xref: /netbsd-src/sys/dev/raidframe/rf_declusterPQ.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: rf_declusterPQ.c,v 1.5 2001/01/26 14:06:17 oster Exp $	*/
2 /*
3  * Copyright (c) 1995 Carnegie-Mellon University.
4  * All rights reserved.
5  *
6  * Authors: Daniel Stodolsky, Mark Holland, Jim Zelenka
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  * rf_declusterPQ.c
31  *
32  * mapping code for declustered P & Q or declustered EvenOdd
33  * much code borrowed from rf_decluster.c
34  *
35  *--------------------------------------------------*/
36 
37 #include "rf_archs.h"
38 #include "rf_types.h"
39 #include "rf_raid.h"
40 #include "rf_configure.h"
41 #include "rf_decluster.h"
42 #include "rf_declusterPQ.h"
43 #include "rf_debugMem.h"
44 #include "rf_utils.h"
45 #include "rf_alloclist.h"
46 #include "rf_general.h"
47 
48 #if (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) || (RF_INCLUDE_EVENODD > 0)
49 /* configuration code */
50 
51 int
52 rf_ConfigureDeclusteredPQ(
53     RF_ShutdownList_t ** listp,
54     RF_Raid_t * raidPtr,
55     RF_Config_t * cfgPtr)
56 {
57 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
58 	int     b, v, k, r, lambda;	/* block design params */
59 	int     i, j, l;
60 	int    *first_avail_slot;
61 	int     complete_FT_count, SUID;
62 	RF_DeclusteredConfigInfo_t *info;
63 	int     numCompleteFullTablesPerDisk;
64 	int     PUsPerDisk, spareRegionDepthInPUs, numCompleteSpareRegionsPerDisk = 0,
65 	        extraPUsPerDisk;
66 	int     totSparePUsPerDisk;
67 	int     diskOffsetOfLastFullTableInSUs, SpareSpaceInSUs;
68 	char   *cfgBuf = (char *) (cfgPtr->layoutSpecific);
69 
70 	cfgBuf += RF_SPAREMAP_NAME_LEN;
71 
72 	b = *((int *) cfgBuf);
73 	cfgBuf += sizeof(int);
74 	v = *((int *) cfgBuf);
75 	cfgBuf += sizeof(int);
76 	k = *((int *) cfgBuf);
77 	cfgBuf += sizeof(int);
78 	r = *((int *) cfgBuf);
79 	cfgBuf += sizeof(int);
80 	lambda = *((int *) cfgBuf);
81 	cfgBuf += sizeof(int);
82 	raidPtr->noRotate = *((int *) cfgBuf);
83 	cfgBuf += sizeof(int);
84 
85 	if (k <= 2) {
86 		printf("RAIDFRAME: k=%d, minimum value 2\n", k);
87 		return (EINVAL);
88 	}
89 	/* 1. create layout specific structure */
90 	RF_MallocAndAdd(info, sizeof(RF_DeclusteredConfigInfo_t), (RF_DeclusteredConfigInfo_t *), raidPtr->cleanupList);
91 	if (info == NULL)
92 		return (ENOMEM);
93 	layoutPtr->layoutSpecificInfo = (void *) info;
94 
95 	/* the sparemaps are generated assuming that parity is rotated, so we
96 	 * issue a warning if both distributed sparing and no-rotate are on at
97 	 * the same time */
98 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) && raidPtr->noRotate) {
99 		RF_ERRORMSG("Warning:  distributed sparing specified without parity rotation.\n");
100 	}
101 	if (raidPtr->numCol != v) {
102 		RF_ERRORMSG2("RAID: config error: table element count (%d) not equal to no. of cols (%d)\n", v, raidPtr->numCol);
103 		return (EINVAL);
104 	}
105 	/* 3.  set up the values used in devRaidMap */
106 	info->BlocksPerTable = b;
107 	info->NumParityReps = info->groupSize = k;
108 	info->PUsPerBlock = k - 2;	/* PQ */
109 	info->SUsPerTable = b * info->PUsPerBlock * layoutPtr->SUsPerPU;	/* b blks, k-1 SUs each */
110 	info->SUsPerFullTable = k * info->SUsPerTable;	/* rot k times */
111 	info->SUsPerBlock = info->PUsPerBlock * layoutPtr->SUsPerPU;
112 	info->TableDepthInPUs = (b * k) / v;
113 	info->FullTableDepthInPUs = info->TableDepthInPUs * k;	/* k repetitions */
114 
115 	/* used only in distributed sparing case */
116 	info->FullTablesPerSpareRegion = (v - 1) / rf_gcd(r, v - 1);	/* (v-1)/gcd fulltables */
117 	info->TablesPerSpareRegion = k * info->FullTablesPerSpareRegion;
118 	info->SpareSpaceDepthPerRegionInSUs = (r * info->TablesPerSpareRegion / (v - 1)) * layoutPtr->SUsPerPU;
119 
120 	/* check to make sure the block design is sufficiently small */
121 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
