Annotation of sys/dev/raidframe/rf_dagdegwr.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: rf_dagdegwr.c,v 1.6 2006/07/09 22:10:05 mk Exp $ */
! 2: /* $NetBSD: rf_dagdegwr.c,v 1.5 2000/01/07 03:40:57 oster Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1995 Carnegie-Mellon University.
! 6: * All rights reserved.
! 7: *
! 8: * Author: Mark Holland, Daniel Stodolsky, William V. Courtright II
! 9: *
! 10: * Permission to use, copy, modify and distribute this software and
! 11: * its documentation is hereby granted, provided that both the copyright
! 12: * notice and this permission notice appear in all copies of the
! 13: * software, derivative works or modified versions, and any portions
! 14: * thereof, and that both notices appear in supporting documentation.
! 15: *
! 16: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
! 17: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
! 18: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
! 19: *
! 20: * Carnegie Mellon requests users of this software to return to
! 21: *
! 22: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
! 23: * School of Computer Science
! 24: * Carnegie Mellon University
! 25: * Pittsburgh PA 15213-3890
! 26: *
! 27: * any improvements or extensions that they make and grant Carnegie the
! 28: * rights to redistribute these changes.
! 29: */
! 30:
! 31: /*
! 32: * rf_dagdegwr.c
! 33: *
! 34: * Code for creating degraded write DAGs.
! 35: *
! 36: */
! 37:
! 38: #include "rf_types.h"
! 39: #include "rf_raid.h"
! 40: #include "rf_dag.h"
! 41: #include "rf_dagutils.h"
! 42: #include "rf_dagfuncs.h"
! 43: #include "rf_debugMem.h"
! 44: #include "rf_memchunk.h"
! 45: #include "rf_general.h"
! 46: #include "rf_dagdegwr.h"
! 47:
! 48:
! 49: /*****************************************************************************
! 50: *
! 51: * General comments on DAG creation:
! 52: *
! 53: * All DAGs in this file use roll-away error recovery. Each DAG has a single
! 54: * commit node, usually called "Cmt". If an error occurs before the Cmt node
! 55: * is reached, the execution engine will halt forward execution and work
! 56: * backward through the graph, executing the undo functions. Assuming that
! 57: * each node in the graph prior to the Cmt node are undoable and atomic - or -
! 58: * does not make changes to permanent state, the graph will fail atomically.
! 59: * If an error occurs after the Cmt node executes, the engine will roll-forward
! 60: * through the graph, blindly executing nodes until it reaches the end.
! 61: * If a graph reaches the end, it is assumed to have completed successfully.
! 62: *
! 63: * A graph has only 1 Cmt node.
! 64: *
! 65: *****************************************************************************/
! 66:
! 67:
! 68: /*****************************************************************************
! 69: *
! 70: * The following wrappers map the standard DAG creation interface to the
! 71: * DAG creation routines. Additionally, these wrappers enable experimentation
! 72: * with new DAG structures by providing an extra level of indirection, allowing
! 73: * the DAG creation routines to be replaced at this single point.
! 74: *
! 75: *****************************************************************************/
! 76:
! 77: RF_CREATE_DAG_FUNC_DECL(rf_CreateSimpleDegradedWriteDAG)
! 78: {
! 79: rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
! 80: flags, allocList, 1, rf_RecoveryXorFunc, RF_TRUE);
! 81: }
! 82:
! 83: void
! 84: rf_CreateDegradedWriteDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
! 85: RF_DagHeader_t *dag_h, void *bp, RF_RaidAccessFlags_t flags,
! 86: RF_AllocListElem_t *allocList)
! 87: {
! 88: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
! 89: RF_PhysDiskAddr_t *failedPDA = asmap->failedPDAs[0];
! 90:
! 91: RF_ASSERT(asmap->numDataFailed == 1);
! 92: dag_h->creator = "DegradedWriteDAG";
! 93:
! 94: /*
! 95: * If the access writes only a portion of the failed unit, and also
! 96: * writes some portion of at least one surviving unit, we create two
! 97: * DAGs, one for the failed component and one for the non-failed
! 98: * component, and do them sequentially. Note that the fact that we're
! 99: * accessing only a portion of the failed unit indicates that the
! 100: * access either starts or ends in the failed unit, and hence we need
! 101: * create only two dags. This is inefficient in that the same data or
! 102: * parity can get read and written twice using this structure. I need
! 103: * to fix this to do the access all at once.
