xref: /illumos-gate/usr/src/cmd/fm/fmd/common/fmd_case.c (revision 6d1d45ee7157107ef92303ea769d6d3fcf5dfcc8)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*
30  * FMD Case Subsystem
31  *
32  * Diagnosis engines are expected to group telemetry events related to the
33  * diagnosis of a particular problem on the system into a set of cases.  The
34  * diagnosis engine may have any number of cases open at a given point in time.
35  * Some cases may eventually be *solved* by associating a suspect list of one
36  * or more problems with the case, at which point fmd publishes a list.suspect
37  * event for the case and it becomes visible to administrators and agents.
38  *
39  * Every case is named using a UUID, and is globally visible in the case hash.
40  * Cases are reference-counted, except for the reference from the case hash
41  * itself.  Consumers of case references include modules, which store active
42  * cases on the mod_cases list, ASRUs in the resource cache, and the RPC code.
43  *
44  * Cases obey the following state machine.  In states UNSOLVED, SOLVED, and
45  * CLOSE_WAIT, a case's module refers to the owning module (a diagnosis engine
46  * or transport) and the case is referenced by the mod_cases list.  Once the
47  * case reaches the CLOSED or REPAIRED states, a case's module changes to refer
48  * to the root module (fmd.d_rmod) and is deleted from the owner's mod_cases.
49  *
50  *			+------------+
51  *	     +----------|  UNSOLVED  |
52  *	     |		+------------+
53  *	   1 |	             4 |
54  *           |                 |
55  *	+----v---+ /-2->+------v-----+	  3	+--------+
56  *      | SOLVED |<     | CLOSE_WAIT |--------->| CLOSED |
57  *	+--------+ \-5->+------------+		+--------+
58  *	                       |                    |
59  *                           6 |                    | 7
60  *      		+------v-----+              |
61  *	                |  REPAIRED  |<-------------+
62  *			+------------+
63  *
64  * The state machine changes are triggered by calls to fmd_case_transition()
65  * from various locations inside of fmd, as described below:
66  *
67  * [1] Called by: fmd_case_solve()
68  *       Actions: FMD_CF_SOLVED flag is set in ci_flags
69  *                conviction policy is applied to suspect list
70  *                suspects convicted are marked faulty (F) in R$
71  *                list.suspect event logged and dispatched
72  *
73  * [2] Called by: fmd_case_close(), fmd_case_uuclose(), fmd_xprt_event_uuclose()
74  *       Actions: FMD_CF_ISOLATED flag is set in ci_flags
75  *                suspects convicted (F) are marked unusable (U) in R$
76  *                diagnosis engine fmdo_close() entry point scheduled
77  *                case transitions to CLOSED [3] upon exit from CLOSE_WAIT
78  *
79  * [3] Called by: fmd_case_delete() (after fmdo_close() entry point returns)
80  *       Actions: list.isolated event dispatched
81  *                case deleted from module's list of open cases
82  *
83  * [4] Called by: fmd_case_close(), fmd_case_uuclose()
84  *       Actions: diagnosis engine fmdo_close() entry point scheduled
85  *                case is subsequently discarded by fmd_case_delete()
86  *
87  * [5] Called by: fmd_case_repair(), fmd_case_update()
88  *       Actions: FMD_CF_REPAIR flag is set in ci_flags
89  *                diagnosis engine fmdo_close() entry point scheduled
90  *                case transitions to REPAIRED [6] upon exit from CLOSE_WAIT
91  *
92  * [6] Called by: fmd_case_repair(), fmd_case_update()
93  *       Actions: FMD_CF_REPAIR flag is set in ci_flags
94  *                suspects convicted are marked non faulty (!F) in R$
95  *                list.repaired event dispatched
96  *
97  * [7] Called by: fmd_case_repair(), fmd_case_update()
98  *       Actions: FMD_CF_REPAIR flag is set in ci_flags
99  *                suspects convicted are marked non faulty (!F) in R$
100  *                list.repaired event dispatched
101  */
102 
103 #include <sys/fm/protocol.h>
104 #include <uuid/uuid.h>
105 #include <alloca.h>
106 
107 #include <fmd_alloc.h>
108 #include <fmd_module.h>
109 #include <fmd_error.h>
110 #include <fmd_conf.h>
111 #include <fmd_case.h>
112 #include <fmd_string.h>
113 #include <fmd_subr.h>
114 #include <fmd_protocol.h>
115 #include <fmd_event.h>
116 #include <fmd_eventq.h>
117 #include <fmd_dispq.h>
118 #include <fmd_buf.h>
119 #include <fmd_log.h>
120 #include <fmd_asru.h>
121 #include <fmd_fmri.h>
122 #include <fmd_xprt.h>
123 
124 #include <fmd.h>
125 
126 static const char *const _fmd_case_snames[] = {
127 	"UNSOLVED",	/* FMD_CASE_UNSOLVED */
128 	"SOLVED",	/* FMD_CASE_SOLVED */
129 	"CLOSE_WAIT",	/* FMD_CASE_CLOSE_WAIT */
130 	"CLOSED",	/* FMD_CASE_CLOSED */
131 	"REPAIRED"	/* FMD_CASE_REPAIRED */
132 };
133 
134 extern volatile uint32_t fmd_asru_fake_not_present;
135 
136 static fmd_case_impl_t *fmd_case_tryhold(fmd_case_impl_t *);
137 
138 fmd_case_hash_t *
139 fmd_case_hash_create(void)
140 {
141 	fmd_case_hash_t *chp = fmd_alloc(sizeof (fmd_case_hash_t), FMD_SLEEP);
142 
143 	(void) pthread_rwlock_init(&chp->ch_lock, NULL);
144 	chp->ch_hashlen = fmd.d_str_buckets;
145 	chp->ch_hash = fmd_zalloc(sizeof (void *) * chp->ch_hashlen, FMD_SLEEP);
146 	chp->ch_count = 0;
147 
148 	return (chp);
149 }
150 
151 /*
152  * Destroy the case hash.  Unlike most of our hash tables, no active references
153  * are kept by the case hash itself; all references come from other subsystems.
154  * The hash must be destroyed after all modules are unloaded; if anything was
155  * present in the hash it would be by definition a reference count leak.
156  */
157 void
158 fmd_case_hash_destroy(fmd_case_hash_t *chp)
159 {
160 	fmd_free(chp->ch_hash, sizeof (void *) * chp->ch_hashlen);
161 	fmd_free(chp, sizeof (fmd_case_hash_t));
162 }
163 
164 /*
165  * Take a snapshot of the case hash by placing an additional hold on each
166  * member in an auxiliary array, and then call 'func' for each case.
167  */
168 void
169 fmd_case_hash_apply(fmd_case_hash_t *chp,
170     void (*func)(fmd_case_t *, void *), void *arg)
171 {
172 	fmd_case_impl_t *cp, **cps, **cpp;
173 	uint_t cpc, i;
174 
175 	(void) pthread_rwlock_rdlock(&chp->ch_lock);
176 
177 	cps = cpp = fmd_alloc(chp->ch_count * sizeof (fmd_case_t *), FMD_SLEEP);
178 	cpc = chp->ch_count;
179 
180 	for (i = 0; i < chp->ch_hashlen; i++) {
181 		for (cp = chp->ch_hash[i]; cp != NULL; cp = cp->ci_next) {
182 			fmd_case_hold((fmd_case_t *)cp);
183 			*cpp++ = cp;
184 		}
185 	}
186 
187 	ASSERT(cpp == cps + cpc);
188 	(void) pthread_rwlock_unlock(&chp->ch_lock);
189 
190 	for (i = 0; i < cpc; i++) {
191 		func((fmd_case_t *)cps[i], arg);
192 		fmd_case_rele((fmd_case_t *)cps[i]);
193 	}
194 
195 	fmd_free(cps, cpc * sizeof (fmd_case_t *));
196 }
197 
198 /*
199  * Look up the diagcode for this case and cache it in ci_code.  If no suspects
200  * were defined for this case or if the lookup fails, the event dictionary or
201  * module code is broken, and we set the event code to a precomputed default.
