1 /* $NetBSD: rf_decluster.c,v 1.14 2002/11/19 01:49:42 oster Exp $ */ 2 /* 3 * Copyright (c) 1995 Carnegie-Mellon University. 4 * All rights reserved. 5 * 6 * Author: Mark Holland 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_decluster.c -- code related to the declustered layout 32 * 33 * Created 10-21-92 (MCH) 34 * 35 * Nov 93: adding support for distributed sparing. This code is a little 36 * complex: the basic layout used is as follows: 37 * let F = (v-1)/GCD(r,v-1). The spare space for each set of 38 * F consecutive fulltables is grouped together and placed after 39 * that set of tables. 40 * +------------------------------+ 41 * | F fulltables | 42 * | Spare Space | 43 * | F fulltables | 44 * | Spare Space | 45 * | ... | 46 * +------------------------------+ 47 * 48 *--------------------------------------------------------------------*/ 49 50 #include <sys/cdefs.h> 51 __KERNEL_RCSID(0, "$NetBSD: rf_decluster.c,v 1.14 2002/11/19 01:49:42 oster Exp $"); 52 53 #include <dev/raidframe/raidframevar.h> 54 55 #include "rf_archs.h" 56 #include "rf_raid.h" 57 #include "rf_decluster.h" 58 #include "rf_debugMem.h" 59 #include "rf_utils.h" 60 #include "rf_alloclist.h" 61 #include "rf_general.h" 62 #include "rf_kintf.h" 63 #include "rf_shutdown.h" 64 65 #if (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) 66 67 /* configuration code */ 68 69 int 70 rf_ConfigureDeclustered( 71 RF_ShutdownList_t ** listp, 72 RF_Raid_t * raidPtr, 73 RF_Config_t * cfgPtr) 74 { 75 RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); 76 int b, v, k, r, lambda; /* block design params */ 77 int i, j; 78 RF_RowCol_t *first_avail_slot; 79 RF_StripeCount_t complete_FT_count, numCompleteFullTablesPerDisk; 80 RF_DeclusteredConfigInfo_t *info; 81 RF_StripeCount_t PUsPerDisk, spareRegionDepthInPUs, numCompleteSpareRegionsPerDisk, 82 extraPUsPerDisk; 83 RF_StripeCount_t totSparePUsPerDisk; 84 RF_SectorNum_t diskOffsetOfLastFullTableInSUs; 85 RF_SectorCount_t SpareSpaceInSUs; 86 char *cfgBuf = (char *) (cfgPtr->layoutSpecific); 87 RF_StripeNum_t l, SUID; 88 89 SUID = l = 0; 90 numCompleteSpareRegionsPerDisk = 0; 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 info->SpareTable = NULL; 98 99 /* 2. extract parameters from the config structure */ 100 if (layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) { 101 (void)memcpy(info->sparemap_fname, cfgBuf, RF_SPAREMAP_NAME_LEN); 102 } 103 cfgBuf += RF_SPAREMAP_NAME_LEN; 104 105 b = *((int *) cfgBuf); 106 cfgBuf += sizeof(int); 107 v = *((int *) cfgBuf); 108 cfgBuf += sizeof(int); 109 k = *((int *) cfgBuf); 110 cfgBuf += sizeof(int); 111 r = *((int *) cfgBuf); 112 cfgBuf += sizeof(int); 113 lambda = *((int *) cfgBuf); 114 cfgBuf += sizeof(int); 115 raidPtr->noRotate = *((int *) cfgBuf); 116 cfgBuf += sizeof(int); 117 118 /* the sparemaps are generated assuming that parity is rotated, so we 119 * issue a warning if both distributed sparing and no-rotate are on at 120 * the same time */ 121 if ((layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) && raidPtr->noRotate) { 122 RF_ERRORMSG("Warning: distributed sparing specified without parity rotation.