136 lines
2.8 KiB
C
136 lines
2.8 KiB
C
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/*
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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 Public
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* License.
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* %End-Header%
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*/
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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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#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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#ifdef __linux__
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#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
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#define my_llseek lseek64
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#else
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#if defined(HAVE_LLSEEK)
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#include <syscall.h>
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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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#define my_llseek llseek
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#else /* ! HAVE_LLSEEK */
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#if defined(__alpha__) || defined (__ia64__)
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#define llseek lseek
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#else /* !__alpha__ && !__ia64__*/
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#include <linux/unistd.h>
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#ifndef __NR__llseek
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#define __NR__llseek 140
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#endif
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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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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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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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#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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#endif /* __alpha__ || __ia64__ */
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#endif /* HAVE_LLSEEK */
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#endif /* defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE) */
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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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ext2_loff_t result;
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static int do_compat = 0;
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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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return lseek(fd, (off_t) offset, origin);
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if (do_compat) {
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errno = EINVAL;
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return -1;
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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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errno = EINVAL;
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}
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return result;
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}
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#else /* !linux */
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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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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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#endif /* linux */
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