122 		if (info->FullTableDepthInPUs * layoutPtr->SUsPerPU + info->SpareSpaceDepthPerRegionInSUs > layoutPtr->stripeUnitsPerDisk) {
123 			RF_ERRORMSG3("RAID: config error: Full Table depth (%d) + Spare Space (%d) larger than disk size (%d) (BD too big)\n",
124 			    (int) info->FullTableDepthInPUs,
125 			    (int) info->SpareSpaceDepthPerRegionInSUs,
126 			    (int) layoutPtr->stripeUnitsPerDisk);
127 			return (EINVAL);
128 		}
129 	} else {
130 		if (info->TableDepthInPUs * layoutPtr->SUsPerPU > layoutPtr->stripeUnitsPerDisk) {
131 			RF_ERRORMSG2("RAID: config error: Table depth (%d) larger than disk size (%d) (BD too big)\n",
132 			    (int) (info->TableDepthInPUs * layoutPtr->SUsPerPU),
133 			    (int) layoutPtr->stripeUnitsPerDisk);
134 			return (EINVAL);
135 		}
136 	}
137 
138 
139 	/* compute the size of each disk, and the number of tables in the last
140 	 * fulltable (which need not be complete) */
141 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
142 
143 		PUsPerDisk = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU;
144 		spareRegionDepthInPUs = (info->TablesPerSpareRegion * info->TableDepthInPUs +
145 		    (info->TablesPerSpareRegion * info->TableDepthInPUs) / (v - 1));
146 		info->SpareRegionDepthInSUs = spareRegionDepthInPUs * layoutPtr->SUsPerPU;
147 
148 		numCompleteSpareRegionsPerDisk = PUsPerDisk / spareRegionDepthInPUs;
149 		info->NumCompleteSRs = numCompleteSpareRegionsPerDisk;
150 		extraPUsPerDisk = PUsPerDisk % spareRegionDepthInPUs;
151 
152 		/* assume conservatively that we need the full amount of spare
153 		 * space in one region in order to provide spares for the
154 		 * partial spare region at the end of the array.  We set "i"
155 		 * to the number of tables in the partial spare region.  This
156 		 * may actually include some fulltables. */
157 		extraPUsPerDisk -= (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
158 		if (extraPUsPerDisk <= 0)
159 			i = 0;
160 		else
161 			i = extraPUsPerDisk / info->TableDepthInPUs;
162 
163 		complete_FT_count = raidPtr->numRow * (numCompleteSpareRegionsPerDisk * (info->TablesPerSpareRegion / k) + i / k);
164 		info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
165 		info->ExtraTablesPerDisk = i % k;
166 
167 		/* note that in the last spare region, the spare space is
168 		 * complete even though data/parity space is not */
169 		totSparePUsPerDisk = (numCompleteSpareRegionsPerDisk + 1) * (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
170 		info->TotSparePUsPerDisk = totSparePUsPerDisk;
171 
172 		layoutPtr->stripeUnitsPerDisk =
173 		    ((complete_FT_count / raidPtr->numRow) * info->FullTableDepthInPUs +	/* data & parity space */
174 		    info->ExtraTablesPerDisk * info->TableDepthInPUs +
175 		    totSparePUsPerDisk	/* spare space */
176 		    ) * layoutPtr->SUsPerPU;
177 		layoutPtr->dataStripeUnitsPerDisk =
178 		    (complete_FT_count * info->FullTableDepthInPUs + info->ExtraTablesPerDisk * info->TableDepthInPUs)
179 		    * layoutPtr->SUsPerPU * (k - 1) / k;
180 
181 	} else {
182 		/* non-dist spare case:  force each disk to contain an
183 		 * integral number of tables */
184 		layoutPtr->stripeUnitsPerDisk /= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
185 		layoutPtr->stripeUnitsPerDisk *= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
186 
187 		/* compute the number of tables in the last fulltable, which
188 		 * need not be complete */
189 		complete_FT_count =
190 		    ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->FullTableDepthInPUs) * raidPtr->numRow;
191 
192 		info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
193 		info->ExtraTablesPerDisk =
194 		    ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->TableDepthInPUs) % k;
195 	}
196 
197 	raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
198 
199 	/* find the disk offset of the stripe unit where the last fulltable
200 	 * starts */
