busybox-1.19.3/e2fsprogs/old_e2fsprogs/ext2fs/test_io.c - nest-learning-thermostat/5.1/busybox - Git at Google

 /* vi: set sw=4 ts=4: */
 /*
  * test_io.c --- This is the Test I/O interface.
  *
  * Copyright (C) 1996 Theodore Ts'o.
  *
  * %Begin-Header%
  * This file may be redistributed under the terms of the GNU Public
  * License.
  * %End-Header%
  */

 #include <stdio.h>
 #include <string.h>
 #if HAVE_UNISTD_H
 #include <unistd.h>
 #endif
 #include <fcntl.h>
 #include <time.h>
 #if HAVE_SYS_STAT_H
 #include <sys/stat.h>
 #endif
 #if HAVE_SYS_TYPES_H
 #include <sys/types.h>
 #endif

 #include "ext2_fs.h"
 #include "ext2fs.h"

 /*
  * For checking structure magic numbers...
  */

 #define EXT2_CHECK_MAGIC(struct, code) \
 	  if ((struct)->magic != (code)) return (code)

 struct test_private_data {
 	int	magic;
 	io_channel real;
 	int flags;
 	FILE *outfile;
 	unsigned long block;
 	int read_abort_count, write_abort_count;
 	void (*read_blk)(unsigned long block, int count, errcode_t err);
 	void (*write_blk)(unsigned long block, int count, errcode_t err);
 	void (*set_blksize)(int blksize, errcode_t err);
 	void (*write_byte)(unsigned long block, int count, errcode_t err);
 };

 static errcode_t test_open(const char *name, int flags, io_channel *channel);
 static errcode_t test_close(io_channel channel);
 static errcode_t test_set_blksize(io_channel channel, int blksize);
 static errcode_t test_read_blk(io_channel channel, unsigned long block,
 			       int count, void *data);
 static errcode_t test_write_blk(io_channel channel, unsigned long block,
 				int count, const void *data);
 static errcode_t test_flush(io_channel channel);
 static errcode_t test_write_byte(io_channel channel, unsigned long offset,
 				 int count, const void *buf);
 static errcode_t test_set_option(io_channel channel, const char *option,
 				 const char *arg);

 static struct struct_io_manager struct_test_manager = {
 	EXT2_ET_MAGIC_IO_MANAGER,
 	"Test I/O Manager",
 	test_open,
 	test_close,
 	test_set_blksize,
 	test_read_blk,
 	test_write_blk,
 	test_flush,
 	test_write_byte,
 	test_set_option
 };

 io_manager test_io_manager = &struct_test_manager;

 /*
  * These global variable can be set by the test program as
  * necessary *before* calling test_open
  */
 io_manager test_io_backing_manager = 0;
 void (*test_io_cb_read_blk)
 	(unsigned long block, int count, errcode_t err) = 0;
 void (*test_io_cb_write_blk)
 	(unsigned long block, int count, errcode_t err) = 0;
 void (*test_io_cb_set_blksize)
 	(int blksize, errcode_t err) = 0;
 void (*test_io_cb_write_byte)
 	(unsigned long block, int count, errcode_t err) = 0;

 /*
  * Test flags
  */
 #define TEST_FLAG_READ			0x01
 #define TEST_FLAG_WRITE			0x02
 #define TEST_FLAG_SET_BLKSIZE		0x04
 #define TEST_FLAG_FLUSH			0x08
 #define TEST_FLAG_DUMP			0x10
 #define TEST_FLAG_SET_OPTION		0x20

 static void test_dump_block(io_channel channel,
 			    struct test_private_data *data,
 			    unsigned long block, const void *buf)
 {
 	const unsigned char *cp;
 	FILE *f = data->outfile;
 	int	i;
 	unsigned long	cksum = 0;

 	for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
 		cksum += *cp;
 	}
 	fprintf(f, "Contents of block %lu, checksum %08lu:\n", block, cksum);
 	for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
 		if ((i % 16) == 0)
 			fprintf(f, "%04x: ", i);
 		fprintf(f, "%02x%c", *cp, ((i % 16) == 15) ? '\n' : ' ');
 	}
 }

 static void test_abort(io_channel channel, unsigned long block)
 {
 	struct test_private_data *data;
 	FILE *f;

 	data = (struct test_private_data *) channel->private_data;
 	f = data->outfile;
 	test_flush(channel);

 	fprintf(f, "Aborting due to I/O to block %lu\n", block);
 	fflush(f);
 	abort();
 }

