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/param.h>
44 #include <sys/malloc.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
48 #include <sys/mutex.h>
50 #include <sys/errno.h>
52 #include <geom/geom.h>
53 #include <geom/geom_int.h>
55 #include <machine/stdarg.h>
57 TAILQ_HEAD(event_tailq_head, g_event);
59 static struct event_tailq_head g_events = TAILQ_HEAD_INITIALIZER(g_events);
60 static u_int g_pending_events;
61 static TAILQ_HEAD(,g_provider) g_doorstep = TAILQ_HEAD_INITIALIZER(g_doorstep);
62 static struct mtx g_eventlock;
63 static int g_wither_work;
65 #define G_N_EVENTREFS 20
68 TAILQ_ENTRY(g_event) events;
72 void *ref[G_N_EVENTREFS];
75 #define EV_DONE 0x80000
76 #define EV_WAKEUP 0x40000
77 #define EV_CANCELED 0x20000
78 #define EV_INPROGRESS 0x10000
81 g_waitidle(struct thread *td)
84 g_topology_assert_not();
86 mtx_lock(&g_eventlock);
87 TSWAIT("GEOM events");
88 while (!TAILQ_EMPTY(&g_events))
89 msleep(&g_pending_events, &g_eventlock, PPAUSE,
91 TSUNWAIT("GEOM events");
92 mtx_unlock(&g_eventlock);
93 td->td_pflags &= ~TDP_GEOM;
97 ast_geom(struct thread *td, int tda __unused)
100 * If this thread tickled GEOM, we need to wait for the giggling to
101 * stop before we return to userland.
107 geom_event_init(void *arg __unused)
109 ast_register(TDA_GEOM, ASTR_ASTF_REQUIRED | ASTR_TDP | ASTR_KCLEAR,
112 SYSINIT(geom_event, SI_SUB_INTRINSIC, SI_ORDER_ANY, geom_event_init, NULL);
114 struct g_attrchanged_args {
115 struct g_provider *pp;
120 g_attr_changed_event(void *arg, int flag)
122 struct g_attrchanged_args *args;
123 struct g_provider *pp;
124 struct g_consumer *cp;
125 struct g_consumer *next_cp;
131 if (flag != EV_CANCEL && g_shutdown == 0) {
133 * Tell all consumers of the change.
135 LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, next_cp) {
136 if (cp->geom->attrchanged != NULL)
137 cp->geom->attrchanged(cp, args->attr);
144 g_attr_changed(struct g_provider *pp, const char *attr, int flag)
146 struct g_attrchanged_args *args;
149 args = g_malloc(sizeof *args, flag);
154 error = g_post_event(g_attr_changed_event, args, flag, pp, NULL);
161 g_orphan_provider(struct g_provider *pp, int error)
164 /* G_VALID_PROVIDER(pp) We likely lack topology lock */
165 g_trace(G_T_TOPOLOGY, "g_orphan_provider(%p(%s), %d)",
166 pp, pp->name, error);
168 ("g_orphan_provider(%p(%s), 0) error must be non-zero\n",
172 mtx_lock(&g_eventlock);
173 KASSERT(!(pp->flags & G_PF_ORPHAN),
174 ("g_orphan_provider(%p(%s)), already an orphan", pp, pp->name));
175 pp->flags |= G_PF_ORPHAN;
176 TAILQ_INSERT_TAIL(&g_doorstep, pp, orphan);
177 mtx_unlock(&g_eventlock);
178 wakeup(&g_wait_event);
182 * This function is called once on each provider which the event handler
183 * finds on its g_doorstep.
187 g_orphan_register(struct g_provider *pp)
189 struct g_consumer *cp, *cp2;
193 G_VALID_PROVIDER(pp);
194 g_trace(G_T_TOPOLOGY, "g_orphan_register(%s)", pp->name);
198 wf = pp->flags & G_PF_WITHER;
199 pp->flags &= ~G_PF_WITHER;
202 * Tell all consumers the bad news.
203 * Don't be surprised if they self-destruct.
205 LIST_FOREACH_SAFE(cp, &pp->consumers, consumers, cp2) {
206 KASSERT(cp->geom->orphan != NULL,
207 ("geom %s has no orphan, class %s",
208 cp->geom->name, cp->geom->class->name));
210 * XXX: g_dev_orphan method does deferred destroying
211 * and it is possible, that other event could already
212 * call the orphan method. Check consumer's flags to
213 * do not schedule it twice.
