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/*
Copyright (C) 1994,1995,1996,2000,2006 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "priv.h"
#include "io_S.h"
#include <unistd.h>
/* Implement io_seek as described in <hurd/io.defs>. */
kern_return_t
diskfs_S_io_seek (struct protid *cred,
off_t offset,
int whence,
off_t *newoffset)
{
error_t err = 0;
struct node *np;
if (!cred)
return EOPNOTSUPP;
np = cred->po->np;
pthread_mutex_lock (&np->lock);
iohelp_get_conch (&np->conch);
switch (whence)
{
case SEEK_CUR:
offset += cred->po->filepointer;
goto check;
case SEEK_END:
offset += np->dn_stat.st_size;
case SEEK_SET:
check:
/* pager_memcpy inherently uses vm_offset_t, which may be smaller than
off_t. */
if (sizeof(off_t) > sizeof(vm_offset_t) &&
offset > ((off_t) 1) << (sizeof(vm_offset_t) * 8))
{
err = EFBIG;
break;
}
if (offset >= 0)
{
*newoffset = cred->po->filepointer = offset;
break;
}
default:
err = EINVAL;
break;
}
pthread_mutex_unlock (&np->lock);
return err;
}
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