xref: /netbsd/sys/dev/raidframe/rf_raid1.c (revision bf9ec67e)
1 /*	$NetBSD: rf_raid1.c,v 1.8 2001/11/13 07:11:16 lukem Exp $	*/
2 /*
3  * Copyright (c) 1995 Carnegie-Mellon University.
4  * All rights reserved.
5  *
6  * Author: William V. Courtright II
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 /*****************************************************************************
30  *
31  * rf_raid1.c -- implements RAID Level 1
32  *
33  *****************************************************************************/
34 
35 #include <sys/cdefs.h>
36 __KERNEL_RCSID(0, "$NetBSD: rf_raid1.c,v 1.8 2001/11/13 07:11:16 lukem Exp $");
37 
38 #include "rf_raid.h"
39 #include "rf_raid1.h"
40 #include "rf_dag.h"
41 #include "rf_dagffrd.h"
42 #include "rf_dagffwr.h"
43 #include "rf_dagdegrd.h"
44 #include "rf_dagutils.h"
45 #include "rf_dagfuncs.h"
46 #include "rf_diskqueue.h"
47 #include "rf_general.h"
48 #include "rf_utils.h"
49 #include "rf_parityscan.h"
50 #include "rf_mcpair.h"
51 #include "rf_layout.h"
52 #include "rf_map.h"
53 #include "rf_engine.h"
54 #include "rf_reconbuffer.h"
55 
56 typedef struct RF_Raid1ConfigInfo_s {
57 	RF_RowCol_t **stripeIdentifier;
58 }       RF_Raid1ConfigInfo_t;
59 /* start of day code specific to RAID level 1 */
60 int
61 rf_ConfigureRAID1(
62     RF_ShutdownList_t ** listp,
63     RF_Raid_t * raidPtr,
64     RF_Config_t * cfgPtr)
65 {
66 	RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
67 	RF_Raid1ConfigInfo_t *info;
68 	RF_RowCol_t i;
69 
70 	/* create a RAID level 1 configuration structure */
71 	RF_MallocAndAdd(info, sizeof(RF_Raid1ConfigInfo_t), (RF_Raid1ConfigInfo_t *), raidPtr->cleanupList);
72 	if (info == NULL)
73 		return (ENOMEM);
74 	layoutPtr->layoutSpecificInfo = (void *) info;
75 
76 	/* ... and fill it in. */
77 	info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol / 2, 2, raidPtr->cleanupList);
78 	if (info->stripeIdentifier == NULL)
79 		return (ENOMEM);
80 	for (i = 0; i < (raidPtr->numCol / 2); i++) {
81 		info->stripeIdentifier[i][0] = (2 * i);
82 		info->stripeIdentifier[i][1] = (2 * i) + 1;
83 	}
84 
85 	RF_ASSERT(raidPtr->numRow == 1);
86 
87 	/* this implementation of RAID level 1 uses one row of numCol disks
88 	 * and allows multiple (numCol / 2) stripes per row.  A stripe
89 	 * consists of a single data unit and a single parity (mirror) unit.
