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rf_declusterPQ.c revision 1.7
      1 /*	$NetBSD: rf_declusterPQ.c,v 1.7 2001/11/13 07:11:13 lukem 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 (at) 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 <sys/cdefs.h>
     38 __KERNEL_RCSID(0, "$NetBSD: rf_declusterPQ.c,v 1.7 2001/11/13 07:11:13 lukem Exp $");
     39 
     40 #include <dev/raidframe/raidframevar.h>
     41 
     42 #include "rf_archs.h"
     43 #include "rf_raid.h"
     44 #include "rf_decluster.h"
     45 #include "rf_declusterPQ.h"
     46 #include "rf_debugMem.h"
     47 #include "rf_utils.h"
     48 #include "rf_alloclist.h"
     49 #include "rf_general.h"
     50 
     51 #if (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) || (RF_INCLUDE_EVENODD > 0)
     52 /* configuration code */
     53 
     54 int
     55 rf_ConfigureDeclusteredPQ(
     56     RF_ShutdownList_t ** listp,
     57     RF_Raid_t * raidPtr,
     58     RF_Config_t * cfgPtr)
     59 {
     60 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
     61 	int     b, v, k, r, lambda;	/* block design params */
     62 	int     i, j, l;
     63 	int    *first_avail_slot;
     64 	int     complete_FT_count, SUID;
     65 	RF_DeclusteredConfigInfo_t *info;
     66 	int     numCompleteFullTablesPerDisk;
     67 	int     PUsPerDisk, spareRegionDepthInPUs, numCompleteSpareRegionsPerDisk = 0,
     68 	        extraPUsPerDisk;
     69 	int     totSparePUsPerDisk;
     70 	int     diskOffsetOfLastFullTableInSUs, SpareSpaceInSUs;
     71 	char   *cfgBuf = (char *) (cfgPtr->layoutSpecific);
     72 
     73 	cfgBuf += RF_SPAREMAP_NAME_LEN;
     74 
     75 	b = *((int *) cfgBuf);
     76 	cfgBuf += sizeof(int);
     77 	v = *((int *) cfgBuf);
     78 	cfgBuf += sizeof(int);
     79 	k = *((int *) cfgBuf);
     80 	cfgBuf += sizeof(int);
     81 	r = *((int *) cfgBuf);
     82 	cfgBuf += sizeof(int);
     83 	lambda = *((int *) cfgBuf);
     84 	cfgBuf += sizeof(int);
     85 	raidPtr->noRotate = *((int *) cfgBuf);
     86 	cfgBuf += sizeof(int);
     87 
     88 	if (k <= 2) {
     89 		printf("RAIDFRAME: k=%d, minimum value 2\n", k);
     90 		return (EINVAL);
     91 	}
     92 	/* 1. create layout specific structure */
     93 	RF_MallocAndAdd(info, sizeof(RF_DeclusteredConfigInfo_t), (RF_DeclusteredConfigInfo_t *), raidPtr->cleanupList);
     94 	if (info == NULL)
     95 		return (ENOMEM);
     96 	layoutPtr->layoutSpecificInfo = (void *) info;
     97 
     98 	/* the sparemaps are generated assuming that parity is rotated, so we
     99 	 * issue a warning if both distributed sparing and no-rotate are on at
    100 	 * the same time */
    101 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) && raidPtr->noRotate) {
    102 		RF_ERRORMSG("Warning:  distributed sparing specified without parity rotation.\n");
    103 	}
    104 	if (raidPtr->numCol != v) {
    105 		RF_ERRORMSG2("RAID: config error: table element count (%d) not equal to no. of cols (%d)\n", v, raidPtr->numCol);
    106 		return (EINVAL);
    107 	}
    108 	/* 3.  set up the values used in devRaidMap */
    109 	info->BlocksPerTable = b;
    110 	info->NumParityReps = info->groupSize = k;
    111 	info->PUsPerBlock = k - 2;	/* PQ */
    112 	info->SUsPerTable = b * info->PUsPerBlock * layoutPtr->SUsPerPU;	/* b blks, k-1 SUs each */
    113 	info->SUsPerFullTable = k * info->SUsPerTable;	/* rot k times */
    114 	info->SUsPerBlock = info->PUsPerBlock * layoutPtr->SUsPerPU;
    115 	info->TableDepthInPUs = (b * k) / v;
    116 	info->FullTableDepthInPUs = info->TableDepthInPUs * k;	/* k repetitions */
    117 
    118 	/* used only in distributed sparing case */
    119 	info->FullTablesPerSpareRegion = (v - 1) / rf_gcd(r, v - 1);	/* (v-1)/gcd fulltables */
    120 	info->TablesPerSpareRegion = k * info->FullTablesPerSpareRegion;
    121 	info->SpareSpaceDepthPerRegionInSUs = (r * info->TablesPerSpareRegion / (v - 1)) * layoutPtr->SUsPerPU;
    122 
    123 	/* check to make sure the block design is sufficiently small */
    124 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    125 		if (info->FullTableDepthInPUs * layoutPtr->SUsPerPU + info->SpareSpaceDepthPerRegionInSUs > layoutPtr->stripeUnitsPerDisk) {
