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/* Change to/from read-only

   Copyright (C) 1995 Free Software Foundation, Inc.

   Written by Miles Bader <miles@gnu.ai.mit.edu>

   This file is part of the GNU Hurd.

   The GNU Hurd 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.

   The GNU Hurd 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 <fcntl.h>

#include "priv.h"

/* Change an active filesystem between read-only and writable modes, setting
   the global variable DISKFS_READONLY to reflect the current mode.  If an
   error is returned, nothing will have changed.  The user should hold
   DISKFS_FSYS_LOCK while calling this routine.  */
error_t
diskfs_set_readonly (int readonly)
{
  error_t err = 0;

  if (readonly != diskfs_readonly)
    {
      ports_inhibit_class_rpcs (diskfs_protid_class);

      if (readonly)
	{
	  error_t peropen_writable (void *pi)
	    {
	      if (((struct port_info *)pi)->class == diskfs_protid_class
		  && (((struct protid *)pi)->po->openstat & O_WRITE))
		return EBUSY;
	      else
		return 0;
	    }

	  /* Any writable open files?  */
	  err = ports_bucket_iterate (diskfs_port_bucket, peropen_writable);

	  /* Any writable pagers?  */
	  if (!err && (diskfs_max_user_pager_prot () & VM_PROT_WRITE))
	    err = EBUSY;

	  if (!err)
	    /* Sync */
	    {
	      diskfs_sync_everything (1);
	      diskfs_set_hypermetadata (1, 1);
	      sleep (1);	/* XXX! */
	    }
	}

      if (!err)
	{
	  diskfs_readonly = readonly;
	  diskfs_readonly_changed (readonly);
	}

      ports_resume_class_rpcs (diskfs_protid_class);
    }

  return err;
}