shithub: lwext4

ref: ec44609460479138e9f4b506b32a45670208af64
dir: /blockdev/filedev_win/io_raw.c/

/*
 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - 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.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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 <ext4_config.h>
#include <ext4_blockdev.h>
#include <ext4_errno.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>

#ifdef WIN32
#include <windows.h>
#include <winioctl.h>

/**@brief   Default filename.*/
static const char *fname = "ext2";

/**@brief   IO block size.*/
#define EXT4_IORAW_BSIZE 512

/**@brief   Image file descriptor.*/
static HANDLE dev_file;

/**********************BLOCKDEV INTERFACE**************************************/
static int io_raw_open(struct ext4_blockdev *bdev);
static int io_raw_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
                        uint32_t blk_cnt);
static int io_raw_bwrite(struct ext4_blockdev *bdev, const void *buf,
                         uint64_t blk_id, uint32_t blk_cnt);
static int io_raw_close(struct ext4_blockdev *bdev);

/******************************************************************************/
EXT4_BLOCKDEV_STATIC_INSTANCE(_filedev, EXT4_IORAW_BSIZE, 0, io_raw_open,
                              io_raw_bread, io_raw_bwrite, io_raw_close);

/******************************************************************************/
static int io_raw_open(struct ext4_blockdev *bdev)
{
    char path[64];
    DISK_GEOMETRY pdg;
    uint64_t disk_size;
    BOOL bResult = FALSE;
    DWORD junk;

    sprintf(path, "\\\\.\\%s", fname);

    dev_file =
        CreateFile(path, GENERIC_READ | GENERIC_WRITE,
                   FILE_SHARE_WRITE | FILE_SHARE_READ, NULL, OPEN_EXISTING,
                   FILE_FLAG_NO_BUFFERING | FILE_FLAG_WRITE_THROUGH, NULL);

    if (dev_file == INVALID_HANDLE_VALUE) {
        return EIO;
    }

    bResult = DeviceIoControl(dev_file, IOCTL_DISK_GET_DRIVE_GEOMETRY, NULL, 0,
                              &pdg, sizeof(pdg), &junk, (LPOVERLAPPED)NULL);

    if (bResult == FALSE) {
        CloseHandle(dev_file);
        return EIO;
    }

    disk_size = pdg.Cylinders.QuadPart * (ULONG)pdg.TracksPerCylinder *
                (ULONG)pdg.SectorsPerTrack * (ULONG)pdg.BytesPerSector;

    _filedev.ph_bsize = pdg.BytesPerSector;
    _filedev.ph_bcnt = disk_size / pdg.BytesPerSector;

    return EOK;
}

/******************************************************************************/

static int io_raw_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
                        uint32_t blk_cnt)
{
    long hipart = blk_id >> (32 - 9);
    long lopart = blk_id << 9;
    long err;

    SetLastError(0);
    lopart = SetFilePointer(dev_file, lopart, &hipart, FILE_BEGIN);

    if (lopart == -1 && NO_ERROR != (err = GetLastError())) {
        return EIO;
    }

    DWORD n;

    if (!ReadFile(dev_file, buf, blk_cnt * 512, &n, NULL)) {
        err = GetLastError();
        return EIO;
    }
    return EOK;
}

/******************************************************************************/
static int io_raw_bwrite(struct ext4_blockdev *bdev, const void *buf,
                         uint64_t blk_id, uint32_t blk_cnt)
{
    long hipart = blk_id >> (32 - 9);
    long lopart = blk_id << 9;
    long err;

    SetLastError(0);
    lopart = SetFilePointer(dev_file, lopart, &hipart, FILE_BEGIN);

    if (lopart == -1 && NO_ERROR != (err = GetLastError())) {
        return EIO;
    }

    DWORD n;

    if (!WriteFile(dev_file, buf, blk_cnt * 512, &n, NULL)) {
        err = GetLastError();
        return EIO;
    }
    return EOK;
}

/******************************************************************************/
static int io_raw_close(struct ext4_blockdev *bdev)
{
    CloseHandle(dev_file);
    return EOK;
}

/******************************************************************************/
struct ext4_blockdev *ext4_io_raw_dev_get(void) { return &_filedev; }
/******************************************************************************/
void ext4_io_raw_filename(const char *n) { fname = n; }

/******************************************************************************/
#endif