diff options
Diffstat (limited to 'sys/dev/vinum/vinumlock.c')
-rw-r--r-- | sys/dev/vinum/vinumlock.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/sys/dev/vinum/vinumlock.c b/sys/dev/vinum/vinumlock.c new file mode 100644 index 0000000..9376364 --- /dev/null +++ b/sys/dev/vinum/vinumlock.c @@ -0,0 +1,137 @@ +/*- + * 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 1.1.1.1 1998/09/16 05:56:21 grog Exp $ + */ + +#define REALLYKERNEL +#include "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); + } +} |