215 if (cp->flags & G_CF_ORPHAN)
217 cp->flags |= G_CF_ORPHAN;
218 cp->geom->orphan(cp);
220 if (LIST_EMPTY(&pp->consumers) && wf)
221 g_destroy_provider(pp);
225 cp = LIST_FIRST(&pp->consumers);
228 if (pp->geom->flags & G_GEOM_WITHER)
229 g_destroy_provider(pp);
237 struct g_provider *pp;
240 mtx_lock(&g_eventlock);
241 pp = TAILQ_FIRST(&g_doorstep);
243 G_VALID_PROVIDER(pp);
244 TAILQ_REMOVE(&g_doorstep, pp, orphan);
245 mtx_unlock(&g_eventlock);
246 g_orphan_register(pp);
250 ep = TAILQ_FIRST(&g_events);
252 wakeup(&g_pending_events);
255 ep->flag |= EV_INPROGRESS;
256 mtx_unlock(&g_eventlock);
258 ep->func(ep->arg, 0);
260 mtx_lock(&g_eventlock);
261 TSRELEASE("GEOM events");
262 TAILQ_REMOVE(&g_events, ep, events);
263 ep->flag &= ~EV_INPROGRESS;
264 if (ep->flag & EV_WAKEUP) {
267 mtx_unlock(&g_eventlock);
269 mtx_unlock(&g_eventlock);
283 mtx_assert(&g_eventlock, MA_OWNED);
286 mtx_unlock(&g_eventlock);
291 msleep(&g_wait_event, &g_eventlock, PRIBIO | PDROP,
299 g_cancel_event(void *ref)
301 struct g_event *ep, *epn;
302 struct g_provider *pp;
305 mtx_lock(&g_eventlock);
306 TAILQ_FOREACH(pp, &g_doorstep, orphan) {
309 TAILQ_REMOVE(&g_doorstep, pp, orphan);
312 TAILQ_FOREACH_SAFE(ep, &g_events, events, epn) {
313 if (ep->flag & EV_INPROGRESS)
315 for (n = 0; n < G_N_EVENTREFS; n++) {
316 if (ep->ref[n] == NULL)
318 if (ep->ref[n] != ref)
320 TSRELEASE("GEOM events");
321 TAILQ_REMOVE(&g_events, ep, events);
322 ep->func(ep->arg, EV_CANCEL);
323 mtx_assert(&g_eventlock, MA_OWNED);
324 if (ep->flag & EV_WAKEUP) {
325 ep->flag |= (EV_DONE|EV_CANCELED);
333 if (TAILQ_EMPTY(&g_events))
334 wakeup(&g_pending_events);
335 mtx_unlock(&g_eventlock);
339 g_alloc_event(int flag)
341 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
342 ("Wrong flag to g_alloc_event"));
344 return (g_malloc(sizeof(struct g_event), flag | M_ZERO));
348 g_post_event_ep_va(g_event_t *func, void *arg, int wuflag,
349 struct g_event *ep, va_list ap)
355 for (n = 0; n < G_N_EVENTREFS; n++) {
356 p = va_arg(ap, void *);
359 g_trace(G_T_TOPOLOGY, " ref %p", p);
362 KASSERT(p == NULL, ("Too many references to event"));
365 mtx_lock(&g_eventlock);
366 TSHOLD("GEOM events");
367 TAILQ_INSERT_TAIL(&g_events, ep, events);
368 mtx_unlock(&g_eventlock);
369 wakeup(&g_wait_event);
370 curthread->td_pflags |= TDP_GEOM;
371 ast_sched(curthread, TDA_GEOM);
375 g_post_event_ep(g_event_t *func, void *arg, struct g_event *ep, ...)
380 g_post_event_ep_va(func, arg, 0, ep, ap);
386 g_post_event_x(g_event_t *func, void *arg, int flag, int wuflag, struct g_event **epp, va_list ap)
390 g_trace(G_T_TOPOLOGY, "g_post_event_x(%p, %p, %d, %d)",
391 func, arg, flag, wuflag);
392 KASSERT(wuflag == 0 || wuflag == EV_WAKEUP,
393 ("Wrong wuflag in g_post_event_x(0x%x)", wuflag));
394 ep = g_alloc_event(flag);
399 g_post_event_ep_va(func, arg, wuflag, ep, ap);
404 g_post_event(g_event_t *func, void *arg, int flag, ...)
409 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
410 ("Wrong flag to g_post_event"));
412 i = g_post_event_x(func, arg, flag, 0, NULL, ap);
421 mtx_lock(&g_eventlock);
423 mtx_unlock(&g_eventlock);
424 wakeup(&g_wait_event);
428 * XXX: It might actually be useful to call this function with topology held.
429 * XXX: This would ensure that the event gets created before anything else
430 * XXX: changes. At present all users have a handle on things in some other
431 * XXX: way, so this remains an XXX for now.
435 g_waitfor_event(g_event_t *func, void *arg, int flag, ...)
441 g_topology_assert_not();
442 KASSERT(flag == M_WAITOK || flag == M_NOWAIT,
443 ("Wrong flag to g_post_event"));
445 error = g_post_event_x(func, arg, flag, EV_WAKEUP, &ep, ap);
450 mtx_lock(&g_eventlock);
451 while (!(ep->flag & EV_DONE))
452 msleep(ep, &g_eventlock, PRIBIO, "g_waitfor_event", 0);
453 if (ep->flag & EV_CANCELED)
455 mtx_unlock(&g_eventlock);
465 mtx_init(&g_eventlock, "GEOM orphanage", NULL, MTX_DEF);