geom_event.c revision 93774
1/*- 2 * Copyright (c) 2002 Poul-Henning Kamp 3 * Copyright (c) 2002 Networks Associates Technology, Inc. 4 * All rights reserved. 5 * 6 * This software was developed for the FreeBSD Project by Poul-Henning Kamp 7 * and NAI Labs, the Security Research Division of Network Associates, Inc. 8 * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the 9 * DARPA CHATS research program. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. The names of the authors may not be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * $FreeBSD: head/sys/geom/geom_event.c 93774 2002-04-04 09:41:47Z phk $ 36 */ 37 38/* 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 ? 41 */ 42 43#include <sys/param.h> 44#ifndef _KERNEL 45#include <stdio.h> 46#include <unistd.h> 47#include <string.h> 48#include <stdlib.h> 49#include <signal.h> 50#include <err.h> 51#else 52#include <sys/malloc.h> 53#include <sys/systm.h> 54#include <sys/kernel.h> 55#include <sys/lock.h> 56#include <sys/mutex.h> 57#endif 58#include <sys/errno.h> 59#include <sys/time.h> 60#include <geom/geom.h> 61#include <geom/geom_int.h> 62 63static struct event_tailq_head g_events = TAILQ_HEAD_INITIALIZER(g_events); 64static u_int g_pending_events, g_silence_events; 65static void g_do_event(struct g_event *ep); 66static TAILQ_HEAD(,g_provider) g_doorstep = TAILQ_HEAD_INITIALIZER(g_doorstep); 67static struct mtx g_doorlock; 68 69void 70g_silence(void) 71{ 72 73 g_silence_events = 1; 74} 75 76void 77g_rattle(void) 78{ 79 80 g_silence_events = 0; 81 mtx_lock(&Giant); 82 wakeup(&g_silence_events); 83 while (g_pending_events) 84 tsleep(&g_pending_events, PPAUSE, "g_rattle", hz/5); 85 mtx_unlock(&Giant); 86} 87 88void 89g_orphan_provider(struct g_provider *pp, int error) 90{ 91 92 g_trace(G_T_TOPOLOGY, "g_orphan_provider(%p(%s), %d)", 93 pp, pp->name, error); 94 KASSERT(error != 0, 95 ("g_orphan_provider(%p(%s), 0) error must be non-zero\n", 96 pp, pp->name)); 97 pp->error = error; 98 mtx_lock(&g_doorlock); 99 TAILQ_INSERT_TAIL(&g_doorstep, pp, orphan); 100 mtx_unlock(&g_doorlock); 101 mtx_lock(&Giant); 102 wakeup(&g_wait_event); 103 mtx_unlock(&Giant); 104} 105 106/* 107 * This function is called once on each provider which the event handler 108 * finds on its g_doorstep. 109 */ 110 111static void 112g_orphan_register(struct g_provider *pp) 113{ 114 struct g_consumer *cp, *cp2; 115 116 g_trace(G_T_TOPOLOGY, "g_orphan_register(%s)", pp->name); 117 g_topology_assert(); 118 119 /* 120 * Tell all consumers the bad news. 121 * Don't get surprised if they self-destruct. 122 */ 123 cp = LIST_FIRST(&pp->consumers); 124 while (cp != NULL) { 125 cp2 = LIST_NEXT(cp, consumers); 126 KASSERT(cp->geom->class->orphan != NULL, 127 ("class %s has no orphan, geom %s", 128 cp->geom->class->name, cp->geom->name)); 129 cp->geom->class->orphan(cp); 130 cp = cp2; 131 } 132} 133 134static void 135g_destroy_event(struct g_event *ep) 136{ 137 138 g_free(ep); 139} 140 141static void 142g_do_event(struct g_event *ep) 143{ 144 struct g_class *mp, *mp2; 145 struct g_geom *gp; 146 struct g_consumer *cp, *cp2; 147 struct g_provider *pp; 148 int i; 149 150 g_trace(G_T_TOPOLOGY, "g_do_event(%p) %d m:%p g:%p p:%p c:%p - ", 151 ep, ep->event, ep->class, ep->geom, ep->provider, ep->consumer); 152 g_topology_assert(); 153 switch (ep->event) { 154 case EV_NEW_CLASS: 155 mp2 = ep->class; 156 if (mp2->taste == NULL) 157 break; 158 LIST_FOREACH(mp, &g_classes, class) { 159 if (mp2 == mp) 160 continue; 161 LIST_FOREACH(gp, &mp->geom, geom) { 162 LIST_FOREACH(pp, &gp->provider, provider) { 163 mp2->taste(ep->class, pp, 0); 164 g_topology_assert(); 165 } 166 } 167 } 168 break; 169 case EV_NEW_PROVIDER: 170 g_trace(G_T_TOPOLOGY, "EV_NEW_PROVIDER(%s)", 171 ep->provider->name); 172 LIST_FOREACH(mp, &g_classes, class) { 173 if (mp->taste == NULL) 174 continue; 175 i = 1; 176 LIST_FOREACH(cp, &ep->provider->consumers, consumers) 177 if(cp->geom->class == mp) 178 i = 0; 179 if (i) { 180 mp->taste(mp, ep->provider, 0); 181 g_topology_assert(); 182 } 183 } 184 break; 185 case EV_SPOILED: 186 g_trace(G_T_TOPOLOGY, "EV_SPOILED(%p(%s),%p)", 187 ep->provider, ep->provider->name, ep->consumer); 188 cp = LIST_FIRST(&ep->provider->consumers); 189 while (cp != NULL) { 190 cp2 = LIST_NEXT(cp, consumers); 191 if (cp->spoiled) { 192 g_trace(G_T_TOPOLOGY, "spoiling %p (%s) (%p)", 193 cp, cp->geom->name, cp->geom->spoiled); 194 if (cp->geom->spoiled != NULL) 195 cp->geom->spoiled(cp); 196 cp->spoiled = 0; 197 } 198 cp = cp2; 199 } 200 break; 201 case EV_LAST: 202 default: 203 KASSERT(1 == 0, ("Unknown event %d", ep->event)); 204 } 205} 206 207static int 208one_event(void) 209{ 210 struct g_event *ep; 211 struct g_provider *pp; 212 213 g_topology_lock(); 214 for (;;) { 215 mtx_lock(&g_doorlock); 216 pp = TAILQ_FIRST(&g_doorstep); 217 if (pp != NULL) 218 TAILQ_REMOVE(&g_doorstep, pp, orphan); 219 mtx_unlock(&g_doorlock); 220 if (pp == NULL) 221 break; 222 g_orphan_register(pp); 223 } 224 ep = TAILQ_FIRST(&g_events); 225 if (ep == NULL) { 226 g_topology_unlock(); 227 return (0); 228 } 229 TAILQ_REMOVE(&g_events, ep, events); 230 if (ep->class != NULL) 231 ep->class->event = NULL; 232 if (ep->geom != NULL) 233 ep->geom->event = NULL; 234 if (ep->provider != NULL) 235 ep->provider->event = NULL; 236 if (ep->consumer != NULL) 237 ep->consumer->event = NULL; 238 g_do_event(ep); 239 g_pending_events--; 240 if (g_pending_events == 0) { 241 mtx_lock(&Giant); 242 wakeup(&g_pending_events); 243 mtx_unlock(&Giant); 244 } 245 g_topology_unlock(); 246 g_destroy_event(ep); 247 return (1); 248} 249 250void 251g_run_events() 252{ 253 254 while (one_event()) 255 ; 256} 257 258void 259g_post_event(enum g_events ev, struct g_class *mp, struct g_geom *gp, struct g_provider *pp, struct g_consumer *cp) 260{ 261 struct g_event *ep; 262 263 g_trace(G_T_TOPOLOGY, "g_post_event(%d, %p, %p, %p, %p)", 264 ev, mp, gp, pp, cp); 265 g_topology_assert(); 266 ep = g_malloc(sizeof *ep, M_WAITOK | M_ZERO); 267 ep->event = ev; 268 if (mp != NULL) { 269 ep->class = mp; 270 KASSERT(mp->event == NULL, ("Double event on class")); 271 mp->event = ep; 272 } 273 if (gp != NULL) { 274 ep->geom = gp; 275 KASSERT(gp->event == NULL, ("Double event on geom")); 276 gp->event = ep; 277 } 278 if (pp != NULL) { 279 ep->provider = pp; 280 KASSERT(pp->event == NULL, ("Double event on provider")); 281 pp->event = ep; 282 } 283 if (cp != NULL) { 284 ep->consumer = cp; 285 KASSERT(cp->event == NULL, ("Double event on consumer")); 286 cp->event = ep; 287 } 288 g_pending_events++; 289 TAILQ_INSERT_TAIL(&g_events, ep, events); 290 mtx_lock(&Giant); 291 wakeup(&g_wait_event); 292 mtx_unlock(&Giant); 293} 294 295void 296g_event_init() 297{ 298 299 mtx_init(&g_doorlock, "GEOM orphanage", MTX_DEF); 300} 301