xref: /netbsd-src/sys/dev/raidframe/rf_states.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /*	$NetBSD: rf_states.c,v 1.44 2009/11/17 18:54:26 jld 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 1.44 2009/11/17 18:54:26 jld 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 	 * If this is not an async request, wake up the caller
221 	 */
222 	if (desc->async_flag == 0)
223 		wakeup(desc->bp);
224 
225 	/*
226 	 * That's all the IO for this one... unbusy the 'disk'.
227 	 */
228 
229 	rf_disk_unbusy(desc);
230 
231 	/*
232 	 * Wakeup any requests waiting to go.
233 	 */
234 
235 	RF_LOCK_MUTEX(((RF_Raid_t *) desc->raidPtr)->mutex);
236 	((RF_Raid_t *) desc->raidPtr)->openings++;
237 	RF_UNLOCK_MUTEX(((RF_Raid_t *) desc->raidPtr)->mutex);
238 
239 	wakeup(&(desc->raidPtr->iodone));
240 
241 	/*
242 	 * The parity_map hook has to go here, because the iodone
243 	 * callback goes straight into the kintf layer.
244 	 */
245 	if (desc->raidPtr->parity_map != NULL &&
246 	    desc->type == RF_IO_TYPE_WRITE)
247 		rf_paritymap_end(desc->raidPtr->parity_map,
248 		    desc->raidAddress, desc->numBlocks);
249 
250 	/* printf("Calling biodone on 0x%x\n",desc->bp); */
251 	biodone(desc->bp);	/* access came through ioctl */
252 
253 	if (callbackFunc)
254 		callbackFunc(callbackArg);
255 	rf_FreeRaidAccDesc(desc);
256 
257 	return RF_FALSE;
258 }
259 
260 int
261 rf_State_IncrAccessCount(RF_RaidAccessDesc_t *desc)
262 {
263 	RF_Raid_t *raidPtr;
264 
265 	raidPtr = desc->raidPtr;
266 	/* Bummer. We have to do this to be 100% safe w.r.t. the increment
267 	 * below */
268 	RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
269 	raidPtr->accs_in_flight++;	/* used to detect quiescence */
270 	RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
271 
272 	desc->state++;
273 	return RF_FALSE;
274 }
275 
276 int
277 rf_State_DecrAccessCount(RF_RaidAccessDesc_t *desc)
278 {
279 	RF_Raid_t *raidPtr;
280 
281 	raidPtr = desc->raidPtr;
282 
283 	RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
284 	raidPtr->accs_in_flight--;
285 	if (raidPtr->accesses_suspended && raidPtr->accs_in_flight == 0) {
286 		rf_SignalQuiescenceLock(raidPtr);
287 	}
288 	RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
289 
290 	desc->state++;
291 	return RF_FALSE;
292 }
293 
294 int
295 rf_State_Quiesce(RF_RaidAccessDesc_t *desc)
296 {
297 #if RF_ACC_TRACE > 0
298 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
299 	RF_Etimer_t timer;
300 #endif
301 	RF_CallbackDesc_t *cb;
302 	RF_Raid_t *raidPtr;
303 	int     suspended = RF_FALSE;
304 	int need_cb, used_cb;
305 
306 	raidPtr = desc->raidPtr;
307 
308 #if RF_ACC_TRACE > 0
309 	RF_ETIMER_START(timer);
310 	RF_ETIMER_START(desc->timer);
311 #endif
312 
313 	need_cb = 0;
314 	used_cb = 0;
315 	cb = NULL;
316 
317 	RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
318 	/* Do an initial check to see if we might need a callback structure */
319 	if (raidPtr->accesses_suspended) {
320 		need_cb = 1;
321 	}
322 	RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
323 
324 	if (need_cb) {
325 		/* create a callback if we might need it...