 static errcode_t test_open(const char *name, int flags, io_channel *channel)
 {
 	io_channel	io = NULL;
 	struct test_private_data *data = NULL;
 	errcode_t	retval;
 	char		*value;

 	if (name == 0)
 		return EXT2_ET_BAD_DEVICE_NAME;
 	retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
 	if (retval)
 		return retval;
 	memset(io, 0, sizeof(struct struct_io_channel));
 	io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
 	retval = ext2fs_get_mem(sizeof(struct test_private_data), &data);
 	if (retval) {
 		retval = EXT2_ET_NO_MEMORY;
 		goto cleanup;
 	}
 	io->manager = test_io_manager;
 	retval = ext2fs_get_mem(strlen(name)+1, &io->name);
 	if (retval)
 		goto cleanup;

 	strcpy(io->name, name);
 	io->private_data = data;
 	io->block_size = 1024;
 	io->read_error = 0;
 	io->write_error = 0;
 	io->refcount = 1;

 	memset(data, 0, sizeof(struct test_private_data));
 	data->magic = EXT2_ET_MAGIC_TEST_IO_CHANNEL;
 	if (test_io_backing_manager) {
 		retval = test_io_backing_manager->open(name, flags,
 						       &data->real);
 		if (retval)
 			goto cleanup;
 	} else
 		data->real = 0;
 	data->read_blk =	test_io_cb_read_blk;
 	data->write_blk =	test_io_cb_write_blk;
 	data->set_blksize =	test_io_cb_set_blksize;
 	data->write_byte =	test_io_cb_write_byte;

 	data->outfile = NULL;
 	if ((value = getenv("TEST_IO_LOGFILE")) != NULL)
 		data->outfile = fopen_for_write(value);
 	if (!data->outfile)
 		data->outfile = stderr;

 	data->flags = 0;
 	if ((value = getenv("TEST_IO_FLAGS")) != NULL)
 		data->flags = strtoul(value, NULL, 0);

 	data->block = 0;
 	if ((value = getenv("TEST_IO_BLOCK")) != NULL)
 		data->block = strtoul(value, NULL, 0);

 	data->read_abort_count = 0;
 	if ((value = getenv("TEST_IO_READ_ABORT")) != NULL)
 		data->read_abort_count = strtoul(value, NULL, 0);

 	data->write_abort_count = 0;
 	if ((value = getenv("TEST_IO_WRITE_ABORT")) != NULL)
 		data->write_abort_count = strtoul(value, NULL, 0);

 	*channel = io;
 	return 0;

 cleanup:
 	ext2fs_free_mem(&io);
 	ext2fs_free_mem(&data);
 	return retval;
 }

 static errcode_t test_close(io_channel channel)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (--channel->refcount > 0)
 		return 0;

 	if (data->real)
 		retval = io_channel_close(data->real);

 	if (data->outfile && data->outfile != stderr)
 		fclose(data->outfile);

 	ext2fs_free_mem(&channel->private_data);
 	ext2fs_free_mem(&channel->name);
 	ext2fs_free_mem(&channel);
 	return retval;
 }

 static errcode_t test_set_blksize(io_channel channel, int blksize)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (data->real)
 		retval = io_channel_set_blksize(data->real, blksize);
 	if (data->set_blksize)
 		data->set_blksize(blksize, retval);
 	if (data->flags & TEST_FLAG_SET_BLKSIZE)
 		fprintf(data->outfile,
 			"Test_io: set_blksize(%d) returned %s\n",
 			blksize, retval ? error_message(retval) : "OK");
 	channel->block_size = blksize;
 	return retval;
 }


 static errcode_t test_read_blk(io_channel channel, unsigned long block,
 			       int count, void *buf)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (data->real)
 		retval = io_channel_read_blk(data->real, block, count, buf);
 	if (data->read_blk)
 		data->read_blk(block, count, retval);
 	if (data->flags & TEST_FLAG_READ)
 		fprintf(data->outfile,
 			"Test_io: read_blk(%lu, %d) returned %s\n",
 			block, count, retval ? error_message(retval) : "OK");
 	if (data->block && data->block == block) {
 		if (data->flags & TEST_FLAG_DUMP)
 			test_dump_block(channel, data, block, buf);
 		if (--data->read_abort_count == 0)
 			test_abort(channel, block);
 	}
 	return retval;
 }

