146 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			146 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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|  * llseek.c -- stub calling the llseek system call
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|  *
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|  * Copyright (C) 1994, 1995, 1996, 1997 Theodore Ts'o.
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|  *
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|  * %Begin-Header%
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|  * This file may be redistributed under the terms of the GNU Library
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|  * General Public License, version 2.
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|  * %End-Header%
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|  */
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| 
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| #ifndef _LARGEFILE_SOURCE
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| #define _LARGEFILE_SOURCE
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| #endif
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| #ifndef _LARGEFILE64_SOURCE
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| #define _LARGEFILE64_SOURCE
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| #endif
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| 
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| #include "config.h"
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| #if HAVE_SYS_TYPES_H
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| #include <sys/types.h>
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| #endif
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| 
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| #if HAVE_ERRNO_H
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| #include <errno.h>
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| #endif
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| #if HAVE_UNISTD_H
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| #include <unistd.h>
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| #endif
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| #ifdef __MSDOS__
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| #include <io.h>
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| #endif
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| #include "et/com_err.h"
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| #include "ext2fs/ext2_io.h"
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| 
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| #ifdef __linux__
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| 
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| #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
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| 
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| #define my_llseek lseek64
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| 
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| #else
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| #if defined(HAVE_LLSEEK)
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| #include <sys/syscall.h>
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| 
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| #ifndef HAVE_LLSEEK_PROTOTYPE
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| extern long long llseek (int fd, long long offset, int origin);
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| #endif
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| 
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| #define my_llseek llseek
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| 
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| #else	/* ! HAVE_LLSEEK */
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| 
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| #if SIZEOF_LONG == SIZEOF_LONG_LONG
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| 
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| #define my_llseek lseek
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| 
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| #else /* SIZEOF_LONG != SIZEOF_LONG_LONG */
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| 
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| #include <linux/unistd.h>
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| 
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| #ifndef __NR__llseek
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| #define __NR__llseek            140
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| #endif
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| 
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| #ifndef __i386__
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| static int _llseek (unsigned int, unsigned long,
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| 		   unsigned long, ext2_loff_t *, unsigned int);
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| 
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| static _syscall5(int,_llseek,unsigned int,fd,unsigned long,offset_high,
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| 		 unsigned long, offset_low,ext2_loff_t *,result,
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| 		 unsigned int, origin)
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| #endif
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| 
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| static ext2_loff_t my_llseek (int fd, ext2_loff_t offset, int origin)
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| {
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| 	ext2_loff_t result;
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| 	int retval;
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| 
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| #ifndef __i386__
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| 	retval = _llseek(fd, ((unsigned long long) offset) >> 32,
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| #else
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| 	retval = syscall(__NR__llseek, fd, (unsigned long long) (offset >> 32),
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| #endif
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| 			  ((unsigned long long) offset) & 0xffffffff,
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| 			&result, origin);
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| 	return (retval == -1 ? (ext2_loff_t) retval : result);
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| }
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| 
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| #endif	/* SIZE_LONG == SIZEOF_LONG_LONG */
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| 
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| #endif /* HAVE_LLSEEK */
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| #endif /* defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) */
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| 
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| ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin)
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| {
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| #if SIZEOF_OFF_T >= SIZEOF_LONG_LONG
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| 	return my_llseek (fd, offset, origin);
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| #else
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| 	ext2_loff_t result;
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| 	static int do_compat = 0;
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| 
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| 	if (do_compat)
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| 		goto fallback;
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| 
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| 	result = my_llseek (fd, offset, origin);
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| 	if (result == -1 && errno == ENOSYS) {
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| 		/*
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| 		 * Just in case this code runs on top of an old kernel
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| 		 * which does not support the llseek system call
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| 		 */
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| 		do_compat++;
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| 	fallback:
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| 		if (offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))
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| 			return lseek(fd, (off_t) offset, origin);
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| 		errno = EINVAL;
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| 		return -1;
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| 	}
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| 	return result;
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| #endif
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| }
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| 
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| #else /* !linux */
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| 
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| #ifndef EINVAL
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| #define EINVAL EXT2_ET_INVALID_ARGUMENT
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| #endif
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| 
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| ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin)
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| {
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| #if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
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| 	return lseek64 (fd, offset, origin);
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| #else
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| 	if ((sizeof(off_t) < sizeof(ext2_loff_t)) &&
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| 	    (offset >= ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))) {
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| 		errno = EINVAL;
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| 		return -1;
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| 	}
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| 	return lseek (fd, (off_t) offset, origin);
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| #endif
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| }
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| 
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| #endif 	/* linux */
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| 
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| 
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