202  */
203 static const char *
204 fmd_case_mkcode(fmd_case_t *cp)
205 {
206 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
207 	fmd_case_susp_t *cis;
208 
209 	char **keys, **keyp;
210 	const char *s;
211 
212 	ASSERT(MUTEX_HELD(&cip->ci_lock));
213 	ASSERT(cip->ci_state >= FMD_CASE_SOLVED);
214 
215 	fmd_free(cip->ci_code, cip->ci_codelen);
216 	cip->ci_codelen = cip->ci_mod->mod_codelen;
217 	cip->ci_code = fmd_zalloc(cip->ci_codelen, FMD_SLEEP);
218 	keys = keyp = alloca(sizeof (char *) * (cip->ci_nsuspects + 1));
219 
220 	for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
221 		if (nvlist_lookup_string(cis->cis_nvl, FM_CLASS, keyp) == 0)
222 			keyp++;
223 	}
224 
225 	*keyp = NULL; /* mark end of keys[] array for libdiagcode */
226 
227 	if (cip->ci_nsuspects == 0 || fmd_module_dc_key2code(
228 	    cip->ci_mod, keys, cip->ci_code, cip->ci_codelen) != 0) {
229 		(void) fmd_conf_getprop(fmd.d_conf, "nodiagcode", &s);
230 		fmd_free(cip->ci_code, cip->ci_codelen);
231 		cip->ci_codelen = strlen(s) + 1;
232 		cip->ci_code = fmd_zalloc(cip->ci_codelen, FMD_SLEEP);
233 		(void) strcpy(cip->ci_code, s);
234 	}
235 
236 	return (cip->ci_code);
237 }
238 
239 nvlist_t *
240 fmd_case_mkevent(fmd_case_t *cp, const char *class)
241 {
242 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
243 	fmd_case_susp_t *cis;
244 
245 	fmd_asru_hash_t *ahp = fmd.d_asrus;
246 	fmd_asru_t *asru;
247 
248 	nvlist_t **nva, **nvp, *nvl, *fmri;
249 	uint8_t *ba, *bp;
250 
251 	int msg = B_TRUE;
252 	boolean_t b;
253 
254 	(void) pthread_mutex_lock(&cip->ci_lock);
255 	ASSERT(cip->ci_state >= FMD_CASE_SOLVED);
256 
257 	nva = nvp = alloca(sizeof (nvlist_t *) * cip->ci_nsuspects);
258 	ba = bp = alloca(sizeof (uint8_t) * cip->ci_nsuspects);
259 
260 	/*
261 	 * For each suspect associated with the case, store its fault event
262 	 * nvlist in 'nva'.  We also look to see if any of the suspect faults
263 	 * have asked not to be messaged.  If any of them have made such a
264 	 * request, propagate that attribute to the composite list.* event.
265 	 * Finally, store each suspect's faulty status into the bitmap 'ba'.
266 	 */
267 	for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
268 		if (nvlist_lookup_boolean_value(cis->cis_nvl,
269 		    FM_SUSPECT_MESSAGE, &b) == 0 && b == B_FALSE)
270 			msg = B_FALSE;
271 
272 		if (nvlist_lookup_nvlist(cis->cis_nvl,
273 		    FM_FAULT_ASRU, &fmri) == 0 && (asru =
274 		    fmd_asru_hash_lookup_nvl(ahp, fmri, FMD_B_FALSE)) != NULL) {
275 			*bp = 0;
276 			if (fmd_asru_fake_not_present ||
277 			    !fmd_fmri_present(asru->asru_fmri))
278 				*bp |= FM_SUSPECT_NOT_PRESENT;
279 			if (fmd_asru_fake_not_present ||
280 			    fmd_fmri_unusable(asru->asru_fmri))
281 				*bp |= FM_SUSPECT_UNUSABLE;
282 			if (asru->asru_flags & FMD_ASRU_FAULTY)
283 				*bp |= FM_SUSPECT_FAULTY;
284 			bp++;
285 			fmd_asru_hash_release(ahp, asru);
286 		} else
287 			*bp++ = 0;
288 
289 		*nvp++ = cis->cis_nvl;
290 	}
291 
292 	if (cip->ci_code == NULL)
293 		(void) fmd_case_mkcode(cp);
294 
295 	if (msg == B_FALSE)
296 		cip->ci_flags |= FMD_CF_INVISIBLE;
297 
298 	nvl = fmd_protocol_list(class, cip->ci_mod->mod_fmri, cip->ci_uuid,
299 	    cip->ci_code, cip->ci_nsuspects, nva, ba, msg, &cip->ci_tv);
300 
301 	(void) pthread_mutex_unlock(&cip->ci_lock);
302 	return (nvl);
303 }
304 
305 /*
306  * Convict suspects in a case by applying a conviction policy and updating the
307  * resource cache prior to emitting the list.suspect event for the given case.
308  * At present, our policy is very simple: convict every suspect in the case.
309  * In the future, this policy can be extended and made configurable to permit:
310  *
311  * - convicting the suspect with the highest FIT rate
312  * - convicting the suspect with the cheapest FRU
313  * - convicting the suspect with the FRU that is in a depot's inventory
314  * - convicting the suspect with the longest lifetime
315  *
316  * and so forth.  A word to the wise: this problem is significantly harder that
317  * it seems at first glance.  Future work should heed the following advice:
318  *
319  * Hacking the policy into C code here is a very bad idea.  The policy needs to
320  * be decided upon very carefully and fundamentally encodes knowledge of what
321  * suspect list combinations can be emitted by what diagnosis engines.  As such
322  * fmd's code is the wrong location, because that would require fmd itself to
323  * be updated for every diagnosis engine change, defeating the entire design.
324  * The FMA Event Registry knows the suspect list combinations: policy inputs
325  * can be derived from it and used to produce per-module policy configuration.
326  *
327  * If the policy needs to be dynamic and not statically fixed at either fmd
328  * startup or module load time, any implementation of dynamic policy retrieval
329  * must employ some kind of caching mechanism or be part of a built-in module.
330  * The fmd_case_convict() function is called with locks held inside of fmd and
331  * is not a place where unbounded blocking on some inter-process or inter-
332  * system communication to another service (e.g. another daemon) can occur.