90 	 * stripe id = raidAddr / stripeUnitSize */
91 	raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * (raidPtr->numCol / 2) * layoutPtr->sectorsPerStripeUnit;
92 	layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk * (raidPtr->numCol / 2);
93 	layoutPtr->dataSectorsPerStripe = layoutPtr->sectorsPerStripeUnit;
94 	layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
95 	layoutPtr->numDataCol = 1;
96 	layoutPtr->numParityCol = 1;
97 	return (0);
98 }
99 
100 
101 /* returns the physical disk location of the primary copy in the mirror pair */
102 void
103 rf_MapSectorRAID1(
104     RF_Raid_t * raidPtr,
105     RF_RaidAddr_t raidSector,
106     RF_RowCol_t * row,
107     RF_RowCol_t * col,
108     RF_SectorNum_t * diskSector,
109     int remap)
110 {
111 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
112 	RF_RowCol_t mirrorPair = SUID % (raidPtr->numCol / 2);
113 
114 	*row = 0;
115 	*col = 2 * mirrorPair;
116 	*diskSector = ((SUID / (raidPtr->numCol / 2)) * raidPtr->Layout.sectorsPerStripeUnit) + (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
117 }
118 
119 
120 /* Map Parity
121  *
122  * returns the physical disk location of the secondary copy in the mirror
123  * pair
124  */
125 void
126 rf_MapParityRAID1(
127     RF_Raid_t * raidPtr,
128     RF_RaidAddr_t raidSector,
129     RF_RowCol_t * row,
130     RF_RowCol_t * col,
131     RF_SectorNum_t * diskSector,
132     int remap)
133 {
134 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
135 	RF_RowCol_t mirrorPair = SUID % (raidPtr->numCol / 2);
136 
137 	*row = 0;
138 	*col = (2 * mirrorPair) + 1;
139 
140 	*diskSector = ((SUID / (raidPtr->numCol / 2)) * raidPtr->Layout.sectorsPerStripeUnit) + (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
141 }
142 
143 
144 /* IdentifyStripeRAID1
145  *
146  * returns a list of disks for a given redundancy group
147  */
148 void
149 rf_IdentifyStripeRAID1(
150     RF_Raid_t * raidPtr,
151     RF_RaidAddr_t addr,
152     RF_RowCol_t ** diskids,
153     RF_RowCol_t * outRow)
154 {
155 	RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
156 	RF_Raid1ConfigInfo_t *info = raidPtr->Layout.layoutSpecificInfo;
157 	RF_ASSERT(stripeID >= 0);
158 	RF_ASSERT(addr >= 0);
159 	*outRow = 0;
160 	*diskids = info->stripeIdentifier[stripeID % (raidPtr->numCol / 2)];
161 	RF_ASSERT(*diskids);
162 }
163 
164 
165 /* MapSIDToPSIDRAID1
166  *
167  * maps a logical stripe to a stripe in the redundant array
168  */
169 void
170 rf_MapSIDToPSIDRAID1(
171     RF_RaidLayout_t * layoutPtr,
172     RF_StripeNum_t stripeID,
173     RF_StripeNum_t * psID,
174     RF_ReconUnitNum_t * which_ru)
175 {
176 	*which_ru = 0;
177 	*psID = stripeID;
178 }
179 
180 
181 
182 /******************************************************************************
183  * select a graph to perform a single-stripe access
184  *
185  * Parameters:  raidPtr    - description of the physical array
186  *              type       - type of operation (read or write) requested
187  *              asmap      - logical & physical addresses for this access
188  *              createFunc - name of function to use to create the graph
189  *****************************************************************************/
190 
191 void
192 rf_RAID1DagSelect(
193     RF_Raid_t * raidPtr,
194     RF_IoType_t type,
195     RF_AccessStripeMap_t * asmap,
196     RF_VoidFuncPtr * createFunc)
197 {
198 	RF_RowCol_t frow, fcol, or, oc;
199 	RF_PhysDiskAddr_t *failedPDA;
200 	int     prior_recon;
201 	RF_RowStatus_t rstat;
202 	RF_SectorNum_t oo;
203 
204 
205 	RF_ASSERT(RF_IO_IS_R_OR_W(type));
206 
207 	if (asmap->numDataFailed + asmap->numParityFailed > 1) {
208 		RF_ERRORMSG("Multiple disks failed in a single group!  Aborting I/O operation.\n");
209 		*createFunc = NULL;
210 		return;
211 	}
212 	if (asmap->numDataFailed + asmap->numParityFailed) {
213 		/*
214 	         * We've got a fault. Re-map to spare space, iff applicable.
215 	         * Shouldn't the arch-independent code do this for us?
216 	         * Anyway, it turns out if we don't do this here, then when
217 	         * we're reconstructing, writes go only to the surviving
218 	         * original disk, and aren't reflected on the reconstructed
219 	         * spare. Oops. --jimz
220 	         */
221 		failedPDA = asmap->failedPDAs[0];
222 		frow = failedPDA->row;
223 		fcol = failedPDA->col;
224 		rstat = raidPtr->status[frow];
225 		prior_recon = (rstat == rf_rs_reconfigured) || (
226 		    (rstat == rf_rs_reconstructing) ?
227 		    rf_CheckRUReconstructed(raidPtr->reconControl[frow]->reconMap, failedPDA->startSector) : 0
228 		    );
229 		if (prior_recon) {
230 			or = frow;
231 			oc = fcol;
232 			oo = failedPDA->startSector;
233 			/*
234 		         * If we did distributed sparing, we'd monkey with that here.
