db_open.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

	case DB_QUEUE:
		ret = __qam_new_file(dbp, txn, fhp, name);
		break;
	default:
		__db_err(dbp->dbenv,
		    "%s: Invalid type %d specified", name, dbp->type);
		ret = EINVAL;
		break;
	}

	DB_TEST_RECOVERY(dbp, DB_TEST_POSTLOGMETA, ret, name);
	/* Sync the file in preparation for moving it into place. */
	if (ret == 0 && fhp != NULL)
		ret = __os_fsync(dbp->dbenv, fhp);

	DB_TEST_RECOVERY(dbp, DB_TEST_POSTSYNC, ret, name);

DB_TEST_RECOVERY_LABEL
	return (ret);
}

/*
 * __db_init_subdb --
 *	Initialize the dbp for a subdb.
 *
 * PUBLIC: int __db_init_subdb __P((DB *, DB *, const char *, DB_TXN *));
 */
int
__db_init_subdb(mdbp, dbp, name, txn)
	DB *mdbp, *dbp;
	const char *name;
	DB_TXN *txn;
{
	DBMETA *meta;
	DB_MPOOLFILE *mpf;
	int ret, t_ret;

	ret = 0;
	if (!F_ISSET(dbp, DB_AM_CREATED)) {
		/* Subdb exists; read meta-data page and initialize. */
		mpf = mdbp->mpf;
		if  ((ret = mpf->get(mpf, &dbp->meta_pgno, 0, &meta)) != 0)
			goto err;
		ret = __db_meta_setup(mdbp->dbenv, dbp, name, meta, 0, 0);
		if ((t_ret = mpf->put(mpf, meta, 0)) != 0 && ret == 0)
			ret = t_ret;
		/*
		 * If __db_meta_setup found that the meta-page hadn't
		 * been written out during recovery, we can just return.
		 */
		if (ret == ENOENT)
			ret = 0;
		goto err;
	}

	/* Handle the create case here. */
	switch (dbp->type) {
	case DB_BTREE:
	case DB_RECNO:
		ret = __bam_new_subdb(mdbp, dbp, txn);
		break;
	case DB_HASH:
		ret = __ham_new_subdb(mdbp, dbp, txn);
		break;
	case DB_QUEUE:
		ret = EINVAL;
		break;
	default:
		__db_err(dbp->dbenv,
		    "Invalid subdatabase type %d specified", dbp->type);
		return (EINVAL);
	}

err:	return (ret);
}

/*
 * __db_chk_meta --
 *	Take a buffer containing a meta-data page and check it for a checksum
 *	(and verify the checksum if necessary) and possibly decrypt it.
 *
 *	Return 0 on success, >0 (errno) on error, -1 on checksum mismatch.
 *
 * PUBLIC: int __db_chk_meta __P((DB_ENV *, DB *, DBMETA *, int));
 */
int
__db_chk_meta(dbenv, dbp, meta, do_metachk)
	DB_ENV *dbenv;
	DB *dbp;
	DBMETA *meta;
	int do_metachk;
{
	int is_hmac, ret;
	u_int8_t *chksum;

	ret = 0;

	if (FLD_ISSET(meta->metaflags, DBMETA_CHKSUM)) {
		if (dbp != NULL)
			F_SET(dbp, DB_AM_CHKSUM);

		is_hmac = meta->encrypt_alg == 0 ? 0 : 1;
		chksum = ((BTMETA *)meta)->chksum;
		if (do_metachk && ((ret = __db_check_chksum(dbenv,
		    (DB_CIPHER *)dbenv->crypto_handle, chksum, meta,
		    DBMETASIZE, is_hmac)) != 0))
			return (ret);
	}

#ifdef HAVE_CRYPTO
	ret = __crypto_decrypt_meta(dbenv, dbp, (u_int8_t *)meta, do_metachk);
#endif
	return (ret);
}

/*
 * __db_meta_setup --
 *
 * Take a buffer containing a meta-data page and figure out if it's
 * valid, and if so, initialize the dbp from the meta-data page.
 *
 * PUBLIC: int __db_meta_setup __P((DB_ENV *,
 * PUBLIC:     DB *, const char *, DBMETA *, u_int32_t, int));
 */
int
__db_meta_setup(dbenv, dbp, name, meta, oflags, do_metachk)
	DB_ENV *dbenv;
	DB *dbp;
	const char *name;
	DBMETA *meta;
	u_int32_t oflags;
	int do_metachk;
{
	u_int32_t flags, magic;
	int ret;

	ret = 0;