201 	numCompleteFullTablesPerDisk = complete_FT_count / raidPtr->numRow;
202 	diskOffsetOfLastFullTableInSUs = numCompleteFullTablesPerDisk * info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
203 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
204 		SpareSpaceInSUs = numCompleteSpareRegionsPerDisk * info->SpareSpaceDepthPerRegionInSUs;
205 		diskOffsetOfLastFullTableInSUs += SpareSpaceInSUs;
206 		info->DiskOffsetOfLastSpareSpaceChunkInSUs =
207 		    diskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU;
208 	}
209 	info->DiskOffsetOfLastFullTableInSUs = diskOffsetOfLastFullTableInSUs;
210 	info->numCompleteFullTablesPerDisk = numCompleteFullTablesPerDisk;
211 
212 	/* 4.  create and initialize the lookup tables */
213 	info->LayoutTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
214 	if (info->LayoutTable == NULL)
215 		return (ENOMEM);
216 	info->OffsetTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
217 	if (info->OffsetTable == NULL)
218 		return (ENOMEM);
219 	info->BlockTable = rf_make_2d_array(info->TableDepthInPUs * layoutPtr->SUsPerPU, raidPtr->numCol, raidPtr->cleanupList);
220 	if (info->BlockTable == NULL)
221 		return (ENOMEM);
222 
223 	first_avail_slot = (int *) rf_make_1d_array(v, NULL);
224 	if (first_avail_slot == NULL)
225 		return (ENOMEM);
226 
227 	for (i = 0; i < b; i++)
228 		for (j = 0; j < k; j++)
229 			info->LayoutTable[i][j] = *cfgBuf++;
230 
231 	/* initialize offset table */
232 	for (i = 0; i < b; i++)
233 		for (j = 0; j < k; j++) {
234 			info->OffsetTable[i][j] = first_avail_slot[info->LayoutTable[i][j]];
235 			first_avail_slot[info->LayoutTable[i][j]]++;
236 		}
237 
238 	/* initialize block table */
239 	for (SUID = l = 0; l < layoutPtr->SUsPerPU; l++) {
240 		for (i = 0; i < b; i++) {
241 			for (j = 0; j < k; j++) {
242 				info->BlockTable[(info->OffsetTable[i][j] * layoutPtr->SUsPerPU) + l]
243 				    [info->LayoutTable[i][j]] = SUID;
244 			}
245 			SUID++;
246 		}
247 	}
248 
249 	rf_free_1d_array(first_avail_slot, v);
250 
251 	/* 5.  set up the remaining redundant-but-useful parameters */
252 
253 	raidPtr->totalSectors = (k * complete_FT_count + raidPtr->numRow * info->ExtraTablesPerDisk) *
254 	    info->SUsPerTable * layoutPtr->sectorsPerStripeUnit;
255 	layoutPtr->numStripe = (raidPtr->totalSectors / layoutPtr->sectorsPerStripeUnit) / (k - 2);
256 
257 	/* strange evaluation order below to try and minimize overflow
258 	 * problems */
259 
260 	layoutPtr->dataSectorsPerStripe = (k - 2) * layoutPtr->sectorsPerStripeUnit;
261 	layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
262 	layoutPtr->numDataCol = k - 2;
263 	layoutPtr->numParityCol = 2;
264 
265 	return (0);
266 }
267 
268 int
269 rf_GetDefaultNumFloatingReconBuffersPQ(RF_Raid_t * raidPtr)
270 {
271 	int     def_decl;
272 
273 	def_decl = rf_GetDefaultNumFloatingReconBuffersDeclustered(raidPtr);
274 	return (RF_MAX(3 * raidPtr->numCol, def_decl));
275 }
276 
277 void
278 rf_MapSectorDeclusteredPQ(
279     RF_Raid_t * raidPtr,
280     RF_RaidAddr_t raidSector,
281     RF_RowCol_t * row,
282     RF_RowCol_t * col,
283     RF_SectorNum_t * diskSector,
284     int remap)
285 {
286 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
287 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
288 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
289 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
290 	RF_StripeNum_t BlockID, BlockOffset, RepIndex;
291 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
292 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
293 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0;
294 
295 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
296 
297 	FullTableID = SUID / sus_per_fulltable;	/* fulltable ID within array
298 						 * (across rows) */
299 	*row = FullTableID % raidPtr->numRow;
300 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
301 					 * disk */
302 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