    126 			RF_ERRORMSG3("RAID: config error: Full Table depth (%d) + Spare Space (%d) larger than disk size (%d) (BD too big)\n",
    127 			    (int) info->FullTableDepthInPUs,
    128 			    (int) info->SpareSpaceDepthPerRegionInSUs,
    129 			    (int) layoutPtr->stripeUnitsPerDisk);
    130 			return (EINVAL);
    131 		}
    132 	} else {
    133 		if (info->TableDepthInPUs * layoutPtr->SUsPerPU > layoutPtr->stripeUnitsPerDisk) {
    134 			RF_ERRORMSG2("RAID: config error: Table depth (%d) larger than disk size (%d) (BD too big)\n",
    135 			    (int) (info->TableDepthInPUs * layoutPtr->SUsPerPU),
    136 			    (int) layoutPtr->stripeUnitsPerDisk);
    137 			return (EINVAL);
    138 		}
    139 	}
    140 
    141 
    142 	/* compute the size of each disk, and the number of tables in the last
    143 	 * fulltable (which need not be complete) */
    144 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    145 
    146 		PUsPerDisk = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU;
    147 		spareRegionDepthInPUs = (info->TablesPerSpareRegion * info->TableDepthInPUs +
    148 		    (info->TablesPerSpareRegion * info->TableDepthInPUs) / (v - 1));
    149 		info->SpareRegionDepthInSUs = spareRegionDepthInPUs * layoutPtr->SUsPerPU;
    150 
    151 		numCompleteSpareRegionsPerDisk = PUsPerDisk / spareRegionDepthInPUs;
    152 		info->NumCompleteSRs = numCompleteSpareRegionsPerDisk;
    153 		extraPUsPerDisk = PUsPerDisk % spareRegionDepthInPUs;
    154 
    155 		/* assume conservatively that we need the full amount of spare
    156 		 * space in one region in order to provide spares for the
    157 		 * partial spare region at the end of the array.  We set "i"
    158 		 * to the number of tables in the partial spare region.  This
    159 		 * may actually include some fulltables. */
    160 		extraPUsPerDisk -= (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
    161 		if (extraPUsPerDisk <= 0)
    162 			i = 0;
    163 		else
    164 			i = extraPUsPerDisk / info->TableDepthInPUs;
    165 
    166 		complete_FT_count = raidPtr->numRow * (numCompleteSpareRegionsPerDisk * (info->TablesPerSpareRegion / k) + i / k);
    167 		info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
    168 		info->ExtraTablesPerDisk = i % k;
    169 
    170 		/* note that in the last spare region, the spare space is
    171 		 * complete even though data/parity space is not */
    172 		totSparePUsPerDisk = (numCompleteSpareRegionsPerDisk + 1) * (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
    173 		info->TotSparePUsPerDisk = totSparePUsPerDisk;
    174 
    175 		layoutPtr->stripeUnitsPerDisk =
    176 		    ((complete_FT_count / raidPtr->numRow) * info->FullTableDepthInPUs +	/* data & parity space */
    177 		    info->ExtraTablesPerDisk * info->TableDepthInPUs +
    178 		    totSparePUsPerDisk	/* spare space */
    179 		    ) * layoutPtr->SUsPerPU;
    180 		layoutPtr->dataStripeUnitsPerDisk =
    181 		    (complete_FT_count * info->FullTableDepthInPUs + info->ExtraTablesPerDisk * info->TableDepthInPUs)
    182 		    * layoutPtr->SUsPerPU * (k - 1) / k;
    183 
    184 	} else {
    185 		/* non-dist spare case:  force each disk to contain an
    186 		 * integral number of tables */
    187 		layoutPtr->stripeUnitsPerDisk /= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
    188 		layoutPtr->stripeUnitsPerDisk *= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
    189 
    190 		/* compute the number of tables in the last fulltable, which
    191 		 * need not be complete */
    192 		complete_FT_count =
    193 		    ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->FullTableDepthInPUs) * raidPtr->numRow;
    194 
    195 		info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
    196 		info->ExtraTablesPerDisk =
    197 		    ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->TableDepthInPUs) % k;
    198 	}
    199 
    200 	raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
    201 
    202 	/* find the disk offset of the stripe unit where the last fulltable
    203 	 * starts */
    204 	numCompleteFullTablesPerDisk = complete_FT_count / raidPtr->numRow;
    205 	diskOffsetOfLastFullTableInSUs = numCompleteFullTablesPerDisk * info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
