1 /* daemon.c: kernel part of Vinum daemon */
3 * Copyright (c) 1997, 1998
4 * Nan Yang Computer Services Limited. All rights reserved.
6 * This software is distributed under the so-called ``Berkeley
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by Nan Yang Computer
21 * 4. Neither the name of the Company nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
25 * This software is provided ``as is'', and any express or implied
26 * warranties, including, but not limited to, the implied warranties of
27 * merchantability and fitness for a particular purpose are disclaimed.
28 * In no event shall the company or contributors be liable for any
29 * direct, indirect, incidental, special, exemplary, or consequential
30 * damages (including, but not limited to, procurement of substitute
31 * goods or services; loss of use, data, or profits; or business
32 * interruption) however caused and on any theory of liability, whether
33 * in contract, strict liability, or tort (including negligence or
34 * otherwise) arising in any way out of the use of this software, even if
35 * advised of the possibility of such damage.
37 * $Id: vinumdaemon.c,v 1.8 2000/01/03 05:22:03 grog Exp grog $
38 * $FreeBSD: src/sys/dev/vinum/vinumdaemon.c,v 1.16 2000/01/05 06:03:56 grog Exp $
39 * $DragonFly: src/sys/dev/raid/vinum/vinumdaemon.c,v 1.3 2003/07/19 21:14:31 dillon Exp $
42 #include <dev/vinum/vinumhdr.h>
43 #include <dev/vinum/request.h>
46 #include <sys/reboot.h>
50 void recover_io(struct request *rq);
52 int daemon_options = 0; /* options */
53 int daemonpid; /* PID of daemon */
54 struct daemonq *daemonq; /* daemon's work queue */
55 struct daemonq *dqend; /* and the end of the queue */
58 * We normally call Malloc to get a queue element. In interrupt
59 * context, we can't guarantee that we'll get one, since we're not
60 * allowed to wait. If malloc fails, use one of these elements.
64 struct daemonq intq[INTQSIZE]; /* queue elements for interrupt context */
65 struct daemonq *intqp; /* and pointer in it */
71 struct daemonq *request;
73 curproc->p_flag |= P_INMEM | P_SYSTEM; /* we're a system process */
74 daemon_save_config(); /* start by saving the configuration */
75 daemonpid = curproc->p_pid; /* mark our territory */
77 tsleep(&vinum_daemon, 0, "vinum", 0); /* wait for something to happen */
80 * It's conceivable that, as the result of an
81 * I/O error, we'll be out of action long
82 * enough that another daemon gets started.
83 * That's OK, just give up gracefully.
85 if (curproc->p_pid != daemonpid) { /* we've been ousted in our sleep */
86 if (daemon_options & daemon_verbose)
87 log(LOG_INFO, "vinum: abdicating\n");
90 while (daemonq != NULL) { /* we have work to do, */
91 s = splhigh(); /* don't get interrupted here */
92 request = daemonq; /* get the request */
93 daemonq = daemonq->next; /* and detach it */
94 if (daemonq == NULL) /* got to the end, */
95 dqend = NULL; /* no end any more */
98 switch (request->type) {
100 * We had an I/O error on a request. Go through the
101 * request and try to salvage it
103 case daemonrq_ioerror:
104 if (daemon_options & daemon_verbose) {
105 struct request *rq = request->info.rq;
108 "vinum: recovering I/O request: %p\n%s dev %d.%d, offset 0x%x, length %ld\n",
110 rq->bp->b_flags & B_READ ? "Read" : "Write",
111 major(rq->bp->b_dev),
112 minor(rq->bp->b_dev),
116 recover_io(request->info.rq); /* the failed request */
120 * Write the config to disk. We could end up with
121 * quite a few of these in a row. Only honour the
124 case daemonrq_saveconfig:
125 if ((daemonq == NULL) /* no more requests */
126 ||(daemonq->type != daemonrq_saveconfig)) { /* or the next isn't the same */
127 if (((daemon_options & daemon_noupdate) == 0) /* we're allowed to do it */
