2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 2002 Poul-Henning Kamp
5 * Copyright (c) 2002 Networks Associates Technology, Inc.
8 * This software was developed for the FreeBSD Project by Poul-Henning Kamp
9 * and NAI Labs, the Security Research Division of Network Associates, Inc.
10 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
11 * DARPA CHATS research program.
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. The names of the authors may not be used to endorse or promote
22 * products derived from this software without specific prior written
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * XXX: How do we in general know that objects referenced in events
40 * have not been destroyed before we get around to handle the event ?
43 #include <sys/cdefs.h>
44 #include <sys/param.h>
45 #include <sys/malloc.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
49 #include <sys/mutex.h>
51 #include <sys/errno.h>
53 #include <geom/geom.h>
54 #include <geom/geom_int.h>
56 #include <machine/stdarg.h>
58 TAILQ_HEAD(event_tailq_head, g_event);
60 static struct event_tailq_head g_events = TAILQ_HEAD_INITIALIZER(g_events);
61 static u_int g_pending_events;
62 static TAILQ_HEAD(,g_provider) g_doorstep = TAILQ_HEAD_INITIALIZER(g_doorstep);
63 static struct mtx g_eventlock;
64 static int g_wither_work;
66 #define G_N_EVENTREFS 20
69 TAILQ_ENTRY(g_event) events;
73 void *ref[G_N_EVENTREFS];
76 #define EV_DONE 0x80000
77 #define EV_WAKEUP 0x40000
78 #define EV_CANCELED 0x20000
79 #define EV_INPROGRESS 0x10000
82 g_waitidle(struct thread *td)
85 g_topology_assert_not();
87 mtx_lock(&g_eventlock);
88 TSWAIT("GEOM events");
89 while (!TAILQ_EMPTY(&g_events))
90 msleep(&g_pending_events, &g_eventlock, PPAUSE,
92 TSUNWAIT("GEOM events");
93 mtx_unlock(&g_eventlock);
94 td->td_pflags &= ~TDP_GEOM;
98 ast_geom(struct thread *td, int tda __unused)
101 * If this thread tickled GEOM, we need to wait for the giggling to
102 * stop before we return to userland.
108 geom_event_init(void *arg __unused)
110 ast_register(TDA_GEOM, ASTR_ASTF_REQUIRED | ASTR_TDP | ASTR_KCLEAR,
113 SYSINIT(geom_event, SI_SUB_INTRINSIC, SI_ORDER_ANY, geom_event_init, NULL);
115 struct g_attrchanged_args {
116 struct g_provider *pp;
121 g_attr_changed_event(void *arg, int flag)
123 struct g_attrchanged_args *args;
124 struct g_provider *pp;
125 struct g_consumer *cp;
126 struct g_consumer *next_cp;
132 if (flag != EV_CANCEL && g_shutdown == 0) {
134 * Tell all consumers of the change.
136 LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
137 if (cp->geom->attrchanged != NULL)
138 cp->geom->attrchanged(cp, args->attr);
145 g_attr_changed(struct g_provider *pp, const char *attr, int flag)
147 struct g_attrchanged_args *args;
150 args = g_malloc(sizeof *args, flag);
155 error = g_post_event(g_attr_changed_event, args, flag, pp, NULL);
162 g_orphan_provider(struct g_provider *pp, int error)
165 /* G_VALID_PROVIDER(pp) We likely lack topology lock */
166 g_trace(G_T_TOPOLOGY, "g_orphan_provider(%p(%s), %d)",
167 pp, pp->name, error);
169 ("g_orphan_provider(%p(%s), 0) error must be non-zero\n",
173 mtx_lock(&g_eventlock);
174 KASSERT(!(pp->flags & G_PF_ORPHAN),
175 ("g_orphan_provider(%p(%s)), already an orphan", pp, pp->name));
176 pp->flags |= G_PF_ORPHAN;
177 TAILQ_INSERT_TAIL(&g_doorstep, pp, orphan);
178 mtx_unlock(&g_eventlock);
179 wakeup(&g_wait_event);
183 * This function is called once on each provider which the event handler
184 * finds on its g_doorstep.
188 g_orphan_register(struct g_provider *pp)
190 struct g_consumer *cp, *cp2;
194 G_VALID_PROVIDER(pp);
195 g_trace(G_T_TOPOLOGY, "g_orphan_register(%s)", pp->name);
199 wf = pp->flags & G_PF_WITHER;
200 pp->flags &= ~G_PF_WITHER;
203 * Tell all consumers the bad news.
204 * Don't be surprised if they self-destruct.
206 LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
207 KASSERT(cp->geom->orphan != NULL,
208 ("geom %s has no orphan, class %s",
209 cp->geom->name, cp->geom->class->name));
211 * XXX: g_dev_orphan method does deferred destroying
212 * and it is possible, that other event could already
213 * call the orphan method. Check consumer's flags to
214 * do not schedule it twice.
