freebsd-dev/sys/dev/vinum/vinumlock.c
Peter Wemm c285ca1254 Some relatively minor tweaks to enable vinum to be built into a static
kernel as a pseudo-device.  The changes were:
- #ifdef DEBUG -> #ifdef VINUMDEBUG
- opt_vinum.h for holding above config variable
- Fixing up a few stray problems where DEBUG wasn't optional.
- config.c -> vinumconfig.c (there's already a config.o)
- Other *.c -> vinum*.c (wasn't strictly necessary, but done in case we end
  up with something else conflicting later on and we might have to have yet
  more repository copies of files).
- include file paths fixups..  (ie: get them all from the kernel tree
  instead of partly from the kernel and partly from /usr/include/machine)

I've spoken with Greg about this..  I hope this doesn't mess him around
too much..
1998-12-28 16:28:24 +00:00

139 lines
4.2 KiB
C

/*-
* Copyright (c) 1997, 1998
* Nan Yang Computer Services Limited. All rights reserved.
*
* This software is distributed under the so-called ``Berkeley
* License'':
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Nan Yang Computer
* Services Limited.
* 4. Neither the name of the Company nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* This software is provided ``as is'', and any express or implied
* warranties, including, but not limited to, the implied warranties of
* merchantability and fitness for a particular purpose are disclaimed.
* In no event shall the company or contributors be liable for any
* direct, indirect, incidental, special, exemplary, or consequential
* damages (including, but not limited to, procurement of substitute
* goods or services; loss of use, data, or profits; or business
* interruption) however caused and on any theory of liability, whether
* in contract, strict liability, or tort (including negligence or
* otherwise) arising in any way out of the use of this software, even if
* advised of the possibility of such damage.
*
* $Id: lock.c,v 1.3 1998/12/28 04:56:23 peter Exp $
*/
#define REALLYKERNEL
#include "opt_vinum.h"
#include <dev/vinum/vinumhdr.h>
/* Lock routines. Currently, we lock either an individual volume
* or the global configuration. I don't think tsleep and
* wakeup are SMP safe. FIXME XXX */
/* Lock a volume, wait if it's in use */
int
lockvol(struct volume *vol)
{
int error;
while ((vol->flags & VF_LOCKED) != 0) {
vol->flags |= VF_LOCKING;
/* It would seem to make more sense to sleep on
* the address 'vol'. Unfortuntaly we can't
* guarantee that this address won't change due to
* table expansion. The address we choose won't change. */
if ((error = tsleep(&vinum_conf.volume + vol->devno,
PRIBIO | PCATCH,
"volock",
0)) != 0)
return error;
}
vol->flags |= VF_LOCKED;
return 0;
}
/* Unlock a volume and let the next one at it */
void
unlockvol(struct volume *vol)
{
vol->flags &= ~VF_LOCKED;
if ((vol->flags & VF_LOCKING) != 0) {
vol->flags &= ~VF_LOCKING;
wakeup(&vinum_conf.volume + vol->devno);
}
}
/* Lock a plex, wait if it's in use */
int
lockplex(struct plex *plex)
{
int error;
while ((plex->flags & VF_LOCKED) != 0) {
plex->flags |= VF_LOCKING;
/* It would seem to make more sense to sleep on
* the address 'plex'. Unfortuntaly we can't
* guarantee that this address won't change due to
* table expansion. The address we choose won't change. */
if ((error = tsleep(&vinum_conf.plex + plex->sdnos[0],
PRIBIO | PCATCH,
"plexlk",
0)) != 0)
return error;
}
plex->flags |= VF_LOCKED;
return 0;
}
/* Unlock a plex and let the next one at it */
void
unlockplex(struct plex *plex)
{
plex->flags &= ~VF_LOCKED;
if ((plex->flags & VF_LOCKING) != 0) {
plex->flags &= ~VF_LOCKING;
wakeup(&vinum_conf.plex + plex->plexno);
}
}
/* Get a lock for the global config, wait if it's not available */
int
lock_config(void)
{
int error;
while ((vinum_conf.flags & VF_LOCKED) != 0) {
vinum_conf.flags |= VF_LOCKING;
if ((error = tsleep(&vinum_conf, PRIBIO | PCATCH, "vincfg", 0)) != 0)
return error;
}
vinum_conf.flags |= VF_LOCKED;
return 0;
}
/* Unlock and wake up any waiters */
void
unlock_config(void)
{
vinum_conf.flags &= ~VF_LOCKED;
if ((vinum_conf.flags & VF_LOCKING) != 0) {
vinum_conf.flags &= ~VF_LOCKING;
wakeup(&vinum_conf);
}
}