 static errcode_t test_write_blk(io_channel channel, unsigned long block,
 			       int count, const void *buf)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (data->real)
 		retval = io_channel_write_blk(data->real, block, count, buf);
 	if (data->write_blk)
 		data->write_blk(block, count, retval);
 	if (data->flags & TEST_FLAG_WRITE)
 		fprintf(data->outfile,
 			"Test_io: write_blk(%lu, %d) returned %s\n",
 			block, count, retval ? error_message(retval) : "OK");
 	if (data->block && data->block == block) {
 		if (data->flags & TEST_FLAG_DUMP)
 			test_dump_block(channel, data, block, buf);
 		if (--data->write_abort_count == 0)
 			test_abort(channel, block);
 	}
 	return retval;
 }

 static errcode_t test_write_byte(io_channel channel, unsigned long offset,
 			       int count, const void *buf)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (data->real && data->real->manager->write_byte)
 		retval = io_channel_write_byte(data->real, offset, count, buf);
 	if (data->write_byte)
 		data->write_byte(offset, count, retval);
 	if (data->flags & TEST_FLAG_WRITE)
 		fprintf(data->outfile,
 			"Test_io: write_byte(%lu, %d) returned %s\n",
 			offset, count, retval ? error_message(retval) : "OK");
 	return retval;
 }

 /*
  * Flush data buffers to disk.
  */
 static errcode_t test_flush(io_channel channel)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

 	if (data->real)
 		retval = io_channel_flush(data->real);

 	if (data->flags & TEST_FLAG_FLUSH)
 		fprintf(data->outfile, "Test_io: flush() returned %s\n",
 			retval ? error_message(retval) : "OK");

 	return retval;
 }

 static errcode_t test_set_option(io_channel channel, const char *option,
 				 const char *arg)
 {
 	struct test_private_data *data;
 	errcode_t	retval = 0;

 	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
 	data = (struct test_private_data *) channel->private_data;
 	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);


 	if (data->flags & TEST_FLAG_SET_OPTION)
 		fprintf(data->outfile, "Test_io: set_option(%s, %s) ",
 			option, arg);
 	if (data->real && data->real->manager->set_option) {
 		retval = (data->real->manager->set_option)(data->real,
 							   option, arg);
 		if (data->flags & TEST_FLAG_SET_OPTION)
 			fprintf(data->outfile, "returned %s\n",
 				retval ? error_message(retval) : "OK");
 	} else {
 		if (data->flags & TEST_FLAG_SET_OPTION)
 			fprintf(data->outfile, "not implemented\n");
 	}
 	return retval;
 }
	/* vi: set sw=4 ts=4: */
	/*
	* test_io.c --- This is the Test I/O interface.
	*
	* Copyright (C) 1996 Theodore Ts'o.
	*
	* %Begin-Header%
	* This file may be redistributed under the terms of the GNU Public
	* License.
	* %End-Header%
	*/

	#include <stdio.h>
	#include <string.h>
	#if HAVE_UNISTD_H
	#include <unistd.h>
	#endif
	#include <fcntl.h>
	#include <time.h>
	#if HAVE_SYS_STAT_H
	#include <sys/stat.h>
	#endif
	#if HAVE_SYS_TYPES_H
	#include <sys/types.h>
	#endif

	#include "ext2_fs.h"
	#include "ext2fs.h"

	/*
	* For checking structure magic numbers...
	*/

	#define EXT2_CHECK_MAGIC(struct, code) \
	if ((struct)->magic != (code)) return (code)

	struct test_private_data {
	int magic;
	io_channel real;
	int flags;
	FILE *outfile;
	unsigned long block;
	int read_abort_count, write_abort_count;
	void (*read_blk)(unsigned long block, int count, errcode_t err);
	void (*write_blk)(unsigned long block, int count, errcode_t err);
	void (*set_blksize)(int blksize, errcode_t err);
	void (*write_byte)(unsigned long block, int count, errcode_t err);
	};

	static errcode_t test_open(const char name, int flags, io_channel channel);
	static errcode_t test_close(io_channel channel);
	static errcode_t test_set_blksize(io_channel channel, int blksize);
	static errcode_t test_read_blk(io_channel channel, unsigned long block,
	int count, void *data);
	static errcode_t test_write_blk(io_channel channel, unsigned long block,
	int count, const void *data);
	static errcode_t test_flush(io_channel channel);
	static errcode_t test_write_byte(io_channel channel, unsigned long offset,
	int count, const void *buf);
	static errcode_t test_set_option(io_channel channel, const char *option,
	const char *arg);

	static struct struct_io_manager struct_test_manager = {
	EXT2_ET_MAGIC_IO_MANAGER,
	"Test I/O Manager",
	test_open,
	test_close,
	test_set_blksize,
	test_read_blk,
	test_write_blk,
	test_flush,
	test_write_byte,
	test_set_option
	};

	io_manager test_io_manager = &struct_test_manager;

