| 1 | /* $NetBSD: rf_chaindecluster.c,v 1.15 2006/11/16 01:33:23 christos 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_chaindecluster.c -- implements chained declustering |
| 32 | * |
| 33 | *****************************************************************************/ |
| 34 | |
| 35 | #include <sys/cdefs.h> |
| 36 | __KERNEL_RCSID(0, "$NetBSD: rf_chaindecluster.c,v 1.15 2006/11/16 01:33:23 christos Exp $" ); |
| 37 | |
| 38 | #include "rf_archs.h" |
| 39 | |
| 40 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) |
| 41 | |
| 42 | #include <dev/raidframe/raidframevar.h> |
| 43 | |
| 44 | #include "rf_raid.h" |
| 45 | #include "rf_chaindecluster.h" |
| 46 | #include "rf_dag.h" |
| 47 | #include "rf_dagutils.h" |
| 48 | #include "rf_dagffrd.h" |
| 49 | #include "rf_dagffwr.h" |
| 50 | #include "rf_dagdegrd.h" |
| 51 | #include "rf_dagfuncs.h" |
| 52 | #include "rf_general.h" |
| 53 | #include "rf_utils.h" |
| 54 | |
| 55 | typedef struct RF_ChaindeclusterConfigInfo_s { |
| 56 | RF_RowCol_t **stripeIdentifier; /* filled in at config time and used |
| 57 | * by IdentifyStripe */ |
| 58 | RF_StripeCount_t numSparingRegions; |
| 59 | RF_StripeCount_t stripeUnitsPerSparingRegion; |
| 60 | RF_SectorNum_t mirrorStripeOffset; |
| 61 | } RF_ChaindeclusterConfigInfo_t; |
| 62 | |
| 63 | int |
| 64 | rf_ConfigureChainDecluster(RF_ShutdownList_t **listp, |
| 65 | RF_Raid_t *raidPtr, RF_Config_t *cfgPtr) |
| 66 | { |
| 67 | RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; |
| 68 | RF_StripeCount_t num_used_stripeUnitsPerDisk; |
| 69 | RF_ChaindeclusterConfigInfo_t *info; |
| 70 | RF_RowCol_t i; |
| 71 | |
| 72 | /* create a Chained Declustering configuration structure */ |
| 73 | RF_MallocAndAdd(info, sizeof(RF_ChaindeclusterConfigInfo_t), (RF_ChaindeclusterConfigInfo_t *), raidPtr->cleanupList); |
| 74 | if (info == NULL) |
| 75 | return (ENOMEM); |
| 76 | layoutPtr->layoutSpecificInfo = (void *) info; |
| 77 | |
| 78 | /* fill in the config structure. */ |
| 79 | info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, 2, raidPtr->cleanupList); |
| 80 | if (info->stripeIdentifier == NULL) |
| 81 | return (ENOMEM); |
| 82 | for (i = 0; i < raidPtr->numCol; i++) { |
| 83 | info->stripeIdentifier[i][0] = i % raidPtr->numCol; |
| 84 | info->stripeIdentifier[i][1] = (i + 1) % raidPtr->numCol; |
| 85 | } |
| 86 | |
| 87 | /* fill in the remaining layout parameters */ |
| 88 | num_used_stripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk - (layoutPtr->stripeUnitsPerDisk % |
| 89 | (2 * raidPtr->numCol - 2)); |
| 90 | info->numSparingRegions = num_used_stripeUnitsPerDisk / (2 * raidPtr->numCol - 2); |
| 91 | info->stripeUnitsPerSparingRegion = raidPtr->numCol * (raidPtr->numCol - 1); |
| 92 | info->mirrorStripeOffset = info->numSparingRegions * (raidPtr->numCol - 1); |
| 93 | layoutPtr->numStripe = info->numSparingRegions * info->stripeUnitsPerSparingRegion; |
| 94 | layoutPtr->numDataCol = 1; |
| 95 | layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit; |
| 96 | layoutPtr->numParityCol = 1; |
| 97 | |
| 98 | layoutPtr->dataStripeUnitsPerDisk = num_used_stripeUnitsPerDisk; |
| 99 | |
| 100 | raidPtr->sectorsPerDisk = |
| 101 | num_used_stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit; |
| 102 | |
| 103 | raidPtr->totalSectors = |
| 104 | (layoutPtr->numStripe) * layoutPtr->sectorsPerStripeUnit; |
| 105 | |
| 106 | layoutPtr->stripeUnitsPerDisk = raidPtr->sectorsPerDisk / layoutPtr->sectorsPerStripeUnit; |
| 107 | |