303 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
304 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
305 	}
306 	FullTableOffset = SUID % sus_per_fulltable;
307 	TableID = FullTableOffset / info->SUsPerTable;
308 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
309 	BlockID = TableOffset / info->PUsPerBlock;
310 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
311 	BlockID %= info->BlocksPerTable;
312 	RF_ASSERT(BlockOffset < info->groupSize - 2);
313 	/*
314            TableIDs go from 0 .. GroupSize-1 inclusive.
315            PUsPerBlock is k-2.
316            We want the tableIDs to rotate from the
317            right, so use GroupSize
318            */
319 	RepIndex = info->groupSize - 1 - TableID;
320 	RF_ASSERT(RepIndex >= 0);
321 	if (!raidPtr->noRotate) {
322 		if (TableID == 0)
323 			BlockOffset++;	/* P on last drive, Q on first */
324 		else
325 			BlockOffset += ((BlockOffset >= RepIndex) ? 2 : 0);	/* skip over PQ */
326 		RF_ASSERT(BlockOffset < info->groupSize);
327 		*col = info->LayoutTable[BlockID][BlockOffset];
328 	}
329 	/* remap to distributed spare space if indicated */
330 	if (remap) {
331 		rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU);
332 	} else {
333 
334 		outSU = base_suid;
335 		outSU += FullTableID * fulltable_depth;	/* offs to strt of FT */
336 		outSU += SpareSpace;	/* skip rsvd spare space */
337 		outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;	/* offs to strt of tble */
338 		outSU += info->OffsetTable[BlockID][BlockOffset] * layoutPtr->SUsPerPU;	/* offs to the PU */
339 	}
340 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);	/* offs to the SU within
341 										 * a PU */
342 
343 	/* convert SUs to sectors, and, if not aligned to SU boundary, add in
344 	 * offset to sector */
345 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
346 }
347 
348 
349 void
350 rf_MapParityDeclusteredPQ(
351     RF_Raid_t * raidPtr,
352     RF_RaidAddr_t raidSector,
353     RF_RowCol_t * row,
354     RF_RowCol_t * col,
355     RF_SectorNum_t * diskSector,
356     int remap)
357 {
358 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
359 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
360 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
361 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
362 	RF_StripeNum_t BlockID, BlockOffset, RepIndex;
363 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
364 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
365 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion, SpareSpace = 0;
366 
367 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
368 
369 	/* compute row & (possibly) spare space exactly as before */
370 	FullTableID = SUID / sus_per_fulltable;
371 	*row = FullTableID % raidPtr->numRow;
372 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
373 					 * disk */
374 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
375 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
376 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
377 	}
378 	/* compute BlockID and RepIndex exactly as before */
379 	FullTableOffset = SUID % sus_per_fulltable;
380 	TableID = FullTableOffset / info->SUsPerTable;
381 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
382 	BlockID = TableOffset / info->PUsPerBlock;
383 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
384 	BlockID %= info->BlocksPerTable;
385 
386 	/* the parity block is in the position indicated by RepIndex */
387 	RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->groupSize - 1 - TableID;
388 	*col = info->LayoutTable[BlockID][RepIndex];
389 
390 	if (remap)
391 		RF_PANIC();
392 
393 	/* compute sector as before, except use RepIndex instead of
394 	 * BlockOffset */
395 	outSU = base_suid;
396 	outSU += FullTableID * fulltable_depth;
397 	outSU += SpareSpace;	/* skip rsvd spare space */
398 	outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;