326 		   and we likely do. */
327 		cb = rf_AllocCallbackDesc();
328 	}
329 
330 	RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
331 	if (raidPtr->accesses_suspended) {
332 		cb->callbackFunc = (void (*) (RF_CBParam_t)) rf_ContinueRaidAccess;
333 		cb->callbackArg.p = (void *) desc;
334 		cb->next = raidPtr->quiesce_wait_list;
335 		raidPtr->quiesce_wait_list = cb;
336 		suspended = RF_TRUE;
337 		used_cb = 1;
338 	}
339 	RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
340 
341 	if ((need_cb == 1) && (used_cb == 0)) {
342 		rf_FreeCallbackDesc(cb);
343 	}
344 
345 #if RF_ACC_TRACE > 0
346 	RF_ETIMER_STOP(timer);
347 	RF_ETIMER_EVAL(timer);
348 	tracerec->specific.user.suspend_ovhd_us += RF_ETIMER_VAL_US(timer);
349 #endif
350 
351 #if RF_DEBUG_QUIESCE
352 	if (suspended && rf_quiesceDebug)
353 		printf("Stalling access due to quiescence lock\n");
354 #endif
355 	desc->state++;
356 	return suspended;
357 }
358 
359 int
360 rf_State_Map(RF_RaidAccessDesc_t *desc)
361 {
362 	RF_Raid_t *raidPtr = desc->raidPtr;
363 #if RF_ACC_TRACE > 0
364 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
365 	RF_Etimer_t timer;
366 
367 	RF_ETIMER_START(timer);
368 #endif
369 
370 	if (!(desc->asmap = rf_MapAccess(raidPtr, desc->raidAddress, desc->numBlocks,
371 		    desc->bufPtr, RF_DONT_REMAP)))
372 		RF_PANIC();
373 
374 #if RF_ACC_TRACE > 0
375 	RF_ETIMER_STOP(timer);
376 	RF_ETIMER_EVAL(timer);
377 	tracerec->specific.user.map_us = RF_ETIMER_VAL_US(timer);
378 #endif
379 
380 	desc->state++;
381 	return RF_FALSE;
382 }
383 
384 int
385 rf_State_Lock(RF_RaidAccessDesc_t *desc)
386 {
387 #if RF_ACC_TRACE > 0
388 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
389 	RF_Etimer_t timer;
390 #endif
391 	RF_Raid_t *raidPtr = desc->raidPtr;
392 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
393 	RF_AccessStripeMap_t *asm_p;
394 	RF_StripeNum_t lastStripeID = -1;
395 	int     suspended = RF_FALSE;
396 
397 #if RF_ACC_TRACE > 0
398 	RF_ETIMER_START(timer);
399 #endif
400 
401 	/* acquire each lock that we don't already hold */
402 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
403 		RF_ASSERT(RF_IO_IS_R_OR_W(desc->type));
404 		if (!rf_suppressLocksAndLargeWrites &&
405 		    asm_p->parityInfo &&
406 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS) &&
407 		    !(asm_p->flags & RF_ASM_FLAGS_LOCK_TRIED)) {
408 			asm_p->flags |= RF_ASM_FLAGS_LOCK_TRIED;
409 				/* locks must be acquired hierarchically */
410 			RF_ASSERT(asm_p->stripeID > lastStripeID);
411 			lastStripeID = asm_p->stripeID;
412 
413 			RF_INIT_LOCK_REQ_DESC(asm_p->lockReqDesc, desc->type,
414 					      (void (*) (struct buf *)) rf_ContinueRaidAccess, desc, asm_p,
415 					      raidPtr->Layout.dataSectorsPerStripe);
416 			if (rf_AcquireStripeLock(raidPtr->lockTable, asm_p->stripeID,
417 						 &asm_p->lockReqDesc)) {
418 				suspended = RF_TRUE;
419 				break;
420 			}
421 		}
422 		if (desc->type == RF_IO_TYPE_WRITE &&
423 		    raidPtr->status == rf_rs_reconstructing) {
424 			if (!(asm_p->flags & RF_ASM_FLAGS_FORCE_TRIED)) {
425 				int     val;
426 
427 				asm_p->flags |= RF_ASM_FLAGS_FORCE_TRIED;
428 				val = rf_ForceOrBlockRecon(raidPtr, asm_p,
429 							   (void (*) (RF_Raid_t *, void *)) rf_ContinueRaidAccess, desc);
430 				if (val == 0) {
431 					asm_p->flags |= RF_ASM_FLAGS_RECON_BLOCKED;
432 				} else {
433 					suspended = RF_TRUE;
434 					break;
435 				}
436 			} else {
437 #if RF_DEBUG_PSS > 0
438 				if (rf_pssDebug) {
439 					printf("raid%d: skipping force/block because already done, psid %ld\n",
440 					       desc->raidPtr->raidid,
441 					       (long) asm_p->stripeID);
442 				}
443 #endif
444 			}
445 		} else {
446 #if RF_DEBUG_PSS > 0
447 			if (rf_pssDebug) {
448 				printf("raid%d: skipping force/block because not write or not under recon, psid %ld\n",
449 				       desc->raidPtr->raidid,
450 				       (long) asm_p->stripeID);
451 			}
452 #endif
453 		}
454 	}
455 #if RF_ACC_TRACE > 0
456 	RF_ETIMER_STOP(timer);
457 	RF_ETIMER_EVAL(timer);
458 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
459 #endif
460 	if (suspended)
461 		return (RF_TRUE);
462 
463 	desc->state++;
464 	return (RF_FALSE);
465 }
466 /*
467  * the following three states create, execute, and post-process dags
468  * the error recovery unit is a single dag.