	/*
	 * 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 = meta->magic;

swap_retry:
	switch (magic) {
	case DB_BTREEMAGIC:
	case DB_HASHMAGIC:
	case DB_QAMMAGIC:
	case DB_RENAMEMAGIC:
		break;
	case 0:
		/*
		 * The only time this should be 0 is if we're in the
		 * midst of opening a subdb during recovery and that
		 * subdatabase had its meta-data page allocated, but
		 * not yet initialized.
		 */
		if (F_ISSET(dbp, DB_AM_SUBDB) && ((IS_RECOVERING(dbenv) &&
		    F_ISSET((DB_LOG *) dbenv->lg_handle, DBLOG_FORCE_OPEN)) ||
		    meta->pgno != PGNO_INVALID))
			return (ENOENT);

		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;
	}

	/*
	 * We can only check the meta page if we are sure we have a meta page.
	 * If it is random data, then this check can fail.  So only now can we
	 * checksum and decrypt.  Don't distinguish between configuration and
	 * checksum match errors here, because we haven't opened the database
	 * and even a checksum error isn't a reason to panic the environment.
	 */
	if ((ret = __db_chk_meta(dbenv, dbp, meta, do_metachk)) != 0) {
		if (ret == -1)
			__db_err(dbenv,
			    "%s: metadata page checksum error", name);
		goto bad_format;
	}

	switch (magic) {
	case DB_BTREEMAGIC:
		flags = meta->flags;
		if (F_ISSET(dbp, DB_AM_SWAP))
			M_32_SWAP(flags);
		if (LF_ISSET(BTM_RECNO))
			dbp->type = DB_RECNO;
		else
			dbp->type = DB_BTREE;
		if ((oflags & DB_TRUNCATE) == 0 && (ret =
		    __bam_metachk(dbp, name, (BTMETA *)meta)) != 0)
			return (ret);
		break;
	case DB_HASHMAGIC:
		dbp->type = DB_HASH;
		if ((oflags & DB_TRUNCATE) == 0 && (ret =
		    __ham_metachk(dbp, name, (HMETA *)meta)) != 0)
			return (ret);
		break;
	case DB_QAMMAGIC:
		dbp->type = DB_QUEUE;
		if ((oflags & DB_TRUNCATE) == 0 && (ret =
		    __qam_metachk(dbp, name, (QMETA *)meta)) != 0)
			return (ret);
		break;
	case DB_RENAMEMAGIC:
		F_SET(dbp, DB_AM_IN_RENAME);
		break;
	}
	return (0);

bad_format:
	__db_err(dbenv, "%s: unexpected file type or format", name);
	return (ret == 0 ? EINVAL : ret);
}

/*
 * __db_openchk --
 *	Interface error checking for open calls.
 */
static int
__db_openchk(dbp, txn, name, subdb, type, flags)
	DB *dbp;
	DB_TXN *txn;
	const char *name, *subdb;
	DBTYPE type;
	u_int32_t flags;
{
	DB_ENV *dbenv;
	int ret;
	u_int32_t ok_flags;

	dbenv = dbp->dbenv;

	/* Validate arguments. */
#define	OKFLAGS								\
    (DB_AUTO_COMMIT | DB_CREATE | DB_DIRTY_READ | DB_EXCL |		\
     DB_FCNTL_LOCKING | DB_NOMMAP | DB_RDONLY | DB_RDWRMASTER |		\
     DB_THREAD | DB_TRUNCATE | DB_WRITEOPEN)
	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);
	}

	/* DB_TRUNCATE is not transaction recoverable. */
	if (LF_ISSET(DB_TRUNCATE) && txn != NULL) {
		__db_err(dbenv,
		    "DB_TRUNCATE illegal with transaction specified");
		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);
		}

		/* Truncate is a physical file operation */
		if (LF_ISSET(DB_TRUNCATE)) {
			__db_err(dbenv,
			    "DB_TRUNCATE illegal with multiple databases");
			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);
		}
	}

	return (0);
}