the same locker id on the
		 * open.  We pass the txnid along to ensure this.
		 */
		ret = __dbreg_open_file(dbenv,
		    op == DB_TXN_ABORT || op == DB_TXN_POPENFILES ?
		    argp->txnid : NULL, argp, info);
		if (ret == ENOENT || ret == EINVAL) {
			/*
			 * If this is an OPEN while rolling forward, it's
			 * possible that the file was recreated since last
			 * time we got here.  In that case, we've got deleted
			 * set and probably shouldn't, so we need to check
			 * for that case and possibly retry.
			 */
			if (op == DB_TXN_FORWARD_ROLL &&
			    argp->txnid != 0 &&
			    dblp->dbentry[argp->fileid].deleted) {
				dblp->dbentry[argp->fileid].deleted = 0;
				ret =
				    __dbreg_open_file(dbenv, NULL, argp, info);
			}
			ret = 0;
		}
		F_CLR(dblp, DBLOG_FORCE_OPEN);
	}

	if (do_close) {
		/*
		 * If we are undoing an open, or redoing a close,
		 * then we need to close the file.
		 *
		 * If the file is deleted, then we can just ignore this close.
		 * Otherwise, we should usually have a valid dbp we should
		 * close or whose reference count should be decremented.
		 * However, if we shut down without closing a file, we may, in
		 * fact, not have the file open, and that's OK.
		 */
		do_rem = 0;
		MUTEX_THREAD_LOCK(dbenv, dblp->mutexp);
		if (argp->fileid < dblp->dbentry_cnt) {
			/*
			 * Typically, closes should match an open which means
			 * that if this is a close, there should be a valid
			 * entry in the dbentry table when we get here,
			 * however there is an exception.  If this is an
			 * OPENFILES pass, then we may have started from
			 * a log file other than the first, and the
			 * corresponding open appears in an earlier file.
			 * We can ignore that case, but all others are errors.
			 */
			dbe = &dblp->dbentry[argp->fileid];
			if (dbe->dbp == NULL && !dbe->deleted) {
				/* No valid entry here. */
				if ((argp->opcode != LOG_CLOSE &&
				    argp->opcode != LOG_RCLOSE) ||
				    (op != DB_TXN_OPENFILES &&
				    op !=DB_TXN_POPENFILES)) {
					__db_err(dbenv,
					    "Improper file close at %lu/%lu",
					    (u_long)lsnp->file,
					    (u_long)lsnp->offset);
					ret = EINVAL;
				}
				MUTEX_THREAD_UNLOCK(dbenv, dblp->mutexp);
				goto done;
			}

			/* We have either an open entry or a deleted entry. */
			if ((dbp = dbe->dbp) != NULL) {
				MUTEX_THREAD_UNLOCK(dbenv, dblp->mutexp);
				(void)__dbreg_revoke_id(dbp, 0);

				/*
				 * If we're a replication client, it's
				 * possible to get here with a dbp that
				 * the user opened, but which we later
				 * assigned a fileid to.  Be sure that
				 * we only close dbps that we opened in
				 * the recovery code;  they should have
				 * DB_AM_RECOVER set.
				 *
				 * The only exception is if we're aborting
				 * in a normal environment;  then we might
				 * get here with a non-AM_RECOVER database.
				 */
				if (F_ISSET(dbp, DB_AM_RECOVER) ||
				    op == DB_TXN_ABORT)
					do_rem = 1;
			} else if (dbe->deleted) {
				MUTEX_THREAD_UNLOCK(dbenv, dblp->mutexp);
				__dbreg_rem_dbentry(dblp, argp->fileid);
			}
		} else
			MUTEX_THREAD_UNLOCK(dbenv, dblp->mutexp);
		if (do_rem) {
			/*
			 * If we are undoing a create we'd better discard
			 * any buffers from the memory pool.
			 */
			if (dbp != NULL && dbp->mpf != NULL && argp->id != 0) {
				if ((ret = dbp->mpf->close(dbp->mpf,
				    DB_MPOOL_DISCARD)) != 0)
					goto out;
				dbp->mpf = NULL;
			}

