예제 #1
0
//
// Routines
//
partition_map_header *
open_partition_map(char *name, int *valid_file, int ask_logical_size)
{
    media *fd;
    partition_map_header * map;
    int writeable;
#ifdef __linux__
    struct stat info;
#endif
    int size;

    fd = open_media(name, (rflag)?O_RDONLY:O_RDWR);
    if (fd == 0) {
	fd = open_media(name, O_RDONLY);
	if (fd == 0) {
	    error(errno, "can't open file '%s'", name);
	    *valid_file = 0;
	    return NULL;
	} else {
	    writeable = 0;
	}
    } else {
	writeable = 1;
    }
    *valid_file = 1;

    map = (partition_map_header *) malloc(sizeof(partition_map_header));
    if (map == NULL) {
	error(errno, "can't allocate memory for open partition map");
	close_media(fd);
	return NULL;
    }
    map->fd = fd;
    map->name = name;
    map->writeable = (rflag)?0:writeable;
    map->changed = 0;
    map->disk_order = NULL;
    map->base_order = NULL;

    map->physical_block = fd->block_size;	/* preflight */
    map->misc = (Block0 *) malloc(PBLOCK_SIZE);
    if (map->misc == NULL) {
	error(errno, "can't allocate memory for block zero buffer");
	close_media(map->fd);
	free(map);
	return NULL;
    } else if (read_media(map->fd, 0, (char *)map->misc, 0) == 0
	    || convert_block0(map->misc, 1)
	    || coerce_block0(map)) {
	// if I can't read block 0 I might as well give up
	close_partition_map(map);
	return NULL;
    }
    map->physical_block = map->misc->sbBlkSize;
    // printf("physical block size is %d\n", map->physical_block);

    if (ask_logical_size && interactive) {
	size = PBLOCK_SIZE;
	printf("A logical block is %d bytes: ", size);
	flush_to_newline(0);
	get_number_argument("what should be the logical block size? ",
		(long *)&size, size);
	map->logical_block = (size / PBLOCK_SIZE) * PBLOCK_SIZE;
    } else {
	map->logical_block = PBLOCK_SIZE;
    }
    if (map->logical_block > MAXIOSIZE) {
	map->logical_block = MAXIOSIZE;
    }
    if (map->logical_block > map->physical_block) {
	map->physical_block = map->logical_block;
    }
    map->blocks_in_map = 0;
    map->maximum_in_map = -1;
    map->media_size = compute_device_size(map, map);
    sync_device_size(map);

#ifdef __linux__
    if (fstat(fd, &info) < 0) {
	error(errno, "can't stat file '%s'", name);
	map->regular_file = 0;
    } else {
	map->regular_file = S_ISREG(info.st_mode);
    }
#else
    map->regular_file = 0;
#endif

    if (read_partition_map(map) < 0) {
	// some sort of failure reading the map
    } else {
	// got it!
	;
	return map;
    }
    close_partition_map(map);
    return NULL;
}
예제 #2
0
파일: partition_map.c 프로젝트: aosm/pdisk
//
// Routines
//
partition_map_header *
open_partition_map(char *name, int *valid_file, int ask_logical_size, int oflag)
{
    MEDIA m;
    partition_map_header * map;
    int writable;
    long size;

    m = open_pathname_as_media(name, oflag);
    if (m == 0) {
	m = open_pathname_as_media(name, O_RDONLY);
	if (m == 0) {
	    error(errno, "can't open file '%s'", name);
	    *valid_file = 0;
	    return NULL;
	} else {
	    writable = 0;
	}
    } else {
	writable = 1;
    }
    *valid_file = 1;

    map = (partition_map_header *) malloc(sizeof(partition_map_header));
    if (map == NULL) {
	error(errno, "can't allocate memory for open partition map");
	close_media(m);
	return NULL;
    }
    map->name = name;
    map->writable = (oflag == O_RDONLY)?0:writable;
    map->changed = 0;
    map->written = 0;
    map->disk_order = NULL;
    map->base_order = NULL;

    map->physical_block = media_granularity(m);	/* preflight */
    m = open_deblock_media(PBLOCK_SIZE, m);
    map->m = m;
    map->misc = (Block0 *) malloc(PBLOCK_SIZE);
    if (map->misc == NULL) {
	error(errno, "can't allocate memory for block zero buffer");
	close_media(map->m);
	free(map);
	return NULL;
    } else if (read_media(map->m, (long long) 0, PBLOCK_SIZE, (char *)map->misc) == 0
	    || convert_block0(map->misc, 1)
	    || coerce_block0(map)) {
	// if I can't read block 0 I might as well give up
	error(-1, "Can't read block 0 from '%s'", name);
	close_partition_map(map);
	return NULL;
    }
    map->physical_block = map->misc->sbBlkSize;
    //printf("physical block size is %d\n", map->physical_block);

    if (ask_logical_size && interactive) {
	size = PBLOCK_SIZE;
	printf("A logical block is %ld bytes: ", size);
	flush_to_newline(0);
	get_number_argument("what should be the logical block size? ",
		&size, size);
	size = (size / PBLOCK_SIZE) * PBLOCK_SIZE;
	if (size < PBLOCK_SIZE) {
	    size = PBLOCK_SIZE;
	}
	map->logical_block = size;
    } else {
	map->logical_block = PBLOCK_SIZE;
    }
    if (map->logical_block > MAXIOSIZE) {
	map->logical_block = MAXIOSIZE;
    }
    if (map->logical_block > map->physical_block) {
	map->physical_block = map->logical_block;
    }
    map->blocks_in_map = 0;
    map->maximum_in_map = -1;
    map->media_size = compute_device_size(map, map);

    if (read_partition_map(map) < 0) {
	// some sort of failure reading the map
    } else {
	// got it!
	;
	return map;
    }
    close_partition_map(map);
    return NULL;
}