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/*
* 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>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if 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_PROGRAM
int 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
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