399 	outSU += info->OffsetTable[BlockID][RepIndex] * layoutPtr->SUsPerPU;
400 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);
401 
402 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
403 }
404 
405 void
406 rf_MapQDeclusteredPQ(
407     RF_Raid_t * raidPtr,
408     RF_RaidAddr_t raidSector,
409     RF_RowCol_t * row,
410     RF_RowCol_t * col,
411     RF_SectorNum_t * diskSector,
412     int remap)
413 {
414 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
415 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
416 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
417 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
418 	RF_StripeNum_t BlockID, BlockOffset, RepIndex, RepIndexQ;
419 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
420 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
421 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion, SpareSpace = 0;
422 
423 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
424 
425 	/* compute row & (possibly) spare space exactly as before */
426 	FullTableID = SUID / sus_per_fulltable;
427 	*row = FullTableID % raidPtr->numRow;
428 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
429 					 * disk */
430 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
431 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
432 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
433 	}
434 	/* compute BlockID and RepIndex exactly as before */
435 	FullTableOffset = SUID % sus_per_fulltable;
436 	TableID = FullTableOffset / info->SUsPerTable;
437 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
438 	BlockID = TableOffset / info->PUsPerBlock;
439 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
440 	BlockID %= info->BlocksPerTable;
441 
442 	/* the q block is in the position indicated by RepIndex */
443 	RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->groupSize - 1 - TableID;
444 	RepIndexQ = ((RepIndex == (info->groupSize - 1)) ? 0 : RepIndex + 1);
445 	*col = info->LayoutTable[BlockID][RepIndexQ];
446 
447 	if (remap)
448 		RF_PANIC();
449 
450 	/* compute sector as before, except use RepIndex instead of
451 	 * BlockOffset */
452 	outSU = base_suid;
453 	outSU += FullTableID * fulltable_depth;
454 	outSU += SpareSpace;	/* skip rsvd spare space */
455 	outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;
456 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);
457 
458 	outSU += info->OffsetTable[BlockID][RepIndexQ] * layoutPtr->SUsPerPU;
459 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
460 }
461 /* returns an array of ints identifying the disks that comprise the stripe containing the indicated address.
462  * the caller must _never_ attempt to modify this array.
463  */
464 void
465 rf_IdentifyStripeDeclusteredPQ(
466     RF_Raid_t * raidPtr,
467     RF_RaidAddr_t addr,
468     RF_RowCol_t ** diskids,
469     RF_RowCol_t * outRow)
470 {
471 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
472 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
473 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
474 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
475 	RF_StripeNum_t base_suid = 0;
476 	RF_StripeNum_t SUID = rf_RaidAddressToStripeUnitID(layoutPtr, addr);
477 	RF_StripeNum_t stripeID, FullTableID;
478 	int     tableOffset;
479 
480 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
481 	FullTableID = SUID / sus_per_fulltable;	/* fulltable ID within array
482 						 * (across rows) */
483 	*outRow = FullTableID % raidPtr->numRow;
484 	stripeID = rf_StripeUnitIDToStripeID(layoutPtr, SUID);	/* find stripe offset
485 								 * into array */
486 	tableOffset = (stripeID % info->BlocksPerTable);	/* find offset into
487 								 * block design table */
488 	*diskids = info->LayoutTable[tableOffset];
489 }
490 #endif /* (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) || (RF_INCLUDE_EVENODD > 0) */
491