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/* daemon.c: kernel part of Vinum daemon */
/*-
* 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: vinumdaemon.c,v 1.1 1999/01/21 00:31:31 grog Exp $
*/
#define REALLYKERNEL
#include <dev/vinum/vinumhdr.h>
#include <dev/vinum/request.h>
#ifdef VINUMDEBUG
#include <sys/reboot.h>
#endif
/* declarations */
void recover_io(struct request *rq);
struct daemonq *daemonq; /* daemon's work queue */
struct daemonq *dqend; /* and the end of the queue */
int daemon_options = 0; /* options */
void
vinum_daemon(void)
{
struct daemonq *request;
int s;
daemon_save_config(); /* start by saving the configuration */
while (1) {
tsleep(&vinum_daemon, PRIBIO, "vinum", 0); /* wait for something to happen */
while (daemonq != NULL) { /* we have work to do, */
s = splhigh(); /* don't get interrupted here */
request = daemonq; /* get the request */
daemonq = daemonq->next; /* and detach it */
if (daemonq == NULL) /* got to the end, */
dqend = NULL; /* no end any more */
splx(s);
switch (request->type) {
/* We had an I/O error on a request. Go through the
* request and try to salvage it */
case daemonrq_ioerror:
if (daemon_options & daemon_verbose) {
struct request *rq = request->info.rq;
printf("vinumd: recovering I/O request: %x\n%s dev 0x%x, offset 0x%x, length %ld\n",
(u_int) rq,
rq->bp->b_flags & B_READ ? "Read" : "Write",
rq->bp->b_dev,
rq->bp->b_blkno,
rq->bp->b_bcount);
}
recover_io(request->info.rq); /* the failed request */
break;
/* Write the config to disk. We could end up with
* quite a few of these in a row. Only honour the
* last one */
case daemonrq_saveconfig:
if ((daemonq == NULL) /* no more requests */
||(daemonq->type != daemonrq_saveconfig)) { /* or the next isn't the same */
if ((daemon_options & daemon_noupdate) == 0) { /* we can do it */
if (daemon_options & daemon_verbose)
printf("vinumd: saving config\n");
daemon_save_config(); /* save it */
}
}
break;
case daemonrq_return: /* been told to stop */
if (daemon_options & daemon_verbose)
printf("vinumd: stopping\n");
daemon_options |= daemon_stopped; /* note that we've stopped */
wakeup(vinum_daemon); /* in case somebody's waiting for us to stop */
return;
break;
case daemonrq_ping: /* tell the caller we're here */
if (daemon_options & daemon_verbose)
printf("vinumd: ping reply\n");
wakeup(&vinum_finddaemon); /* wake up the caller */
break;
case daemonrq_init: /* initialize a plex */
/* XXX */
case daemonrq_revive: /* revive a subdisk */
/* XXX */
default:
printf("Invalid request\n");
break;
}
Free(request);
}
}
}
/* Recover a failed I/O operation.
* The correct way to do this is to examine the request and determine
* how to recover each individual failure. In the case of a write,
* this could be as simple as doing nothing: the defective drives may
* already be down, and there may be nothing else to do. In case of
* a read, it will be necessary to retry if there are alternative
* copies of the data.
*
* The easy way (here) is just to reissue the request. This will take
* a little longer, but nothing like as long as the failure will have
* taken.
*
*/
void
recover_io(struct request *rq)
{
vinumstrategy(rq->bp); /* reissue the command */
}
/* Functions called to interface with the daemon */
/* queue a request for the daemon */
void
queue_daemon_request(enum daemonrq type, union daemoninfo info)
{
int s;
struct daemonq *qelt = (struct daemonq *) Malloc(sizeof(struct daemonq));
qelt->next = NULL; /* end of the chain */
qelt->type = type;
qelt->info = info;
s = splhigh();
if (daemonq) { /* something queued already */
dqend->next = qelt;
dqend = qelt;
} else { /* queue is empty, */
daemonq = qelt; /* this is the whole queue */
dqend = qelt;
}
splx(s);
wakeup(&vinum_daemon); /* and give the dæmon a kick */
}
/* see if the daemon is running. Return 0 (no error)
* if it is, ESRCH otherwise */
int
vinum_finddaemon()
{
int result;
int i;
for (i = 0; i < 2; i++) { /* try twice */
queue_daemon_request(daemonrq_ping, NULL); /* queue a ping */
do
result = tsleep(&vinum_finddaemon, PUSER, "recolte", 20 * hz);
while (result == ERESTART); /* let it finish */
}
if (result) /* will be EWOULDBLOCK or EINTR */
return ESRCH; /* no process */
return 0;
}
int
vinum_setdaemonopts(int options)
{
daemon_options = options;
return 0;
}
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