    206 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    207 		SpareSpaceInSUs = numCompleteSpareRegionsPerDisk * info->SpareSpaceDepthPerRegionInSUs;
    208 		diskOffsetOfLastFullTableInSUs += SpareSpaceInSUs;
    209 		info->DiskOffsetOfLastSpareSpaceChunkInSUs =
    210 		    diskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU;
    211 	}
    212 	info->DiskOffsetOfLastFullTableInSUs = diskOffsetOfLastFullTableInSUs;
    213 	info->numCompleteFullTablesPerDisk = numCompleteFullTablesPerDisk;
    214 
    215 	/* 4.  create and initialize the lookup tables */
    216 	info->LayoutTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
    217 	if (info->LayoutTable == NULL)
    218 		return (ENOMEM);
    219 	info->OffsetTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
    220 	if (info->OffsetTable == NULL)
    221 		return (ENOMEM);
    222 	info->BlockTable = rf_make_2d_array(info->TableDepthInPUs * layoutPtr->SUsPerPU, raidPtr->numCol, raidPtr->cleanupList);
    223 	if (info->BlockTable == NULL)
    224 		return (ENOMEM);
    225 
    226 	first_avail_slot = (int *) rf_make_1d_array(v, NULL);
    227 	if (first_avail_slot == NULL)
    228 		return (ENOMEM);
    229 
    230 	for (i = 0; i < b; i++)
    231 		for (j = 0; j < k; j++)
    232 			info->LayoutTable[i][j] = *cfgBuf++;
    233 
    234 	/* initialize offset table */
    235 	for (i = 0; i < b; i++)
    236 		for (j = 0; j < k; j++) {
    237 			info->OffsetTable[i][j] = first_avail_slot[info->LayoutTable[i][j]];
    238 			first_avail_slot[info->LayoutTable[i][j]]++;
    239 		}
    240 
    241 	/* initialize block table */
    242 	for (SUID = l = 0; l < layoutPtr->SUsPerPU; l++) {
    243 		for (i = 0; i < b; i++) {
    244 			for (j = 0; j < k; j++) {
    245 				info->BlockTable[(info->OffsetTable[i][j] * layoutPtr->SUsPerPU) + l]
    246 				    [info->LayoutTable[i][j]] = SUID;
    247 			}
    248 			SUID++;
    249 		}
    250 	}
    251 
    252 	rf_free_1d_array(first_avail_slot, v);
    253 
    254 	/* 5.  set up the remaining redundant-but-useful parameters */
    255 
    256 	raidPtr->totalSectors = (k * complete_FT_count + raidPtr->numRow * info->ExtraTablesPerDisk) *
    257 	    info->SUsPerTable * layoutPtr->sectorsPerStripeUnit;
    258 	layoutPtr->numStripe = (raidPtr->totalSectors / layoutPtr->sectorsPerStripeUnit) / (k - 2);
    259 
    260 	/* strange evaluation order below to try and minimize overflow
    261 	 * problems */
    262 
    263 	layoutPtr->dataSectorsPerStripe = (k - 2) * layoutPtr->sectorsPerStripeUnit;
    264 	layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
    265 	layoutPtr->numDataCol = k - 2;
    266 	layoutPtr->numParityCol = 2;
    267 
    268 	return (0);
    269 }
    270 
    271 int
    272 rf_GetDefaultNumFloatingReconBuffersPQ(RF_Raid_t * raidPtr)
    273 {
    274 	int     def_decl;
    275 
    276 	def_decl = rf_GetDefaultNumFloatingReconBuffersDeclustered(raidPtr);
    277 	return (RF_MAX(3 * raidPtr->numCol, def_decl));
    278 }
    279 
    280 void
    281 rf_MapSectorDeclusteredPQ(
    282     RF_Raid_t * raidPtr,
    283     RF_RaidAddr_t raidSector,
    284     RF_RowCol_t * row,
    285     RF_RowCol_t * col,
    286     RF_SectorNum_t * diskSector,
    287     int remap)
    288 {
    289 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
    290 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
    291 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
    292 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
    293 	RF_StripeNum_t BlockID, BlockOffset, RepIndex;
    294 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
    295 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
    296 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0;
    297 
    298 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
    299 
    300 	FullTableID = SUID / sus_per_fulltable;	/* fulltable ID within array
    301 						 * (across rows) */
    302 	*row = FullTableID % raidPtr->numRow;
    303 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
    304 					 * disk */
    305 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    306 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