235 		         * But we don't, so we'll
236 		         */
237 			failedPDA->row = raidPtr->Disks[frow][fcol].spareRow;
238 			failedPDA->col = raidPtr->Disks[frow][fcol].spareCol;
239 			/*
240 		         * Redirect other components, iff necessary. This looks
241 		         * pretty suspicious to me, but it's what the raid5
242 		         * DAG select does.
243 		         */
244 			if (asmap->parityInfo->next) {
245 				if (failedPDA == asmap->parityInfo) {
246 					failedPDA->next->row = failedPDA->row;
247 					failedPDA->next->col = failedPDA->col;
248 				} else {
249 					if (failedPDA == asmap->parityInfo->next) {
250 						asmap->parityInfo->row = failedPDA->row;
251 						asmap->parityInfo->col = failedPDA->col;
252 					}
253 				}
254 			}
255 			if (rf_dagDebug || rf_mapDebug) {
256 				printf("raid%d: Redirected type '%c' r %d c %d o %ld -> r %d c %d o %ld\n",
257 				       raidPtr->raidid, type, or, oc,
258 				       (long) oo, failedPDA->row,
259 				       failedPDA->col,
260 				       (long) failedPDA->startSector);
261 			}
262 			asmap->numDataFailed = asmap->numParityFailed = 0;
263 		}
264 	}
265 	if (type == RF_IO_TYPE_READ) {
266 		if (asmap->numDataFailed == 0)
267 			*createFunc = (RF_VoidFuncPtr) rf_CreateMirrorIdleReadDAG;
268 		else
269 			*createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneDegradedReadDAG;
270 	} else {
271 		*createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG;
272 	}
273 }
274 
275 int
276 rf_VerifyParityRAID1(
277     RF_Raid_t * raidPtr,
278     RF_RaidAddr_t raidAddr,
279     RF_PhysDiskAddr_t * parityPDA,
280     int correct_it,
281     RF_RaidAccessFlags_t flags)
282 {
283 	int     nbytes, bcount, stripeWidth, ret, i, j, nbad, *bbufs;
284 	RF_DagNode_t *blockNode, *unblockNode, *wrBlock;
285 	RF_DagHeader_t *rd_dag_h, *wr_dag_h;
286 	RF_AccessStripeMapHeader_t *asm_h;
287 	RF_AllocListElem_t *allocList;
288 	RF_AccTraceEntry_t tracerec;
289 	RF_ReconUnitNum_t which_ru;
290 	RF_RaidLayout_t *layoutPtr;
291 	RF_AccessStripeMap_t *aasm;
292 	RF_SectorCount_t nsector;
293 	RF_RaidAddr_t startAddr;
294 	char   *buf, *buf1, *buf2;
295 	RF_PhysDiskAddr_t *pda;
296 	RF_StripeNum_t psID;
297 	RF_MCPair_t *mcpair;
298 
299 	layoutPtr = &raidPtr->Layout;
300 	startAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, raidAddr);
301 	nsector = parityPDA->numSector;
302 	nbytes = rf_RaidAddressToByte(raidPtr, nsector);
303 	psID = rf_RaidAddressToParityStripeID(layoutPtr, raidAddr, &which_ru);
304 
305 	asm_h = NULL;
306 	rd_dag_h = wr_dag_h = NULL;
307 	mcpair = NULL;
308 
309 	ret = RF_PARITY_COULD_NOT_VERIFY;
310 
311 	rf_MakeAllocList(allocList);
312 	if (allocList == NULL)
313 		return (RF_PARITY_COULD_NOT_VERIFY);
314 	mcpair = rf_AllocMCPair();
315 	if (mcpair == NULL)
316 		goto done;
317 	RF_ASSERT(layoutPtr->numDataCol == layoutPtr->numParityCol);
318 	stripeWidth = layoutPtr->numDataCol + layoutPtr->numParityCol;
319 	bcount = nbytes * (layoutPtr->numDataCol + layoutPtr->numParityCol);
320 	RF_MallocAndAdd(buf, bcount, (char *), allocList);
321 	if (buf == NULL)
322 		goto done;
323 	if (rf_verifyParityDebug) {
324 		printf("raid%d: RAID1 parity verify: buf=%lx bcount=%d (%lx - %lx)\n",
325 		       raidPtr->raidid, (long) buf, bcount, (long) buf,
326 		       (long) buf + bcount);
327 	}
328 	/*
329          * Generate a DAG which will read the entire stripe- then we can
330          * just compare data chunks versus "parity" chunks.