469  * by default, SelectAlgorithm creates an array of dags, one per parity stripe
470  * in some tricky cases, multiple dags per stripe are created
471  *   - dags within a parity stripe are executed sequentially (arbitrary order)
472  *   - dags for distinct parity stripes are executed concurrently
473  *
474  * repeat until all dags complete successfully -or- dag selection fails
475  *
476  * while !done
477  *   create dag(s) (SelectAlgorithm)
478  *   if dag
479  *     execute dag (DispatchDAG)
480  *     if dag successful
481  *       done (SUCCESS)
482  *     else
483  *       !done (RETRY - start over with new dags)
484  *   else
485  *     done (FAIL)
486  */
487 int
488 rf_State_CreateDAG(RF_RaidAccessDesc_t *desc)
489 {
490 #if RF_ACC_TRACE > 0
491 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
492 	RF_Etimer_t timer;
493 #endif
494 	RF_DagHeader_t *dag_h;
495 	RF_DagList_t *dagList;
496 	struct buf *bp;
497 	int     i, selectStatus;
498 
499 	/* generate a dag for the access, and fire it off.  When the dag
500 	 * completes, we'll get re-invoked in the next state. */
501 #if RF_ACC_TRACE > 0
502 	RF_ETIMER_START(timer);
503 #endif
504 	/* SelectAlgorithm returns one or more dags */
505 	selectStatus = rf_SelectAlgorithm(desc, desc->flags | RF_DAG_SUPPRESS_LOCKS);
506 #if RF_DEBUG_VALIDATE_DAG
507 	if (rf_printDAGsDebug) {
508 		dagList = desc->dagList;
509 		for (i = 0; i < desc->numStripes; i++) {
510 			rf_PrintDAGList(dagList->dags);
511 			dagList = dagList->next;
512 		}
513 	}
514 #endif /* RF_DEBUG_VALIDATE_DAG */
515 #if RF_ACC_TRACE > 0
516 	RF_ETIMER_STOP(timer);
517 	RF_ETIMER_EVAL(timer);
518 	/* update time to create all dags */
519 	tracerec->specific.user.dag_create_us = RF_ETIMER_VAL_US(timer);
520 #endif
521 
522 	desc->status = 0;	/* good status */
523 
524 	if (selectStatus || (desc->numRetries > RF_RETRY_THRESHOLD)) {
525 		/* failed to create a dag */
526 		/* this happens when there are too many faults or incomplete
527 		 * dag libraries */
528 		if (selectStatus) {
529 			printf("raid%d: failed to create a dag. "
530 			       "Too many component failures.\n",
531 			       desc->raidPtr->raidid);
532 		} else {
533 			printf("raid%d: IO failed after %d retries.\n",
534 			       desc->raidPtr->raidid, RF_RETRY_THRESHOLD);
535 		}
536 
537 		desc->status = 1; /* bad status */
538 		/* skip straight to rf_State_Cleanup() */
539 		desc->state = rf_CleanupState;
540 		bp = (struct buf *)desc->bp;
541 		bp->b_error = EIO;
542 		bp->b_resid = bp->b_bcount;
543 	} else {
544 		/* bind dags to desc */
545 		dagList = desc->dagList;
546 		for (i = 0; i < desc->numStripes; i++) {
547 			dag_h = dagList->dags;
548 			while (dag_h) {
549 				dag_h->bp = (struct buf *) desc->bp;
550 #if RF_ACC_TRACE > 0
551 				dag_h->tracerec = tracerec;
552 #endif
553 				dag_h = dag_h->next;
554 			}
555 			dagList = dagList->next;
556 		}
557 		desc->flags |= RF_DAG_DISPATCH_RETURNED;
558 		desc->state++;	/* next state should be rf_State_ExecuteDAG */
559 	}
560 	return RF_FALSE;
561 }
562 
563 
564 
565 /* the access has an list of dagLists, one dagList per parity stripe.