333  */
334 static void
335 fmd_case_convict(fmd_case_t *cp)
336 {
337 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
338 	fmd_asru_hash_t *ahp = fmd.d_asrus;
339 
340 	fmd_case_susp_t *cis;
341 	fmd_asru_t *asru;
342 	nvlist_t *fmri;
343 
344 	(void) pthread_mutex_lock(&cip->ci_lock);
345 	(void) fmd_case_mkcode(cp);
346 
347 	for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
348 		if (nvlist_lookup_nvlist(cis->cis_nvl, FM_FAULT_ASRU, &fmri))
349 			continue; /* no ASRU provided by diagnosis engine */
350 
351 		if ((asru = fmd_asru_hash_lookup_nvl(ahp,
352 		    fmri, FMD_B_TRUE)) == NULL) {
353 			fmd_error(EFMD_CASE_EVENT, "cannot convict suspect in "
354 			    "%s: %s\n", cip->ci_uuid, fmd_strerror(errno));
355 			continue;
356 		}
357 
358 		(void) fmd_asru_clrflags(asru,
359 		    FMD_ASRU_UNUSABLE, cp, cis->cis_nvl);
360 		(void) fmd_asru_setflags(asru,
361 		    FMD_ASRU_FAULTY, cp, cis->cis_nvl);
362 
363 		fmd_asru_hash_release(ahp, asru);
364 	}
365 
366 	(void) pthread_mutex_unlock(&cip->ci_lock);
367 }
368 
369 void
370 fmd_case_publish(fmd_case_t *cp, uint_t state)
371 {
372 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
373 	fmd_event_t *e;
374 	nvlist_t *nvl;
375 	char *class;
376 
377 	if (state == FMD_CASE_CURRENT)
378 		state = cip->ci_state; /* use current state */
379 
380 	switch (state) {
381 	case FMD_CASE_SOLVED:
382 		(void) pthread_mutex_lock(&cip->ci_lock);
383 		if (cip->ci_tv_valid == 0) {
384 			fmd_time_gettimeofday(&cip->ci_tv);
385 			cip->ci_tv_valid = 1;
386 		}
387 		(void) pthread_mutex_unlock(&cip->ci_lock);
388 		fmd_case_convict(cp);
389 		nvl = fmd_case_mkevent(cp, FM_LIST_SUSPECT_CLASS);
390 		(void) nvlist_lookup_string(nvl, FM_CLASS, &class);
391 
392 		e = fmd_event_create(FMD_EVT_PROTOCOL, FMD_HRT_NOW, nvl, class);
393 		(void) pthread_rwlock_rdlock(&fmd.d_log_lock);
394 		fmd_log_append(fmd.d_fltlog, e, cp);
395 		(void) pthread_rwlock_unlock(&fmd.d_log_lock);
396 		fmd_dispq_dispatch(fmd.d_disp, e, class);
397 
398 		(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
399 		cip->ci_mod->mod_stats->ms_casesolved.fmds_value.ui64++;
400 		(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
401 
402 		break;
403 
404 	case FMD_CASE_CLOSE_WAIT:
405 		fmd_case_hold(cp);
406 		e = fmd_event_create(FMD_EVT_CLOSE, FMD_HRT_NOW, NULL, cp);
407 		fmd_eventq_insert_at_head(cip->ci_mod->mod_queue, e);
408 
409 		(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
410 		cip->ci_mod->mod_stats->ms_caseclosed.fmds_value.ui64++;
411 		(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
412 
413 		break;
414 
415 	case FMD_CASE_CLOSED:
416 		nvl = fmd_case_mkevent(cp, FM_LIST_ISOLATED_CLASS);
417 		(void) nvlist_lookup_string(nvl, FM_CLASS, &class);
418 		e = fmd_event_create(FMD_EVT_PROTOCOL, FMD_HRT_NOW, nvl, class);
419 		fmd_dispq_dispatch(fmd.d_disp, e, class);
420 		break;
421 
422 	case FMD_CASE_REPAIRED:
423 		nvl = fmd_case_mkevent(cp, FM_LIST_REPAIRED_CLASS);
424 		(void) nvlist_lookup_string(nvl, FM_CLASS, &class);
425 		e = fmd_event_create(FMD_EVT_PROTOCOL, FMD_HRT_NOW, nvl, class);
426 		fmd_dispq_dispatch(fmd.d_disp, e, class);
427 		break;
428 	}
429 }
430 
431 fmd_case_t *
432 fmd_case_hash_lookup(fmd_case_hash_t *chp, const char *uuid)
433 {
434 	fmd_case_impl_t *cip;
435 	uint_t h;
436 
437 	(void) pthread_rwlock_rdlock(&chp->ch_lock);
438 	h = fmd_strhash(uuid) % chp->ch_hashlen;
439 
440 	for (cip = chp->ch_hash[h]; cip != NULL; cip = cip->ci_next) {
441 		if (strcmp(cip->ci_uuid, uuid) == 0)
442 			break;
443 	}
444 
445 	/*
446 	 * If deleting bit is set, treat the case as if it doesn't exist.
447 	 */
448 	if (cip != NULL)
449 		cip = fmd_case_tryhold(cip);
450 
451 	if (cip == NULL)
452 		(void) fmd_set_errno(EFMD_CASE_INVAL);
453 
454 	(void) pthread_rwlock_unlock(&chp->ch_lock);
455 	return ((fmd_case_t *)cip);
456 }
457 
458 static fmd_case_impl_t *
459 fmd_case_hash_insert(fmd_case_hash_t *chp, fmd_case_impl_t *cip)
460 {
461 	fmd_case_impl_t *eip;
462 	uint_t h;
463 
464 	(void) pthread_rwlock_wrlock(&chp->ch_lock);
465 	h = fmd_strhash(cip->ci_uuid) % chp->ch_hashlen;
466 
467 	for (eip = chp->ch_hash[h]; eip != NULL; eip = eip->ci_next) {
468 		if (strcmp(cip->ci_uuid, eip->ci_uuid) == 0 &&
469 		    fmd_case_tryhold(eip) != NULL) {
470 			(void) pthread_rwlock_unlock(&chp->ch_lock);
471 			return (eip); /* uuid already present */
472 		}
473 	}
474 
475 	cip->ci_next = chp->ch_hash[h];
476 	chp->ch_hash[h] = cip;
477 
478 	chp->ch_count++;
479 	ASSERT(chp->ch_count != 0);
480 
481 	(void) pthread_rwlock_unlock(&chp->ch_lock);
482 	return (cip);
483 }
484 
485 static void
486 fmd_case_hash_delete(fmd_case_hash_t *chp, fmd_case_impl_t *cip)
487 {
488 	fmd_case_impl_t *cp, **pp;
489 	uint_t h;
490 
491 	ASSERT(MUTEX_HELD(&cip->ci_lock));
492 
493 	cip->ci_flags |= FMD_CF_DELETING;
494 	(void) pthread_mutex_unlock(&cip->ci_lock);
495 
496 	(void) pthread_rwlock_wrlock(&chp->ch_lock);
497 
498 	h = fmd_strhash(cip->ci_uuid) % chp->ch_hashlen;
499 	pp = &chp->ch_hash[h];
500 
501 	for (cp = *pp; cp != NULL; cp = cp->ci_next) {
502 		if (cp != cip)
503 			pp = &cp->ci_next;
504 		else
505 			break;
506 	}
507 
508 	if (cp == NULL) {
509 		fmd_panic("case %p (%s) not found on hash chain %u\n",
510 		    (void *)cip, cip->ci_uuid, h);
511 	}
512 
513 	*pp = cp->ci_next;
514 	cp->ci_next = NULL;
515 
516 	ASSERT(chp->ch_count != 0);
517 	chp->ch_count--;
518 
519 	(void) pthread_rwlock_unlock(&chp->ch_lock);
520 
521 	(void) pthread_mutex_lock(&cip->ci_lock);
522 	ASSERT(cip->ci_flags & FMD_CF_DELETING);
523 }
524 
525 fmd_case_t *
526 fmd_case_create(fmd_module_t *mp, void *data)
527 {
528 	fmd_case_impl_t *cip = fmd_zalloc(sizeof (fmd_case_impl_t), FMD_SLEEP);
529 	fmd_case_impl_t *eip = NULL;
530 	uuid_t uuid;
531 
532 	(void) pthread_mutex_init(&cip->ci_lock, NULL);
533 	fmd_buf_hash_create(&cip->ci_bufs);
534 
535 	fmd_module_hold(mp);
536 	cip->ci_mod = mp;
537 	cip->ci_refs = 1;
538 	cip->ci_state = FMD_CASE_UNSOLVED;
539 	cip->ci_flags = FMD_CF_DIRTY;
540 	cip->ci_data = data;
541 
542 	/*
543 	 * Calling libuuid: get a clue.  The library interfaces cleverly do not
544 	 * define any constant for the length of an unparse string, and do not
545 	 * permit the caller to specify a buffer length for safety.  The spec
546 	 * says it will be 36 bytes, but we make it tunable just in case.