331          */
332 
333 	rd_dag_h = rf_MakeSimpleDAG(raidPtr, stripeWidth, nbytes, buf,
334 	    rf_DiskReadFunc, rf_DiskReadUndoFunc, "Rod", allocList, flags,
335 	    RF_IO_NORMAL_PRIORITY);
336 	if (rd_dag_h == NULL)
337 		goto done;
338 	blockNode = rd_dag_h->succedents[0];
339 	unblockNode = blockNode->succedents[0]->succedents[0];
340 
341 	/*
342          * Map the access to physical disk addresses (PDAs)- this will
343          * get us both a list of data addresses, and "parity" addresses
344          * (which are really mirror copies).
345          */
346 	asm_h = rf_MapAccess(raidPtr, startAddr, layoutPtr->dataSectorsPerStripe,
347 	    buf, RF_DONT_REMAP);
348 	aasm = asm_h->stripeMap;
349 
350 	buf1 = buf;
351 	/*
352          * Loop through the data blocks, setting up read nodes for each.
353          */
354 	for (pda = aasm->physInfo, i = 0; i < layoutPtr->numDataCol; i++, pda = pda->next) {
355 		RF_ASSERT(pda);
356 
357 		rf_RangeRestrictPDA(raidPtr, parityPDA, pda, 0, 1);
358 
359 		RF_ASSERT(pda->numSector != 0);
360 		if (rf_TryToRedirectPDA(raidPtr, pda, 0)) {
361 			/* cannot verify parity with dead disk */
362 			goto done;
363 		}
364 		pda->bufPtr = buf1;
365 		blockNode->succedents[i]->params[0].p = pda;
366 		blockNode->succedents[i]->params[1].p = buf1;
367 		blockNode->succedents[i]->params[2].v = psID;
368 		blockNode->succedents[i]->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
369 		buf1 += nbytes;
370 	}
371 	RF_ASSERT(pda == NULL);
372 	/*
373          * keep i, buf1 running
374          *
375          * Loop through parity blocks, setting up read nodes for each.
376          */
377 	for (pda = aasm->parityInfo; i < layoutPtr->numDataCol + layoutPtr->numParityCol; i++, pda = pda->next) {
378 		RF_ASSERT(pda);
379 		rf_RangeRestrictPDA(raidPtr, parityPDA, pda, 0, 1);
380 		RF_ASSERT(pda->numSector != 0);
381 		if (rf_TryToRedirectPDA(raidPtr, pda, 0)) {
382 			/* cannot verify parity with dead disk */
383 			goto done;
384 		}
385 		pda->bufPtr = buf1;
386 		blockNode->succedents[i]->params[0].p = pda;
387 		blockNode->succedents[i]->params[1].p = buf1;
388 		blockNode->succedents[i]->params[2].v = psID;
389 		blockNode->succedents[i]->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
390 		buf1 += nbytes;
391 	}
392 	RF_ASSERT(pda == NULL);
393 
394 	memset((char *) &tracerec, 0, sizeof(tracerec));
395 	rd_dag_h->tracerec = &tracerec;
396 
397 	if (rf_verifyParityDebug > 1) {
398 		printf("raid%d: RAID1 parity verify read dag:\n",
399 		       raidPtr->raidid);
400 		rf_PrintDAGList(rd_dag_h);
401 	}
402 	RF_LOCK_MUTEX(mcpair->mutex);
403 	mcpair->flag = 0;
404 	rf_DispatchDAG(rd_dag_h, (void (*) (void *)) rf_MCPairWakeupFunc,
405 	    (void *) mcpair);
406 	while (mcpair->flag == 0) {
407 		RF_WAIT_MCPAIR(mcpair);
408 	}
409 	RF_UNLOCK_MUTEX(mcpair->mutex);
410 
411 	if (rd_dag_h->status != rf_enable) {
412 		RF_ERRORMSG("Unable to verify raid1 parity: can't read stripe\n");
413 		ret = RF_PARITY_COULD_NOT_VERIFY;
414 		goto done;
415 	}
416 	/*
417          * buf1 is the beginning of the data blocks chunk
418          * buf2 is the beginning of the parity blocks chunk
419          */
420 	buf1 = buf;
421 	buf2 = buf + (nbytes * layoutPtr->numDataCol);
422 	ret = RF_PARITY_OKAY;
423 	/*
424          * bbufs is "bad bufs"- an array whose entries are the data
425          * column numbers where we had miscompares. (That is, column 0
426          * and column 1 of the array are mirror copies, and are considered
427          * "data column 0" for this purpose).
