init.c

ldap服务器源码

/* init.c - initialize bdb backend */
/* $OpenLDAP: pkg/ldap/servers/slapd/back-bdb/init.c,v 1.177.2.27 2007/01/25 12:42:38 hyc Exp $ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 2000-2007 The OpenLDAP Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in the file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */

#include "portable.h"

#include <stdio.h>
#include <ac/string.h>
#include <ac/unistd.h>
#include <ac/stdlib.h>
#include <ac/errno.h>
#include <sys/stat.h>
#include "back-bdb.h"
#include <lutil.h>
#include <ldap_rq.h>
#include "alock.h"

static const struct bdbi_database {
	char *file;
	char *name;
	int type;
	int flags;
} bdbi_databases[] = {
	{ "id2entry" BDB_SUFFIX, "id2entry", DB_BTREE, 0 },
	{ "dn2id" BDB_SUFFIX, "dn2id", DB_BTREE, 0 },
	{ NULL, NULL, 0, 0 }
};

typedef void * db_malloc(size_t);
typedef void * db_realloc(void *, size_t);

static int
bdb_db_init( BackendDB *be )
{
	struct bdb_info	*bdb;

	Debug( LDAP_DEBUG_TRACE,
		LDAP_XSTRING(bdb_db_init) ": Initializing " BDB_UCTYPE " database\n",
		0, 0, 0 );

	/* allocate backend-database-specific stuff */
	bdb = (struct bdb_info *) ch_calloc( 1, sizeof(struct bdb_info) );

	/* DBEnv parameters */
	bdb->bi_dbenv_home = ch_strdup( SLAPD_DEFAULT_DB_DIR );
	bdb->bi_dbenv_xflags = 0;
	bdb->bi_dbenv_mode = SLAPD_DEFAULT_DB_MODE;

	bdb->bi_cache.c_maxsize = DEFAULT_CACHE_SIZE;
	bdb->bi_cache.c_minfree = 1;

	bdb->bi_lock_detect = DB_LOCK_DEFAULT;
	bdb->bi_search_stack_depth = DEFAULT_SEARCH_STACK_DEPTH;
	bdb->bi_search_stack = NULL;

	ldap_pvt_thread_mutex_init( &bdb->bi_database_mutex );
	ldap_pvt_thread_mutex_init( &bdb->bi_lastid_mutex );
#ifdef BDB_HIER
	ldap_pvt_thread_mutex_init( &bdb->bi_modrdns_mutex );
#endif
	ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_head_mutex );
	ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_tail_mutex );
	ldap_pvt_thread_mutex_init( &bdb->bi_cache.c_dntree.bei_kids_mutex );
	ldap_pvt_thread_rdwr_init ( &bdb->bi_cache.c_rwlock );
	ldap_pvt_thread_rdwr_init( &bdb->bi_idl_tree_rwlock );
	ldap_pvt_thread_mutex_init( &bdb->bi_idl_tree_lrulock );

	be->be_private = bdb;
	be->be_cf_ocs = be->bd_info->bi_cf_ocs;

	return 0;
}

static int
bdb_db_close( BackendDB *be );

static int
bdb_db_open( BackendDB *be )
{
	int rc, i;
	struct bdb_info *bdb = (struct bdb_info *) be->be_private;
	struct stat stat1, stat2;
	u_int32_t flags;
	char path[MAXPATHLEN];
	char *dbhome;
	int do_recover = 0, do_alock_recover = 0, open_env = 1;
	int alockt, quick = 0;

	if ( be->be_suffix == NULL ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: need suffix\n",
			0, 0, 0 );
		return -1;
	}

	Debug( LDAP_DEBUG_ARGS,
		"bdb_db_open: %s\n",
		be->be_suffix[0].bv_val, 0, 0 );

#ifndef BDB_MULTIPLE_SUFFIXES
	if ( be->be_suffix[1].bv_val ) {
	Debug( LDAP_DEBUG_ANY,
		"bdb_db_open: only one suffix allowed\n", 0, 0, 0 );
		return -1;
	}
#endif

