1 /* $NetBSD: rf_parityscan.c,v 1.17 2002/09/24 00:53:58 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_parityscan.c -- misc utilities related to parity verification 32 * 33 *****************************************************************************/ 34 35 #include <sys/cdefs.h> 36 __KERNEL_RCSID(0, "$NetBSD: rf_parityscan.c,v 1.17 2002/09/24 00:53:58 oster Exp $"); 37 38 #include <dev/raidframe/raidframevar.h> 39 40 #include "rf_raid.h" 41 #include "rf_dag.h" 42 #include "rf_dagfuncs.h" 43 #include "rf_dagutils.h" 44 #include "rf_mcpair.h" 45 #include "rf_general.h" 46 #include "rf_engine.h" 47 #include "rf_parityscan.h" 48 #include "rf_map.h" 49 50 /***************************************************************************************** 51 * 52 * walk through the entire arry and write new parity. 53 * This works by creating two DAGs, one to read a stripe of data and one to 54 * write new parity. The first is executed, the data is xored together, and 55 * then the second is executed. To avoid constantly building and tearing down 56 * the DAGs, we create them a priori and fill them in with the mapping 57 * information as we go along. 58 * 59 * there should never be more than one thread running this. 60 * 61 ****************************************************************************************/ 62 63 int 64 rf_RewriteParity(raidPtr) 65 RF_Raid_t *raidPtr; 66 { 67 RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; 68 RF_AccessStripeMapHeader_t *asm_h; 69 int ret_val; 70 int rc; 71 RF_SectorNum_t i; 72 73 if (raidPtr->Layout.map->faultsTolerated == 0) { 74 /* There isn't any parity. Call it "okay." */ 75 return (RF_PARITY_OKAY); 76 } 77 if (raidPtr->status[0] != rf_rs_optimal) { 78 /* 79 * We're in degraded mode. Don't try to verify parity now! 80 * XXX: this should be a "we don't want to", not a 81 * "we can't" error. 82 */ 83 return (RF_PARITY_COULD_NOT_VERIFY); 84 } 85 86 ret_val = 0; 87 88 rc = RF_PARITY_OKAY; 89 90 for (i = 0; i < raidPtr->totalSectors && 91 rc <= RF_PARITY_CORRECTED; 92 i += layoutPtr->dataSectorsPerStripe) { 93 if (raidPtr->waitShutdown) { 94 /* Someone is pulling the plug on this set... 95 abort the re-write */ 96 return (1); 97 } 98 asm_h = rf_MapAccess(raidPtr, i, 99 layoutPtr->dataSectorsPerStripe, 100 NULL, RF_DONT_REMAP); 101 raidPtr->parity_rewrite_stripes_done = 102 i / layoutPtr->dataSectorsPerStripe ; 103 rc = rf_VerifyParity(raidPtr, asm_h->stripeMap, 1, 0); 104 105 switch (rc) { 106 case RF_PARITY_OKAY: 107 case RF_PARITY_CORRECTED: 108 break; 109 case RF_PARITY_BAD: 110 printf("Parity bad during correction\n"); 111 ret_val = 1; 112 break; 113 case RF_PARITY_COULD_NOT_CORRECT: 114 printf("Could not correct bad parity\n"); 115 ret_val = 1; 116 break; 117 case RF_PARITY_COULD_NOT_VERIFY: 118 printf("Could not verify parity\n"); 119 ret_val = 1; 120 break; 121 default: 122 printf("Bad rc=%d from VerifyParity in RewriteParity\n", rc); 123 ret_val = 1; 124 } 125 rf_FreeAccessStripeMap(asm_h); 126 } 127 return (ret_val); 128 } 129 /***************************************************************************************** 130 * 131 * verify that the parity in a particular stripe is correct. 132 * we validate only the range of parity defined by parityPDA, since 133 * this is all we have locked. The way we do this is to create an asm 134 * that maps the whole stripe and then range-restrict it to the parity 135 * region defined by the parityPDA. 