	/*
	* These global variable can be set by the test program as
	* necessary before calling test_open
	*/
	io_manager test_io_backing_manager = 0;
	void (*test_io_cb_read_blk)
	(unsigned long block, int count, errcode_t err) = 0;
	void (*test_io_cb_write_blk)
	(unsigned long block, int count, errcode_t err) = 0;
	void (*test_io_cb_set_blksize)
	(int blksize, errcode_t err) = 0;
	void (*test_io_cb_write_byte)
	(unsigned long block, int count, errcode_t err) = 0;

	/*
	* Test flags
	*/
	#define TEST_FLAG_READ 0x01
	#define TEST_FLAG_WRITE 0x02
	#define TEST_FLAG_SET_BLKSIZE 0x04
	#define TEST_FLAG_FLUSH 0x08
	#define TEST_FLAG_DUMP 0x10
	#define TEST_FLAG_SET_OPTION 0x20

	static void test_dump_block(io_channel channel,
	struct test_private_data *data,
	unsigned long block, const void *buf)
	{
	const unsigned char *cp;
	FILE *f = data->outfile;
	int i;
	unsigned long cksum = 0;

	for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
	cksum += *cp;
	}
	fprintf(f, "Contents of block %lu, checksum %08lu:\n", block, cksum);
	for (i=0, cp = buf; i < channel->block_size; i++, cp++) {
	if ((i % 16) == 0)
	fprintf(f, "%04x: ", i);
	fprintf(f, "%02x%c", *cp, ((i % 16) == 15) ? '\n' : ' ');
	}
	}

	static void test_abort(io_channel channel, unsigned long block)
	{
	struct test_private_data *data;
	FILE *f;

	data = (struct test_private_data *) channel->private_data;
	f = data->outfile;
	test_flush(channel);

	fprintf(f, "Aborting due to I/O to block %lu\n", block);
	fflush(f);
	abort();
	}

	static errcode_t test_open(const char name, int flags, io_channel channel)
	{
	io_channel io = NULL;
	struct test_private_data *data = NULL;
	errcode_t retval;
	char *value;

	if (name == 0)
	return EXT2_ET_BAD_DEVICE_NAME;
	retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);
	if (retval)
	return retval;
	memset(io, 0, sizeof(struct struct_io_channel));
	io->magic = EXT2_ET_MAGIC_IO_CHANNEL;
	retval = ext2fs_get_mem(sizeof(struct test_private_data), &data);
	if (retval) {
	retval = EXT2_ET_NO_MEMORY;
	goto cleanup;
	}
	io->manager = test_io_manager;
	retval = ext2fs_get_mem(strlen(name)+1, &io->name);
	if (retval)
	goto cleanup;

	strcpy(io->name, name);
	io->private_data = data;
	io->block_size = 1024;
	io->read_error = 0;
	io->write_error = 0;
	io->refcount = 1;

	memset(data, 0, sizeof(struct test_private_data));
	data->magic = EXT2_ET_MAGIC_TEST_IO_CHANNEL;
	if (test_io_backing_manager) {
	retval = test_io_backing_manager->open(name, flags,
	&data->real);
	if (retval)
	goto cleanup;
	} else
	data->real = 0;
	data->read_blk = test_io_cb_read_blk;
	data->write_blk = test_io_cb_write_blk;
	data->set_blksize = test_io_cb_set_blksize;
	data->write_byte = test_io_cb_write_byte;

	data->outfile = NULL;
	if ((value = getenv("TEST_IO_LOGFILE")) != NULL)
	data->outfile = fopen_for_write(value);
	if (!data->outfile)
	data->outfile = stderr;

	data->flags = 0;
	if ((value = getenv("TEST_IO_FLAGS")) != NULL)
	data->flags = strtoul(value, NULL, 0);

	data->block = 0;
	if ((value = getenv("TEST_IO_BLOCK")) != NULL)
	data->block = strtoul(value, NULL, 0);

	data->read_abort_count = 0;
	if ((value = getenv("TEST_IO_READ_ABORT")) != NULL)
	data->read_abort_count = strtoul(value, NULL, 0);

	data->write_abort_count = 0;
	if ((value = getenv("TEST_IO_WRITE_ABORT")) != NULL)
	data->write_abort_count = strtoul(value, NULL, 0);

