1 /* $NetBSD: rf_interdecluster.c,v 1.5 2001/01/26 05:09:13 oster Exp $ */ 2 /* 3 * Copyright (c) 1995 Carnegie-Mellon University. 4 * All rights reserved. 5 * 6 * Author: Khalil Amiri 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_interdecluster.c -- implements interleaved declustering 32 * 33 ************************************************************/ 34 35 #include "rf_archs.h" 36 37 #if RF_INCLUDE_INTERDECLUSTER > 0 38 39 #include "rf_types.h" 40 #include "rf_raid.h" 41 #include "rf_interdecluster.h" 42 #include "rf_dag.h" 43 #include "rf_dagutils.h" 44 #include "rf_dagfuncs.h" 45 #include "rf_general.h" 46 #include "rf_utils.h" 47 #include "rf_dagffrd.h" 48 #include "rf_dagdegrd.h" 49 #include "rf_dagffwr.h" 50 #include "rf_dagdegwr.h" 51 52 typedef struct RF_InterdeclusterConfigInfo_s { 53 RF_RowCol_t **stripeIdentifier; /* filled in at config time and used 54 * by IdentifyStripe */ 55 RF_StripeCount_t numSparingRegions; 56 RF_StripeCount_t stripeUnitsPerSparingRegion; 57 RF_SectorNum_t mirrorStripeOffset; 58 } RF_InterdeclusterConfigInfo_t; 59 60 int 61 rf_ConfigureInterDecluster( 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_StripeCount_t num_used_stripeUnitsPerDisk; 68 RF_InterdeclusterConfigInfo_t *info; 69 RF_RowCol_t i, tmp, SUs_per_region; 70 71 /* create an Interleaved Declustering configuration structure */ 72 RF_MallocAndAdd(info, sizeof(RF_InterdeclusterConfigInfo_t), (RF_InterdeclusterConfigInfo_t *), 73 raidPtr->cleanupList); 74 if (info == NULL) 75 return (ENOMEM); 76 layoutPtr->layoutSpecificInfo = (void *) info; 77 78 /* fill in the config structure. */ 79 SUs_per_region = raidPtr->numCol * (raidPtr->numCol - 1); 80 info->stripeIdentifier = rf_make_2d_array(SUs_per_region, 2, raidPtr->cleanupList); 81 if (info->stripeIdentifier == NULL) 82 return (ENOMEM); 83 for (i = 0; i < SUs_per_region; i++) { 84 info->stripeIdentifier[i][0] = i / (raidPtr->numCol - 1); 85 tmp = i / raidPtr->numCol; 86 info->stripeIdentifier[i][1] = (i + 1 + tmp) % raidPtr->numCol; 87 } 88 89 /* no spare tables */ 90 RF_ASSERT(raidPtr->numRow == 1); 91 92 /* fill in the remaining layout parameters */ 93 94 /* total number of stripes should a multiple of 2*numCol: Each sparing 95 * region consists of 2*numCol stripes: n-1 primary copy, n-1 96 * secondary copy and 2 for spare .. */ 97 num_used_stripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk - (layoutPtr->stripeUnitsPerDisk % 98 (2 * raidPtr->numCol)); 99 info->numSparingRegions = num_used_stripeUnitsPerDisk / (2 * raidPtr->numCol); 100 /* this is in fact the number of stripe units (that are primary data 101 * copies) in the sparing region */ 102 info->stripeUnitsPerSparingRegion = raidPtr->numCol * (raidPtr->numCol - 1); 103 info->mirrorStripeOffset = info->numSparingRegions * (raidPtr->numCol + 1); 104 layoutPtr->numStripe = info->numSparingRegions * info->stripeUnitsPerSparingRegion; 105 layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector; 106 layoutPtr->numDataCol = 1; 107 layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit; 108 layoutPtr->numParityCol = 1; 109 110 layoutPtr->dataStripeUnitsPerDisk = num_used_stripeUnitsPerDisk; 111 112 raidPtr->sectorsPerDisk = 113 num_used_stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit; 114 115 raidPtr->totalSectors = 116 (layoutPtr->numStripe) * layoutPtr->sectorsPerStripeUnit; 117 118 layoutPtr->stripeUnitsPerDisk = raidPtr->sectorsPerDisk / layoutPtr->sectorsPerStripeUnit; 119 120 return (0); 121 } 122 123 int 124 rf_GetDefaultNumFloatingReconBuffersInterDecluster(RF_Raid_t * raidPtr) 125 { 126 return (30); 127 } 128 129 RF_HeadSepLimit_t 130 rf_GetDefaultHeadSepLimitInterDecluster(RF_Raid_t * raidPtr) 131 { 132 return (raidPtr->sectorsPerDisk); 133 } 134 135 RF_ReconUnitCount_t 136 rf_GetNumSpareRUsInterDecluster( 137 RF_Raid_t * raidPtr) 138 { 139 RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 140 141 return (2 * ((RF_ReconUnitCount_t) info->numSparingRegions)); 142 /* the layout uses two stripe units per disk as spare within each 143 * sparing region */ 144 } 145 /* Maps to the primary copy of the data, i.e. the first mirror pair */ 146 void 147 rf_MapSectorInterDecluster( 148 RF_Raid_t * raidPtr, 149 RF_RaidAddr_t raidSector, 150 RF_RowCol_t * row, 151 RF_RowCol_t * col, 152 RF_SectorNum_t * diskSector, 153 int remap) 154 { 155 RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 156 RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; 157 RF_StripeNum_t su_offset_into_disk, mirror_su_offset_into_disk; 158 RF_StripeNum_t sparing_region_id, index_within_region; 159 int col_before_remap; 160 161 *row = 0; 162 sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; 163 index_within_region = SUID % info->stripeUnitsPerSparingRegion; 164 su_offset_into_disk = index_within_region % (raidPtr->numCol - 1); 165 mirror_su_offset_into_disk = index_within_region / raidPtr->numCol; 166 col_before_remap = index_within_region / (raidPtr->numCol - 1); 167 168 if (!remap) { 169 *col = col_before_remap;; 170 *diskSector = (su_offset_into_disk + ((raidPtr->numCol - 1) * sparing_region_id)) * 171 raidPtr->Layout.sectorsPerStripeUnit; 172 *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); 173 } else { 174 /* remap sector to spare space... */ 175 *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; 176 *diskSector += (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit; 177 *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); 178 *col = (index_within_region + 1 + mirror_su_offset_into_disk) % raidPtr->numCol; 179 *col = (*col + 1) % raidPtr->numCol; 180 if (*col == col_before_remap) 181 *col = (*col + 1) % raidPtr->numCol; 182 } 183 } 184 /* Maps to the second copy of the mirror pair. */ 185 void 186 rf_MapParityInterDecluster( 187 RF_Raid_t * raidPtr, 188 RF_RaidAddr_t raidSector, 189 RF_RowCol_t * row, 190 RF_RowCol_t * col, 191 RF_SectorNum_t * diskSector, 192 int remap) 193 { 194 RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 195 RF_StripeNum_t sparing_region_id, index_within_region, mirror_su_offset_into_disk; 196 RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; 197 int col_before_remap; 198 199 sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; 200 index_within_region = SUID % info->stripeUnitsPerSparingRegion; 201 mirror_su_offset_into_disk = index_within_region / raidPtr->numCol; 202 col_before_remap = (index_within_region + 1 + mirror_su_offset_into_disk) % raidPtr->numCol; 203 204 *row = 0; 205 if (!remap) { 206 *col = col_before_remap; 207 *diskSector = info->mirrorStripeOffset * raidPtr->Layout.sectorsPerStripeUnit; 208 *diskSector += sparing_region_id * (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit; 209 *diskSector += mirror_su_offset_into_disk * raidPtr->Layout.sectorsPerStripeUnit; 210 *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); 211 } else { 212 /* remap parity to spare space ... */ 213 *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; 214 *diskSector += (raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit; 215 *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); 216 *col = index_within_region / (raidPtr->numCol - 1); 217 *col = (*col + 1) % raidPtr->numCol; 218 if (*col == col_before_remap) 219 *col = (*col + 1) % raidPtr->numCol; 220 } 221 } 222 223 void 224 rf_IdentifyStripeInterDecluster( 225 RF_Raid_t * raidPtr, 226 RF_RaidAddr_t addr, 227 RF_RowCol_t ** diskids, 228 RF_RowCol_t * outRow) 229 { 230 RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; 231 RF_StripeNum_t SUID; 232 233 SUID = addr / raidPtr->Layout.sectorsPerStripeUnit; 234 SUID = SUID % info->stripeUnitsPerSparingRegion; 235 236 *outRow = 0; 237 *diskids = info->stripeIdentifier[SUID]; 238 } 239 240 void 241 rf_MapSIDToPSIDInterDecluster( 242 RF_RaidLayout_t * layoutPtr, 243 RF_StripeNum_t stripeID, 244 RF_StripeNum_t * psID, 245 RF_ReconUnitNum_t * which_ru) 246 { 247 *which_ru = 0; 248 *psID = stripeID; 249 } 250 /****************************************************************************** 251 * select a graph to perform a single-stripe access 252 * 253 * Parameters: raidPtr - description of the physical array 254 * type - type of operation (read or write) requested 255 * asmap - logical & physical addresses for this access 256 * createFunc - name of function to use to create the graph 257 *****************************************************************************/ 258 259 void 260 rf_RAIDIDagSelect( 261 RF_Raid_t * raidPtr, 262 RF_IoType_t type, 263 RF_AccessStripeMap_t * asmap, 264 RF_VoidFuncPtr * createFunc) 265 { 266 RF_ASSERT(RF_IO_IS_R_OR_W(type)); 267 268 if (asmap->numDataFailed + asmap->numParityFailed > 1) { 269 RF_ERRORMSG("Multiple disks failed in a single group! Aborting I/O operation.\n"); 270 *createFunc = NULL; 271 return; 272 } 273 *createFunc = (type == RF_IO_TYPE_READ) ? (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG : (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; 274 if (type == RF_IO_TYPE_READ) { 275 if (asmap->numDataFailed == 0) 276 *createFunc = (RF_VoidFuncPtr) rf_CreateMirrorPartitionReadDAG; 277 else 278 *createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneDegradedReadDAG; 279 } else 280 *createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; 281 } 282 #endif /* RF_INCLUDE_INTERDECLUSTER > 0 */ 283