fdisk.c

Util-linux 软件包包含许多工具。其中比较重要的是加载、卸载、格式化、分区和管理硬盘驱动器

	p->end_sector = 0;
	p->end_cyl = 0;
	set_start_sect(p,0);
	set_nr_sects(p,0);
}

static void
set_partition(int i, int doext, unsigned int start, unsigned int stop,
	      int sysid) {
	struct partition *p;
	unsigned int offset;

	if (doext) {
		p = ptes[i].ext_pointer;
		offset = extended_offset;
	} else {
		p = ptes[i].part_table;
		offset = ptes[i].offset;
	}
	p->boot_ind = 0;
	p->sys_ind = sysid;
	set_start_sect(p, start - offset);
	set_nr_sects(p, stop - start + 1);
	if (dos_compatible_flag && (start/(sectors*heads) > 1023))
		start = heads*sectors*1024 - 1;
	set_hsc(p->head, p->sector, p->cyl, start);
	if (dos_compatible_flag && (stop/(sectors*heads) > 1023))
		stop = heads*sectors*1024 - 1;
	set_hsc(p->end_head, p->end_sector, p->end_cyl, stop);
	ptes[i].changed = 1;
}

static int
test_c(char **m, char *mesg) {
	int val = 0;
	if (!*m)
		fprintf(stderr, _("You must set"));
	else {
		fprintf(stderr, " %s", *m);
		val = 1;
	}
	*m = mesg;
	return val;
}

static int
warn_geometry(void) {
	char *m = NULL;
	int prev = 0;
	if (!heads)
		prev = test_c(&m, _("heads"));
	if (!sectors)
		prev = test_c(&m, _("sectors"));
	if (!cylinders)
		prev = test_c(&m, _("cylinders"));
	if (!m)
		return 0;
	fprintf(stderr,
		_("%s%s.\nYou can do this from the extra functions menu.\n"),
		prev ? _(" and ") : " ", m);
	return 1;
}

void update_units(void)
{
	int cyl_units = heads * sectors;

	if (display_in_cyl_units && cyl_units)
		units_per_sector = cyl_units;
	else
		units_per_sector = 1; 	/* in sectors */
}

static void
warn_cylinders(void) {
	if (dos_label && cylinders > 1024 && !nowarn)
		fprintf(stderr, _("\n"
"The number of cylinders for this disk is set to %d.\n"
"There is nothing wrong with that, but this is larger than 1024,\n"
"and could in certain setups cause problems with:\n"
"1) software that runs at boot time (e.g., old versions of LILO)\n"
"2) booting and partitioning software from other OSs\n"
"   (e.g., DOS FDISK, OS/2 FDISK)\n"),
			cylinders);
}

static void
read_extended(int ext) {
	int i;
	struct pte *pex;
	struct partition *p, *q;

	ext_index = ext;
	pex = &ptes[ext];
	pex->ext_pointer = pex->part_table;

	p = pex->part_table;
	if (!get_start_sect(p)) {
		fprintf(stderr,
			_("Bad offset in primary extended partition\n"));
		return;
	}

	while (IS_EXTENDED (p->sys_ind)) {
		struct pte *pe = &ptes[partitions];

		if (partitions >= MAXIMUM_PARTS) {
			/* This is not a Linux restriction, but
			   this program uses arrays of size MAXIMUM_PARTS.
			   Do not try to `improve' this test. */
			struct pte *pre = &ptes[partitions-1];

			fprintf(stderr,
				_("Warning: omitting partitions after %d\n"),
				partitions);
			clear_partition(pre->ext_pointer);
			pre->changed = 1;
			return;
		}

		read_pte(fd, partitions, extended_offset + get_start_sect(p));

		if (!extended_offset)
			extended_offset = get_start_sect(p);

		q = p = pt_offset(pe->sectorbuffer, 0);
		for (i = 0; i < 4; i++, p++) if (get_nr_sects(p)) {
			if (IS_EXTENDED (p->sys_ind)) {
				if (pe->ext_pointer)
					fprintf(stderr,
						_("Warning: extra link "
						  "pointer in partition table"
						  " %d\n"), partitions + 1);
				else
					pe->ext_pointer = p;
			} else if (p->sys_ind) {
				if (pe->part_table)
					fprintf(stderr,
						_("Warning: ignoring extra "
						  "data in partition table"
						  " %d\n"), partitions + 1);
				else
					pe->part_table = p;
			}
		}