	*channel = io;
	return 0;

	cleanup:
	ext2fs_free_mem(&io);
	ext2fs_free_mem(&data);
	return retval;
	}

	static errcode_t test_close(io_channel channel)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (--channel->refcount > 0)
	return 0;

	if (data->real)
	retval = io_channel_close(data->real);

	if (data->outfile && data->outfile != stderr)
	fclose(data->outfile);

	ext2fs_free_mem(&channel->private_data);
	ext2fs_free_mem(&channel->name);
	ext2fs_free_mem(&channel);
	return retval;
	}

	static errcode_t test_set_blksize(io_channel channel, int blksize)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (data->real)
	retval = io_channel_set_blksize(data->real, blksize);
	if (data->set_blksize)
	data->set_blksize(blksize, retval);
	if (data->flags & TEST_FLAG_SET_BLKSIZE)
	fprintf(data->outfile,
	"Test_io: set_blksize(%d) returned %s\n",
	blksize, retval ? error_message(retval) : "OK");
	channel->block_size = blksize;
	return retval;
	}


	static errcode_t test_read_blk(io_channel channel, unsigned long block,
	int count, void *buf)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (data->real)
	retval = io_channel_read_blk(data->real, block, count, buf);
	if (data->read_blk)
	data->read_blk(block, count, retval);
	if (data->flags & TEST_FLAG_READ)
	fprintf(data->outfile,
	"Test_io: read_blk(%lu, %d) returned %s\n",
	block, count, retval ? error_message(retval) : "OK");
	if (data->block && data->block == block) {
	if (data->flags & TEST_FLAG_DUMP)
	test_dump_block(channel, data, block, buf);
	if (--data->read_abort_count == 0)
	test_abort(channel, block);
	}
	return retval;
	}

	static errcode_t test_write_blk(io_channel channel, unsigned long block,
	int count, const void *buf)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (data->real)
	retval = io_channel_write_blk(data->real, block, count, buf);
	if (data->write_blk)
	data->write_blk(block, count, retval);
	if (data->flags & TEST_FLAG_WRITE)
	fprintf(data->outfile,
	"Test_io: write_blk(%lu, %d) returned %s\n",
	block, count, retval ? error_message(retval) : "OK");
	if (data->block && data->block == block) {
	if (data->flags & TEST_FLAG_DUMP)
	test_dump_block(channel, data, block, buf);
	if (--data->write_abort_count == 0)
	test_abort(channel, block);
	}
	return retval;
	}

	static errcode_t test_write_byte(io_channel channel, unsigned long offset,
	int count, const void *buf)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (data->real && data->real->manager->write_byte)
	retval = io_channel_write_byte(data->real, offset, count, buf);
	if (data->write_byte)
	data->write_byte(offset, count, retval);
	if (data->flags & TEST_FLAG_WRITE)
	fprintf(data->outfile,
	"Test_io: write_byte(%lu, %d) returned %s\n",
	offset, count, retval ? error_message(retval) : "OK");
	return retval;
	}

	/*
	* Flush data buffers to disk.
	*/
	static errcode_t test_flush(io_channel channel)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);

	if (data->real)
	retval = io_channel_flush(data->real);

	if (data->flags & TEST_FLAG_FLUSH)
	fprintf(data->outfile, "Test_io: flush() returned %s\n",
	retval ? error_message(retval) : "OK");

	return retval;
	}

	static errcode_t test_set_option(io_channel channel, const char *option,
	const char *arg)
	{
	struct test_private_data *data;
	errcode_t retval = 0;

	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);
	data = (struct test_private_data *) channel->private_data;
	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_TEST_IO_CHANNEL);


	if (data->flags & TEST_FLAG_SET_OPTION)
	fprintf(data->outfile, "Test_io: set_option(%s, %s) ",
	option, arg);
	if (data->real && data->real->manager->set_option) {
	retval = (data->real->manager->set_option)(data->real,
	option, arg);
	if (data->flags & TEST_FLAG_SET_OPTION)
	fprintf(data->outfile, "returned %s\n",
	retval ? error_message(retval) : "OK");
	} else {
	if (data->flags & TEST_FLAG_SET_OPTION)
	fprintf(data->outfile, "not implemented\n");
	}
	return retval;
	}