547 	 */
548 	(void) fmd_conf_getprop(fmd.d_conf, "uuidlen", &cip->ci_uuidlen);
549 	cip->ci_uuid = fmd_zalloc(cip->ci_uuidlen + 1, FMD_SLEEP);
550 
551 	/*
552 	 * We expect this loop to execute only once, but code it defensively
553 	 * against the possibility of libuuid bugs.  Keep generating uuids and
554 	 * attempting to do a hash insert until we get a unique one.
555 	 */
556 	do {
557 		if (eip != NULL)
558 			fmd_case_rele((fmd_case_t *)eip);
559 		uuid_generate(uuid);
560 		uuid_unparse(uuid, cip->ci_uuid);
561 	} while ((eip = fmd_case_hash_insert(fmd.d_cases, cip)) != cip);
562 
563 	ASSERT(fmd_module_locked(mp));
564 	fmd_list_append(&mp->mod_cases, cip);
565 	fmd_module_setcdirty(mp);
566 
567 	(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
568 	cip->ci_mod->mod_stats->ms_caseopen.fmds_value.ui64++;
569 	(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
570 
571 	return ((fmd_case_t *)cip);
572 }
573 
574 static void
575 fmd_case_destroy_suspects(fmd_case_impl_t *cip)
576 {
577 	fmd_case_susp_t *cis, *ncis;
578 
579 	ASSERT(MUTEX_HELD(&cip->ci_lock));
580 
581 	for (cis = cip->ci_suspects; cis != NULL; cis = ncis) {
582 		ncis = cis->cis_next;
583 		nvlist_free(cis->cis_nvl);
584 		fmd_free(cis, sizeof (fmd_case_susp_t));
585 	}
586 
587 	cip->ci_suspects = NULL;
588 	cip->ci_nsuspects = 0;
589 }
590 
591 fmd_case_t *
592 fmd_case_recreate(fmd_module_t *mp, fmd_xprt_t *xp,
593     uint_t state, const char *uuid, const char *code)
594 {
595 	fmd_case_impl_t *cip = fmd_zalloc(sizeof (fmd_case_impl_t), FMD_SLEEP);
596 	fmd_case_impl_t *eip;
597 
598 	ASSERT(state < FMD_CASE_REPAIRED);
599 
600 	(void) pthread_mutex_init(&cip->ci_lock, NULL);
601 	fmd_buf_hash_create(&cip->ci_bufs);
602 
603 	fmd_module_hold(mp);
604 	cip->ci_mod = mp;
605 	cip->ci_xprt = xp;
606 	cip->ci_refs = 1;
607 	cip->ci_state = state;
608 	cip->ci_uuid = fmd_strdup(uuid, FMD_SLEEP);
609 	cip->ci_uuidlen = strlen(cip->ci_uuid);
610 	cip->ci_code = fmd_strdup(code, FMD_SLEEP);
611 	cip->ci_codelen = cip->ci_code ? strlen(cip->ci_code) + 1 : 0;
612 
613 	if (state > FMD_CASE_CLOSE_WAIT)
614 		cip->ci_flags |= FMD_CF_SOLVED;
615 
616 	/*
617 	 * Insert the case into the global case hash.  If the specified UUID is
618 	 * already present, check to see if it is an orphan: if so, reclaim it;
619 	 * otherwise if it is owned by a different module then return NULL.
620 	 */
621 	if ((eip = fmd_case_hash_insert(fmd.d_cases, cip)) != cip) {
622 		(void) pthread_mutex_lock(&cip->ci_lock);
623 		cip->ci_refs--; /* decrement to zero */
624 		fmd_case_destroy((fmd_case_t *)cip, B_FALSE);
625 
626 		cip = eip; /* switch 'cip' to the existing case */
627 		(void) pthread_mutex_lock(&cip->ci_lock);
628 
629 		/*
630 		 * If the ASRU cache is trying to recreate an orphan, then just
631 		 * return the existing case that we found without changing it.
632 		 */
633 		if (mp == fmd.d_rmod) {
634 			(void) pthread_mutex_unlock(&cip->ci_lock);
635 			fmd_case_rele((fmd_case_t *)cip);
636 			return ((fmd_case_t *)cip);
637 		}
638 
639 		/*
640 		 * If the existing case isn't an orphan or is being proxied,
641 		 * then we have a UUID conflict: return failure to the caller.
642 		 */
643 		if (cip->ci_mod != fmd.d_rmod || xp != NULL) {
644 			(void) pthread_mutex_unlock(&cip->ci_lock);
645 			fmd_case_rele((fmd_case_t *)cip);
646 			return (NULL);
647 		}
648 
649 		/*
650 		 * If the new module is reclaiming an orphaned case, remove
651 		 * the case from the root module, switch ci_mod, and then fall
652 		 * through to adding the case to the new owner module 'mp'.
653 		 */
654 		fmd_module_lock(cip->ci_mod);
655 		fmd_list_delete(&cip->ci_mod->mod_cases, cip);
656 		fmd_module_unlock(cip->ci_mod);
657 
658 		fmd_module_rele(cip->ci_mod);
659 		cip->ci_mod = mp;
660 		fmd_module_hold(mp);
661 
662 		fmd_case_destroy_suspects(cip);
663 		cip->ci_state = state;
664 
665 		(void) pthread_mutex_unlock(&cip->ci_lock);
666 		fmd_case_rele((fmd_case_t *)cip);
667 	}
668 
669 	ASSERT(fmd_module_locked(mp));
670 	fmd_list_append(&mp->mod_cases, cip);
671 
672 	(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
673 	cip->ci_mod->mod_stats->ms_caseopen.fmds_value.ui64++;
674 	(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
675 
676 	return ((fmd_case_t *)cip);
677 }
678 
679 void
680 fmd_case_destroy(fmd_case_t *cp, int visible)
681 {
682 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
683 	fmd_case_item_t *cit, *ncit;
684 
685 	ASSERT(MUTEX_HELD(&cip->ci_lock));
686 	ASSERT(cip->ci_refs == 0);
687 
688 	if (visible) {
689 		TRACE((FMD_DBG_CASE, "deleting case %s", cip->ci_uuid));
690 		fmd_case_hash_delete(fmd.d_cases, cip);
691 	}
692 
693 	for (cit = cip->ci_items; cit != NULL; cit = ncit) {
694 		ncit = cit->cit_next;
695 		fmd_event_rele(cit->cit_event);
696 		fmd_free(cit, sizeof (fmd_case_item_t));
697 	}
698 
699 	fmd_case_destroy_suspects(cip);
700 
701 	if (cip->ci_principal != NULL)
702 		fmd_event_rele(cip->ci_principal);
703 
704 	fmd_free(cip->ci_uuid, cip->ci_uuidlen + 1);
705 	fmd_free(cip->ci_code, cip->ci_codelen);
706 	(void) fmd_buf_hash_destroy(&cip->ci_bufs);
707 
708 	fmd_module_rele(cip->ci_mod);
709 	fmd_free(cip, sizeof (fmd_case_impl_t));
710 }
711 
712 void
713 fmd_case_hold(fmd_case_t *cp)
714 {
715 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
716 
717 	(void) pthread_mutex_lock(&cip->ci_lock);
718 	fmd_case_hold_locked(cp);
719 	(void) pthread_mutex_unlock(&cip->ci_lock);
720 }
721 
722 void
723 fmd_case_hold_locked(fmd_case_t *cp)
724 {
725 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
726 
727 	ASSERT(MUTEX_HELD(&cip->ci_lock));
728 	if (cip->ci_flags & FMD_CF_DELETING)
729 		fmd_panic("attempt to hold a deleting case %p (%s)\n",
730 		    (void *)cip, cip->ci_uuid);
731 	cip->ci_refs++;
732 	ASSERT(cip->ci_refs != 0);
733 }
734 
735 static fmd_case_impl_t *
736 fmd_case_tryhold(fmd_case_impl_t *cip)
737 {
738 	/*
739 	 * If the case's "deleting" bit is unset, hold and return case,
740 	 * otherwise, return NULL.