| 108 | return (0); |
| 109 | } |
| 110 | |
| 111 | RF_ReconUnitCount_t |
| 112 | rf_GetNumSpareRUsChainDecluster(RF_Raid_t *raidPtr) |
| 113 | { |
| 114 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
| 115 | |
| 116 | /* |
| 117 | * The layout uses two stripe units per disk as spare within each |
| 118 | * sparing region. |
| 119 | */ |
| 120 | return (2 * info->numSparingRegions); |
| 121 | } |
| 122 | |
| 123 | |
| 124 | /* Maps to the primary copy of the data, i.e. the first mirror pair */ |
| 125 | void |
| 126 | rf_MapSectorChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector, |
| 127 | RF_RowCol_t *col, RF_SectorNum_t *diskSector, |
| 128 | int remap) |
| 129 | { |
| 130 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
| 131 | RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; |
| 132 | RF_SectorNum_t index_within_region, index_within_disk; |
| 133 | RF_StripeNum_t sparing_region_id; |
| 134 | int col_before_remap; |
| 135 | |
| 136 | sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; |
| 137 | index_within_region = SUID % info->stripeUnitsPerSparingRegion; |
| 138 | index_within_disk = index_within_region / raidPtr->numCol; |
| 139 | col_before_remap = SUID % raidPtr->numCol; |
| 140 | |
| 141 | if (!remap) { |
| 142 | *col = col_before_remap; |
| 143 | *diskSector = (index_within_disk + ((raidPtr->numCol - 1) * sparing_region_id)) * |
| 144 | raidPtr->Layout.sectorsPerStripeUnit; |
| 145 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
| 146 | } else { |
| 147 | /* remap sector to spare space... */ |
| 148 | *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; |
| 149 | *diskSector += (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit; |
| 150 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
| 151 | index_within_disk = index_within_region / raidPtr->numCol; |
| 152 | if (index_within_disk < col_before_remap) |
| 153 | *col = index_within_disk; |
| 154 | else |
| 155 | if (index_within_disk == raidPtr->numCol - 2) { |
| 156 | *col = (col_before_remap + raidPtr->numCol - 1) % raidPtr->numCol; |
| 157 | *diskSector += raidPtr->Layout.sectorsPerStripeUnit; |
| 158 | } else |
| 159 | *col = (index_within_disk + 2) % raidPtr->numCol; |
| 160 | } |
| 161 | |
| 162 | } |
| 163 | |
| 164 | |
| 165 | |
| 166 | /* Maps to the second copy of the mirror pair, which is chain declustered. The second copy is contained |
| 167 | in the next disk (mod numCol) after the disk containing the primary copy. |
| 168 | The offset into the disk is one-half disk down */ |
| 169 | void |
| 170 | rf_MapParityChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector, |
| 171 | RF_RowCol_t *col, RF_SectorNum_t *diskSector, |
| 172 | int remap) |
| 173 | { |
| 174 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
| 175 | RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; |
| 176 | RF_SectorNum_t index_within_region, index_within_disk; |
| 177 | RF_StripeNum_t sparing_region_id; |
| 178 | int col_before_remap; |
| 179 | |
| 180 | if (!remap) { |
| 181 | *col = SUID % raidPtr->numCol; |
| 182 | *col = (*col + 1) % raidPtr->numCol; |
| 183 | *diskSector = info->mirrorStripeOffset * raidPtr->Layout.sectorsPerStripeUnit; |
| 184 | *diskSector += (SUID / raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit; |
| 185 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
| 186 | } else { |
| 187 | /* remap parity to spare space ... */ |
| 188 | sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; |
