xref: /netbsd-src/sys/dev/raidframe/rf_states.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: rf_states.c,v 1.49 2011/05/11 18:13:12 mrg Exp $	*/
2 /*
3  * Copyright (c) 1995 Carnegie-Mellon University.
4  * All rights reserved.
5  *
6  * Author: Mark Holland, William V. Courtright II, Robby Findler
7  *
8  * Permission to use, copy, modify and distribute this software and
9  * its documentation is hereby granted, provided that both the copyright
10  * notice and this permission notice appear in all copies of the
11  * software, derivative works or modified versions, and any portions
12  * thereof, and that both notices appear in supporting documentation.
13  *
14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17  *
18  * Carnegie Mellon requests users of this software to return to
19  *
20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
21  *  School of Computer Science
22  *  Carnegie Mellon University
23  *  Pittsburgh PA 15213-3890
24  *
25  * any improvements or extensions that they make and grant Carnegie the
26  * rights to redistribute these changes.
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: rf_states.c,v 1.49 2011/05/11 18:13:12 mrg Exp $");
31 
32 #include <sys/errno.h>
33 
34 #include "rf_archs.h"
35 #include "rf_threadstuff.h"
36 #include "rf_raid.h"
37 #include "rf_dag.h"
38 #include "rf_desc.h"
39 #include "rf_aselect.h"
40 #include "rf_general.h"
41 #include "rf_states.h"
42 #include "rf_dagutils.h"
43 #include "rf_driver.h"
44 #include "rf_engine.h"
45 #include "rf_map.h"
46 #include "rf_etimer.h"
47 #include "rf_kintf.h"
48 #include "rf_paritymap.h"
49 
50 #ifndef RF_DEBUG_STATES
51 #define RF_DEBUG_STATES 0
52 #endif
53 
54 /* prototypes for some of the available states.
55 
56    States must:
57 
58      - not block.
59 
60      - either schedule rf_ContinueRaidAccess as a callback and return
61        RF_TRUE, or complete all of their work and return RF_FALSE.
62 
63      - increment desc->state when they have finished their work.
64 */
65 
66 #if RF_DEBUG_STATES
67 static char *
68 StateName(RF_AccessState_t state)
69 {
70 	switch (state) {
71 		case rf_QuiesceState:return "QuiesceState";
72 	case rf_MapState:
73 		return "MapState";
74 	case rf_LockState:
75 		return "LockState";
76 	case rf_CreateDAGState:
77 		return "CreateDAGState";
78 	case rf_ExecuteDAGState:
79 		return "ExecuteDAGState";
80 	case rf_ProcessDAGState:
81 		return "ProcessDAGState";
82 	case rf_CleanupState:
83 		return "CleanupState";
84 	case rf_LastState:
85 		return "LastState";
86 	case rf_IncrAccessesCountState:
87 		return "IncrAccessesCountState";
88 	case rf_DecrAccessesCountState:
89 		return "DecrAccessesCountState";
90 	default:
91 		return "!!! UnnamedState !!!";
92 	}
93 }
94 #endif
95 
96 void
97 rf_ContinueRaidAccess(RF_RaidAccessDesc_t *desc)
98 {
99 	int     suspended = RF_FALSE;
100 	int     current_state_index = desc->state;
101 	RF_AccessState_t current_state = desc->states[current_state_index];
102 #if RF_DEBUG_STATES
103 	int     unit = desc->raidPtr->raidid;
104 #endif
105 
106 	do {
107 
108 		current_state_index = desc->state;
109 		current_state = desc->states[current_state_index];
110 
111 		switch (current_state) {
112 
113 		case rf_QuiesceState:
114 			suspended = rf_State_Quiesce(desc);
115 			break;
