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 GNU Library 8 * General Public License, version 2. 9 * %End-Header% 10 */ 11 12 #ifndef _LARGEFILE_SOURCE 13 #define _LARGEFILE_SOURCE 14 #endif 15 #ifndef _LARGEFILE64_SOURCE 16 #define _LARGEFILE64_SOURCE 17 #endif 18 19 #include "config.h" 20 #if HAVE_SYS_TYPES_H 21 #include <sys/types.h> 22 #endif 23 24 #if HAVE_ERRNO_H 25 #include <errno.h> 26 #endif 27 #if HAVE_UNISTD_H 28 #include <unistd.h> 29 #endif 30 #ifdef __MSDOS__ 31 #include <io.h> 32 #endif 33 #include "et/com_err.h" 34 #include "ext2fs/ext2_io.h" 35 36 #ifdef __linux__ 37 38 #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) 39 40 #define my_llseek lseek64 41 42 #else 43 #if defined(HAVE_LLSEEK) 44 #include <sys/syscall.h> 45 46 #ifndef HAVE_LLSEEK_PROTOTYPE 47 extern long long llseek (int fd, long long offset, int origin); 48 #endif 49 50 #define my_llseek llseek 51 52 #else /* ! HAVE_LLSEEK */ 53 54 #if SIZEOF_LONG == SIZEOF_LONG_LONG 55 56 #define my_llseek lseek 57 58 #else /* SIZEOF_LONG != SIZEOF_LONG_LONG */ 59 60 #include <linux/unistd.h> 61 62 #ifndef __NR__llseek 63 #define __NR__llseek 140 64 #endif 65 66 #ifndef __i386__ 67 static int _llseek (unsigned int, unsigned long, 68 unsigned long, ext2_loff_t *, unsigned int); 69 70 static _syscall5(int,_llseek,unsigned int,fd,unsigned long,offset_high, 71 unsigned long, offset_low,ext2_loff_t *,result, 72 unsigned int, origin) 73 #endif 74 75 static ext2_loff_t my_llseek (int fd, ext2_loff_t offset, int origin) 76 { 77 ext2_loff_t result; 78 int retval; 79 80 #ifndef __i386__ 81 retval = _llseek(fd, ((unsigned long long) offset) >> 32, 82 #else 83 retval = syscall(__NR__llseek, fd, (unsigned long long) (offset >> 32), 84 #endif 85 ((unsigned long long) offset) & 0xffffffff, 86 &result, origin); 87 return (retval == -1 ? (ext2_loff_t) retval : result); 88 } 89 90 #endif /* SIZE_LONG == SIZEOF_LONG_LONG */ 91 92 #endif /* HAVE_LLSEEK */ 93 #endif /* defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) */ 94 95 ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin) 96 { 97 #if SIZEOF_OFF_T >= SIZEOF_LONG_LONG 98 return my_llseek (fd, offset, origin); 99 #else 100 ext2_loff_t result; 101 static int do_compat = 0; 102 103 if (do_compat) 104 goto fallback; 105 106 result = my_llseek (fd, offset, origin); 107 if (result == -1 && errno == ENOSYS) { 108 /* 109 * Just in case this code runs on top of an old kernel 110 * which does not support the llseek system call 111 */ 112 do_compat++; 113 fallback: 114 if (offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1))) 115 return lseek(fd, (off_t) offset, origin); 116 errno = EINVAL; 117 return -1; 118 } 119 return result; 120 #endif 121 } 122 123 #else /* !linux */ 124 125 #ifndef EINVAL 126 #define EINVAL EXT2_ET_INVALID_ARGUMENT 127 #endif 128 129 ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin) 130 { 131 #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) 132 return lseek64 (fd, offset, origin); 133 #else 134 if ((sizeof(off_t) < sizeof(ext2_loff_t)) && 135 (offset >= ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))) { 136 errno = EINVAL; 137 return -1; 138 } 139 return lseek (fd, (off_t) offset, origin); 140 #endif 141 } 142 143 #endif /* linux */ 144 145 146