    307 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
    308 	}
    309 	FullTableOffset = SUID % sus_per_fulltable;
    310 	TableID = FullTableOffset / info->SUsPerTable;
    311 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
    312 	BlockID = TableOffset / info->PUsPerBlock;
    313 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
    314 	BlockID %= info->BlocksPerTable;
    315 	RF_ASSERT(BlockOffset < info->groupSize - 2);
    316 	/*
    317            TableIDs go from 0 .. GroupSize-1 inclusive.
    318            PUsPerBlock is k-2.
    319            We want the tableIDs to rotate from the
    320            right, so use GroupSize
    321            */
    322 	RepIndex = info->groupSize - 1 - TableID;
    323 	RF_ASSERT(RepIndex >= 0);
    324 	if (!raidPtr->noRotate) {
    325 		if (TableID == 0)
    326 			BlockOffset++;	/* P on last drive, Q on first */
    327 		else
    328 			BlockOffset += ((BlockOffset >= RepIndex) ? 2 : 0);	/* skip over PQ */
    329 		RF_ASSERT(BlockOffset < info->groupSize);
    330 		*col = info->LayoutTable[BlockID][BlockOffset];
    331 	}
    332 	/* remap to distributed spare space if indicated */
    333 	if (remap) {
    334 		rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU);
    335 	} else {
    336 
    337 		outSU = base_suid;
    338 		outSU += FullTableID * fulltable_depth;	/* offs to strt of FT */
    339 		outSU += SpareSpace;	/* skip rsvd spare space */
    340 		outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;	/* offs to strt of tble */
    341 		outSU += info->OffsetTable[BlockID][BlockOffset] * layoutPtr->SUsPerPU;	/* offs to the PU */
    342 	}
    343 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);	/* offs to the SU within
    344 										 * a PU */
    345 
    346 	/* convert SUs to sectors, and, if not aligned to SU boundary, add in
    347 	 * offset to sector */
    348 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
    349 }
    350 
    351 
    352 void
    353 rf_MapParityDeclusteredPQ(
    354     RF_Raid_t * raidPtr,
    355     RF_RaidAddr_t raidSector,
    356     RF_RowCol_t * row,
    357     RF_RowCol_t * col,
    358     RF_SectorNum_t * diskSector,
    359     int remap)
    360 {
    361 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
    362 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
    363 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
    364 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
    365 	RF_StripeNum_t BlockID, BlockOffset, RepIndex;
    366 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
    367 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
    368 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion, SpareSpace = 0;
    369 
    370 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
    371 
    372 	/* compute row & (possibly) spare space exactly as before */
    373 	FullTableID = SUID / sus_per_fulltable;
    374 	*row = FullTableID % raidPtr->numRow;
    375 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
    376 					 * disk */
    377 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    378 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
    379 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
    380 	}
    381 	/* compute BlockID and RepIndex exactly as before */
    382 	FullTableOffset = SUID % sus_per_fulltable;
    383 	TableID = FullTableOffset / info->SUsPerTable;
    384 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
    385 	BlockID = TableOffset / info->PUsPerBlock;
    386 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
    387 	BlockID %= info->BlocksPerTable;
    388 
    389 	/* the parity block is in the position indicated by RepIndex */
    390 	RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->groupSize - 1 - TableID;
    391 	*col = info->LayoutTable[BlockID][RepIndex];
    392 
    393 	if (remap)
    394 		RF_PANIC();
    395 
    396 	/* compute sector as before, except use RepIndex instead of
    397 	 * BlockOffset */
    398 	outSU = base_suid;
    399 	outSU += FullTableID * fulltable_depth;
    400 	outSU += SpareSpace;	/* skip rsvd spare space */
    401 	outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;
    402 	outSU += info->OffsetTable[BlockID][RepIndex] * layoutPtr->SUsPerPU;