	/* Check existence of dbenv_home. Any error means trouble */
	rc = stat( bdb->bi_dbenv_home, &stat1 );
	if( rc !=0 ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: Cannot access database directory %s (%d)\n",
			bdb->bi_dbenv_home, errno, 0 );
			return -1;
	}

	/* Perform database use arbitration/recovery logic */
	alockt = (slapMode & SLAP_TOOL_READONLY) ? ALOCK_LOCKED : ALOCK_UNIQUE;
	if ( slapMode & SLAP_TOOL_QUICK ) {
		alockt |= ALOCK_NOSAVE;
		quick = 1;
	}

	rc = alock_open( &bdb->bi_alock_info, 
				"slapd", 
				bdb->bi_dbenv_home, alockt );

	/* alockt is TRUE if the existing environment was created in Quick mode */
	alockt = (rc & ALOCK_NOSAVE) ? 1 : 0;
	rc &= ~ALOCK_NOSAVE;

	if( rc == ALOCK_RECOVER ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: unclean shutdown detected;"
			" attempting recovery.\n", 
			0, 0, 0 );
		do_alock_recover = 1;
		do_recover = DB_RECOVER;
	} else if( rc == ALOCK_BUSY ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: database already in use\n", 
			0, 0, 0 );
		return -1;
	} else if( rc != ALOCK_CLEAN ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: alock package is unstable\n", 
			0, 0, 0 );
		return -1;
	}

	/*
	 * The DB_CONFIG file may have changed. If so, recover the
	 * database so that new settings are put into effect. Also
	 * note the possible absence of DB_CONFIG in the log.
	 */
	if( stat( bdb->bi_db_config_path, &stat1 ) == 0 ) {
		if ( !do_recover ) {
			char *ptr = lutil_strcopy(path, bdb->bi_dbenv_home);
			*ptr++ = LDAP_DIRSEP[0];
			strcpy( ptr, "__db.001" );
			if( stat( path, &stat2 ) == 0 ) {
				if( stat2.st_mtime < stat1.st_mtime ) {
					Debug( LDAP_DEBUG_ANY,
						"bdb_db_open: DB_CONFIG for suffix %s has changed.\n"
						"Performing database recovery to activate new settings.\n",
						be->be_suffix[0].bv_val, 0, 0 );
					do_recover = DB_RECOVER;
				}
			}
		}
	}
	else {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: Warning - No DB_CONFIG file found "
			"in directory %s: (%d)\n"
			"Expect poor performance for suffix %s.\n",
			bdb->bi_dbenv_home, errno, be->be_suffix[0].bv_val );
	}

	/* Always let slapcat run, regardless of environment state.
	 * This can be used to cause a cache flush after an unclean
	 * shutdown.
	 */
	if ( do_recover && ( slapMode & SLAP_TOOL_READONLY )) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: Recovery skipped in read-only mode. "
			"Run manual recovery if errors are encountered.\n",
			0, 0, 0 );
		do_recover = 0;
		quick = alockt;
	}

	/* An existing environment in Quick mode has nothing to recover. */
	if ( alockt && do_recover ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: cannot recover, database must be reinitialized.\n", 
			0, 0, 0 );
		rc = -1;
		goto fail;
	}

	rc = db_env_create( &bdb->bi_dbenv, 0 );
	if( rc != 0 ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: db_env_create failed: %s (%d)\n",
			db_strerror(rc), rc, 0 );
		goto fail;
	}

#ifdef HAVE_EBCDIC
	strcpy( path, bdb->bi_dbenv_home );
	__atoe( path );
	dbhome = path;
#else
	dbhome = bdb->bi_dbenv_home;
#endif