136 * 137 ****************************************************************************************/ 138 int 139 rf_VerifyParity(raidPtr, aasm, correct_it, flags) 140 RF_Raid_t *raidPtr; 141 RF_AccessStripeMap_t *aasm; 142 int correct_it; 143 RF_RaidAccessFlags_t flags; 144 { 145 RF_PhysDiskAddr_t *parityPDA; 146 RF_AccessStripeMap_t *doasm; 147 RF_LayoutSW_t *lp; 148 int lrc, rc; 149 150 lp = raidPtr->Layout.map; 151 if (lp->faultsTolerated == 0) { 152 /* 153 * There isn't any parity. Call it "okay." 154 */ 155 return (RF_PARITY_OKAY); 156 } 157 rc = RF_PARITY_OKAY; 158 if (lp->VerifyParity) { 159 for (doasm = aasm; doasm; doasm = doasm->next) { 160 for (parityPDA = doasm->parityInfo; parityPDA; 161 parityPDA = parityPDA->next) { 162 lrc = lp->VerifyParity(raidPtr, 163 doasm->raidAddress, 164 parityPDA, 165 correct_it, flags); 166 if (lrc > rc) { 167 /* see rf_parityscan.h for why this 168 * works */ 169 rc = lrc; 170 } 171 } 172 } 173 } else { 174 rc = RF_PARITY_COULD_NOT_VERIFY; 175 } 176 return (rc); 177 } 178 179 int 180 rf_VerifyParityBasic(raidPtr, raidAddr, parityPDA, correct_it, flags) 181 RF_Raid_t *raidPtr; 182 RF_RaidAddr_t raidAddr; 183 RF_PhysDiskAddr_t *parityPDA; 184 int correct_it; 185 RF_RaidAccessFlags_t flags; 186 { 187 RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); 188 RF_RaidAddr_t startAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, 189 raidAddr); 190 RF_SectorCount_t numsector = parityPDA->numSector; 191 int numbytes = rf_RaidAddressToByte(raidPtr, numsector); 192 int bytesPerStripe = numbytes * layoutPtr->numDataCol; 193 RF_DagHeader_t *rd_dag_h, *wr_dag_h; /* read, write dag */ 194 RF_DagNode_t *blockNode, *wrBlock; 195 RF_AccessStripeMapHeader_t *asm_h; 196 RF_AccessStripeMap_t *asmap; 197 RF_AllocListElem_t *alloclist; 198 RF_PhysDiskAddr_t *pda; 199 char *pbuf, *buf, *end_p, *p; 200 int i, retcode; 201 RF_ReconUnitNum_t which_ru; 202 RF_StripeNum_t psID = rf_RaidAddressToParityStripeID(layoutPtr, 203 raidAddr, 204 &which_ru); 205 int stripeWidth = layoutPtr->numDataCol + layoutPtr->numParityCol; 206 RF_AccTraceEntry_t tracerec; 207 RF_MCPair_t *mcpair; 208 209 retcode = RF_PARITY_OKAY; 210 211 mcpair = rf_AllocMCPair(); 212 rf_MakeAllocList(alloclist); 213 RF_MallocAndAdd(buf, numbytes * (layoutPtr->numDataCol + layoutPtr->numParityCol), (char *), alloclist); 214 RF_CallocAndAdd(pbuf, 1, numbytes, (char *), alloclist); /* use calloc to make 215 * sure buffer is zeroed */ 216 end_p = buf + bytesPerStripe; 217 218 rd_dag_h = rf_MakeSimpleDAG(raidPtr, stripeWidth, numbytes, buf, rf_DiskReadFunc, rf_DiskReadUndoFunc, 219 "Rod", alloclist, flags, RF_IO_NORMAL_PRIORITY); 220 blockNode = rd_dag_h->succedents[0]; 221 222 /* map the stripe and fill in the PDAs in the dag */ 223 asm_h = rf_MapAccess(raidPtr, startAddr, layoutPtr->dataSectorsPerStripe, buf, RF_DONT_REMAP); 224 asmap = asm_h->stripeMap; 225 226 for (pda = asmap->physInfo, i = 0; i < layoutPtr->numDataCol; i++, pda = pda->next) { 227 RF_ASSERT(pda); 228 rf_RangeRestrictPDA(raidPtr, parityPDA, pda, 0, 1); 229 RF_ASSERT(pda->numSector != 0); 230 if (rf_TryToRedirectPDA(raidPtr, pda, 0)) 231 goto out; /* no way to verify parity if disk is 232 * dead. return w/ good status */ 233 blockNode->succedents[i]->params[0].p = pda; 234 blockNode->succedents[i]->params[2].v = psID; 235 blockNode->succedents[i]->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); 236 } 237 238 RF_ASSERT(!asmap->parityInfo->next); 239 rf_RangeRestrictPDA(raidPtr, parityPDA, asmap->parityInfo, 0, 1); 240 RF_ASSERT(asmap->parityInfo->numSector != 0); 241 if (rf_TryToRedirectPDA(raidPtr, asmap->parityInfo, 1)) 242 goto out; 243 blockNode->succedents[layoutPtr->numDataCol]->params[0].p = asmap->parityInfo; 244 245 /* fire off the DAG */ 246 memset((char *) &tracerec, 0, sizeof(tracerec)); 247 rd_dag_h->tracerec = &tracerec; 248 #if 0 249 if (rf_verifyParityDebug) { 250 printf("Parity verify read dag:\n"); 251 rf_PrintDAGList(rd_dag_h); 252 } 253 #endif 254 RF_LOCK_MUTEX(mcpair->mutex); 255 mcpair->flag = 0; 