741 	 */
742 	(void) pthread_mutex_lock(&cip->ci_lock);
743 	if (cip->ci_flags & FMD_CF_DELETING) {
744 		(void) pthread_mutex_unlock(&cip->ci_lock);
745 		cip = NULL;
746 	} else {
747 		fmd_case_hold_locked((fmd_case_t *)cip);
748 		(void) pthread_mutex_unlock(&cip->ci_lock);
749 	}
750 	return (cip);
751 }
752 
753 void
754 fmd_case_rele(fmd_case_t *cp)
755 {
756 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
757 
758 	(void) pthread_mutex_lock(&cip->ci_lock);
759 	ASSERT(cip->ci_refs != 0);
760 
761 	if (--cip->ci_refs == 0)
762 		fmd_case_destroy((fmd_case_t *)cip, B_TRUE);
763 	else
764 		(void) pthread_mutex_unlock(&cip->ci_lock);
765 }
766 
767 int
768 fmd_case_insert_principal(fmd_case_t *cp, fmd_event_t *ep)
769 {
770 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
771 	fmd_case_item_t *cit;
772 	fmd_event_t *oep;
773 	uint_t state;
774 	int new;
775 
776 	fmd_event_hold(ep);
777 	(void) pthread_mutex_lock(&cip->ci_lock);
778 
779 	if (cip->ci_flags & FMD_CF_SOLVED)
780 		state = FMD_EVS_DIAGNOSED;
781 	else
782 		state = FMD_EVS_ACCEPTED;
783 
784 	oep = cip->ci_principal;
785 	cip->ci_principal = ep;
786 
787 	for (cit = cip->ci_items; cit != NULL; cit = cit->cit_next) {
788 		if (cit->cit_event == ep)
789 			break;
790 	}
791 
792 	cip->ci_flags |= FMD_CF_DIRTY;
793 	new = cit == NULL && ep != oep;
794 
795 	(void) pthread_mutex_unlock(&cip->ci_lock);
796 
797 	fmd_module_setcdirty(cip->ci_mod);
798 	fmd_event_transition(ep, state);
799 
800 	if (oep != NULL)
801 		fmd_event_rele(oep);
802 
803 	return (new);
804 }
805 
806 int
807 fmd_case_insert_event(fmd_case_t *cp, fmd_event_t *ep)
808 {
809 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
810 	fmd_case_item_t *cit;
811 	uint_t state;
812 	int new;
813 
814 	(void) pthread_mutex_lock(&cip->ci_lock);
815 
816 	if (cip->ci_flags & FMD_CF_SOLVED)
817 		state = FMD_EVS_DIAGNOSED;
818 	else
819 		state = FMD_EVS_ACCEPTED;
820 
821 	for (cit = cip->ci_items; cit != NULL; cit = cit->cit_next) {
822 		if (cit->cit_event == ep)
823 			break;
824 	}
825 
826 	new = cit == NULL && ep != cip->ci_principal;
827 
828 	/*
829 	 * If the event is already in the case or the case is already solved,
830 	 * there is no reason to save it: just transition it appropriately.
831 	 */
832 	if (cit != NULL || (cip->ci_flags & FMD_CF_SOLVED)) {
833 		(void) pthread_mutex_unlock(&cip->ci_lock);
834 		fmd_event_transition(ep, state);
835 		return (new);
836 	}
837 
838 	cit = fmd_alloc(sizeof (fmd_case_item_t), FMD_SLEEP);
839 	fmd_event_hold(ep);
840 
841 	cit->cit_next = cip->ci_items;
842 	cit->cit_event = ep;
843 
844 	cip->ci_items = cit;
845 	cip->ci_nitems++;
846 
847 	cip->ci_flags |= FMD_CF_DIRTY;
848 	(void) pthread_mutex_unlock(&cip->ci_lock);
849 
850 	fmd_module_setcdirty(cip->ci_mod);
851 	fmd_event_transition(ep, state);
852 
853 	return (new);
854 }
855 
856 void
857 fmd_case_insert_suspect(fmd_case_t *cp, nvlist_t *nvl)
858 {
859 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
860 	fmd_case_susp_t *cis = fmd_alloc(sizeof (fmd_case_susp_t), FMD_SLEEP);
861 
862 	(void) pthread_mutex_lock(&cip->ci_lock);
863 	ASSERT(cip->ci_state < FMD_CASE_SOLVED);
864 	cip->ci_flags |= FMD_CF_DIRTY;
865 
866 	cis->cis_next = cip->ci_suspects;
867 	cis->cis_nvl = nvl;
868 
869 	cip->ci_suspects = cis;
870 	cip->ci_nsuspects++;
871 
872 	(void) pthread_mutex_unlock(&cip->ci_lock);
873 	fmd_module_setcdirty(cip->ci_mod);
874 }
875 
876 void
877 fmd_case_recreate_suspect(fmd_case_t *cp, nvlist_t *nvl)
878 {
879 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
880 	fmd_case_susp_t *cis = fmd_alloc(sizeof (fmd_case_susp_t), FMD_SLEEP);
881 	boolean_t b;
882 
883 	(void) pthread_mutex_lock(&cip->ci_lock);
884 	ASSERT(cip->ci_state == FMD_CASE_CLOSED);
885 	ASSERT(cip->ci_mod == fmd.d_rmod);
886 
887 	cis->cis_next = cip->ci_suspects;
888 	cis->cis_nvl = nvl;
889 
890 	if (nvlist_lookup_boolean_value(nvl,
891 	    FM_SUSPECT_MESSAGE, &b) == 0 && b == B_FALSE)
892 		cip->ci_flags |= FMD_CF_INVISIBLE;
893 
894 	cip->ci_suspects = cis;
895 	cip->ci_nsuspects++;
896 
897 	(void) pthread_mutex_unlock(&cip->ci_lock);
898 }
899 
900 void
901 fmd_case_reset_suspects(fmd_case_t *cp)
902 {
903 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
904 
905 	(void) pthread_mutex_lock(&cip->ci_lock);
906 	ASSERT(cip->ci_state < FMD_CASE_SOLVED);
907 
908 	fmd_case_destroy_suspects(cip);
909 	cip->ci_flags |= FMD_CF_DIRTY;
910 
911 	(void) pthread_mutex_unlock(&cip->ci_lock);
912 	fmd_module_setcdirty(cip->ci_mod);
913 }
914 
915 /*
916  * Grab ci_lock and update the case state and set the dirty bit.  Then perform
917  * whatever actions and emit whatever events are appropriate for the state.