    403 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);
    404 
    405 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
    406 }
    407 
    408 void
    409 rf_MapQDeclusteredPQ(
    410     RF_Raid_t * raidPtr,
    411     RF_RaidAddr_t raidSector,
    412     RF_RowCol_t * row,
    413     RF_RowCol_t * col,
    414     RF_SectorNum_t * diskSector,
    415     int remap)
    416 {
    417 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
    418 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
    419 	RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
    420 	RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
    421 	RF_StripeNum_t BlockID, BlockOffset, RepIndex, RepIndexQ;
    422 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
    423 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
    424 	RF_StripeNum_t base_suid = 0, outSU, SpareRegion, SpareSpace = 0;
    425 
    426 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
    427 
    428 	/* compute row & (possibly) spare space exactly as before */
    429 	FullTableID = SUID / sus_per_fulltable;
    430 	*row = FullTableID % raidPtr->numRow;
    431 	FullTableID /= raidPtr->numRow;	/* convert to fulltable ID on this
    432 					 * disk */
    433 	if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
    434 		SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
    435 		SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
    436 	}
    437 	/* compute BlockID and RepIndex exactly as before */
    438 	FullTableOffset = SUID % sus_per_fulltable;
    439 	TableID = FullTableOffset / info->SUsPerTable;
    440 	TableOffset = FullTableOffset - TableID * info->SUsPerTable;
    441 	BlockID = TableOffset / info->PUsPerBlock;
    442 	BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
    443 	BlockID %= info->BlocksPerTable;
    444 
    445 	/* the q block is in the position indicated by RepIndex */
    446 	RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->groupSize - 1 - TableID;
    447 	RepIndexQ = ((RepIndex == (info->groupSize - 1)) ? 0 : RepIndex + 1);
    448 	*col = info->LayoutTable[BlockID][RepIndexQ];
    449 
    450 	if (remap)
    451 		RF_PANIC();
    452 
    453 	/* compute sector as before, except use RepIndex instead of
    454 	 * BlockOffset */
    455 	outSU = base_suid;
    456 	outSU += FullTableID * fulltable_depth;
    457 	outSU += SpareSpace;	/* skip rsvd spare space */
    458 	outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;
    459 	outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);
    460 
    461 	outSU += info->OffsetTable[BlockID][RepIndexQ] * layoutPtr->SUsPerPU;
    462 	*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
    463 }
    464 /* returns an array of ints identifying the disks that comprise the stripe containing the indicated address.
    465  * the caller must _never_ attempt to modify this array.
    466  */
    467 void
    468 rf_IdentifyStripeDeclusteredPQ(
    469     RF_Raid_t * raidPtr,
    470     RF_RaidAddr_t addr,
    471     RF_RowCol_t ** diskids,
    472     RF_RowCol_t * outRow)
    473 {
    474 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
    475 	RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
    476 	RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
    477 	RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
    478 	RF_StripeNum_t base_suid = 0;
    479 	RF_StripeNum_t SUID = rf_RaidAddressToStripeUnitID(layoutPtr, addr);
    480 	RF_StripeNum_t stripeID, FullTableID;
    481 	int     tableOffset;
    482 
    483 	rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
    484 	FullTableID = SUID / sus_per_fulltable;	/* fulltable ID within array
    485 						 * (across rows) */
    486 	*outRow = FullTableID % raidPtr->numRow;
    487 	stripeID = rf_StripeUnitIDToStripeID(layoutPtr, SUID);	/* find stripe offset
    488 								 * into array */
    489 	tableOffset = (stripeID % info->BlocksPerTable);	/* find offset into
    490 								 * block design table */
    491 	*diskids = info->LayoutTable[tableOffset];
    492 }
    493 #endif /* (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) || (RF_INCLUDE_EVENODD > 0) */
    494