source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/blkid/blkid_getsize.c @ 821

Last change on this file since 821 was 821, checked in by Bruno Cornec, 13 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

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