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/*
* 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.
*/
#define _LARGEFILE64_SOURCE
#define _FILE_OFFSET_BITS 64
#include <ext4_config.h>
#include <ext4_blockdev.h>
#include <ext4_errno.h>
#include <ext4_debug.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#ifdef __APPLE__
#include <fcntl.h>
#include <sys/disk.h>
#include <stdlib.h>
#include <sys/socket.h>
#endif
/**@brief Default filename.*/
static const char *fname = "ext2";
/**@brief Image block size.*/
#define EXT4_FILEDEV_BSIZE 512
/**@brief Image file descriptor.*/
static int dev_file;
#define DROP_LINUXCACHE_BUFFERS 0
/**********************BLOCKDEV INTERFACE**************************************/
static int file_dev_open(struct ext4_blockdev *bdev);
static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
uint32_t blk_cnt);
static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf,
uint64_t blk_id, uint32_t blk_cnt);
static int file_dev_close(struct ext4_blockdev *bdev);
/******************************************************************************/
EXT4_BLOCKDEV_STATIC_INSTANCE(file_dev, EXT4_FILEDEV_BSIZE, 0, file_dev_open,
file_dev_bread, file_dev_bwrite, file_dev_close, 0, 0);
/******************************************************************************/
static int file_dev_open(struct ext4_blockdev *bdev)
{
dev_file = open(fname, O_RDWR);
if (dev_file < 0) {
printf("open of %s failed %d\n", fname, errno);
ext4_blockdev_errno = errno;
return EIO;
}
#ifdef __APPLE__
/* The lseek approach to finding the device's size does not seem
* to work on macOS so do it this way instead.
*/
uint64_t sectors = 0;
if (ioctl(dev_file, DKIOCGETBLOCKCOUNT, §ors) < 0) {
printf("ioctl DKIOCGETBLOCKCOUNT failed %d\n", errno);
close(dev_file);
return EFAULT;
}
uint32_t sector_size = 0;
if (ioctl(dev_file, DKIOCGETBLOCKSIZE, §or_size) < 0) {
printf("ioctl DKIOCGETBLOCKSIZE failed %d\n", errno);
close(dev_file);
return EFAULT;
}
off_t size = sectors * sector_size;
#else
off_t size = lseek(dev_file, 0, SEEK_END);
if (size == ((off_t) -1)) {
return EFAULT;
}
#endif
file_dev.part_offset = 0;
file_dev.part_size = size;
file_dev.bdif->ph_bcnt = file_dev.part_size / file_dev.bdif->ph_bsize;
return EOK;
}
/******************************************************************************/
static int file_dev_bread(struct ext4_blockdev *bdev, void *buf, uint64_t blk_id,
uint32_t blk_cnt)
{
if (lseek(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET) < 0) {
ext4_blockdev_errno = errno;
printf("lseek failed %d\n", errno);
return EIO;
}
if (!blk_cnt)
return EOK;
if (read(dev_file, buf, bdev->bdif->ph_bsize * blk_cnt) < 0) {
ext4_blockdev_errno = errno;
printf("read failed %d\n", errno);
return EIO;
}
return EOK;
}
static void drop_cache(void)
{
#if defined(__linux__) && DROP_LINUXCACHE_BUFFERS
int fd;
char *data = "3";
sync();
fd = open("/proc/sys/vm/drop_caches", O_WRONLY);
write(fd, data, sizeof(char));
close(fd);
#endif
}
/******************************************************************************/
static int file_dev_bwrite(struct ext4_blockdev *bdev, const void *buf,
uint64_t blk_id, uint32_t blk_cnt)
{
if (lseek(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET) < 0) {
ext4_blockdev_errno = errno;
printf("fseeko failed %d\n", errno);
return EIO;
}
if (!blk_cnt)
return EOK;
if (write(dev_file, buf, bdev->bdif->ph_bsize * blk_cnt) < 0) {
ext4_blockdev_errno = errno;
printf("write failed %d\n", errno);
return EIO;
}
drop_cache();
return EOK;
}
/******************************************************************************/
static int file_dev_close(struct ext4_blockdev *bdev)
{
close(dev_file);
return EOK;
}
/******************************************************************************/
struct ext4_blockdev *file_dev_get(void)
{
return &file_dev;
}
/******************************************************************************/
void file_dev_name_set(const char *n)
{
fname = n;
}
/******************************************************************************/
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