140 lines
2.8 KiB
C
140 lines
2.8 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
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* GNU Lesser General Public 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 "blkidP.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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#elif 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, unsigned long,
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blkid_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, blkid_loff_t *, result,
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unsigned int, origin)
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#endif
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static blkid_loff_t my_llseek(int fd, blkid_loff_t offset, int origin)
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{
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blkid_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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((unsigned long long)offset) & 0xffffffff,
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&result, origin);
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#else
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retval = syscall(__NR__llseek, fd, ((unsigned long long) offset) >> 32,
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((unsigned long long)offset) & 0xffffffff,
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&result, origin);
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#endif
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return (retval == -1 ? (blkid_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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blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int whence)
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{
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blkid_loff_t result;
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static int do_compat = 0;
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if ((sizeof(off_t) >= sizeof(blkid_loff_t)) ||
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(offset < ((blkid_loff_t) 1 << ((sizeof(off_t)*8) -1))))
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return lseek(fd, (off_t) offset, whence);
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if (do_compat) {
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errno = EOVERFLOW;
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return -1;
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}
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result = my_llseek(fd, offset, whence);
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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 = EOVERFLOW;
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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 EOVERFLOW
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#ifdef EXT2_ET_INVALID_ARGUMENT
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#define EOVERFLOW EXT2_ET_INVALID_ARGUMENT
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#else
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#define EOVERFLOW 112
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#endif
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#endif
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blkid_loff_t blkid_llseek(int fd, blkid_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(blkid_loff_t)) &&
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(offset >= ((blkid_loff_t) 1 << ((sizeof(off_t)*8) - 1)))) {
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errno = EOVERFLOW;
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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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