116 		case rf_IncrAccessesCountState:
117 			suspended = rf_State_IncrAccessCount(desc);
118 			break;
119 		case rf_MapState:
120 			suspended = rf_State_Map(desc);
121 			break;
122 		case rf_LockState:
123 			suspended = rf_State_Lock(desc);
124 			break;
125 		case rf_CreateDAGState:
126 			suspended = rf_State_CreateDAG(desc);
127 			break;
128 		case rf_ExecuteDAGState:
129 			suspended = rf_State_ExecuteDAG(desc);
130 			break;
131 		case rf_ProcessDAGState:
132 			suspended = rf_State_ProcessDAG(desc);
133 			break;
134 		case rf_CleanupState:
135 			suspended = rf_State_Cleanup(desc);
136 			break;
137 		case rf_DecrAccessesCountState:
138 			suspended = rf_State_DecrAccessCount(desc);
139 			break;
140 		case rf_LastState:
141 			suspended = rf_State_LastState(desc);
142 			break;
143 		}
144 
145 		/* after this point, we cannot dereference desc since
146 		 * desc may have been freed. desc is only freed in
147 		 * LastState, so if we renter this function or loop
148 		 * back up, desc should be valid. */
149 
150 #if RF_DEBUG_STATES
151 		if (rf_printStatesDebug) {
152 			printf("raid%d: State: %-24s StateIndex: %3i desc: 0x%ld %s\n",
153 			       unit, StateName(current_state),
154 			       current_state_index, (long) desc,
155 			       suspended ? "callback scheduled" : "looping");
156 		}
157 #endif
158 	} while (!suspended && current_state != rf_LastState);
159 
160 	return;
161 }
162 
163 
164 void
165 rf_ContinueDagAccess(RF_DagList_t *dagList)
166 {
167 #if RF_ACC_TRACE > 0
168 	RF_AccTraceEntry_t *tracerec = &(dagList->desc->tracerec);
169 	RF_Etimer_t timer;
170 #endif
171 	RF_RaidAccessDesc_t *desc;
172 	RF_DagHeader_t *dag_h;
173 	int     i;
174 
175 	desc = dagList->desc;
176 
177 #if RF_ACC_TRACE > 0
178 	timer = tracerec->timer;
179 	RF_ETIMER_STOP(timer);
180 	RF_ETIMER_EVAL(timer);
181 	tracerec->specific.user.exec_us = RF_ETIMER_VAL_US(timer);
182 	RF_ETIMER_START(tracerec->timer);
183 #endif
184 
185 	/* skip to dag which just finished */
186 	dag_h = dagList->dags;
187 	for (i = 0; i < dagList->numDagsDone; i++) {
188 		dag_h = dag_h->next;
189 	}
190 
191 	/* check to see if retry is required */
192 	if (dag_h->status == rf_rollBackward) {
193 		/* when a dag fails, mark desc status as bad and allow
194 		 * all other dags in the desc to execute to
195 		 * completion.  then, free all dags and start over */
196 		desc->status = 1;	/* bad status */
197 #if 0
198 		printf("raid%d: DAG failure: %c addr 0x%lx "
199 		       "(%ld) nblk 0x%x (%d) buf 0x%lx state %d\n",
200 		       desc->raidPtr->raidid, desc->type,
201 		       (long) desc->raidAddress,
202 		       (long) desc->raidAddress, (int) desc->numBlocks,
203 		       (int) desc->numBlocks,
204 		       (unsigned long) (desc->bufPtr), desc->state);
205 #endif
206 	}
207 	dagList->numDagsDone++;
208 	rf_ContinueRaidAccess(desc);
209 }
210 
211 int
212 rf_State_LastState(RF_RaidAccessDesc_t *desc)
213 {
214 	void    (*callbackFunc) (RF_CBParam_t) = desc->callbackFunc;
215 	RF_CBParam_t callbackArg;
216 
217 	callbackArg.p = desc->callbackArg;
218 
219 	/*
220 	 * We don't support non-async IO.
221 	 */
222 	KASSERT(desc->async_flag);
223 
224 	/*
225 	 * That's all the IO for this one... unbusy the 'disk'.
226 	 */
227 
228 	rf_disk_unbusy(desc);
229 
230 	/*
231 	 * Wakeup any requests waiting to go.