128 &&((vinum_conf.flags & VF_READING_CONFIG) == 0)) { /* and we're not building the config now */
130 * We obviously don't want to save a
131 * partial configuration. Less obviously,
132 * we don't need to do anything if we're
133 * asked to write the config when we're
134 * building it up, because we save it at
137 if (daemon_options & daemon_verbose)
138 log(LOG_INFO, "vinum: saving config\n");
139 daemon_save_config(); /* save it */
144 case daemonrq_return: /* been told to stop */
145 if (daemon_options & daemon_verbose)
146 log(LOG_INFO, "vinum: stopping\n");
147 daemon_options |= daemon_stopped; /* note that we've stopped */
149 while (daemonq != NULL) { /* backed up requests, */
150 request = daemonq; /* get the request */
151 daemonq = daemonq->next; /* and detach it */
152 Free(request); /* then free it */
154 wakeup(&vinumclose); /* and wake any waiting vinum(8)s */
157 case daemonrq_ping: /* tell the caller we're here */
158 if (daemon_options & daemon_verbose)
159 log(LOG_INFO, "vinum: ping reply\n");
160 wakeup(&vinum_finddaemon); /* wake up the caller */
163 case daemonrq_closedrive: /* close a drive */
164 close_drive(request->info.drive); /* do it */
167 case daemonrq_init: /* initialize a plex */
169 case daemonrq_revive: /* revive a subdisk */
173 log(LOG_WARNING, "Invalid request\n");
176 if (request->privateinuse) /* one of ours, */
177 request->privateinuse = 0; /* no longer in use */
179 Free(request); /* return it */
185 * Recover a failed I/O operation.
187 * The correct way to do this is to examine the request and determine
188 * how to recover each individual failure. In the case of a write,
189 * this could be as simple as doing nothing: the defective drives may
190 * already be down, and there may be nothing else to do. In case of
191 * a read, it will be necessary to retry if there are alternative
192 * copies of the data.
194 * The easy way (here) is just to reissue the request. This will take
195 * a little longer, but nothing like as long as the failure will have
200 recover_io(struct request *rq)
205 * vinumstrategy(rq->bp);
207 * Negotiate with phk to get it fixed.
209 BUF_STRATEGY(rq->bp, 0); /* reissue the command */
212 /* Functions called to interface with the daemon */
214 /* queue a request for the daemon */
216 queue_daemon_request(enum daemonrq type, union daemoninfo info)
220 struct daemonq *qelt = (struct daemonq *) Malloc(sizeof(struct daemonq));
222 if (qelt == NULL) { /* malloc failed, we're prepared for that */
224 * Take one of our spares. Give up if it's still in use; the only
225 * message we're likely to get here is a 'drive failed' message,
226 * and that'll come by again if we miss it.
228 if (intqp->privateinuse) /* still in use? */
229 return; /* yes, give up */
231 if (intqp == &intq[INTQSIZE]) /* got to the end, */
232 intqp = intq; /* wrap around */
233 qelt->privateinuse = 1; /* it's ours, and it's in use */
235 qelt->privateinuse = 0;
237 qelt->next = NULL; /* end of the chain */
241 if (daemonq) { /* something queued already */
244 } else { /* queue is empty, */
245 daemonq = qelt; /* this is the whole queue */
249 wakeup(&vinum_daemon); /* and give the dæmon a kick */
253 * see if the daemon is running. Return 0 (no error)
254 * if it is, ESRCH otherwise
261 if (daemonpid != 0) { /* we think we have a daemon, */
262 queue_daemon_request(daemonrq_ping, (union daemoninfo) NULL); /* queue a ping */
263 result = tsleep(&vinum_finddaemon, 0, "reap", 2 * hz);
264 if (result == 0) /* yup, the daemon's up and running */
267 /* no daemon, or we couldn't talk to it: start it */
268 vinum_daemon(); /* start the daemon */
273 vinum_setdaemonopts(int options)
275 daemon_options = options;