glibc/sysdeps/unix/sysv/linux/fpathconf.c

/* Linux specific extensions to fpathconf.
   Copyright (C) 1991,95,96,98,99,2000,2001,2002 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <sys/statfs.h>

#include "linux_fsinfo.h"


/* The Linux kernel header mentioned this as a kind of generic value.  */
#define LINUX_LINK_MAX	127

static long int posix_fpathconf (int fd, int name);


/* Get file-specific information about descriptor FD.  */
long int
__fpathconf (fd, name)
     int fd;
     int name;
{
  if (name == _PC_LINK_MAX)
    {
      struct statfs fsbuf;

      /* Determine the filesystem type.  */
      if (__fstatfs (fd, &fsbuf) < 0)
	{
	  if (errno == ENOSYS)
	    /* not possible, return the default value.  */
	    return LINUX_LINK_MAX;

	  /* Some error occured.  */
          return -1;
	}

      switch (fsbuf.f_type)
	{
	case EXT2_SUPER_MAGIC:
	  return EXT2_LINK_MAX;

	case MINIX_SUPER_MAGIC:
	case MINIX_SUPER_MAGIC2:
	  return MINIX_LINK_MAX;

	case MINIX2_SUPER_MAGIC:
	case MINIX2_SUPER_MAGIC2:
	  return MINIX2_LINK_MAX;

	case XENIX_SUPER_MAGIC:
	  return XENIX_LINK_MAX;

	case SYSV4_SUPER_MAGIC:
	case SYSV2_SUPER_MAGIC:
	  return SYSV_LINK_MAX;

	case COH_SUPER_MAGIC:
	  return COH_LINK_MAX;

	case UFS_MAGIC:
	case UFS_CIGAM:
	  return UFS_LINK_MAX;

	case REISERFS_SUPER_MAGIC:
	  return REISERFS_LINK_MAX;

	case XFS_SUPER_MAGIC:
	  return XFS_LINK_MAX;

	default:
	  return LINUX_LINK_MAX;
	}
    }

  return posix_fpathconf (fd, name);
}

#define __fpathconf static posix_fpathconf
#include <sysdeps/posix/fpathconf.c>