| 189 | index_within_region = SUID % info->stripeUnitsPerSparingRegion; |
| 190 | index_within_disk = index_within_region / raidPtr->numCol; |
| 191 | *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; |
| 192 | *diskSector += (raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit; |
| 193 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
| 194 | col_before_remap = SUID % raidPtr->numCol; |
| 195 | if (index_within_disk < col_before_remap) |
| 196 | *col = index_within_disk; |
| 197 | else |
| 198 | if (index_within_disk == raidPtr->numCol - 2) { |
| 199 | *col = (col_before_remap + 2) % raidPtr->numCol; |
| 200 | *diskSector -= raidPtr->Layout.sectorsPerStripeUnit; |
| 201 | } else |
| 202 | *col = (index_within_disk + 2) % raidPtr->numCol; |
| 203 | } |
| 204 | |
| 205 | } |
| 206 | |
| 207 | void |
| 208 | rf_IdentifyStripeChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t addr, |
| 209 | RF_RowCol_t **diskids) |
| 210 | { |
| 211 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
| 212 | RF_StripeNum_t SUID; |
| 213 | RF_RowCol_t col; |
| 214 | |
| 215 | SUID = addr / raidPtr->Layout.sectorsPerStripeUnit; |
| 216 | col = SUID % raidPtr->numCol; |
| 217 | *diskids = info->stripeIdentifier[col]; |
| 218 | } |
| 219 | |
| 220 | void |
| 221 | rf_MapSIDToPSIDChainDecluster(RF_RaidLayout_t *layoutPtr, |
| 222 | RF_StripeNum_t stripeID, |
| 223 | RF_StripeNum_t *psID, |
| 224 | RF_ReconUnitNum_t *which_ru) |
| 225 | { |
| 226 | *which_ru = 0; |
| 227 | *psID = stripeID; |
| 228 | } |
| 229 | /****************************************************************************** |
| 230 | * select a graph to perform a single-stripe access |
| 231 | * |
| 232 | * Parameters: raidPtr - description of the physical array |
| 233 | * type - type of operation (read or write) requested |
| 234 | * asmap - logical & physical addresses for this access |
| 235 | * createFunc - function to use to create the graph (return value) |
| 236 | *****************************************************************************/ |
| 237 | |
| 238 | void |
| 239 | rf_RAIDCDagSelect(RF_Raid_t *raidPtr, RF_IoType_t type, |
| 240 | RF_AccessStripeMap_t *asmap, RF_VoidFuncPtr *createFunc) |
| 241 | #if 0 |
| 242 | void (**createFunc) (RF_Raid_t *, RF_AccessStripeMap_t *, |
| 243 | RF_DagHeader_t *, void *, RF_RaidAccessFlags_t, |
| 244 | RF_AllocListElem_t *) |
| 245 | #endif |
| 246 | { |
| 247 | RF_ASSERT(RF_IO_IS_R_OR_W(type)); |
| 248 | |
| 249 | if (asmap->numDataFailed + asmap->numParityFailed > 1) { |
| 250 | RF_ERRORMSG("Multiple disks failed in a single group! Aborting I/O operation.\n" ); |
| 251 | *createFunc = NULL; |
| 252 | return; |
| 253 | } |
| 254 | *createFunc = (type == RF_IO_TYPE_READ) ? (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG : (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; |
| 255 | |
| 256 | if (type == RF_IO_TYPE_READ) { |
| 257 | if ((raidPtr->status == rf_rs_degraded) || (raidPtr->status == rf_rs_reconstructing)) |
| 258 | *createFunc = (RF_VoidFuncPtr) rf_CreateRaidCDegradedReadDAG; /* array status is |
| 259 | * degraded, implement |
| 260 | * workload shifting */ |
| 261 | else |
| 262 | *createFunc = (RF_VoidFuncPtr) rf_CreateMirrorPartitionReadDAG; /* array status not |
| 263 | * degraded, so use |
| 264 | * mirror partition dag */ |
| 265 | } else |
| 266 | *createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; |
| 267 | } |
| 268 | #endif /* (RF_INCLUDE_CHAINDECLUSTER > 0) */ |
| 269 | |