918  * Refer to the topmost block comment explaining the state machine for details.
919  */
920 void
921 fmd_case_transition(fmd_case_t *cp, uint_t state, uint_t flags)
922 {
923 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
924 
925 	fmd_case_susp_t *cis;
926 	fmd_case_item_t *cit;
927 	fmd_asru_t *asru;
928 	fmd_event_t *e;
929 	nvlist_t *nvl;
930 
931 	ASSERT(state <= FMD_CASE_REPAIRED);
932 	(void) pthread_mutex_lock(&cip->ci_lock);
933 
934 	if (!(cip->ci_flags & FMD_CF_SOLVED) && !(flags & FMD_CF_SOLVED))
935 		flags &= ~(FMD_CF_ISOLATED | FMD_CF_REPAIRED);
936 
937 	cip->ci_flags |= flags;
938 
939 	if (cip->ci_state >= state) {
940 		(void) pthread_mutex_unlock(&cip->ci_lock);
941 		return; /* already in specified state */
942 	}
943 
944 	TRACE((FMD_DBG_CASE, "case %s %s->%s", cip->ci_uuid,
945 	    _fmd_case_snames[cip->ci_state], _fmd_case_snames[state]));
946 
947 	cip->ci_state = state;
948 	cip->ci_flags |= FMD_CF_DIRTY;
949 
950 	if (cip->ci_xprt == NULL && cip->ci_mod != fmd.d_rmod)
951 		fmd_module_setcdirty(cip->ci_mod);
952 
953 	switch (state) {
954 	case FMD_CASE_SOLVED:
955 		for (cit = cip->ci_items; cit != NULL; cit = cit->cit_next)
956 			fmd_event_transition(cit->cit_event, FMD_EVS_DIAGNOSED);
957 
958 		if (cip->ci_principal != NULL) {
959 			fmd_event_transition(cip->ci_principal,
960 			    FMD_EVS_DIAGNOSED);
961 		}
962 		break;
963 
964 	case FMD_CASE_CLOSE_WAIT:
965 		/*
966 		 * If the case was never solved, do not change ASRUs.
967 		 * If the case was never fmd_case_closed, do not change ASRUs.
968 		 * If the case was repaired, do not change ASRUs.
969 		 */
970 		if ((cip->ci_flags & (FMD_CF_SOLVED | FMD_CF_ISOLATED |
971 		    FMD_CF_REPAIRED)) != (FMD_CF_SOLVED | FMD_CF_ISOLATED))
972 			goto close_wait_finish;
973 
974 		/*
975 		 * For each fault event in the suspect list, attempt to look up
976 		 * the corresponding ASRU in the ASRU dictionary.  If the ASRU
977 		 * is found there and is marked faulty, we now mark it unusable
978 		 * and record the case meta-data and fault event with the ASRU.
979 		 */
980 		for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
981 			if (nvlist_lookup_nvlist(cis->cis_nvl, FM_FAULT_ASRU,
982 			    &nvl) == 0 && (asru = fmd_asru_hash_lookup_nvl(
983 			    fmd.d_asrus, nvl, FMD_B_FALSE)) != NULL) {
984 				(void) fmd_asru_setflags(asru,
985 				    FMD_ASRU_UNUSABLE, cp, cis->cis_nvl);
986 				fmd_asru_hash_release(fmd.d_asrus, asru);
987 			}
988 		}
989 
990 	close_wait_finish:
991 		/*
992 		 * If an orphaned case transitions to CLOSE_WAIT, the owning
993 		 * module is no longer loaded: continue on to CASE_CLOSED.
994 		 */
995 		if (fmd_case_orphaned(cp))
996 			state = cip->ci_state = FMD_CASE_CLOSED;
997 		break;
998 
999 	case FMD_CASE_REPAIRED:
1000 		ASSERT(fmd_case_orphaned(cp));
1001 		fmd_module_lock(cip->ci_mod);
1002 		fmd_list_delete(&cip->ci_mod->mod_cases, cip);
1003 		fmd_module_unlock(cip->ci_mod);
1004 		break;
1005 	}
1006 
1007 	(void) pthread_mutex_unlock(&cip->ci_lock);
1008 
1009 	/*
1010 	 * If the module has initialized, then publish the appropriate event
1011 	 * for the new case state.  If not, we are being called from the
1012 	 * checkpoint code during module load, in which case the module's
1013 	 * _fmd_init() routine hasn't finished yet, and our event dictionaries
1014 	 * may not be open yet, which will prevent us from computing the event
1015 	 * code.  Defer the call to fmd_case_publish() by enqueuing a PUBLISH
1016 	 * event in our queue: this won't be processed until _fmd_init is done.
1017 	 */
1018 	if (cip->ci_mod->mod_flags & FMD_MOD_INIT)
1019 		fmd_case_publish(cp, state);
1020 	else {
1021 		fmd_case_hold(cp);
1022 		e = fmd_event_create(FMD_EVT_PUBLISH, FMD_HRT_NOW, NULL, cp);
1023 		fmd_eventq_insert_at_head(cip->ci_mod->mod_queue, e);
1024 	}
1025 
1026 	/*
1027 	 * If we transitioned to REPAIRED, adjust the reference count to
1028 	 * reflect our removal from fmd.d_rmod->mod_cases.  If the caller has
1029 	 * not placed an additional hold on the case, it will now be freed.
1030 	 */
1031 	if (state == FMD_CASE_REPAIRED)
1032 		fmd_case_rele(cp);
1033 }
1034 
1035 /*
1036  * Transition the specified case to *at least* the specified state by first
1037  * re-validating the suspect list using the resource cache.  This function is
1038  * employed by the checkpoint code when restoring a saved, solved case to see
1039  * if the state of the case has effectively changed while fmd was not running
1040  * or the module was not loaded.  If none of the suspects are present anymore,
1041  * advance the state to REPAIRED.  If none are usable, advance to CLOSE_WAIT.
1042  */
1043 void
1044 fmd_case_transition_update(fmd_case_t *cp, uint_t state, uint_t flags)
1045 {
1046 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1047 	fmd_case_susp_t *cis;
1048 	fmd_asru_t *asru;
1049 	nvlist_t *nvl;
1050 
1051 	int faulty = 0;		/* are any suspects faulty? */
1052 	int usable = 0;		/* are any suspects usable? */
1053 
1054 	ASSERT(state >= FMD_CASE_SOLVED);
1055 	(void) pthread_mutex_lock(&cip->ci_lock);
1056 
1057 	for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
1058 		if (nvlist_lookup_nvlist(cis->cis_nvl, FM_FAULT_ASRU,
1059 		    &nvl) == 0 && (asru = fmd_asru_hash_lookup_nvl(
1060 		    fmd.d_asrus, nvl, FMD_B_TRUE)) != NULL) {
1061 
1062 			if (asru->asru_flags & FMD_ASRU_FAULTY)
1063 				faulty++;
1064 
1065 			if (fmd_asru_fake_not_present == 0 &&
1066 			    fmd_fmri_unusable(asru->asru_fmri) <= 0)
1067 				usable++;
1068 
1069 			fmd_asru_hash_release(fmd.d_asrus, asru);
1070 		}
1071 	}
1072 
1073 	(void) pthread_mutex_unlock(&cip->ci_lock);
1074 
1075 	/*
1076 	 * If none of the suspects were faulty, it implies they were either
1077 	 * repaired already or not present and the rsrc.age time has expired.
