/* vi: set sw=4 ts=4: *//* * getsize.c --- get the size of a partition. * * Copyright (C) 1995, 1995 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the * GNU Lesser General Public License. * %End-Header% *//* include this before sys/queues.h! */#include "blkidP.h"#include <stdio.h>#include <unistd.h>#ifdef HAVE_ERRNO_H#include <errno.h>#endif#include <fcntl.h>#ifdef HAVE_SYS_IOCTL_H#include <sys/ioctl.h>#endif#ifdef HAVE_LINUX_FD_H#include <linux/fd.h>#endif#ifdef HAVE_SYS_DISKLABEL_H#include <sys/disklabel.h>#include <sys/stat.h>#endif#ifdef HAVE_SYS_DISK_H#ifdef HAVE_SYS_QUEUE_H#include <sys/queue.h> /* for LIST_HEAD */#endif#include <sys/disk.h>#endif#ifdef __linux__#include <sys/utsname.h>#endif#if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)#define BLKGETSIZE _IO(0x12,96)	/* return device size */#endif#if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64)#define BLKGETSIZE64 _IOR(0x12,114,size_t)	/* return device size in bytes (u64 *arg) */#endif#ifdef APPLE_DARWIN#define BLKGETSIZE DKIOCGETBLOCKCOUNT32#endif /* APPLE_DARWIN */static int valid_offset(int fd, blkid_loff_t offset){	char ch;	if (blkid_llseek(fd, offset, 0) < 0)		return 0;	if (read(fd, &ch, 1) < 1)		return 0;	return 1;}/* * Returns the number of blocks in a partition */blkid_loff_t blkid_get_dev_size(int fd){	int valid_blkgetsize64 = 1;#ifdef __linux__	struct		utsname ut;#endif	unsigned long long size64;	unsigned long size;	blkid_loff_t high, low;#ifdef FDGETPRM	struct floppy_struct this_floppy;#endif#ifdef HAVE_SYS_DISKLABEL_H	int part = -1;	struct disklabel lab;	struct partition *pp;	char ch;	struct stat st;#endif /* HAVE_SYS_DISKLABEL_H */#ifdef DKIOCGETBLOCKCOUNT	/* For Apple Darwin */	if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) {		if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))		    && (size64 << 9 > 0xFFFFFFFF))			return 0; /* EFBIG */		return (blkid_loff_t) size64 << 9;	}#endif#ifdef BLKGETSIZE64#ifdef __linux__	if ((uname(&ut) == 0) &&	    ((ut.release[0] == '2') && (ut.release[1] == '.') &&	     (ut.release[2] < '6') && (ut.release[3] == '.')))		valid_blkgetsize64 = 0;#endif	if (valid_blkgetsize64 &&	    ioctl(fd, BLKGETSIZE64, &size64) >= 0) {		if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))		    && ((size64) > 0xFFFFFFFF))			return 0; /* EFBIG */		return size64;	}#endif#ifdef BLKGETSIZE	if (ioctl(fd, BLKGETSIZE, &size) >= 0)		return (blkid_loff_t)size << 9;#endif#ifdef FDGETPRM	if (ioctl(fd, FDGETPRM, &this_floppy) >= 0)		return (blkid_loff_t)this_floppy.size << 9;#endif#ifdef HAVE_SYS_DISKLABEL_H#if 0	/*	 * This should work in theory but I haven't tested it.  Anyone	 * on a BSD system want to test this for me?  In the meantime,	 * binary search mechanism should work just fine.	 */	if ((fstat(fd, &st) >= 0) && S_ISBLK(st.st_mode))		part = st.st_rdev & 7;	if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {		pp = &lab.d_partitions[part];		if (pp->p_size)			return pp->p_size << 9;	}#endif#endif /* HAVE_SYS_DISKLABEL_H */	/*	 * OK, we couldn't figure it out by using a specialized ioctl,	 * which is generally the best way.  So do binary search to	 * find the size of the partition.	 */	low = 0;	for (high = 1024; valid_offset(fd, high); high *= 2)		low = high;	while (low < high - 1)	{		const blkid_loff_t mid = (low + high) / 2;		if (valid_offset(fd, mid))			low = mid;		else			high = mid;	}	return low + 1;}#ifdef TEST_PROGRAMint main(int argc, char **argv){	blkid_loff_t bytes;	int	fd;	if (argc < 2) {		fprintf(stderr, "Usage: %s device\n"			"Determine the size of a device\n", argv[0]);		return 1;	}	if ((fd = open(argv[1], O_RDONLY)) < 0)		perror(argv[0]);	bytes = blkid_get_dev_size(fd);	printf("Device %s has %lld 1k blocks.\n", argv[1], bytes >> 10);	return 0;}#endif