	/* If existing environment is clean but doesn't support
	 * currently requested modes, remove it.
	 */
	if ( !do_recover && ( alockt ^ quick )) {
		rc = bdb->bi_dbenv->remove( bdb->bi_dbenv, dbhome, DB_FORCE );
		if ( rc ) {
			Debug( LDAP_DEBUG_ANY,
				"bdb_db_open: dbenv remove failed: %s (%d)\n",
				db_strerror(rc), rc, 0 );
			bdb->bi_dbenv = NULL;
			goto fail;
		}
		rc = db_env_create( &bdb->bi_dbenv, 0 );
		if( rc != 0 ) {
			Debug( LDAP_DEBUG_ANY,
				"bdb_db_open: db_env_create failed: %s (%d)\n",
				db_strerror(rc), rc, 0 );
			goto fail;
		}
	}

	bdb->bi_dbenv->set_errpfx( bdb->bi_dbenv, be->be_suffix[0].bv_val );
	bdb->bi_dbenv->set_errcall( bdb->bi_dbenv, bdb_errcall );

	bdb->bi_dbenv->set_lk_detect( bdb->bi_dbenv, bdb->bi_lock_detect );

	/* One long-lived TXN per thread, two TXNs per write op */
	bdb->bi_dbenv->set_tx_max( bdb->bi_dbenv, connection_pool_max * 3 );

	if( bdb->bi_dbenv_xflags != 0 ) {
		rc = bdb->bi_dbenv->set_flags( bdb->bi_dbenv,
			bdb->bi_dbenv_xflags, 1);
		if( rc != 0 ) {
			Debug( LDAP_DEBUG_ANY,
				"bdb_db_open: dbenv_set_flags failed: %s (%d)\n",
				db_strerror(rc), rc, 0 );
			goto fail;
		}
	}

#define	BDB_TXN_FLAGS	(DB_INIT_LOCK | DB_INIT_LOG | DB_INIT_TXN)

	Debug( LDAP_DEBUG_TRACE,
		"bdb_db_open: dbenv_open(%s)\n",
		bdb->bi_dbenv_home, 0, 0);

	flags = DB_INIT_MPOOL | DB_CREATE | DB_THREAD;

	if ( !quick )
		flags |= BDB_TXN_FLAGS;

	/* If a key was set, use shared memory for the BDB environment */
	if ( bdb->bi_shm_key ) {
		bdb->bi_dbenv->set_shm_key( bdb->bi_dbenv, bdb->bi_shm_key );
		flags |= DB_SYSTEM_MEM;
	}
	rc = bdb->bi_dbenv->open( bdb->bi_dbenv, dbhome,
			flags | do_recover, bdb->bi_dbenv_mode );

	if ( rc ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: Database cannot be %s, err %d. "
			"Restore from backup!\n",
				do_recover ? "recovered" : "opened", rc, 0);
		goto fail;
	}

	if ( do_alock_recover && alock_recover (&bdb->bi_alock_info) != 0 ) {
		Debug( LDAP_DEBUG_ANY,
			"bdb_db_open: alock_recover failed\n",
			0, 0, 0 );
		rc = -1;
		goto fail;
	}

#ifdef SLAP_ZONE_ALLOC
	if ( bdb->bi_cache.c_maxsize ) {
		bdb->bi_cache.c_zctx = slap_zn_mem_create(
								SLAP_ZONE_INITSIZE,
								SLAP_ZONE_MAXSIZE,
								SLAP_ZONE_DELTA,
								SLAP_ZONE_SIZE);
	}
#endif

	if ( bdb->bi_idl_cache_max_size ) {
		bdb->bi_idl_tree = NULL;
		bdb->bi_idl_cache_size = 0;
	}

	flags = DB_THREAD | bdb->bi_db_opflags;

#ifdef DB_AUTO_COMMIT
	if ( !quick )
		flags |= DB_AUTO_COMMIT;
#endif

	bdb->bi_databases = (struct bdb_db_info **) ch_malloc(
		BDB_INDICES * sizeof(struct bdb_db_info *) );

	/* open (and create) main database */
	for( i = 0; bdbi_databases[i].name; i++ ) {
		struct bdb_db_info *db;

		db = (struct bdb_db_info *) ch_calloc(1, sizeof(struct bdb_db_info));

		rc = db_create( &db->bdi_db, bdb->bi_dbenv, 0 );
		if( rc != 0 ) {
			Debug( LDAP_DEBUG_ANY,
				"bdb_db_open: db_create(%s) failed: %s (%d)\n",
				bdb->bi_dbenv_home, db_strerror(rc), rc );
			goto fail;