1078 	 * We can move the state on to repaired.
1079 	 */
1080 	if (!faulty) {
1081 		state = MAX(state, FMD_CASE_CLOSE_WAIT);
1082 		flags |= FMD_CF_REPAIRED;
1083 	} else if (!usable) {
1084 		state = MAX(state, FMD_CASE_CLOSE_WAIT);
1085 		flags |= FMD_CF_ISOLATED;
1086 	}
1087 
1088 	fmd_case_transition(cp, state, flags);
1089 }
1090 
1091 void
1092 fmd_case_setdirty(fmd_case_t *cp)
1093 {
1094 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1095 
1096 	(void) pthread_mutex_lock(&cip->ci_lock);
1097 	cip->ci_flags |= FMD_CF_DIRTY;
1098 	(void) pthread_mutex_unlock(&cip->ci_lock);
1099 
1100 	fmd_module_setcdirty(cip->ci_mod);
1101 }
1102 
1103 void
1104 fmd_case_clrdirty(fmd_case_t *cp)
1105 {
1106 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1107 
1108 	(void) pthread_mutex_lock(&cip->ci_lock);
1109 	cip->ci_flags &= ~FMD_CF_DIRTY;
1110 	(void) pthread_mutex_unlock(&cip->ci_lock);
1111 }
1112 
1113 void
1114 fmd_case_commit(fmd_case_t *cp)
1115 {
1116 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1117 	fmd_case_item_t *cit;
1118 
1119 	(void) pthread_mutex_lock(&cip->ci_lock);
1120 
1121 	if (cip->ci_flags & FMD_CF_DIRTY) {
1122 		for (cit = cip->ci_items; cit != NULL; cit = cit->cit_next)
1123 			fmd_event_commit(cit->cit_event);
1124 
1125 		if (cip->ci_principal != NULL)
1126 			fmd_event_commit(cip->ci_principal);
1127 
1128 		fmd_buf_hash_commit(&cip->ci_bufs);
1129 		cip->ci_flags &= ~FMD_CF_DIRTY;
1130 	}
1131 
1132 	(void) pthread_mutex_unlock(&cip->ci_lock);
1133 }
1134 
1135 /*
1136  * Indicate that the case may need to change state because one or more of the
1137  * ASRUs named as a suspect has changed state.  We examine all the suspects
1138  * and if none are still faulty, we initiate a case close transition.
1139  */
1140 void
1141 fmd_case_update(fmd_case_t *cp)
1142 {
1143 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1144 	fmd_case_susp_t *cis;
1145 	fmd_asru_t *asru;
1146 	nvlist_t *nvl;
1147 
1148 	int astate = 0;
1149 	uint_t cstate;
1150 
1151 	(void) pthread_mutex_lock(&cip->ci_lock);
1152 	cstate = cip->ci_state;
1153 
1154 	if ((cip->ci_flags & FMD_CF_REPAIRING) ||
1155 	    cip->ci_xprt != NULL || cip->ci_state < FMD_CASE_SOLVED) {
1156 		(void) pthread_mutex_unlock(&cip->ci_lock);
1157 		return; /* update is not appropriate */
1158 	}
1159 
1160 	for (cis = cip->ci_suspects; cis != NULL; cis = cis->cis_next) {
1161 		if (nvlist_lookup_nvlist(cis->cis_nvl, FM_FAULT_ASRU,
1162 		    &nvl) == 0 && (asru = fmd_asru_hash_lookup_nvl(
1163 		    fmd.d_asrus, nvl, FMD_B_FALSE)) != NULL) {
1164 			astate |= (asru->asru_flags & FMD_ASRU_STATE);
1165 			fmd_asru_hash_release(fmd.d_asrus, asru);
1166 		}
1167 	}
1168 
1169 	(void) pthread_mutex_unlock(&cip->ci_lock);
1170 
1171 	if (astate & FMD_ASRU_FAULTY)
1172 		return; /* one or more suspects are still marked faulty */
1173 
1174 	if (cstate == FMD_CASE_CLOSED)
1175 		fmd_case_transition(cp, FMD_CASE_REPAIRED, FMD_CF_REPAIRED);
1176 	else
1177 		fmd_case_transition(cp, FMD_CASE_CLOSE_WAIT, FMD_CF_REPAIRED);
1178 }
1179 
1180 /*
1181  * Delete a closed case from the module's case list once the fmdo_close() entry
1182  * point has run to completion.  If the case is owned by a transport module,
1183  * tell the transport to proxy a case close on the other end of the transport.
1184  * If not, transition to the appropriate next state based on ci_flags.  This
1185  * function represents the end of CLOSE_WAIT and transitions the case to either
1186  * CLOSED or REPAIRED or discards it entirely because it was never solved;
1187  * refer to the topmost block comment explaining the state machine for details.
1188  */
1189 void
1190 fmd_case_delete(fmd_case_t *cp)
1191 {
1192 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1193 	fmd_modstat_t *msp;
1194 	size_t buftotal;
1195 
1196 	ASSERT(fmd_module_locked(cip->ci_mod));
1197 	fmd_list_delete(&cip->ci_mod->mod_cases, cip);
1198 	buftotal = fmd_buf_hash_destroy(&cip->ci_bufs);
1199 
1200 	(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
1201 	msp = cip->ci_mod->mod_stats;
1202 
1203 	ASSERT(msp->ms_caseopen.fmds_value.ui64 != 0);
1204 	msp->ms_caseopen.fmds_value.ui64--;
1205 
1206 	ASSERT(msp->ms_buftotal.fmds_value.ui64 >= buftotal);
1207 	msp->ms_buftotal.fmds_value.ui64 -= buftotal;
1208 
1209 	(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
1210 
1211 	if (cip->ci_xprt == NULL)
1212 		fmd_module_setcdirty(cip->ci_mod);
1213 
1214 	fmd_module_rele(cip->ci_mod);
1215 	cip->ci_mod = fmd.d_rmod;
1216 	fmd_module_hold(cip->ci_mod);
1217 
1218 	/*
1219 	 * If the case is not proxied and it has been solved, then retain it
1220 	 * on the root module's case list at least until we're transitioned.
1221 	 * Otherwise free the case with our final fmd_case_rele() below.
1222 	 */
1223 	if (cip->ci_xprt == NULL && (cip->ci_flags & FMD_CF_SOLVED)) {
1224 		fmd_module_lock(cip->ci_mod);
1225 		fmd_list_append(&cip->ci_mod->mod_cases, cip);
1226 		fmd_module_unlock(cip->ci_mod);
1227 		fmd_case_hold(cp);
1228 	}
1229 
1230 	/*
1231 	 * If a proxied case finishes CLOSE_WAIT, then it can be discarded
1232 	 * rather than orphaned because by definition it can have no entries
1233 	 * in the resource cache of the current fault manager.
