/* vi: set sw=4 ts=4: *//* * inode_io.c --- This is allows an inode in an ext2 filesystem image *	to be accessed via the I/O manager interface. * * Copyright (C) 2002 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#if HAVE_ERRNO_H#include <errno.h>#endif#include <time.h>#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 inode_private_data {	int				magic;	char				name[32];	ext2_file_t			file;	ext2_filsys			fs;	ext2_ino_t			ino;	struct ext2_inode		inode;	int				flags;	struct inode_private_data	*next;};#define CHANNEL_HAS_INODE	0x8000static struct inode_private_data *top_intern;static int ino_unique = 0;static errcode_t inode_open(const char *name, int flags, io_channel *channel);static errcode_t inode_close(io_channel channel);static errcode_t inode_set_blksize(io_channel channel, int blksize);static errcode_t inode_read_blk(io_channel channel, unsigned long block,			       int count, void *data);static errcode_t inode_write_blk(io_channel channel, unsigned long block,				int count, const void *data);static errcode_t inode_flush(io_channel channel);static errcode_t inode_write_byte(io_channel channel, unsigned long offset,				int size, const void *data);static struct struct_io_manager struct_inode_manager = {	EXT2_ET_MAGIC_IO_MANAGER,	"Inode I/O Manager",	inode_open,	inode_close,	inode_set_blksize,	inode_read_blk,	inode_write_blk,	inode_flush,	inode_write_byte};io_manager inode_io_manager = &struct_inode_manager;errcode_t ext2fs_inode_io_intern2(ext2_filsys fs, ext2_ino_t ino,				  struct ext2_inode *inode,				  char **name){	struct inode_private_data	*data;	errcode_t			retval;	if ((retval = ext2fs_get_mem(sizeof(struct inode_private_data),				     &data)))		return retval;	data->magic = EXT2_ET_MAGIC_INODE_IO_CHANNEL;	sprintf(data->name, "%u:%d", ino, ino_unique++);	data->file = 0;	data->fs = fs;	data->ino = ino;	data->flags = 0;	if (inode) {		memcpy(&data->inode, inode, sizeof(struct ext2_inode));		data->flags |= CHANNEL_HAS_INODE;	}	data->next = top_intern;	top_intern = data;	*name = data->name;	return 0;}errcode_t ext2fs_inode_io_intern(ext2_filsys fs, ext2_ino_t ino,				 char **name){	return ext2fs_inode_io_intern2(fs, ino, NULL, name);}static errcode_t inode_open(const char *name, int flags, io_channel *channel){	io_channel	io = NULL;	struct inode_private_data *prev, *data = NULL;	errcode_t	retval;	int		open_flags;	if (name == 0)		return EXT2_ET_BAD_DEVICE_NAME;	for (data = top_intern, prev = NULL; data;	     prev = data, data = data->next)		if (strcmp(name, data->name) == 0)			break;	if (!data)		return ENOENT;	if (prev)		prev->next = data->next;	else		top_intern = data->next;	retval = ext2fs_get_mem(sizeof(struct struct_io_channel), &io);	if (retval)		goto cleanup;	memset(io, 0, sizeof(struct struct_io_channel));	io->magic = EXT2_ET_MAGIC_IO_CHANNEL;	io->manager = inode_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;	open_flags = (flags & IO_FLAG_RW) ? EXT2_FILE_WRITE : 0;	retval = ext2fs_file_open2(data->fs, data->ino,				   (data->flags & CHANNEL_HAS_INODE) ?				   &data->inode : 0, open_flags,				   &data->file);	if (retval)		goto cleanup;	*channel = io;	return 0;cleanup:	if (data) {		ext2fs_free_mem(&data);	}	if (io)		ext2fs_free_mem(&io);	return retval;}static errcode_t inode_close(io_channel channel){	struct inode_private_data *data;	errcode_t	retval = 0;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	if (--channel->refcount > 0)		return 0;	retval = ext2fs_file_close(data->file);	ext2fs_free_mem(&channel->private_data);	if (channel->name)		ext2fs_free_mem(&channel->name);	ext2fs_free_mem(&channel);	return retval;}static errcode_t inode_set_blksize(io_channel channel, int blksize){	struct inode_private_data *data;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	channel->block_size = blksize;	return 0;}static errcode_t inode_read_blk(io_channel channel, unsigned long block,			       int count, void *buf){	struct inode_private_data *data;	errcode_t	retval;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	if ((retval = ext2fs_file_lseek(data->file,					block * channel->block_size,					EXT2_SEEK_SET, 0)))		return retval;	count = (count < 0) ? -count : (count * channel->block_size);	return ext2fs_file_read(data->file, buf, count, 0);}static errcode_t inode_write_blk(io_channel channel, unsigned long block,				int count, const void *buf){	struct inode_private_data *data;	errcode_t	retval;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	if ((retval = ext2fs_file_lseek(data->file,					block * channel->block_size,					EXT2_SEEK_SET, 0)))		return retval;	count = (count < 0) ? -count : (count * channel->block_size);	return ext2fs_file_write(data->file, buf, count, 0);}static errcode_t inode_write_byte(io_channel channel, unsigned long offset,				 int size, const void *buf){	struct inode_private_data *data;	errcode_t	retval = 0;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	if ((retval = ext2fs_file_lseek(data->file, offset,					EXT2_SEEK_SET, 0)))		return retval;	return ext2fs_file_write(data->file, buf, size, 0);}/* * Flush data buffers to disk. */static errcode_t inode_flush(io_channel channel){	struct inode_private_data *data;	EXT2_CHECK_MAGIC(channel, EXT2_ET_MAGIC_IO_CHANNEL);	data = (struct inode_private_data *) channel->private_data;	EXT2_CHECK_MAGIC(data, EXT2_ET_MAGIC_INODE_IO_CHANNEL);	return ext2fs_file_flush(data->file);}