566  * fire the first dag in each parity stripe (dagList).
567  * dags within a stripe (dagList) must be executed sequentially
568  *  - this preserves atomic parity update
569  * dags for independents parity groups (stripes) are fired concurrently */
570 
571 int
572 rf_State_ExecuteDAG(RF_RaidAccessDesc_t *desc)
573 {
574 	int     i;
575 	RF_DagHeader_t *dag_h;
576 	RF_DagList_t *dagList;
577 
578 	/* next state is always rf_State_ProcessDAG important to do
579 	 * this before firing the first dag (it may finish before we
580 	 * leave this routine) */
581 	desc->state++;
582 
583 	/* sweep dag array, a stripe at a time, firing the first dag
584 	 * in each stripe */
585 	dagList = desc->dagList;
586 	for (i = 0; i < desc->numStripes; i++) {
587 		RF_ASSERT(dagList->numDags > 0);
588 		RF_ASSERT(dagList->numDagsDone == 0);
589 		RF_ASSERT(dagList->numDagsFired == 0);
590 #if RF_ACC_TRACE > 0
591 		RF_ETIMER_START(dagList->tracerec.timer);
592 #endif
593 		/* fire first dag in this stripe */
594 		dag_h = dagList->dags;
595 		RF_ASSERT(dag_h);
596 		dagList->numDagsFired++;
597 		rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess, dagList);
598 		dagList = dagList->next;
599 	}
600 
601 	/* the DAG will always call the callback, even if there was no
602 	 * blocking, so we are always suspended in this state */
603 	return RF_TRUE;
604 }
605 
606 
607 
608 /* rf_State_ProcessDAG is entered when a dag completes.
609  * first, check to all dags in the access have completed
610  * if not, fire as many dags as possible */
611 
612 int
613 rf_State_ProcessDAG(RF_RaidAccessDesc_t *desc)
614 {
615 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
616 	RF_Raid_t *raidPtr = desc->raidPtr;
617 	RF_DagHeader_t *dag_h;
618 	int     i, j, done = RF_TRUE;
619 	RF_DagList_t *dagList, *temp;
620 
621 	/* check to see if this is the last dag */
622 	dagList = desc->dagList;
623 	for (i = 0; i < desc->numStripes; i++) {
624 		if (dagList->numDags != dagList->numDagsDone)
625 			done = RF_FALSE;
626 		dagList = dagList->next;
627 	}
628 
629 	if (done) {
630 		if (desc->status) {
631 			/* a dag failed, retry */
632 			/* free all dags */
633 			dagList = desc->dagList;
634 			for (i = 0; i < desc->numStripes; i++) {
635 				rf_FreeDAG(dagList->dags);
636 				temp = dagList;
637 				dagList = dagList->next;
638 				rf_FreeDAGList(temp);
639 			}
640 			desc->dagList = NULL;
641 
642 			rf_MarkFailuresInASMList(raidPtr, asmh);
643 
644 			/* note the retry so that we'll bail in
645 			   rf_State_CreateDAG() once we've retired
646 			   the IO RF_RETRY_THRESHOLD times */
647 
648 			desc->numRetries++;
649 
650 			/* back up to rf_State_CreateDAG */
651 			desc->state = desc->state - 2;
652 			return RF_FALSE;
653 		} else {
654 			/* move on to rf_State_Cleanup */
655 			desc->state++;
656 		}
657 		return RF_FALSE;
658 	} else {
659 		/* more dags to execute */
660 		/* see if any are ready to be fired.  if so, fire them */
661 		/* don't fire the initial dag in a list, it's fired in
662 		 * rf_State_ExecuteDAG */
663 		dagList = desc->dagList;