232 	 */
233 
234 	rf_lock_mutex2(desc->raidPtr->mutex);
235 	desc->raidPtr->openings++;
236 	rf_unlock_mutex2(desc->raidPtr->mutex);
237 
238 	rf_lock_mutex2(desc->raidPtr->iodone_lock);
239 	rf_signal_cond2(desc->raidPtr->iodone_cv);
240 	rf_unlock_mutex2(desc->raidPtr->iodone_lock);
241 
242 	/*
243 	 * The parity_map hook has to go here, because the iodone
244 	 * callback goes straight into the kintf layer.
245 	 */
246 	if (desc->raidPtr->parity_map != NULL &&
247 	    desc->type == RF_IO_TYPE_WRITE)
248 		rf_paritymap_end(desc->raidPtr->parity_map,
249 		    desc->raidAddress, desc->numBlocks);
250 
251 	/* printf("Calling biodone on 0x%x\n",desc->bp); */
252 	biodone(desc->bp);	/* access came through ioctl */
253 
254 	if (callbackFunc)
255 		callbackFunc(callbackArg);
256 	rf_FreeRaidAccDesc(desc);
257 
258 	return RF_FALSE;
259 }
260 
261 int
262 rf_State_IncrAccessCount(RF_RaidAccessDesc_t *desc)
263 {
264 	RF_Raid_t *raidPtr;
265 
266 	raidPtr = desc->raidPtr;
267 	/* Bummer. We have to do this to be 100% safe w.r.t. the increment
268 	 * below */
269 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
270 	raidPtr->accs_in_flight++;	/* used to detect quiescence */
271 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
272 
273 	desc->state++;
274 	return RF_FALSE;
275 }
276 
277 int
278 rf_State_DecrAccessCount(RF_RaidAccessDesc_t *desc)
279 {
280 	RF_Raid_t *raidPtr;
281 
282 	raidPtr = desc->raidPtr;
283 
284 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
285 	raidPtr->accs_in_flight--;
286 	if (raidPtr->accesses_suspended && raidPtr->accs_in_flight == 0) {
287 		rf_SignalQuiescenceLock(raidPtr);
288 	}
289 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
290 
291 	desc->state++;
292 	return RF_FALSE;
293 }
294 
295 int
296 rf_State_Quiesce(RF_RaidAccessDesc_t *desc)
297 {
298 #if RF_ACC_TRACE > 0
299 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
300 	RF_Etimer_t timer;
301 #endif
302 	RF_CallbackDesc_t *cb;
303 	RF_Raid_t *raidPtr;
304 	int     suspended = RF_FALSE;
305 	int need_cb, used_cb;
306 
307 	raidPtr = desc->raidPtr;
308 
309 #if RF_ACC_TRACE > 0
310 	RF_ETIMER_START(timer);
311 	RF_ETIMER_START(desc->timer);
312 #endif
313 
314 	need_cb = 0;
315 	used_cb = 0;
316 	cb = NULL;
317 
318 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
319 	/* Do an initial check to see if we might need a callback structure */
320 	if (raidPtr->accesses_suspended) {
321 		need_cb = 1;
322 	}
323 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
324 
325 	if (need_cb) {
326 		/* create a callback if we might need it...