		/* very strange code here... */
		if (!pe->part_table) {
			if (q != pe->ext_pointer)
				pe->part_table = q;
			else
				pe->part_table = q + 1;
		}
		if (!pe->ext_pointer) {
			if (q != pe->part_table)
				pe->ext_pointer = q;
			else
				pe->ext_pointer = q + 1;
		}

		p = pe->ext_pointer;
		partitions++;
	}

	/* remove empty links */
 remove:
	for (i = 4; i < partitions; i++) {
		struct pte *pe = &ptes[i];

		if (!get_nr_sects(pe->part_table) &&
		    (partitions > 5 || ptes[4].part_table->sys_ind)) {
			printf("omitting empty partition (%d)\n", i+1);
			delete_partition(i);
			goto remove; 	/* numbering changed */
		}
	}
}

static void
create_doslabel(void) {
	int i;

	fprintf(stderr,
	_("Building a new DOS disklabel. Changes will remain in memory only,\n"
	  "until you decide to write them. After that, of course, the previous\n"
	  "content won't be recoverable.\n\n"));
	sun_nolabel();  /* otherwise always recognised as sun */
	sgi_nolabel();  /* otherwise always recognised as sgi */
	aix_label = osf_label = possibly_osf_label = 0;
	partitions = 4;

	for (i = 510-64; i < 510; i++)
		MBRbuffer[i] = 0;
	write_part_table_flag(MBRbuffer);
	extended_offset = 0;
	set_all_unchanged();
	set_changed(0);
	get_boot(create_empty_dos);
}

#include <sys/utsname.h>
#define MAKE_VERSION(p,q,r)     (65536*(p) + 256*(q) + (r))

static int
linux_version_code(void) {
	static int kernel_version = 0;
        struct utsname my_utsname;
        int p, q, r;

        if (!kernel_version && uname(&my_utsname) == 0) {
                p = atoi(strtok(my_utsname.release, "."));
                q = atoi(strtok(NULL, "."));
                r = atoi(strtok(NULL, "."));
                kernel_version = MAKE_VERSION(p,q,r);
        }
        return kernel_version;
}

static void
get_sectorsize(int fd) {
#if defined(BLKSSZGET)
	if (!user_set_sector_size &&
	    linux_version_code() >= MAKE_VERSION(2,3,3)) {
		int arg;
		if (ioctl(fd, BLKSSZGET, &arg) == 0)
			sector_size = arg;
		if (sector_size != DEFAULT_SECTOR_SIZE)
			printf(_("Note: sector size is %d (not %d)\n"),
			       sector_size, DEFAULT_SECTOR_SIZE);
	}
#else
	/* maybe the user specified it; and otherwise we still
	   have the DEFAULT_SECTOR_SIZE default */
#endif
}

static void
get_kernel_geometry(int fd) {
#ifdef HDIO_GETGEO
	struct hd_geometry geometry;

	if (!ioctl(fd, HDIO_GETGEO, &geometry)) {
		kern_heads = geometry.heads;
		kern_sectors = geometry.sectors;
		/* never use geometry.cylinders - it is truncated */
	}
#endif
}

static int
is_probably_full_disk(char *name) {
#ifdef HDIO_GETGEO
	struct hd_geometry geometry;
	int fd, i = 0;

	fd = open(name, O_RDONLY);
	if (fd >= 0) {
		i = ioctl(fd, HDIO_GETGEO, &geometry);
		close(fd);
	}
	return (fd >= 0 && i == 0 && geometry.start == 0);
#else
	/* silly heuristic */
	while (*name)
		name++;
	return !isdigit(name[-1]);
#endif
}

static void
get_partition_table_geometry(void) {
	unsigned char *bufp = MBRbuffer;
	struct partition *p;
	int i, h, s, hh, ss;
	int first = 1;
	int bad = 0;

	if (!(valid_part_table_flag(bufp)))
		return;

	hh = ss = 0;
	for (i=0; i<4; i++) {
		p = pt_offset(bufp, i);
		if (p->sys_ind != 0) {
			h = p->end_head + 1;
			s = (p->end_sector & 077);
			if (first) {
				hh = h;
				ss = s;
				first = 0;
			} else if (hh != h || ss != s)
				bad = 1;
		}
	}

	if (!first && !bad) {
		pt_heads = hh;
		pt_sectors = ss;
	}
}

void
get_geometry(int fd, struct geom *g) {
	int sec_fac;
	unsigned long long llsectors, llcyls;

	get_sectorsize(fd);
	sec_fac = sector_size / 512;
	guess_device_type(fd);
	heads = cylinders = sectors = 0;
	kern_heads = kern_sectors = 0;
	pt_heads = pt_sectors = 0;

	get_kernel_geometry(fd);
	get_partition_table_geometry();

	heads = user_heads ? user_heads :
		pt_heads ? pt_heads :
		kern_heads ? kern_heads : 255;
	sectors = user_sectors ? user_sectors :
		pt_sectors ? pt_sectors :
		kern_sectors ? kern_sectors : 63;

	if (disksize(fd, &llsectors))
		llsectors = 0;

	total_number_of_sectors = llsectors;

	sector_offset = 1;
	if (dos_compatible_flag)
		sector_offset = sectors;

	llcyls = total_number_of_sectors / (heads * sectors * sec_fac);
	cylinders = llcyls;
	if (cylinders != llcyls)	/* truncated? */
		cylinders = ~0;
	if (!cylinders)
		cylinders = user_cylinders;

	if (g) {
		g->heads = heads;
		g->sectors = sectors;
		g->cylinders = cylinders;
	}
}

