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