256 rf_DispatchDAG(rd_dag_h, (void (*) (void *)) rf_MCPairWakeupFunc, 257 (void *) mcpair); 258 while (!mcpair->flag) 259 RF_WAIT_COND(mcpair->cond, mcpair->mutex); 260 RF_UNLOCK_MUTEX(mcpair->mutex); 261 if (rd_dag_h->status != rf_enable) { 262 RF_ERRORMSG("Unable to verify parity: can't read the stripe\n"); 263 retcode = RF_PARITY_COULD_NOT_VERIFY; 264 goto out; 265 } 266 for (p = buf; p < end_p; p += numbytes) { 267 rf_bxor(p, pbuf, numbytes, NULL); 268 } 269 for (i = 0; i < numbytes; i++) { 270 if (pbuf[i] != buf[bytesPerStripe + i]) { 271 if (!correct_it) 272 RF_ERRORMSG3("Parity verify error: byte %d of parity is 0x%x should be 0x%x\n", 273 i, (u_char) buf[bytesPerStripe + i], (u_char) pbuf[i]); 274 retcode = RF_PARITY_BAD; 275 break; 276 } 277 } 278 279 if (retcode && correct_it) { 280 wr_dag_h = rf_MakeSimpleDAG(raidPtr, 1, numbytes, pbuf, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, 281 "Wnp", alloclist, flags, RF_IO_NORMAL_PRIORITY); 282 wrBlock = wr_dag_h->succedents[0]; 283 wrBlock->succedents[0]->params[0].p = asmap->parityInfo; 284 wrBlock->succedents[0]->params[2].v = psID; 285 wrBlock->succedents[0]->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); 286 memset((char *) &tracerec, 0, sizeof(tracerec)); 287 wr_dag_h->tracerec = &tracerec; 288 #if 0 289 if (rf_verifyParityDebug) { 290 printf("Parity verify write dag:\n"); 291 rf_PrintDAGList(wr_dag_h); 292 } 293 #endif 294 RF_LOCK_MUTEX(mcpair->mutex); 295 mcpair->flag = 0; 296 rf_DispatchDAG(wr_dag_h, (void (*) (void *)) rf_MCPairWakeupFunc, 297 (void *) mcpair); 298 while (!mcpair->flag) 299 RF_WAIT_COND(mcpair->cond, mcpair->mutex); 300 RF_UNLOCK_MUTEX(mcpair->mutex); 301 if (wr_dag_h->status != rf_enable) { 302 RF_ERRORMSG("Unable to correct parity in VerifyParity: can't write the stripe\n"); 303 retcode = RF_PARITY_COULD_NOT_CORRECT; 304 } 305 rf_FreeDAG(wr_dag_h); 306 if (retcode == RF_PARITY_BAD) 307 retcode = RF_PARITY_CORRECTED; 308 } 309 out: 310 rf_FreeAccessStripeMap(asm_h); 311 rf_FreeAllocList(alloclist); 312 rf_FreeDAG(rd_dag_h); 313 rf_FreeMCPair(mcpair); 314 return (retcode); 315 } 316 317 int 318 rf_TryToRedirectPDA(raidPtr, pda, parity) 319 RF_Raid_t *raidPtr; 320 RF_PhysDiskAddr_t *pda; 321 int parity; 322 { 323 if (raidPtr->Disks[pda->row][pda->col].status == rf_ds_reconstructing) { 324 if (rf_CheckRUReconstructed(raidPtr->reconControl[pda->row]->reconMap, pda->startSector)) { 325 if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) { 326 #if RF_DEBUG_VERIFYPARITY 327 RF_RowCol_t or = pda->row, oc = pda->col; 328 RF_SectorNum_t os = pda->startSector; 329 #endif 330 if (parity) { 331 (raidPtr->Layout.map->MapParity) (raidPtr, pda->raidAddress, &pda->row, &pda->col, &pda->startSector, RF_REMAP); 332 #if RF_DEBUG_VERIFYPARITY 333 if (rf_verifyParityDebug) 334 printf("VerifyParity: Redir P r %d c %d sect %ld -> r %d c %d sect %ld\n", 335 or, oc, (long) os, pda->row, pda->col, (long) pda->startSector); 336 #endif 337 } else { 338 (raidPtr->Layout.map->MapSector) (raidPtr, pda->raidAddress, &pda->row, &pda->col, &pda->startSector, RF_REMAP); 339 #if RF_DEBUG_VERIFYPARITY 340 if (rf_verifyParityDebug) 341 printf("VerifyParity: Redir D r %d c %d sect %ld -> r %d c %d sect %ld\n", 342 or, oc, (long) os, pda->row, pda->col, (long) pda->startSector); 343 #endif 344 } 345 } else { 346 RF_RowCol_t spRow = raidPtr->Disks[pda->row][pda->col].spareRow; 347 RF_RowCol_t spCol = raidPtr->Disks[pda->row][pda->col].spareCol; 348 pda->row = spRow; 349 pda->col = spCol; 350 } 351 } 352 } 353 if (RF_DEAD_DISK(raidPtr->Disks[pda->row][pda->col].status)) 354 return (1); 355 return (0); 356 } 357 /***************************************************************************************** 358 * 359 * currently a stub. 360 * 361 * takes as input an ASM describing a write operation and containing one failure, and 362 * verifies that the parity was correctly updated to reflect the write. 