664 		for (i = 0; i < desc->numStripes; i++) {
665 			if ((dagList->numDagsDone < dagList->numDags)
666 			    && (dagList->numDagsDone == dagList->numDagsFired)
667 			    && (dagList->numDagsFired > 0)) {
668 #if RF_ACC_TRACE > 0
669 				RF_ETIMER_START(dagList->tracerec.timer);
670 #endif
671 				/* fire next dag in this stripe */
672 				/* first, skip to next dag awaiting execution */
673 				dag_h = dagList->dags;
674 				for (j = 0; j < dagList->numDagsDone; j++)
675 					dag_h = dag_h->next;
676 				dagList->numDagsFired++;
677 				rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess,
678 				    dagList);
679 			}
680 			dagList = dagList->next;
681 		}
682 		return RF_TRUE;
683 	}
684 }
685 /* only make it this far if all dags complete successfully */
686 int
687 rf_State_Cleanup(RF_RaidAccessDesc_t *desc)
688 {
689 #if RF_ACC_TRACE > 0
690 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
691 	RF_Etimer_t timer;
692 #endif
693 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
694 	RF_Raid_t *raidPtr = desc->raidPtr;
695 	RF_AccessStripeMap_t *asm_p;
696 	RF_DagList_t *dagList;
697 	int i;
698 
699 	desc->state++;
700 
701 #if RF_ACC_TRACE > 0
702 	timer = tracerec->timer;
703 	RF_ETIMER_STOP(timer);
704 	RF_ETIMER_EVAL(timer);
705 	tracerec->specific.user.dag_retry_us = RF_ETIMER_VAL_US(timer);
706 
707 	/* the RAID I/O is complete.  Clean up. */
708 	tracerec->specific.user.dag_retry_us = 0;
709 
710 	RF_ETIMER_START(timer);
711 #endif
712 	/* free all dags */
713 	dagList = desc->dagList;
714 	for (i = 0; i < desc->numStripes; i++) {
715 		rf_FreeDAG(dagList->dags);
716 		dagList = dagList->next;
717 	}
718 #if RF_ACC_TRACE > 0
719 	RF_ETIMER_STOP(timer);
720 	RF_ETIMER_EVAL(timer);
721 	tracerec->specific.user.cleanup_us = RF_ETIMER_VAL_US(timer);
722 
723 	RF_ETIMER_START(timer);
724 #endif
725 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
726 		if (!rf_suppressLocksAndLargeWrites &&
727 		    asm_p->parityInfo &&
728 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS)) {
729 			RF_ASSERT_VALID_LOCKREQ(&asm_p->lockReqDesc);
730 			rf_ReleaseStripeLock(raidPtr->lockTable,
731 					     asm_p->stripeID,
732 					     &asm_p->lockReqDesc);
733 		}
734 		if (asm_p->flags & RF_ASM_FLAGS_RECON_BLOCKED) {
735 			rf_UnblockRecon(raidPtr, asm_p);
736 		}
737 	}
738 #if RF_ACC_TRACE > 0
739 	RF_ETIMER_STOP(timer);
740 	RF_ETIMER_EVAL(timer);
741 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
742 
743 	RF_ETIMER_START(timer);
744 #endif
745 	rf_FreeAccessStripeMap(asmh);
746 #if RF_ACC_TRACE > 0
747 	RF_ETIMER_STOP(timer);
748 	RF_ETIMER_EVAL(timer);
749 	tracerec->specific.user.cleanup_us += RF_ETIMER_VAL_US(timer);
750 
751 	RF_ETIMER_STOP(desc->timer);
752 	RF_ETIMER_EVAL(desc->timer);
753 
754 	timer = desc->tracerec.tot_timer;
755 	RF_ETIMER_STOP(timer);
756 	RF_ETIMER_EVAL(timer);
757 	desc->tracerec.total_us = RF_ETIMER_VAL_US(timer);
758 
759 	rf_LogTraceRec(raidPtr, tracerec);
760 #endif
761 	desc->flags |= RF_DAG_ACCESS_COMPLETE;
762 
763 	return RF_FALSE;
764 }
765