428          */
429 	RF_MallocAndAdd(bbufs, layoutPtr->numParityCol * sizeof(int), (int *),
430 	    allocList);
431 	nbad = 0;
432 	/*
433          * Check data vs "parity" (mirror copy).
434          */
435 	for (i = 0; i < layoutPtr->numDataCol; i++) {
436 		if (rf_verifyParityDebug) {
437 			printf("raid%d: RAID1 parity verify %d bytes: i=%d buf1=%lx buf2=%lx buf=%lx\n",
438 			       raidPtr->raidid, nbytes, i, (long) buf1,
439 			       (long) buf2, (long) buf);
440 		}
441 		ret = memcmp(buf1, buf2, nbytes);
442 		if (ret) {
443 			if (rf_verifyParityDebug > 1) {
444 				for (j = 0; j < nbytes; j++) {
445 					if (buf1[j] != buf2[j])
446 						break;
447 				}
448 				printf("psid=%ld j=%d\n", (long) psID, j);
449 				printf("buf1 %02x %02x %02x %02x %02x\n", buf1[0] & 0xff,
450 				    buf1[1] & 0xff, buf1[2] & 0xff, buf1[3] & 0xff, buf1[4] & 0xff);
451 				printf("buf2 %02x %02x %02x %02x %02x\n", buf2[0] & 0xff,
452 				    buf2[1] & 0xff, buf2[2] & 0xff, buf2[3] & 0xff, buf2[4] & 0xff);
453 			}
454 			if (rf_verifyParityDebug) {
455 				printf("raid%d: RAID1: found bad parity, i=%d\n", raidPtr->raidid, i);
456 			}
457 			/*
458 		         * Parity is bad. Keep track of which columns were bad.
459 		         */
460 			if (bbufs)
461 				bbufs[nbad] = i;
462 			nbad++;
463 			ret = RF_PARITY_BAD;
464 		}
465 		buf1 += nbytes;
466 		buf2 += nbytes;
467 	}
468 
469 	if ((ret != RF_PARITY_OKAY) && correct_it) {
470 		ret = RF_PARITY_COULD_NOT_CORRECT;
471 		if (rf_verifyParityDebug) {
472 			printf("raid%d: RAID1 parity verify: parity not correct\n", raidPtr->raidid);
473 		}
474 		if (bbufs == NULL)
475 			goto done;
476 		/*
477 	         * Make a DAG with one write node for each bad unit. We'll simply
478 	         * write the contents of the data unit onto the parity unit for
479 	         * correction. (It's possible that the mirror copy was the correct
480 	         * copy, and that we're spooging good data by writing bad over it,
481 	         * but there's no way we can know that.
482 	         */
483 		wr_dag_h = rf_MakeSimpleDAG(raidPtr, nbad, nbytes, buf,
484 		    rf_DiskWriteFunc, rf_DiskWriteUndoFunc, "Wnp", allocList, flags,
485 		    RF_IO_NORMAL_PRIORITY);
486 		if (wr_dag_h == NULL)
487 			goto done;
488 		wrBlock = wr_dag_h->succedents[0];
489 		/*
490 	         * Fill in a write node for each bad compare.