\n"); 123 } 124 if (raidPtr->numCol != v) { 125 RF_ERRORMSG2("RAID: config error: table element count (%d) not equal to no. of cols (%d)\n", v, raidPtr->numCol); 126 return (EINVAL); 127 } 128 /* 3. set up the values used in the mapping code */ 129 info->BlocksPerTable = b; 130 info->Lambda = lambda; 131 info->NumParityReps = info->groupSize = k; 132 info->SUsPerTable = b * (k - 1) * layoutPtr->SUsPerPU; /* b blks, k-1 SUs each */ 133 info->SUsPerFullTable = k * info->SUsPerTable; /* rot k times */ 134 info->PUsPerBlock = k - 1; 135 info->SUsPerBlock = info->PUsPerBlock * layoutPtr->SUsPerPU; 136 info->TableDepthInPUs = (b * k) / v; 137 info->FullTableDepthInPUs = info->TableDepthInPUs * k; /* k repetitions */ 138 139 /* used only in distributed sparing case */ 140 info->FullTablesPerSpareRegion = (v - 1) / rf_gcd(r, v - 1); /* (v-1)/gcd fulltables */ 141 info->TablesPerSpareRegion = k * info->FullTablesPerSpareRegion; 142 info->SpareSpaceDepthPerRegionInSUs = (r * info->TablesPerSpareRegion / (v - 1)) * layoutPtr->SUsPerPU; 143 144 /* check to make sure the block design is sufficiently small */ 145 if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) { 146 if (info->FullTableDepthInPUs * layoutPtr->SUsPerPU + info->SpareSpaceDepthPerRegionInSUs > layoutPtr->stripeUnitsPerDisk) { 147 RF_ERRORMSG3("RAID: config error: Full Table depth (%d) + Spare Space (%d) larger than disk size (%d) (BD too big)\n", 148 (int) info->FullTableDepthInPUs, 149 (int) info->SpareSpaceDepthPerRegionInSUs, 150 (int) layoutPtr->stripeUnitsPerDisk); 151 return (EINVAL); 152 } 153 } else { 154 if (info->TableDepthInPUs * layoutPtr->SUsPerPU > layoutPtr->stripeUnitsPerDisk) { 155 RF_ERRORMSG2("RAID: config error: Table depth (%d) larger than disk size (%d) (BD too big)\n", 156 (int) (info->TableDepthInPUs * layoutPtr->SUsPerPU), \ 157 (int) layoutPtr->stripeUnitsPerDisk); 158 return (EINVAL); 159 } 160 } 161 162 163 /* compute the size of each disk, and the number of tables in the last 164 * fulltable (which need not be complete) */ 165 if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) { 166 167 PUsPerDisk = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU; 168 spareRegionDepthInPUs = (info->TablesPerSpareRegion * info->TableDepthInPUs + 169 (info->TablesPerSpareRegion * info->TableDepthInPUs) / (v - 1)); 170 info->SpareRegionDepthInSUs = spareRegionDepthInPUs * layoutPtr->SUsPerPU; 171 172 numCompleteSpareRegionsPerDisk = PUsPerDisk / spareRegionDepthInPUs; 173 info->NumCompleteSRs = numCompleteSpareRegionsPerDisk; 174 extraPUsPerDisk = PUsPerDisk % spareRegionDepthInPUs; 175 176 /* assume conservatively that we need the full amount of spare 177 * space in one region in order to provide spares for the 178 * partial spare region at the end of the array. We set "i" 179 * to the number of tables in the partial spare region. This 180 * may actually include some fulltables. */ 181 extraPUsPerDisk -= (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU); 182 if (extraPUsPerDisk <= 0) 183 i = 0; 184 else 185 i = extraPUsPerDisk / info->TableDepthInPUs; 186 187 complete_FT_count = raidPtr->numRow * (numCompleteSpareRegionsPerDisk * (info->TablesPerSpareRegion / k) + i / k); 188 info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable; 189 info->ExtraTablesPerDisk = i % k; 190 191 /* note that in the last spare region, the spare space is 192 * complete even though data/parity space is not */ 193 totSparePUsPerDisk = (numCompleteSpareRegionsPerDisk + 1) * (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU); 194 info->TotSparePUsPerDisk = totSparePUsPerDisk; 195 196 layoutPtr->stripeUnitsPerDisk = 197 ((complete_FT_count / raidPtr->numRow) * info->FullTableDepthInPUs + /* data & parity space */ 198 info->ExtraTablesPerDisk * info->TableDepthInPUs + 199 totSparePUsPerDisk /* spare space */ 200 ) * layoutPtr->SUsPerPU; 201 layoutPtr->dataStripeUnitsPerDisk = 202 (complete_FT_count * info->FullTableDepthInPUs + info->ExtraTablesPerDisk * info->TableDepthInPUs) 203 * layoutPtr->SUsPerPU * (k - 1) / k; 204 205 } else { 206 /* non-dist spare case: force each disk to contain an 207 * integral number of tables */ 208 layoutPtr->stripeUnitsPerDisk /= (info->TableDepthInPUs * layoutPtr->SUsPerPU); 209 layoutPtr->stripeUnitsPerDisk *= (info->TableDepthInPUs * layoutPtr->SUsPerPU); 210 211 /* compute the number of tables in the last fulltable, which 212 * need not be complete */ 213 complete_FT_count = 214 ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->FullTableDepthInPUs) * raidPtr->numRow; 215 216 info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable; 217 info->ExtraTablesPerDisk = 218 ((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->TableDepthInPUs) % k; 219 } 220 221 raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit; 222 223 /* find the disk offset of the stripe unit where the last fulltable 224 * starts */ 225 numCompleteFullTablesPerDisk = complete_FT_count / raidPtr->numRow; 226 diskOffsetOfLastFullTableInSUs = numCompleteFullTablesPerDisk * info->FullTableDepthInPUs * layoutPtr->SUsPerPU; 227 if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) { 228 SpareSpaceInSUs = numCompleteSpareRegionsPerDisk * info->SpareSpaceDepthPerRegionInSUs; 229 diskOffsetOfLastFullTableInSUs += SpareSpaceInSUs; 230 info->DiskOffsetOfLastSpareSpaceChunkInSUs = 231 diskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU; 232 } 233 info->DiskOffsetOfLastFullTableInSUs = diskOffsetOfLastFullTableInSUs; 234 info->numCompleteFullTablesPerDisk = numCompleteFullTablesPerDisk; 235 236 /* 4. create and initialize the lookup tables */ 237 info->LayoutTable = rf_make_2d_array(b, k, raidPtr->cleanupList); 238 if (info->LayoutTable == NULL) 239 return (ENOMEM); 240 info->OffsetTable = rf_make_2d_array(b, k, raidPtr->cleanupList); 241 if (info->OffsetTable == NULL) 242 return (ENOMEM); 243 info->BlockTable = rf_make_2d_array(info->TableDepthInPUs * layoutPtr->SUsPerPU, raidPtr->numCol, raidPtr->cleanupList); 244 if (info->BlockTable == NULL) 245 return (ENOMEM); 246 247 first_avail_slot = rf_make_1d_array(v, NULL); 248 if (first_avail_slot == NULL) 249 return (ENOMEM); 250 251 for (i = 0; i < b; i++) 252 for (j = 0; j < k; j++) 253 info->LayoutTable[i][j] = *cfgBuf++; 254 255 /* initialize offset table */ 256 for (i = 0; i < b; i++) 257 for (j = 0; j < k; j++) { 258 info->OffsetTable[i][j] = first_avail_slot[info->LayoutTable[i][j]]; 259 first_avail_slot[info->LayoutTable[i][j]]++; 260 } 261 262 /* initialize block table */ 263 for (SUID = l = 0; l < layoutPtr->SUsPerPU; l++) { 264 for (i = 0; i < b; i++) { 265 for (j = 0; j < k; j++) { 266 info->BlockTable[(info->OffsetTable[i][j] * layoutPtr->SUsPerPU) + l] 267 [info->LayoutTable[i][j]] = SUID; 268 } 269 SUID++; 270 } 271 } 272 273 rf_free_1d_array(first_avail_slot, v); 274 275 /* 5. set up the remaining redundant-but-useful parameters */ 276 277 raidPtr->totalSectors = (k * complete_FT_count + raidPtr->numRow * info->ExtraTablesPerDisk) * 278 info->SUsPerTable * layoutPtr->sectorsPerStripeUnit; 279 layoutPtr->numStripe = (raidPtr->totalSectors / layoutPtr->sectorsPerStripeUnit) / (k - 1); 280 281 /* strange evaluation order below to try and minimize overflow 282 * problems */ 283 284 layoutPtr->dataSectorsPerStripe = (k - 1) * layoutPtr->sectorsPerStripeUnit; 285 layoutPtr->numDataCol = k - 1; 286 layoutPtr->numParityCol = 1; 287 288 return (0); 289 } 290 /* declustering with distributed sparing */ 291 static void rf_ShutdownDeclusteredDS(RF_ThreadArg_t); 