blob: 67334785abbed51f01c8354c3ed5d9adfb067b79 [file] [log] [blame]
bigbiff7b4c7a62015-01-01 19:44:14 -05001/*
2 * llseek.c -- stub calling the llseek system call
3 *
4 * Copyright (C) 1994, 1995, 1996, 1997 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#define _LARGEFILE_SOURCE
13#define _LARGEFILE64_SOURCE
14
15#ifdef HAVE_SYS_TYPES_H
16#include <sys/types.h>
17#endif
18
19#ifdef HAVE_ERRNO_H
20#include <errno.h>
21#endif
22#ifdef HAVE_UNISTD_H
23#include <unistd.h>
24#endif
25#ifdef __MSDOS__
26#include <io.h>
27#endif
28
29#include "blkidP.h"
30
31#ifdef __linux__
32
33#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
34
35#define my_llseek lseek64
36
37#elif defined(HAVE_LLSEEK)
38#include <syscall.h>
39
40#ifndef HAVE_LLSEEK_PROTOTYPE
41extern long long llseek(int fd, long long offset, int origin);
42#endif
43
44#define my_llseek llseek
45
46#else /* ! HAVE_LLSEEK */
47
48#if SIZEOF_LONG == SIZEOF_LONG_LONG
49
50#define llseek lseek
51
52#else /* SIZEOF_LONG != SIZEOF_LONG_LONG */
53
54#include <linux/unistd.h>
55
56#ifndef __NR__llseek
57#define __NR__llseek 140
58#endif
59
60#ifndef __i386__
61static int _llseek(unsigned int, unsigned long, unsigned long,
62 blkid_loff_t *, unsigned int);
63
64static _syscall5(int, _llseek, unsigned int, fd, unsigned long, offset_high,
65 unsigned long, offset_low, blkid_loff_t *, result,
66 unsigned int, origin)
67#endif
68/*
69static blkid_loff_t my_llseek(int fd, blkid_loff_t offset, int origin)
70{
71 blkid_loff_t result;
72 int retval;
73
74#ifndef __i386__
75 retval = _llseek(fd, ((unsigned long long) offset) >> 32,
76 ((unsigned long long)offset) & 0xffffffff,
77 &result, origin);
78#else
79 retval = syscall(__NR__llseek, fd, ((unsigned long long) offset) >> 32,
80 ((unsigned long long)offset) & 0xffffffff,
81 &result, origin);
82#endif
83 return (retval == -1 ? (blkid_loff_t) retval : result);
84}
85*/
86#endif /* __alpha__ || __ia64__ */
87
88#endif /* HAVE_LLSEEK */
89
90blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int whence)
91{
92 blkid_loff_t result;
93 static int do_compat = 0;
94
95 if ((sizeof(off_t) >= sizeof(blkid_loff_t)) ||
96 (offset < ((blkid_loff_t) 1 << ((sizeof(off_t)*8) -1))))
97 return lseek(fd, (off_t) offset, whence);
98
99 if (do_compat) {
100 errno = EOVERFLOW;
101 return -1;
102 }
103
104 result = lseek64(fd, offset, whence);
105 if (result == -1 && errno == ENOSYS) {
106 /*
107 * Just in case this code runs on top of an old kernel
108 * which does not support the llseek system call
109 */
110 do_compat++;
111 errno = EOVERFLOW;
112 }
113 return result;
114}
115
116#else /* !linux */
117
118#ifndef EOVERFLOW
119#ifdef EXT2_ET_INVALID_ARGUMENT
120#define EOVERFLOW EXT2_ET_INVALID_ARGUMENT
121#else
122#define EOVERFLOW 112
123#endif
124#endif
125
126blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int origin)
127{
128#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
129 return lseek64 (fd, offset, origin);
130#else
131 if ((sizeof(off_t) < sizeof(blkid_loff_t)) &&
132 (offset >= ((blkid_loff_t) 1 << ((sizeof(off_t)*8) - 1)))) {
133 errno = EOVERFLOW;
134 return -1;
135 }
136 return lseek(fd, (off_t) offset, origin);
137#endif
138}
139
140#endif /* linux */
141
142