327 		   and we likely do. */
328 		cb = rf_AllocCallbackDesc();
329 	}
330 
331 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
332 	if (raidPtr->accesses_suspended) {
333 		cb->callbackFunc = (void (*) (RF_CBParam_t)) rf_ContinueRaidAccess;
334 		cb->callbackArg.p = (void *) desc;
335 		cb->next = raidPtr->quiesce_wait_list;
336 		raidPtr->quiesce_wait_list = cb;
337 		suspended = RF_TRUE;
338 		used_cb = 1;
339 	}
340 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
341 
342 	if ((need_cb == 1) && (used_cb == 0)) {
343 		rf_FreeCallbackDesc(cb);
344 	}
345 
346 #if RF_ACC_TRACE > 0
347 	RF_ETIMER_STOP(timer);
348 	RF_ETIMER_EVAL(timer);
349 	tracerec->specific.user.suspend_ovhd_us += RF_ETIMER_VAL_US(timer);
350 #endif
351 
352 #if RF_DEBUG_QUIESCE
353 	if (suspended && rf_quiesceDebug)
354 		printf("Stalling access due to quiescence lock\n");
355 #endif
356 	desc->state++;
357 	return suspended;
358 }
359 
360 int
361 rf_State_Map(RF_RaidAccessDesc_t *desc)
362 {
363 	RF_Raid_t *raidPtr = desc->raidPtr;
364 #if RF_ACC_TRACE > 0
365 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
366 	RF_Etimer_t timer;
367 
368 	RF_ETIMER_START(timer);
369 #endif
370 
371 	if (!(desc->asmap = rf_MapAccess(raidPtr, desc->raidAddress, desc->numBlocks,
372 		    desc->bufPtr, RF_DONT_REMAP)))
373 		RF_PANIC();
374 
375 #if RF_ACC_TRACE > 0
376 	RF_ETIMER_STOP(timer);
377 	RF_ETIMER_EVAL(timer);
378 	tracerec->specific.user.map_us = RF_ETIMER_VAL_US(timer);
379 #endif
380 
381 	desc->state++;
382 	return RF_FALSE;
383 }
384 
385 int
386 rf_State_Lock(RF_RaidAccessDesc_t *desc)
387 {
388 #if RF_ACC_TRACE > 0
389 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
390 	RF_Etimer_t timer;
391 #endif
392 	RF_Raid_t *raidPtr = desc->raidPtr;
393 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
394 	RF_AccessStripeMap_t *asm_p;
395 	RF_StripeNum_t lastStripeID = -1;
396 	int     suspended = RF_FALSE;
397 
398 #if RF_ACC_TRACE > 0
399 	RF_ETIMER_START(timer);
400 #endif
401 
402 	/* acquire each lock that we don't already hold */
403 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
404 		RF_ASSERT(RF_IO_IS_R_OR_W(desc->type));
405 		if (!rf_suppressLocksAndLargeWrites &&
406 		    asm_p->parityInfo &&
407 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS) &&
408 		    !(asm_p->flags & RF_ASM_FLAGS_LOCK_TRIED)) {
409 			asm_p->flags |= RF_ASM_FLAGS_LOCK_TRIED;
410 				/* locks must be acquired hierarchically */
411 			RF_ASSERT(asm_p->stripeID > lastStripeID);
412 			lastStripeID = asm_p->stripeID;
413 
414 			RF_INIT_LOCK_REQ_DESC(asm_p->lockReqDesc, desc->type,
415 					      (void (*) (struct buf *)) rf_ContinueRaidAccess, desc, asm_p,
416 					      raidPtr->Layout.dataSectorsPerStripe);
417 			if (rf_AcquireStripeLock(raidPtr->lockTable, asm_p->stripeID,
418 						 &asm_p->lockReqDesc)) {
419 				suspended = RF_TRUE;
420 				break;
421 			}
422 		}
423 		if (desc->type == RF_IO_TYPE_WRITE &&
424 		    raidPtr->status == rf_rs_reconstructing) {
425 			if (!(asm_p->flags & RF_ASM_FLAGS_FORCE_TRIED)) {
426 				int     val;
427 
428 				asm_p->flags |= RF_ASM_FLAGS_FORCE_TRIED;
429 				val = rf_ForceOrBlockRecon(raidPtr, asm_p,
430 							   (void (*) (RF_Raid_t *, void *)) rf_ContinueRaidAccess, desc);
431 				if (val == 0) {
432 					asm_p->flags |= RF_ASM_FLAGS_RECON_BLOCKED;
433 				} else {
434 					suspended = RF_TRUE;
435 					break;
436 				}
437 			} else {
438 #if RF_DEBUG_PSS > 0
439 				if (rf_pssDebug) {
440 					printf("raid%d: skipping force/block because already done, psid %ld\n",
441 					       desc->raidPtr->raidid,
442 					       (long) asm_p->stripeID);
443 				}
444 #endif
445 			}
446 		} else {
447 #if RF_DEBUG_PSS > 0
448 			if (rf_pssDebug) {
449 				printf("raid%d: skipping force/block because not write or not under recon, psid %ld\n",
450 				       desc->raidPtr->raidid,
451 				       (long) asm_p->stripeID);
452 			}
453 #endif
454 		}
455 	}
456 #if RF_ACC_TRACE > 0
457 	RF_ETIMER_STOP(timer);
458 	RF_ETIMER_EVAL(timer);
459 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
460 #endif
461 	if (suspended)
462 		return (RF_TRUE);
463 
464 	desc->state++;
465 	return (RF_FALSE);
466 }
467 /*
468  * the following three states create, execute, and post-process dags
469  * the error recovery unit is a single dag.