491 	         */
492 		for (i = 0; i < nbad; i++) {
493 			j = i + layoutPtr->numDataCol;
494 			pda = blockNode->succedents[j]->params[0].p;
495 			pda->bufPtr = blockNode->succedents[i]->params[1].p;
496 			wrBlock->succedents[i]->params[0].p = pda;
497 			wrBlock->succedents[i]->params[1].p = pda->bufPtr;
498 			wrBlock->succedents[i]->params[2].v = psID;
499 			wrBlock->succedents[0]->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
500 		}
501 		memset((char *) &tracerec, 0, sizeof(tracerec));
502 		wr_dag_h->tracerec = &tracerec;
503 		if (rf_verifyParityDebug > 1) {
504 			printf("Parity verify write dag:\n");
505 			rf_PrintDAGList(wr_dag_h);
506 		}
507 		RF_LOCK_MUTEX(mcpair->mutex);
508 		mcpair->flag = 0;
509 		/* fire off the write DAG */
510 		rf_DispatchDAG(wr_dag_h, (void (*) (void *)) rf_MCPairWakeupFunc,
511 		    (void *) mcpair);
512 		while (!mcpair->flag) {
513 			RF_WAIT_COND(mcpair->cond, mcpair->mutex);
514 		}
515 		RF_UNLOCK_MUTEX(mcpair->mutex);
516 		if (wr_dag_h->status != rf_enable) {
517 			RF_ERRORMSG("Unable to correct RAID1 parity in VerifyParity\n");
518 			goto done;
519 		}
520 		ret = RF_PARITY_CORRECTED;
521 	}
522 done:
523 	/*
524          * All done. We might've gotten here without doing part of the function,
525          * so cleanup what we have to and return our running status.
526          */
527 	if (asm_h)
528 		rf_FreeAccessStripeMap(asm_h);
529 	if (rd_dag_h)
530 		rf_FreeDAG(rd_dag_h);
531 	if (wr_dag_h)
532 		rf_FreeDAG(wr_dag_h);
533 	if (mcpair)
534 		rf_FreeMCPair(mcpair);
535 	rf_FreeAllocList(allocList);
536 	if (rf_verifyParityDebug) {
537 		printf("raid%d: RAID1 parity verify, returning %d\n",
538 		       raidPtr->raidid, ret);
539 	}
540 	return (ret);
541 }
542 
543 int
544 rf_SubmitReconBufferRAID1(rbuf, keep_it, use_committed)
545 	RF_ReconBuffer_t *rbuf;	/* the recon buffer to submit */
546 	int     keep_it;	/* whether we can keep this buffer or we have
547 				 * to return it */
548 	int     use_committed;	/* whether to use a committed or an available
549 				 * recon buffer */
550 {
551 	RF_ReconParityStripeStatus_t *pssPtr;
552 	RF_ReconCtrl_t *reconCtrlPtr;
553 	RF_RaidLayout_t *layoutPtr;
554 	int     retcode, created;
555 	RF_CallbackDesc_t *cb, *p;
556 	RF_ReconBuffer_t *t;
557 	RF_Raid_t *raidPtr;
558 	caddr_t ta;
559 
560 	retcode = 0;
561 	created = 0;
562 
563 	raidPtr = rbuf->raidPtr;
564 	layoutPtr = &raidPtr->Layout;
565 	reconCtrlPtr = raidPtr->reconControl[rbuf->row];
566 
567 	RF_ASSERT(rbuf);
568 	RF_ASSERT(rbuf->col != reconCtrlPtr->fcol);
569 
570 	if (rf_reconbufferDebug) {
571 		printf("raid%d: RAID1 reconbuffer submission r%d c%d psid %ld ru%d (failed offset %ld)\n",
572 		       raidPtr->raidid, rbuf->row, rbuf->col,
573 		       (long) rbuf->parityStripeID, rbuf->which_ru,
574 		       (long) rbuf->failedDiskSectorOffset);
575 	}
576 	if (rf_reconDebug) {
577 		printf("RAID1 reconbuffer submit psid %ld buf %lx\n",
578 		    (long) rbuf->parityStripeID, (long) rbuf->buffer);
579 		printf("RAID1 psid %ld   %02x %02x %02x %02x %02x\n",
580 		    (long) rbuf->parityStripeID,
581 		    rbuf->buffer[0], rbuf->buffer[1], rbuf->buffer[2], rbuf->buffer[3],
582 		    rbuf->buffer[4]);
583 	}
584 	RF_LOCK_PSS_MUTEX(raidPtr, rbuf->row, rbuf->parityStripeID);
585 
586 	RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
587 
588 	pssPtr = rf_LookupRUStatus(raidPtr, reconCtrlPtr->pssTable,
589 	    rbuf->parityStripeID, rbuf->which_ru, RF_PSS_NONE, &created);
590 	RF_ASSERT(pssPtr);	/* if it didn't exist, we wouldn't have gotten
591 				 * an rbuf for it */
592 
593 	/*
594          * Since this is simple mirroring, the first submission for a stripe is also
595          * treated as the last.