292 static void 293 rf_ShutdownDeclusteredDS(arg) 294 RF_ThreadArg_t arg; 295 { 296 RF_DeclusteredConfigInfo_t *info; 297 RF_Raid_t *raidPtr; 298 299 raidPtr = (RF_Raid_t *) arg; 300 info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 301 if (info->SpareTable) 302 rf_FreeSpareTable(raidPtr); 303 } 304 305 int 306 rf_ConfigureDeclusteredDS( 307 RF_ShutdownList_t ** listp, 308 RF_Raid_t * raidPtr, 309 RF_Config_t * cfgPtr) 310 { 311 int rc; 312 313 rc = rf_ConfigureDeclustered(listp, raidPtr, cfgPtr); 314 if (rc) 315 return (rc); 316 rc = rf_ShutdownCreate(listp, rf_ShutdownDeclusteredDS, raidPtr); 317 if (rc) { 318 RF_ERRORMSG1("Got %d adding shutdown event for DeclusteredDS\n", rc); 319 rf_ShutdownDeclusteredDS(raidPtr); 320 return (rc); 321 } 322 return (0); 323 } 324 325 void 326 rf_MapSectorDeclustered(raidPtr, raidSector, row, col, diskSector, remap) 327 RF_Raid_t *raidPtr; 328 RF_RaidAddr_t raidSector; 329 RF_RowCol_t *row; 330 RF_RowCol_t *col; 331 RF_SectorNum_t *diskSector; 332 int remap; 333 { 334 RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); 335 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 336 RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit; 337 RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset; 338 RF_StripeNum_t BlockID, BlockOffset, RepIndex; 339 RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable; 340 RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU; 341 RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0; 342 343 rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid); 344 345 FullTableID = SUID / sus_per_fulltable; /* fulltable ID within array 346 * (across rows) */ 347 if (raidPtr->numRow == 1) 348 *row = 0; /* avoid a mod and a div in the common case */ 349 else { 350 *row = FullTableID % raidPtr->numRow; 351 FullTableID /= raidPtr->numRow; /* convert to fulltable ID on 352 * this disk */ 353 } 354 if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) { 355 SpareRegion = FullTableID / info->FullTablesPerSpareRegion; 356 SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs; 357 } 358 FullTableOffset = SUID % sus_per_fulltable; 359 TableID = FullTableOffset / info->SUsPerTable; 360 TableOffset = FullTableOffset - TableID * info->SUsPerTable; 361 BlockID = TableOffset / info->PUsPerBlock; 362 BlockOffset = TableOffset - BlockID * info->PUsPerBlock; 363 BlockID %= info->BlocksPerTable; 364 RepIndex = info->PUsPerBlock - TableID; 365 if (!raidPtr->noRotate) 366 BlockOffset += ((BlockOffset >= RepIndex) ? 1 : 0); 367 *col = info->LayoutTable[BlockID][BlockOffset]; 368 369 /* remap to distributed spare space if indicated */ 370 if (remap) { 371 RF_ASSERT(raidPtr->Disks[*row][*col].status == rf_ds_reconstructing || raidPtr->Disks[*row][*col].status == rf_ds_dist_spared || 372 (rf_copyback_in_progress && raidPtr->Disks[*row][*col].status == rf_ds_optimal)); 373 rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU); 374 } else { 375 376 outSU = base_suid; 377 outSU += FullTableID * fulltable_depth; /* offs to strt of FT */ 378 outSU += SpareSpace; /* skip rsvd spare space */ 379 outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU; /* offs to strt of tble */ 380 outSU += info->OffsetTable[BlockID][BlockOffset] * layoutPtr->SUsPerPU; /* offs to the PU */ 381 } 382 outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock); /* offs to the SU within 383 * a PU */ 384 385 /* convert SUs to sectors, and, if not aligned to SU boundary, add in 386 * offset to sector. */ 387 *diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit); 388 389 RF_ASSERT(*col != -1); 390 } 391 392 393 /* prototyping this inexplicably causes the compile of the layout table (rf_layout.c) to fail */ 394 void 395 rf_MapParityDeclustered( 396 RF_Raid_t * raidPtr, 397 RF_RaidAddr_t raidSector, 398 RF_RowCol_t * row, 399 RF_RowCol_t * col, 400 RF_SectorNum_t * diskSector, 401 int remap) 402 { 403 RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); 404 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 405 RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit; 406 RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset; 407 RF_StripeNum_t BlockID, BlockOffset, RepIndex; 408 RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable; 409 RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU; 410 RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0; 411 412 rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid); 413 414 /* compute row & (possibly) spare space exactly as before */ 415 FullTableID = SUID / sus_per_fulltable; 416 if (raidPtr->numRow == 1) 417 *row = 0; /* avoid a mod and a div in the common case */ 418 else { 419 *row = FullTableID % raidPtr->numRow; 420 FullTableID /= raidPtr->numRow; /* convert to fulltable ID on 421 * this disk */ 422 } 423 if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) { 424 SpareRegion = FullTableID / info->FullTablesPerSpareRegion; 425 SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs; 426 } 427 /* compute BlockID and RepIndex exactly as before */ 428 FullTableOffset = SUID % sus_per_fulltable; 429 TableID = FullTableOffset / info->SUsPerTable; 430 TableOffset = FullTableOffset - TableID * info->SUsPerTable; 431 /* TableOffset = FullTableOffset % info->SUsPerTable; */ 432 /* BlockID = (TableOffset / info->PUsPerBlock) % 433 * info->BlocksPerTable; */ 434 BlockID = TableOffset / info->PUsPerBlock; 435 /* BlockOffset = TableOffset % info->PUsPerBlock; */ 436 BlockOffset = TableOffset - BlockID * info->PUsPerBlock; 437 BlockID %= info->BlocksPerTable; 438 439 /* the parity block is in the position indicated by RepIndex */ 440 RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->PUsPerBlock - TableID; 441 *col = info->LayoutTable[BlockID][RepIndex]; 442 443 if (remap) { 444 RF_ASSERT(raidPtr->Disks[*row][*col].status == rf_ds_reconstructing || raidPtr->Disks[*row][*col].status == rf_ds_dist_spared || 445 (rf_copyback_in_progress && raidPtr->Disks[*row][*col].status == rf_ds_optimal)); 446 rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU); 447 } else { 448 449 /* compute sector as before, except use RepIndex instead of 450 * BlockOffset */ 451 outSU = base_suid; 452 outSU += FullTableID * fulltable_depth; 453 outSU += SpareSpace; /* skip rsvd spare space */ 454 outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU; 455 outSU += info->OffsetTable[BlockID][RepIndex] * layoutPtr->SUsPerPU; 456 } 457 458 outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock); 459 *diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit); 460 461 RF_ASSERT(*col != -1); 462 } 463 /* returns an array of ints identifying the disks that comprise the stripe containing the indicated address. 464 * the caller must _never_ attempt to modify this array. 