1/* 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#if HAVE_SYS_TYPES_H 16#include <sys/types.h> 17#endif 18 19#if HAVE_ERRNO_H 20#include <errno.h> 21#endif 22#if 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 = my_llseek(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 */ 141 142 143