1234 	 */
1235 	if (cip->ci_xprt != NULL)
1236 		fmd_xprt_uuclose(cip->ci_xprt, cip->ci_uuid);
1237 	else if (cip->ci_flags & FMD_CF_REPAIRED)
1238 		fmd_case_transition(cp, FMD_CASE_REPAIRED, 0);
1239 	else if (cip->ci_flags & FMD_CF_ISOLATED)
1240 		fmd_case_transition(cp, FMD_CASE_CLOSED, 0);
1241 
1242 	fmd_case_rele(cp);
1243 }
1244 
1245 void
1246 fmd_case_discard(fmd_case_t *cp)
1247 {
1248 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1249 
1250 	(void) pthread_mutex_lock(&cip->ci_mod->mod_stats_lock);
1251 	cip->ci_mod->mod_stats->ms_caseopen.fmds_value.ui64--;
1252 	(void) pthread_mutex_unlock(&cip->ci_mod->mod_stats_lock);
1253 
1254 	ASSERT(fmd_module_locked(cip->ci_mod));
1255 	fmd_list_delete(&cip->ci_mod->mod_cases, cip);
1256 	fmd_case_rele(cp);
1257 }
1258 
1259 static void
1260 fmd_case_repair_containee(fmd_asru_t *ee, void *er)
1261 {
1262 	if ((ee->asru_flags & FMD_ASRU_FAULTY) &&
1263 	    fmd_fmri_contains(er, ee->asru_fmri) > 0)
1264 		(void) fmd_asru_clrflags(ee, FMD_ASRU_FAULTY, NULL, NULL);
1265 }
1266 
1267 /*
1268  * Indicate that the problem corresponding to a case has been repaired by
1269  * clearing the faulty bit on each ASRU named as a suspect.  If the case hasn't
1270  * already been closed, this function initiates the transition to CLOSE_WAIT.
1271  * The caller must have the case held from fmd_case_hash_lookup(), so we can
1272  * grab and drop ci_lock without the case being able to be freed in between.
1273  */
1274 int
1275 fmd_case_repair(fmd_case_t *cp)
1276 {
1277 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1278 	fmd_case_susp_t *cis;
1279 	nvlist_t *nvl;
1280 	uint_t cstate;
1281 
1282 	fmd_asru_hash_t *ahp = fmd.d_asrus;
1283 	fmd_asru_t **aa;
1284 	uint_t i, an;
1285 
1286 	(void) pthread_mutex_lock(&cip->ci_lock);
1287 	cstate = cip->ci_state;
1288 
1289 	if (cip->ci_xprt != NULL) {
1290 		(void) pthread_mutex_unlock(&cip->ci_lock);
1291 		return (fmd_set_errno(EFMD_CASE_OWNER));
1292 	}
1293 
1294 	if (cstate < FMD_CASE_SOLVED || (cip->ci_flags & FMD_CF_REPAIRING)) {
1295 		(void) pthread_mutex_unlock(&cip->ci_lock);
1296 		return (fmd_set_errno(EFMD_CASE_STATE));
1297 	}
1298 
1299 	/*
1300 	 * Take a snapshot of any ASRUs referenced by the case that are present
1301 	 * in the resource cache.  Then drop ci_lock and clear the faulty bit
1302 	 * on each ASRU (we can't call fmd_asru_clrflags() with ci_lock held).
1303 	 */
1304 	an = cip->ci_nsuspects;
1305 	aa = alloca(sizeof (fmd_asru_t *) * an);
1306 	bzero(aa, sizeof (fmd_asru_t *) * an);
1307 
1308 	for (i = 0, cis = cip->ci_suspects;
1309 	    cis != NULL; cis = cis->cis_next, i++) {
1310 		if (nvlist_lookup_nvlist(cis->cis_nvl,
1311 		    FM_FAULT_ASRU, &nvl) == 0)
1312 			aa[i] = fmd_asru_hash_lookup_nvl(ahp, nvl, FMD_B_FALSE);
1313 	}
1314 
1315 	cip->ci_flags |= FMD_CF_REPAIRING;
1316 	(void) pthread_mutex_unlock(&cip->ci_lock);
1317 
1318 	/*
1319 	 * For each suspect ASRU, if the case associated with this ASRU matches
1320 	 * case 'cp', close all ASRUs contained by 'ap' and clear FAULTY.  Note
1321 	 * that at present, we're assuming that when a given resource FMRI R1
1322 	 * contains another R2, that any faults are related by a common
1323 	 * diagnosis engine.  This is true in our current architecture, but may
1324 	 * not always be true, at which point we'll need more cleverness here.
1325 	 */
1326 	for (i = 0; i < an; i++) {
1327 		if (aa[i] == NULL)
1328 			continue; /* no asru was found */
1329 
1330 		if (aa[i]->asru_case == cp) {
1331 			fmd_asru_hash_apply(fmd.d_asrus,
1332 			    fmd_case_repair_containee, aa[i]->asru_fmri);
1333 			(void) fmd_asru_clrflags(aa[i],
1334 			    FMD_ASRU_FAULTY, NULL, NULL);
1335 		}
1336 
1337 		fmd_asru_hash_release(ahp, aa[i]);
1338 	}
1339 
1340 	(void) pthread_mutex_lock(&cip->ci_lock);
1341 	cip->ci_flags &= ~FMD_CF_REPAIRING;
1342 	(void) pthread_mutex_unlock(&cip->ci_lock);
1343 
1344 	if (cstate == FMD_CASE_CLOSED)
1345 		fmd_case_transition(cp, FMD_CASE_REPAIRED, FMD_CF_REPAIRED);
1346 	else
1347 		fmd_case_transition(cp, FMD_CASE_CLOSE_WAIT, FMD_CF_REPAIRED);
1348 
1349 	return (0);
1350 }
1351 
1352 int
1353 fmd_case_contains(fmd_case_t *cp, fmd_event_t *ep)
1354 {
1355 	fmd_case_impl_t *cip = (fmd_case_impl_t *)cp;
1356 	fmd_case_item_t *cit;
1357 	uint_t state;
1358 	int rv = 0;
1359 
1360 	(void) pthread_mutex_lock(&cip->ci_lock);
1361 
1362 	if (cip->ci_state >= FMD_CASE_SOLVED)
1363 		state = FMD_EVS_DIAGNOSED;
1364 	else
1365 		state = FMD_EVS_ACCEPTED;
1366 
1367 	for (cit = cip->ci_items; cit != NULL; cit = cit->cit_next) {
1368 		if ((rv = fmd_event_equal(ep, cit->cit_event)) != 0)
1369 			break;
1370 	}
1371 
1372 	if (rv == 0 && cip->ci_principal != NULL)
1373 		rv = fmd_event_equal(ep, cip->ci_principal);
1374 
1375 	(void) pthread_mutex_unlock(&cip->ci_lock);
1376 
1377 	if (rv != 0)
1378 		fmd_event_transition(ep, state);
1379 
1380 	return (rv);
1381 }
1382 
1383 int
1384 fmd_case_orphaned(fmd_case_t *cp)
1385 {
1386 	return (((fmd_case_impl_t *)cp)->ci_mod == fmd.d_rmod);
1387 }
1388 
1389 void
1390 fmd_case_settime(fmd_case_t *cp, time_t tv_sec, suseconds_t tv_usec)
1391 {
1392 	((fmd_case_impl_t *)cp)->ci_tv.tv_sec = tv_sec;
1393 	((fmd_case_impl_t *)cp)->ci_tv.tv_usec = tv_usec;
1394 	((fmd_case_impl_t *)cp)->ci_tv_valid = 1;
1395 }
1396