465 */ 466 void 467 rf_IdentifyStripeDeclustered( 468 RF_Raid_t * raidPtr, 469 RF_RaidAddr_t addr, 470 RF_RowCol_t ** diskids, 471 RF_RowCol_t * outRow) 472 { 473 RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); 474 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 475 RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable; 476 RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU; 477 RF_StripeNum_t base_suid = 0; 478 RF_StripeNum_t SUID = rf_RaidAddressToStripeUnitID(layoutPtr, addr); 479 RF_StripeNum_t stripeID, FullTableID; 480 int tableOffset; 481 482 rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid); 483 FullTableID = SUID / sus_per_fulltable; /* fulltable ID within array 484 * (across rows) */ 485 *outRow = FullTableID % raidPtr->numRow; 486 stripeID = rf_StripeUnitIDToStripeID(layoutPtr, SUID); /* find stripe offset 487 * into array */ 488 tableOffset = (stripeID % info->BlocksPerTable); /* find offset into 489 * block design table */ 490 *diskids = info->LayoutTable[tableOffset]; 491 } 492 /* This returns the default head-separation limit, which is measured 493 * in "required units for reconstruction". Each time a disk fetches 494 * a unit, it bumps a counter. The head-sep code prohibits any disk 495 * from getting more than headSepLimit counter values ahead of any 496 * other. 497 * 498 * We assume here that the number of floating recon buffers is already 499 * set. There are r stripes to be reconstructed in each table, and so 500 * if we have a total of B buffers, we can have at most B/r tables 501 * under recon at any one time. In each table, lambda units are required 502 * from each disk, so given B buffers, the head sep limit has to be 503 * (lambda*B)/r units. We subtract one to avoid weird boundary cases. 504 * 505 * for example, suppose were given 50 buffers, r=19, and lambda=4 as in 506 * the 20.5 design. There are 19 stripes/table to be reconstructed, so 507 * we can have 50/19 tables concurrently under reconstruction, which means 508 * we can allow the fastest disk to get 50/19 tables ahead of the slower 509 * disk. There are lambda "required units" for each disk, so the fastest 510 * disk can get 4*50/19 = 10 counter values ahead of the slowest. 511 * 512 * If numBufsToAccumulate is not 1, we need to limit the head sep further 513 * because multiple bufs will be required for each stripe under recon. 514 */ 515 RF_HeadSepLimit_t 516 rf_GetDefaultHeadSepLimitDeclustered( 517 RF_Raid_t * raidPtr) 518 { 519 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 520 521 return (info->Lambda * raidPtr->numFloatingReconBufs / info->TableDepthInPUs / rf_numBufsToAccumulate); 522 } 523 /* returns the default number of recon buffers to use. The value 524 * is somewhat arbitrary...it's intended to be large enough to allow 525 * for a reasonably large head-sep limit, but small enough that you 526 * don't use up all your system memory with buffers. 527 */ 528 int 529 rf_GetDefaultNumFloatingReconBuffersDeclustered(RF_Raid_t * raidPtr) 530 { 531 return (100 * rf_numBufsToAccumulate); 532 } 533 /* sectors in the last fulltable of the array need to be handled 534 * specially since this fulltable can be incomplete. this function 535 * changes the values of certain params to handle this. 536 * 537 * the idea here is that MapSector et. al. figure out which disk the 538 * addressed unit lives on by computing the modulos of the unit number 539 * with the number of units per fulltable, table, etc. In the last 540 * fulltable, there are fewer units per fulltable, so we need to adjust 541 * the number of user data units per fulltable to reflect this. 542 * 543 * so, we (1) convert the fulltable size and depth parameters to 544 * the size of the partial fulltable at the end, (2) compute the 545 * disk sector offset where this fulltable starts, and (3) convert 546 * the users stripe unit number from an offset into the array to 547 * an offset into the last fulltable. 