source: branches/3.2/mindi-busybox/e2fsprogs/old_e2fsprogs/blkid/blkid_getsize.c @ 3232

Last change on this file since 3232 was 3232, checked in by bruno, 5 years ago
  • Update mindi-busybox to 1.21.1
  • Property svn:eol-style set to native
File size: 3.9 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * getsize.c --- get the size of a partition.
4 *
5 * Copyright (C) 1995, 1995 Theodore Ts'o.
6 *
7 * %Begin-Header%
8 * This file may be redistributed under the terms of the
9 * GNU Lesser General Public License.
10 * %End-Header%
11 */
12
13/* include this before sys/queues.h! */
14#include "blkidP.h"
15
16#include <stdio.h>
17#include <unistd.h>
18#ifdef HAVE_ERRNO_H
19#include <errno.h>
20#endif
21#include <fcntl.h>
22#ifdef HAVE_SYS_IOCTL_H
23#include <sys/ioctl.h>
24#endif
25#ifdef HAVE_LINUX_FD_H
26#include <linux/fd.h>
27#endif
28#ifdef HAVE_SYS_DISKLABEL_H
29#include <sys/disklabel.h>
30#include <sys/stat.h>
31#endif
32#ifdef HAVE_SYS_DISK_H
33#ifdef HAVE_SYS_QUEUE_H
34#include <sys/queue.h> /* for LIST_HEAD */
35#endif
36#include <sys/disk.h>
37#endif
38#ifdef __linux__
39#include <sys/utsname.h>
40#endif
41
42#if defined(__linux__) && defined(_IO) && !defined(BLKGETSIZE)
43#define BLKGETSIZE _IO(0x12,96) /* return device size */
44#endif
45
46#if defined(__linux__) && defined(_IOR) && !defined(BLKGETSIZE64)
47#define BLKGETSIZE64 _IOR(0x12,114,size_t)  /* return device size in bytes (u64 *arg) */
48#endif
49
50#ifdef APPLE_DARWIN
51#define BLKGETSIZE DKIOCGETBLOCKCOUNT32
52#endif /* APPLE_DARWIN */
53
54static int valid_offset(int fd, blkid_loff_t offset)
55{
56    char ch;
57
58    if (blkid_llseek(fd, offset, 0) < 0)
59        return 0;
60    if (read(fd, &ch, 1) < 1)
61        return 0;
62    return 1;
63}
64
65/*
66 * Returns the number of blocks in a partition
67 */
68blkid_loff_t blkid_get_dev_size(int fd)
69{
70    int valid_blkgetsize64 = 1;
71#ifdef __linux__
72    struct      utsname ut;
73#endif
74    unsigned long long size64;
75    unsigned long size;
76    blkid_loff_t high, low;
77#ifdef FDGETPRM
78    struct floppy_struct this_floppy;
79#endif
80#ifdef HAVE_SYS_DISKLABEL_H
81    int part = -1;
82    struct disklabel lab;
83    struct partition *pp;
84    char ch;
85    struct stat st;
86#endif /* HAVE_SYS_DISKLABEL_H */
87
88#ifdef DKIOCGETBLOCKCOUNT   /* For Apple Darwin */
89    if (ioctl(fd, DKIOCGETBLOCKCOUNT, &size64) >= 0) {
90        if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))
91            && (size64 << 9 > 0xFFFFFFFF))
92            return 0; /* EFBIG */
93        return (blkid_loff_t) size64 << 9;
94    }
95#endif
96
97#ifdef BLKGETSIZE64
98#ifdef __linux__
99    uname(&ut);
100    if ((ut.release[0] == '2') && (ut.release[1] == '.') &&
101         (ut.release[2] < '6') && (ut.release[3] == '.'))
102        valid_blkgetsize64 = 0;
103#endif
104    if (valid_blkgetsize64 &&
105        ioctl(fd, BLKGETSIZE64, &size64) >= 0) {
106        if ((sizeof(blkid_loff_t) < sizeof(unsigned long long))
107            && ((size64) > 0xFFFFFFFF))
108            return 0; /* EFBIG */
109        return size64;
110    }
111#endif
112
113#ifdef BLKGETSIZE
114    if (ioctl(fd, BLKGETSIZE, &size) >= 0)
115        return (blkid_loff_t)size << 9;
116#endif
117
118#ifdef FDGETPRM
119    if (ioctl(fd, FDGETPRM, &this_floppy) >= 0)
120        return (blkid_loff_t)this_floppy.size << 9;
121#endif
122#ifdef HAVE_SYS_DISKLABEL_H
123#if 0
124    /*
125     * This should work in theory but I haven't tested it.  Anyone
126     * on a BSD system want to test this for me?  In the meantime,
127     * binary search mechanism should work just fine.
128     */
129    if ((fstat(fd, &st) >= 0) && S_ISBLK(st.st_mode))
130        part = st.st_rdev & 7;
131    if (part >= 0 && (ioctl(fd, DIOCGDINFO, (char *)&lab) >= 0)) {
132        pp = &lab.d_partitions[part];
133        if (pp->p_size)
134            return pp->p_size << 9;
135    }
136#endif
137#endif /* HAVE_SYS_DISKLABEL_H */
138
139    /*
140     * OK, we couldn't figure it out by using a specialized ioctl,
141     * which is generally the best way.  So do binary search to
142     * find the size of the partition.
143     */
144    low = 0;
145    for (high = 1024; valid_offset(fd, high); high *= 2)
146        low = high;
147    while (low < high - 1)
148    {
149        const blkid_loff_t mid = (low + high) / 2;
150
151        if (valid_offset(fd, mid))
152            low = mid;
153        else
154            high = mid;
155    }
156    return low + 1;
157}
158
159#ifdef TEST_PROGRAM
160int main(int argc, char **argv)
161{
162    blkid_loff_t bytes;
163    int fd;
164
165    if (argc < 2) {
166        fprintf(stderr, "Usage: %s device\n"
167            "Determine the size of a device\n", argv[0]);
168        return 1;
169    }
170
171    if ((fd = open(argv[1], O_RDONLY)) < 0)
172        perror(argv[0]);
173
174    bytes = blkid_get_dev_size(fd);
175    printf("Device %s has %lld 1k blocks.\n", argv[1], bytes >> 10);
176
177    return 0;
178}
179#endif
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