216 if (cp->flags & G_CF_ORPHAN)
218 cp->flags |= G_CF_ORPHAN;
219 cp->geom->orphan(cp);
221 if (LIST_EMPTY(&pp->consumers) && wf)
222 g_destroy_provider(pp);
226 cp = LIST_FIRST(&pp->consumers);
229 if (pp->geom->flags & G_GEOM_WITHER)
230 g_destroy_provider(pp);
238 struct g_provider *pp;
241 mtx_lock(&g_eventlock);
242 pp = TAILQ_FIRST(&g_doorstep);
244 G_VALID_PROVIDER(pp);
245 TAILQ_REMOVE(&g_doorstep, pp, orphan);
246 mtx_unlock(&g_eventlock);
247 g_orphan_register(pp);
251 ep = TAILQ_FIRST(&g_events);
253 wakeup(&g_pending_events);
256 ep->flag |= EV_INPROGRESS;
257 mtx_unlock(&g_eventlock);
259 ep->func(ep->arg, 0);
261 mtx_lock(&g_eventlock);
262 TSRELEASE("GEOM events");
263 TAILQ_REMOVE(&g_events, ep, events);
264 ep->flag &= ~EV_INPROGRESS;
265 if (ep->flag & EV_WAKEUP) {
268 mtx_unlock(&g_eventlock);
270 mtx_unlock(&g_eventlock);
284 mtx_assert(&g_eventlock, MA_OWNED);
287 mtx_unlock(&g_eventlock);
292 msleep(&g_wait_event, &g_eventlock, PRIBIO | PDROP,
300 g_cancel_event(void *ref)
302 struct g_event *ep, *epn;
303 struct g_provider *pp;
306 mtx_lock(&g_eventlock);
307 TAILQ_FOREACH(pp, &g_doorstep, orphan) {
310 TAILQ_REMOVE(&g_doorstep, pp, orphan);
313 TAILQ_FOREACH_SAFE(ep, &g_events, events, epn) {
314 if (ep->flag & EV_INPROGRESS)
316 for (n = 0; n < G_N_EVENTREFS; n++) {
317 if (ep->ref[n] == NULL)
319 if (ep->ref[n] != ref)
321 TSRELEASE("GEOM events");
322 TAILQ_REMOVE(&g_events, ep, events);
323 ep->func(ep->arg, EV_CANCEL);
324 mtx_assert(&g_eventlock, MA_OWNED);
325 if (ep->flag & EV_WAKEUP) {
326 ep->flag |= (EV_DONE|EV_CANCELED);
334 if (TAILQ_EMPTY(&g_events))
335 wakeup(&g_pending_events);
336 mtx_unlock(&g_eventlock);
340 g_alloc_event(int flag)
342 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
343 ("Wrong flag to g_alloc_event"));
345 return (g_malloc(sizeof(struct g_event), flag | M_ZERO));
349 g_post_event_ep_va(g_event_t *func, void *arg, int wuflag,
350 struct g_event *ep, va_list ap)
356 for (n = 0; n < G_N_EVENTREFS; n++) {
357 p = va_arg(ap, void *);
360 g_trace(G_T_TOPOLOGY, " ref %p", p);
363 KASSERT(p == NULL, ("Too many references to event"));
366 mtx_lock(&g_eventlock);
367 TSHOLD("GEOM events");
368 TAILQ_INSERT_TAIL(&g_events, ep, events);
369 mtx_unlock(&g_eventlock);
370 wakeup(&g_wait_event);
371 curthread->td_pflags |= TDP_GEOM;
372 ast_sched(curthread, TDA_GEOM);
376 g_post_event_ep(g_event_t *func, void *arg, struct g_event *ep, ...)
381 g_post_event_ep_va(func, arg, 0, ep, ap);
387 g_post_event_x(g_event_t *func, void *arg, int flag, int wuflag, struct g_event **epp, va_list ap)
391 g_trace(G_T_TOPOLOGY, "g_post_event_x(%p, %p, %d, %d)",
392 func, arg, flag, wuflag);
393 KASSERT(wuflag == 0 || wuflag == EV_WAKEUP,
394 ("Wrong wuflag in g_post_event_x(0x%x)", wuflag));
395 ep = g_alloc_event(flag);
400 g_post_event_ep_va(func, arg, wuflag, ep, ap);
405 g_post_event(g_event_t *func, void *arg, int flag, ...)
410 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
411 ("Wrong flag to g_post_event"));
413 i = g_post_event_x(func, arg, flag, 0, NULL, ap);
422 mtx_lock(&g_eventlock);
424 mtx_unlock(&g_eventlock);
425 wakeup(&g_wait_event);
429 * XXX: It might actually be useful to call this function with topology held.
430 * XXX: This would ensure that the event gets created before anything else
431 * XXX: changes. At present all users have a handle on things in some other
432 * XXX: way, so this remains an XXX for now.
436 g_waitfor_event(g_event_t *func, void *arg, int flag, ...)
442 g_topology_assert_not();
443 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
444 ("Wrong flag to g_post_event"));
446 error = g_post_event_x(func, arg, flag, EV_WAKEUP, &ep, ap);
451 mtx_lock(&g_eventlock);
452 while (!(ep->flag & EV_DONE))
453 msleep(ep, &g_eventlock, PRIBIO, "g_waitfor_event", 0);
454 if (ep->flag & EV_CANCELED)
456 mtx_unlock(&g_eventlock);
466 mtx_init(&g_eventlock, "GEOM orphanage", NULL, MTX_DEF);