548 */ 549 void 550 rf_decluster_adjust_params( 551 RF_RaidLayout_t * layoutPtr, 552 RF_StripeNum_t * SUID, 553 RF_StripeCount_t * sus_per_fulltable, 554 RF_StripeCount_t * fulltable_depth, 555 RF_StripeNum_t * base_suid) 556 { 557 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 558 559 if (*SUID >= info->FullTableLimitSUID) { 560 /* new full table size is size of last full table on disk */ 561 *sus_per_fulltable = info->ExtraTablesPerDisk * info->SUsPerTable; 562 563 /* new full table depth is corresponding depth */ 564 *fulltable_depth = info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU; 565 566 /* set up the new base offset */ 567 *base_suid = info->DiskOffsetOfLastFullTableInSUs; 568 569 /* convert users array address to an offset into the last 570 * fulltable */ 571 *SUID -= info->FullTableLimitSUID; 572 } 573 } 574 /* 575 * map a stripe ID to a parity stripe ID. 576 * See comment above RaidAddressToParityStripeID in layout.c. 577 */ 578 void 579 rf_MapSIDToPSIDDeclustered( 580 RF_RaidLayout_t * layoutPtr, 581 RF_StripeNum_t stripeID, 582 RF_StripeNum_t * psID, 583 RF_ReconUnitNum_t * which_ru) 584 { 585 RF_DeclusteredConfigInfo_t *info; 586 587 info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 588 589 *psID = (stripeID / (layoutPtr->SUsPerPU * info->BlocksPerTable)) 590 * info->BlocksPerTable + (stripeID % info->BlocksPerTable); 591 *which_ru = (stripeID % (info->BlocksPerTable * layoutPtr->SUsPerPU)) 592 / info->BlocksPerTable; 593 RF_ASSERT((*which_ru) < layoutPtr->SUsPerPU / layoutPtr->SUsPerRU); 594 } 595 /* 596 * Called from MapSector and MapParity to retarget an access at the spare unit. 597 * Modifies the "col" and "outSU" parameters only. 598 */ 599 void 600 rf_remap_to_spare_space( 601 RF_RaidLayout_t * layoutPtr, 602 RF_DeclusteredConfigInfo_t * info, 603 RF_RowCol_t row, 604 RF_StripeNum_t FullTableID, 605 RF_StripeNum_t TableID, 606 RF_SectorNum_t BlockID, 607 RF_StripeNum_t base_suid, 608 RF_StripeNum_t SpareRegion, 609 RF_RowCol_t * outCol, 610 RF_StripeNum_t * outSU) 611 { 612 RF_StripeNum_t ftID, spareTableStartSU, TableInSpareRegion, lastSROffset, 613 which_ft; 614 615 /* 616 * note that FullTableID and hence SpareRegion may have gotten 617 * tweaked by rf_decluster_adjust_params. We detect this by 618 * noticing that base_suid is not 0. 619 */ 620 if (base_suid == 0) { 621 ftID = FullTableID; 622 } else { 623 /* 624 * There may be > 1.0 full tables in the last (i.e. partial) 625 * spare region. find out which of these we're in. 626 */ 627 lastSROffset = info->NumCompleteSRs * info->SpareRegionDepthInSUs; 628 which_ft = (info->DiskOffsetOfLastFullTableInSUs - lastSROffset) / (info->FullTableDepthInPUs * layoutPtr->SUsPerPU); 629 630 /* compute the actual full table ID */ 631 ftID = info->DiskOffsetOfLastFullTableInSUs / (info->FullTableDepthInPUs * layoutPtr->SUsPerPU) + which_ft; 632 SpareRegion = info->NumCompleteSRs; 633 } 634 TableInSpareRegion = (ftID * info->NumParityReps + TableID) % info->TablesPerSpareRegion; 635 636 *outCol = info->SpareTable[TableInSpareRegion][BlockID].spareDisk; 637 RF_ASSERT(*outCol != -1); 638 639 spareTableStartSU = (SpareRegion == info->NumCompleteSRs) ? 