/*
 * Read MBR.  Returns:
 *   -1: no 0xaa55 flag present (possibly entire disk BSD)
 *    0: found or created label
 *    1: I/O error
 */
int
get_boot(enum action what) {
	int i;

	partitions = 4;
	ext_index = 0;
	extended_offset = 0;

	for (i = 0; i < 4; i++) {
		struct pte *pe = &ptes[i];

		pe->part_table = pt_offset(MBRbuffer, i);
		pe->ext_pointer = NULL;
		pe->offset = 0;
		pe->sectorbuffer = MBRbuffer;
		pe->changed = (what == create_empty_dos);
	}

	if (what == create_empty_sun && check_sun_label())
		return 0;

	memset(MBRbuffer, 0, 512);

	if (what == create_empty_dos)
		goto got_dos_table;		/* skip reading disk */

	if ((fd = open(disk_device, type_open)) < 0) {
	    if ((fd = open(disk_device, O_RDONLY)) < 0) {
		if (what == try_only)
		    return 1;
		fatal(unable_to_open);
	    } else
		printf(_("You will not be able to write "
			 "the partition table.\n"));
	}

	if (512 != read(fd, MBRbuffer, 512)) {
		if (what == try_only)
			return 1;
		fatal(unable_to_read);
	}

	get_geometry(fd, NULL);

	update_units();

	if (check_sun_label())
		return 0;

	if (check_sgi_label())
		return 0;

	if (check_aix_label())
		return 0;

	if (check_osf_label()) {
		possibly_osf_label = 1;
		if (!valid_part_table_flag(MBRbuffer)) {
			osf_label = 1;
			return 0;
		}
		printf(_("This disk has both DOS and BSD magic.\n"
			 "Give the 'b' command to go to BSD mode.\n"));
	}

got_dos_table:

	if (!valid_part_table_flag(MBRbuffer)) {
		switch(what) {
		case fdisk:
			fprintf(stderr,
				_("Device contains neither a valid DOS "
				  "partition table, nor Sun, SGI or OSF "
				  "disklabel\n"));
#ifdef __sparc__
			create_sunlabel();
#else
			create_doslabel();
#endif
			return 0;
		case require:
			return -1;
		case try_only:
		        return -1;
		case create_empty_dos:
		case create_empty_sun:
			break;
		default:
			fprintf(stderr, _("Internal error\n"));
			exit(1);
		}
	}

	warn_cylinders();
	warn_geometry();

	for (i = 0; i < 4; i++) {
		struct pte *pe = &ptes[i];

		if (IS_EXTENDED (pe->part_table->sys_ind)) {
			if (partitions != 4)
				fprintf(stderr, _("Ignoring extra extended "
					"partition %d\n"), i + 1);
			else
				read_extended(i);
		}
	}

	for (i = 3; i < partitions; i++) {
		struct pte *pe = &ptes[i];

		if (!valid_part_table_flag(pe->sectorbuffer)) {
			fprintf(stderr,
				_("Warning: invalid flag 0x%04x of partition "
				"table %d will be corrected by w(rite)\n"),
				part_table_flag(pe->sectorbuffer), i + 1);
			pe->changed = 1;
		}
	}

	return 0;
}

/* read line; return 0 or first char */
int
read_line(void)
{
	static int got_eof = 0;

	line_ptr = line_buffer;
	if (!fgets(line_buffer, LINE_LENGTH, stdin)) {
		if (feof(stdin))
			got_eof++; 	/* user typed ^D ? */
		if (got_eof >= 3) {
			fflush(stdout);
			fprintf(stderr, _("\ngot EOF thrice - exiting..\n"));
			exit(1);
		}
		return 0;
	}
	while (*line_ptr && !isgraph(*line_ptr))
		line_ptr++;
	return *line_ptr;
}

char
read_char(char *mesg)
{
	do {
		fputs(mesg, stdout);
		fflush (stdout);	 /* requested by [e-mail] */
	} while (!read_line());
	return *line_ptr;
}

char
read_chars(char *mesg)
{
        fputs(mesg, stdout);
	fflush (stdout);	/* [e-mail] */
        if (!read_line()) {
		*line_ptr = '\n';
		line_ptr[1] = 0;
	}
	return *line_ptr;
}

int
read_hex(struct systypes *sys)
{
        int hex;

        while (1)
        {
           read_char(_("Hex code (type L to list codes): "));
           if (tolower(*line_ptr) == 'l')
               list_types(sys);
	   else if (isxdigit (*line_ptr))
	   {
	      hex = 0;
	      do