596          */
597 
598 	t = NULL;
599 	if (keep_it) {
600 		if (rf_reconbufferDebug) {
601 			printf("raid%d: RAID1 rbuf submission: keeping rbuf\n",
602 			       raidPtr->raidid);
603 		}
604 		t = rbuf;
605 	} else {
606 		if (use_committed) {
607 			if (rf_reconbufferDebug) {
608 				printf("raid%d: RAID1 rbuf submission: using committed rbuf\n", raidPtr->raidid);
609 			}
610 			t = reconCtrlPtr->committedRbufs;
611 			RF_ASSERT(t);
612 			reconCtrlPtr->committedRbufs = t->next;
613 			t->next = NULL;
614 		} else
615 			if (reconCtrlPtr->floatingRbufs) {
616 				if (rf_reconbufferDebug) {
617 					printf("raid%d: RAID1 rbuf submission: using floating rbuf\n", raidPtr->raidid);
618 				}
619 				t = reconCtrlPtr->floatingRbufs;
620 				reconCtrlPtr->floatingRbufs = t->next;
621 				t->next = NULL;
622 			}
623 	}
624 	if (t == NULL) {
625 		if (rf_reconbufferDebug) {
626 			printf("raid%d: RAID1 rbuf submission: waiting for rbuf\n", raidPtr->raidid);
627 		}
628 		RF_ASSERT((keep_it == 0) && (use_committed == 0));
629 		raidPtr->procsInBufWait++;
630 		if ((raidPtr->procsInBufWait == (raidPtr->numCol - 1))
631 		    && (raidPtr->numFullReconBuffers == 0)) {
632 			/* ruh-ro */
633 			RF_ERRORMSG("Buffer wait deadlock\n");
634 			rf_PrintPSStatusTable(raidPtr, rbuf->row);
635 			RF_PANIC();
636 		}
637 		pssPtr->flags |= RF_PSS_BUFFERWAIT;
638 		cb = rf_AllocCallbackDesc();
639 		cb->row = rbuf->row;
640 		cb->col = rbuf->col;
641 		cb->callbackArg.v = rbuf->parityStripeID;
642 		cb->callbackArg2.v = rbuf->which_ru;
643 		cb->next = NULL;
644 		if (reconCtrlPtr->bufferWaitList == NULL) {
645 			/* we are the wait list- lucky us */
646 			reconCtrlPtr->bufferWaitList = cb;
647 		} else {
648 			/* append to wait list */
649 			for (p = reconCtrlPtr->bufferWaitList; p->next; p = p->next);
650 			p->next = cb;
651 		}
652 		retcode = 1;
653 		goto out;
654 	}
655 	if (t != rbuf) {
656 		t->row = rbuf->row;
657 		t->col = reconCtrlPtr->fcol;
658 		t->parityStripeID = rbuf->parityStripeID;
659 		t->which_ru = rbuf->which_ru;
660 		t->failedDiskSectorOffset = rbuf->failedDiskSectorOffset;
661 		t->spRow = rbuf->spRow;
662 		t->spCol = rbuf->spCol;
663 		t->spOffset = rbuf->spOffset;
664 		/* Swap buffers. DANCE! */
665 		ta = t->buffer;
666 		t->buffer = rbuf->buffer;
667 		rbuf->buffer = ta;
668 	}
669 	/*
670          * Use the rbuf we've been given as the target.
671          */
672 	RF_ASSERT(pssPtr->rbuf == NULL);
673 	pssPtr->rbuf = t;
674 
675 	t->count = 1;
676 	/*
677          * Below, we use 1 for numDataCol (which is equal to the count in the
678          * previous line), so we'll always be done.
679          */
680 	rf_CheckForFullRbuf(raidPtr, reconCtrlPtr, pssPtr, 1);
681 
682 out:
683 	RF_UNLOCK_PSS_MUTEX(raidPtr, rbuf->row, rbuf->parityStripeID);
684 	RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
685 	if (rf_reconbufferDebug) {
686 		printf("raid%d: RAID1 rbuf submission: returning %d\n",
687 		       raidPtr->raidid, retcode);
688 	}
689 	return (retcode);
690 }
691