/* * 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 <stdio.h>#include <stdbool.h>#include <string.h> /**@brief   Default filename.*/static const char *fname = "ext2"; /**@brief   Image block size.*/#define EXT4_FILEDEV_BSIZE 512 /**@brief   Image file descriptor.*/static FILE *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 = fopen(fname, "r+b"); 	if (!dev_file)		return EIO; 	/*No buffering at file.*/	setbuf(dev_file, 0); 	if (fseeko(dev_file, 0, SEEK_END))		return EFAULT; 	file_dev.part_offset = 0;	file_dev.part_size = ftello(dev_file);	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 (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET))		return EIO;	if (!blk_cnt)		return EOK;	if (!fread(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file))		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 (fseeko(dev_file, blk_id * bdev->bdif->ph_bsize, SEEK_SET))		return EIO;	if (!blk_cnt)		return EOK;	if (!fwrite(buf, bdev->bdif->ph_bsize * blk_cnt, 1, dev_file))		return EIO; 	drop_cache();	return EOK;}/******************************************************************************/static int file_dev_close(struct ext4_blockdev *bdev){	fclose(dev_file);	return EOK;} /******************************************************************************/struct ext4_blockdev *file_dev_get(void){	return &file_dev;}/******************************************************************************/void file_dev_name_set(const char *n){	fname = n;}/******************************************************************************/