470  * by default, SelectAlgorithm creates an array of dags, one per parity stripe
471  * in some tricky cases, multiple dags per stripe are created
472  *   - dags within a parity stripe are executed sequentially (arbitrary order)
473  *   - dags for distinct parity stripes are executed concurrently
474  *
475  * repeat until all dags complete successfully -or- dag selection fails
476  *
477  * while !done
478  *   create dag(s) (SelectAlgorithm)
479  *   if dag
480  *     execute dag (DispatchDAG)
481  *     if dag successful
482  *       done (SUCCESS)
483  *     else
484  *       !done (RETRY - start over with new dags)
485  *   else
486  *     done (FAIL)
487  */
488 int
489 rf_State_CreateDAG(RF_RaidAccessDesc_t *desc)
490 {
491 #if RF_ACC_TRACE > 0
492 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
493 	RF_Etimer_t timer;
494 #endif
495 	RF_DagHeader_t *dag_h;
496 	RF_DagList_t *dagList;
497 	struct buf *bp;
498 	int     i, selectStatus;
499 
500 	/* generate a dag for the access, and fire it off.  When the dag
501 	 * completes, we'll get re-invoked in the next state. */
502 #if RF_ACC_TRACE > 0
503 	RF_ETIMER_START(timer);
504 #endif
505 	/* SelectAlgorithm returns one or more dags */
506 	selectStatus = rf_SelectAlgorithm(desc, desc->flags | RF_DAG_SUPPRESS_LOCKS);
507 #if RF_DEBUG_VALIDATE_DAG
508 	if (rf_printDAGsDebug) {
509 		dagList = desc->dagList;
510 		for (i = 0; i < desc->numStripes; i++) {
511 			rf_PrintDAGList(dagList->dags);
512 			dagList = dagList->next;
513 		}
514 	}
515 #endif /* RF_DEBUG_VALIDATE_DAG */
516 #if RF_ACC_TRACE > 0
517 	RF_ETIMER_STOP(timer);
518 	RF_ETIMER_EVAL(timer);
519 	/* update time to create all dags */
520 	tracerec->specific.user.dag_create_us = RF_ETIMER_VAL_US(timer);
521 #endif
522 
523 	desc->status = 0;	/* good status */
524 
525 	if (selectStatus || (desc->numRetries > RF_RETRY_THRESHOLD)) {
526 		/* failed to create a dag */
527 		/* this happens when there are too many faults or incomplete
528 		 * dag libraries */
529 		if (selectStatus) {
530 			printf("raid%d: failed to create a dag. "
531 			       "Too many component failures.\n",
532 			       desc->raidPtr->raidid);
533 		} else {
534 			printf("raid%d: IO failed after %d retries.\n",
535 			       desc->raidPtr->raidid, RF_RETRY_THRESHOLD);
536 		}
537 
538 		desc->status = 1; /* bad status */
539 		/* skip straight to rf_State_Cleanup() */
540 		desc->state = rf_CleanupState;
541 		bp = (struct buf *)desc->bp;
542 		bp->b_error = EIO;
543 		bp->b_resid = bp->b_bcount;
544 	} else {
545 		/* bind dags to desc */
546 		dagList = desc->dagList;
547 		for (i = 0; i < desc->numStripes; i++) {
548 			dag_h = dagList->dags;
549 			while (dag_h) {
550 				dag_h->bp = (struct buf *) desc->bp;
551 #if RF_ACC_TRACE > 0
552 				dag_h->tracerec = tracerec;
553 #endif
554 				dag_h = dag_h->next;
555 			}
556 			dagList = dagList->next;
557 		}
558 		desc->flags |= RF_DAG_DISPATCH_RETURNED;
559 		desc->state++;	/* next state should be rf_State_ExecuteDAG */
560 	}
561 	return RF_FALSE;
562 }
563 
564 
565 
566 /* the access has an list of dagLists, one dagList per parity stripe.