640 info->DiskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU : 641 (SpareRegion + 1) * info->SpareRegionDepthInSUs - info->SpareSpaceDepthPerRegionInSUs; 642 *outSU = spareTableStartSU + info->SpareTable[TableInSpareRegion][BlockID].spareBlockOffsetInSUs; 643 if (*outSU >= layoutPtr->stripeUnitsPerDisk) { 644 printf("rf_remap_to_spare_space: invalid remapped disk SU offset %ld\n", (long) *outSU); 645 } 646 } 647 648 #endif /* (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) */ 649 650 #if (RF_INCLUDE_PARITY_DECLUSTERING_DS > 0) 651 int 652 rf_InstallSpareTable( 653 RF_Raid_t * raidPtr, 654 RF_RowCol_t frow, 655 RF_RowCol_t fcol) 656 { 657 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 658 RF_SparetWait_t *req; 659 int retcode; 660 661 RF_Malloc(req, sizeof(*req), (RF_SparetWait_t *)); 662 req->C = raidPtr->numCol; 663 req->G = raidPtr->Layout.numDataCol + raidPtr->Layout.numParityCol; 664 req->fcol = fcol; 665 req->SUsPerPU = raidPtr->Layout.SUsPerPU; 666 req->TablesPerSpareRegion = info->TablesPerSpareRegion; 667 req->BlocksPerTable = info->BlocksPerTable; 668 req->TableDepthInPUs = info->TableDepthInPUs; 669 req->SpareSpaceDepthPerRegionInSUs = info->SpareSpaceDepthPerRegionInSUs; 670 671 retcode = rf_GetSpareTableFromDaemon(req); 672 RF_ASSERT(!retcode); /* XXX -- fix this to recover gracefully -- 673 * XXX */ 674 return (retcode); 675 } 676 #endif 677 #if (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) 678 /* 679 * Invoked via ioctl to install a spare table in the kernel. 680 */ 681 int 682 rf_SetSpareTable(raidPtr, data) 683 RF_Raid_t *raidPtr; 684 void *data; 685 { 686 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 687 RF_SpareTableEntry_t **ptrs; 688 int i, retcode; 689 690 /* what we need to copyin is a 2-d array, so first copyin the user 691 * pointers to the rows in the table */ 692 RF_Malloc(ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *), (RF_SpareTableEntry_t **)); 693 retcode = copyin((caddr_t) data, (caddr_t) ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *)); 694 695 if (retcode) 696 return (retcode); 697 698 /* now allocate kernel space for the row pointers */ 699 RF_Malloc(info->SpareTable, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *), (RF_SpareTableEntry_t **)); 700 701 /* now allocate kernel space for each row in the table, and copy it in 702 * from user space */ 703 for (i = 0; i < info->TablesPerSpareRegion; i++) { 704 RF_Malloc(info->SpareTable[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t), (RF_SpareTableEntry_t *)); 705 retcode = copyin(ptrs[i], info->SpareTable[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t)); 706 if (retcode) { 707 info->SpareTable = NULL; /* blow off the memory 708 * we've allocated */ 709 return (retcode); 710 } 711 } 712 713 /* free up the temporary array we used */ 714 RF_Free(ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *)); 715 716 return (0); 717 } 718 719 RF_ReconUnitCount_t 720 rf_GetNumSpareRUsDeclustered(raidPtr) 721 RF_Raid_t *raidPtr; 722 { 723 RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; 724 725 return (((RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo)->TotSparePUsPerDisk); 726 } 727 #endif /* (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) */ 728 729 void 730 rf_FreeSpareTable(raidPtr) 731 RF_Raid_t *raidPtr; 732 { 733 long i; 734 RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; 735 RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo; 736 RF_SpareTableEntry_t **table = info->SpareTable; 737 738 for (i = 0; i < info->TablesPerSpareRegion; i++) { 739 RF_Free(table[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t)); 740 } 741 RF_Free(table, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *)); 742 info->SpareTable = (RF_SpareTableEntry_t **) NULL; 743 } 744