			/*
			 * During recovery, all files are closed.  On an abort,
			 * we only close the file if we opened it during the
			 * abort (DB_AM_RECOVER set), otherwise we simply do
			 * a __db_refresh.  For the close case, if remove or
			 * rename has closed the file, don't request a sync,
			 * because the NULL mpf would be a problem.
			 */
			if (dbp != NULL) {
				if (op == DB_TXN_ABORT &&
				    !F_ISSET(dbp, DB_AM_RECOVER))
					t_ret =
					    __db_refresh(dbp, NULL, DB_NOSYNC);
				else
					t_ret = dbp->close(dbp, DB_NOSYNC);
				if (t_ret != 0 && ret == 0)
					ret = t_ret;
			}
		}
	}
done:	if (ret == 0)
		*lsnp = argp->prev_lsn;
out:	if (argp != NULL)
		__os_free(dbenv, argp);
	return (ret);
}

/*
 * __dbreg_open_file --
 *	Called during log_register recovery.  Make sure that we have an
 *	entry in the dbentry table for this ndx.  Returns 0 on success,
 *	non-zero on error.
 */
static int
__dbreg_open_file(dbenv, txn, argp, info)
	DB_ENV *dbenv;
	DB_TXN *txn;
	__dbreg_register_args *argp;
	void *info;
{
	DB_ENTRY *dbe;
	DB_LOG *lp;
	DB *dbp;
	u_int32_t id;

	lp = (DB_LOG *)dbenv->lg_handle;
	/*
	 * We never re-open temporary files.  Temp files are only
	 * useful during aborts in which case the dbp was entered
	 * when the file was registered.  During recovery, we treat
	 * temp files as properly deleted files, allowing the open to
	 * fail and not reporting any errors when recovery fails to
	 * get a valid dbp from __dbreg_id_to_db.
	 */
	if (argp->name.size == 0) {
		(void)__dbreg_add_dbentry(dbenv, lp, NULL, argp->fileid);
		return (ENOENT);
	}

	/*
	 * When we're opening, we have to check that the name we are opening
	 * is what we expect.  If it's not, then we close the old file and
	 * open the new one.
	 */
	MUTEX_THREAD_LOCK(dbenv, lp->mutexp);
	if (argp->fileid < lp->dbentry_cnt)
		dbe = &lp->dbentry[argp->fileid];
	else
		dbe = NULL;

	if (dbe != NULL) {
		if (dbe->deleted) {
			MUTEX_THREAD_UNLOCK(dbenv, lp->mutexp);
			return (ENOENT);
		}
		if ((dbp = dbe->dbp) != NULL) {
			if (dbp->meta_pgno != argp->meta_pgno ||
			    memcmp(dbp->fileid,
			    argp->uid.data, DB_FILE_ID_LEN) != 0) {
				MUTEX_THREAD_UNLOCK(dbenv, lp->mutexp);
				(void)__dbreg_revoke_id(dbp, 0);
				if (F_ISSET(dbp, DB_AM_RECOVER))
					dbp->close(dbp, DB_NOSYNC);
				goto reopen;
			}

			/*
			 * We should only get here if we already have the
			 * dbp from an openfiles pass, in which case, what's
			 * here had better be the same dbp.
			 */
			DB_ASSERT(dbe->dbp == dbp);
			MUTEX_THREAD_UNLOCK(dbenv, lp->mutexp);

			/*
			 * This is a successful open.  We need to record that
			 * in the txnlist so that we know how to handle the
			 * subtransaction that created the file system object.
			 */
			if (argp->id != TXN_INVALID &&
			    __db_txnlist_update(dbenv, info,
			    argp->id, TXN_EXPECTED, NULL) == TXN_NOTFOUND)
				(void)__db_txnlist_add(dbenv,
				    info, argp->id, TXN_EXPECTED, NULL);
			return (0);
		}
	}

	MUTEX_THREAD_UNLOCK(dbenv, lp->mutexp);

	/*
	 * We are about to pass a recovery txn pointer into the main library.
	 * We need to make sure that any accessed fields are set appropriately.
	 */
reopen:	if (txn != NULL) {
		id = txn->txnid;
		memset(txn, 0, sizeof(DB_TXN));
		txn->txnid = id;
		txn->mgrp = dbenv->tx_handle;
	}

	return (__dbreg_do_open(dbenv, txn, lp, argp->uid.data, argp->name.data,
	    argp->ftype, argp->fileid, argp->meta_pgno, info, argp->id));
}