567  * fire the first dag in each parity stripe (dagList).
568  * dags within a stripe (dagList) must be executed sequentially
569  *  - this preserves atomic parity update
570  * dags for independents parity groups (stripes) are fired concurrently */
571 
572 int
573 rf_State_ExecuteDAG(RF_RaidAccessDesc_t *desc)
574 {
575 	int     i;
576 	RF_DagHeader_t *dag_h;
577 	RF_DagList_t *dagList;
578 
579 	/* next state is always rf_State_ProcessDAG important to do
580 	 * this before firing the first dag (it may finish before we
581 	 * leave this routine) */
582 	desc->state++;
583 
584 	/* sweep dag array, a stripe at a time, firing the first dag
585 	 * in each stripe */
586 	dagList = desc->dagList;
587 	for (i = 0; i < desc->numStripes; i++) {
588 		RF_ASSERT(dagList->numDags > 0);
589 		RF_ASSERT(dagList->numDagsDone == 0);
590 		RF_ASSERT(dagList->numDagsFired == 0);
591 #if RF_ACC_TRACE > 0
592 		RF_ETIMER_START(dagList->tracerec.timer);
593 #endif
594 		/* fire first dag in this stripe */
595 		dag_h = dagList->dags;
596 		RF_ASSERT(dag_h);
597 		dagList->numDagsFired++;
598 		rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess, dagList);
599 		dagList = dagList->next;
600 	}
601 
602 	/* the DAG will always call the callback, even if there was no
603 	 * blocking, so we are always suspended in this state */
604 	return RF_TRUE;
605 }
606 
607 
608 
609 /* rf_State_ProcessDAG is entered when a dag completes.
610  * first, check to all dags in the access have completed
611  * if not, fire as many dags as possible */
612 
613 int
614 rf_State_ProcessDAG(RF_RaidAccessDesc_t *desc)
615 {
616 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
617 	RF_Raid_t *raidPtr = desc->raidPtr;
618 	RF_DagHeader_t *dag_h;
619 	int     i, j, done = RF_TRUE;
620 	RF_DagList_t *dagList, *temp;
621 
622 	/* check to see if this is the last dag */
623 	dagList = desc->dagList;
624 	for (i = 0; i < desc->numStripes; i++) {
625 		if (dagList->numDags != dagList->numDagsDone)
626 			done = RF_FALSE;
627 		dagList = dagList->next;
628 	}
629 
630 	if (done) {
631 		if (desc->status) {
632 			/* a dag failed, retry */
633 			/* free all dags */
634 			dagList = desc->dagList;
635 			for (i = 0; i < desc->numStripes; i++) {
636 				rf_FreeDAG(dagList->dags);
637 				temp = dagList;
638 				dagList = dagList->next;
639 				rf_FreeDAGList(temp);
640 			}
641 			desc->dagList = NULL;
642 
643 			rf_MarkFailuresInASMList(raidPtr, asmh);
644 
645 			/* note the retry so that we'll bail in
646 			   rf_State_CreateDAG() once we've retired
647 			   the IO RF_RETRY_THRESHOLD times */
648 
649 			desc->numRetries++;
650 
651 			/* back up to rf_State_CreateDAG */
652 			desc->state = desc->state - 2;
653 			return RF_FALSE;
654 		} else {
655 			/* move on to rf_State_Cleanup */
656 			desc->state++;
657 		}
658 		return RF_FALSE;
659 	} else {
660 		/* more dags to execute */
661 		/* see if any are ready to be fired.  if so, fire them */
662 		/* don't fire the initial dag in a list, it's fired in
663 		 * rf_State_ExecuteDAG */
664 		dagList = desc->dagList;
