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/* Change to/from read-only
Copyright (C) 1995, 1996, 1997, 1999 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 <error.h>
#include "priv.h"
int _diskfs_diskdirty;
int diskfs_readonly = 0;
int diskfs_hard_readonly = 0;
int
diskfs_check_readonly ()
{
error_t err;
if (diskfs_readonly)
return 1;
else
{
if (!_diskfs_diskdirty)
{
err = diskfs_set_hypermetadata (1, 0);
if (err)
{
error (0, 0,
"%s: MEDIA NOT WRITABLE; switching to READ-ONLY",
diskfs_disk_name ?: "-");
diskfs_hard_readonly = diskfs_readonly = 1;
return 1;
}
_diskfs_diskdirty = 1;
}
return 0;
}
}
/* 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 (diskfs_hard_readonly)
return readonly ? 0 : EROFS;
if (readonly != diskfs_readonly)
{
err = ports_inhibit_class_rpcs (diskfs_protid_class);
if (! err)
{
if (readonly)
{
error_t peropen_writable (void *pi)
{
struct protid *const cred = pi;
return (cred->po->openstat & O_WRITE) ? EBUSY : 0;
}
/* Any writable open files? */
err = ports_class_iterate (diskfs_protid_class,
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);
_diskfs_diskdirty = 0;
}
}
if (!err)
{
diskfs_readonly = readonly;
diskfs_readonly_changed (readonly);
}
ports_resume_class_rpcs (diskfs_protid_class);
}
}
return err;
}
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