363 * 364 * if it's a data unit that's failed, we read the other data units in the stripe and 365 * the parity unit, XOR them together, and verify that we get the data intended for 366 * the failed disk. Since it's easy, we also validate that the right data got written 367 * to the surviving data disks. 368 * 369 * If it's the parity that failed, there's really no validation we can do except the 370 * above verification that the right data got written to all disks. This is because 371 * the new data intended for the failed disk is supplied in the ASM, but this is of 372 * course not the case for the new parity. 373 * 374 ****************************************************************************************/ 375 #if 0 376 int 377 rf_VerifyDegrModeWrite(raidPtr, asmh) 378 RF_Raid_t *raidPtr; 379 RF_AccessStripeMapHeader_t *asmh; 380 { 381 return (0); 382 } 383 #endif 384 /* creates a simple DAG with a header, a block-recon node at level 1, 385 * nNodes nodes at level 2, an unblock-recon node at level 3, and 386 * a terminator node at level 4. The stripe address field in 387 * the block and unblock nodes are not touched, nor are the pda 388 * fields in the second-level nodes, so they must be filled in later. 389 * 390 * commit point is established at unblock node - this means that any 391 * failure during dag execution causes the dag to fail 392 */ 393 RF_DagHeader_t * 394 rf_MakeSimpleDAG(raidPtr, nNodes, bytesPerSU, databuf, doFunc, undoFunc, name, alloclist, flags, priority) 395 RF_Raid_t *raidPtr; 396 int nNodes; 397 int bytesPerSU; 398 char *databuf; 399 int (*doFunc) (RF_DagNode_t * node); 400 int (*undoFunc) (RF_DagNode_t * node); 401 char *name; /* node names at the second level */ 402 RF_AllocListElem_t *alloclist; 403 RF_RaidAccessFlags_t flags; 404 int priority; 405 { 406 RF_DagHeader_t *dag_h; 407 RF_DagNode_t *nodes, *termNode, *blockNode, *unblockNode; 408 int i; 409 410 /* create the nodes, the block & unblock nodes, and the terminator 411 * node */ 412 RF_CallocAndAdd(nodes, nNodes + 3, sizeof(RF_DagNode_t), (RF_DagNode_t *), alloclist); 413 blockNode = &nodes[nNodes]; 414 unblockNode = blockNode + 1; 415 termNode = unblockNode + 1; 416 417 dag_h = rf_AllocDAGHeader(); 418 dag_h->raidPtr = (void *) raidPtr; 419 dag_h->allocList = NULL;/* we won't use this alloc list */ 420 dag_h->status = rf_enable; 421 dag_h->numSuccedents = 1; 422 dag_h->creator = "SimpleDAG"; 423 424 /* this dag can not commit until the unblock node is reached errors 425 * prior to the commit point imply the dag has failed */ 426 dag_h->numCommitNodes = 1; 427 dag_h->numCommits = 0; 428 429 dag_h->succedents[0] = blockNode; 430 rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nNodes, 0, 0, 0, dag_h, "Nil", alloclist); 431 rf_InitNode(unblockNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, nNodes, 0, 0, dag_h, "Nil", alloclist); 432 unblockNode->succedents[0] = termNode; 433 for (i = 0; i < nNodes; i++) { 434 blockNode->succedents[i] = unblockNode->antecedents[i] = &nodes[i]; 435 unblockNode->antType[i] = rf_control; 436 rf_InitNode(&nodes[i], rf_wait, RF_FALSE, doFunc, undoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, name, alloclist); 437 nodes[i].succedents[0] = unblockNode; 438 nodes[i].antecedents[0] = blockNode; 439 nodes[i].antType[0] = rf_control; 440 nodes[i].params[1].p = (databuf + (i * bytesPerSU)); 441 } 442 rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", alloclist); 443 termNode->antecedents[0] = unblockNode; 444 termNode->antType[0] = rf_control; 445 return (dag_h); 446 } 447