665 		for (i = 0; i < desc->numStripes; i++) {
666 			if ((dagList->numDagsDone < dagList->numDags)
667 			    && (dagList->numDagsDone == dagList->numDagsFired)
668 			    && (dagList->numDagsFired > 0)) {
669 #if RF_ACC_TRACE > 0
670 				RF_ETIMER_START(dagList->tracerec.timer);
671 #endif
672 				/* fire next dag in this stripe */
673 				/* first, skip to next dag awaiting execution */
674 				dag_h = dagList->dags;
675 				for (j = 0; j < dagList->numDagsDone; j++)
676 					dag_h = dag_h->next;
677 				dagList->numDagsFired++;
678 				rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess,
679 				    dagList);
680 			}
681 			dagList = dagList->next;
682 		}
683 		return RF_TRUE;
684 	}
685 }
686 /* only make it this far if all dags complete successfully */
687 int
688 rf_State_Cleanup(RF_RaidAccessDesc_t *desc)
689 {
690 #if RF_ACC_TRACE > 0
691 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
692 	RF_Etimer_t timer;
693 #endif
694 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
695 	RF_Raid_t *raidPtr = desc->raidPtr;
696 	RF_AccessStripeMap_t *asm_p;
697 	RF_DagList_t *dagList;
698 	int i;
699 
700 	desc->state++;
701 
702 #if RF_ACC_TRACE > 0
703 	timer = tracerec->timer;
704 	RF_ETIMER_STOP(timer);
705 	RF_ETIMER_EVAL(timer);
706 	tracerec->specific.user.dag_retry_us = RF_ETIMER_VAL_US(timer);
707 
708 	/* the RAID I/O is complete.  Clean up. */
709 	tracerec->specific.user.dag_retry_us = 0;
710 
711 	RF_ETIMER_START(timer);
712 #endif
713 	/* free all dags */
714 	dagList = desc->dagList;
715 	for (i = 0; i < desc->numStripes; i++) {
716 		rf_FreeDAG(dagList->dags);
717 		dagList = dagList->next;
718 	}
719 #if RF_ACC_TRACE > 0
720 	RF_ETIMER_STOP(timer);
721 	RF_ETIMER_EVAL(timer);
722 	tracerec->specific.user.cleanup_us = RF_ETIMER_VAL_US(timer);
723 
724 	RF_ETIMER_START(timer);
725 #endif
726 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
727 		if (!rf_suppressLocksAndLargeWrites &&
728 		    asm_p->parityInfo &&
729 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS)) {
730 			RF_ASSERT_VALID_LOCKREQ(&asm_p->lockReqDesc);
731 			rf_ReleaseStripeLock(raidPtr->lockTable,
732 					     asm_p->stripeID,
733 					     &asm_p->lockReqDesc);
734 		}
735 		if (asm_p->flags & RF_ASM_FLAGS_RECON_BLOCKED) {
736 			rf_UnblockRecon(raidPtr, asm_p);
737 		}
738 	}
739 #if RF_ACC_TRACE > 0
740 	RF_ETIMER_STOP(timer);
741 	RF_ETIMER_EVAL(timer);
742 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
743 
744 	RF_ETIMER_START(timer);
745 #endif
746 	rf_FreeAccessStripeMap(asmh);
747 #if RF_ACC_TRACE > 0
748 	RF_ETIMER_STOP(timer);
749 	RF_ETIMER_EVAL(timer);
750 	tracerec->specific.user.cleanup_us += RF_ETIMER_VAL_US(timer);
751 
752 	RF_ETIMER_STOP(desc->timer);
753 	RF_ETIMER_EVAL(desc->timer);
754 
755 	timer = desc->tracerec.tot_timer;
756 	RF_ETIMER_STOP(timer);
757 	RF_ETIMER_EVAL(timer);
758 	desc->tracerec.total_us = RF_ETIMER_VAL_US(timer);
759 
760 	rf_LogTraceRec(raidPtr, tracerec);
761 #endif
762 	desc->flags |= RF_DAG_ACCESS_COMPLETE;
763 
764 	return RF_FALSE;
765 }
766