! 104: */
! 105: RF_ASSERT(!(asmap->numStripeUnitsAccessed != 1 &&
! 106: failedPDA->numSector != layoutPtr->sectorsPerStripeUnit));
! 107: rf_CreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
! 108: flags, allocList);
! 109: }
! 110:
! 111:
! 112:
! 113: /*****************************************************************************
! 114: *
! 115: * DAG creation code begins here.
! 116: *
! 117: *****************************************************************************/
! 118:
! 119:
! 120: /*****************************************************************************
! 121: *
! 122: * CommonCreateSimpleDegradedWriteDAG -- creates a DAG to do a degraded-mode
! 123: * write, which is as follows
! 124: *
! 125: * / {Wnq} --\
! 126: * hdr -> blockNode -> Rod -> Xor -> Cmt -> Wnp ----> unblock -> term
! 127: * \ {Rod} / | Wnd ---/
! 128: * \ {Wnd} -/
! 129: *
! 130: * Commit nodes: Xor, Wnd
! 131: *
! 132: * IMPORTANT:
! 133: * This DAG generator does not work for double-degraded archs since it does not
! 134: * generate Q.
! 135: *
! 136: * This dag is essentially identical to the large-write dag, except that the
! 137: * write to the failed data unit is suppressed.
! 138: *
! 139: * IMPORTANT: this dag does not work in the case where the access writes only
! 140: * a portion of the failed unit, and also writes some portion of at least one
! 141: * surviving SU. this case is handled in CreateDegradedWriteDAG above.
! 142: *
! 143: * The block & unblock nodes are leftovers from a previous version. They
! 144: * do nothing, but I haven't deleted them because it would be a tremendous
! 145: * effort to put them back in.
! 146: *
! 147: * This dag is used whenever one of the data units in a write has failed.
! 148: * If it is the parity unit that failed, the nonredundant write dag (below)
! 149: * is used.
! 150: *
! 151: *****************************************************************************/
! 152:
! 153: void
! 154: rf_CommonCreateSimpleDegradedWriteDAG(RF_Raid_t *raidPtr,
! 155: RF_AccessStripeMap_t *asmap, RF_DagHeader_t *dag_h, void *bp,
! 156: RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, int nfaults,
! 157: int (*redFunc) (RF_DagNode_t *), int allowBufferRecycle)
! 158: {
! 159: int nNodes, nRrdNodes, nWndNodes, nXorBufs, i, j, paramNum,
! 160: rdnodesFaked;
! 161: RF_DagNode_t *blockNode, *unblockNode, *wnpNode, *wnqNode, *termNode;
! 162: RF_DagNode_t *nodes, *wndNodes, *rrdNodes, *xorNode, *commitNode;
! 163: RF_SectorCount_t sectorsPerSU;
! 164: RF_ReconUnitNum_t which_ru;
! 165: char *xorTargetBuf = NULL; /*
! 166: * The target buffer for the XOR
! 167: * operation.
! 168: */
! 169: char *overlappingPDAs; /* A temporary array of flags. */
! 170: RF_AccessStripeMapHeader_t *new_asm_h[2];
! 171: RF_PhysDiskAddr_t *pda, *parityPDA;
! 172: RF_StripeNum_t parityStripeID;
! 173: RF_PhysDiskAddr_t *failedPDA;
! 174: RF_RaidLayout_t *layoutPtr;
! 175:
! 176: layoutPtr = &(raidPtr->Layout);
! 177: parityStripeID = rf_RaidAddressToParityStripeID(layoutPtr,
! 178: asmap->raidAddress, &which_ru);
! 179: sectorsPerSU = layoutPtr->sectorsPerStripeUnit;
! 180: /*
! 181: * failedPDA points to the pda within the asm that targets
! 182: * the failed disk.
! 183: */
! 184: failedPDA = asmap->failedPDAs[0];
! 185:
! 186: if (rf_dagDebug)
! 187: printf("[Creating degraded-write DAG]\n");
! 188:
! 189: RF_ASSERT(asmap->numDataFailed == 1);
! 190: dag_h->creator = "SimpleDegradedWriteDAG";
! 191:
! 192: /*
! 193: * Generate two ASMs identifying the surviving data
! 194: * we need in order to recover the lost data.
! 195: */
! 196: /* overlappingPDAs array must be zero'd */
! 197: RF_Calloc(overlappingPDAs, asmap->numStripeUnitsAccessed,
! 198: sizeof(char), (char *));
! 199: rf_GenerateFailedAccessASMs(raidPtr, asmap, failedPDA, dag_h,
! 200: new_asm_h, &nXorBufs, NULL, overlappingPDAs, allocList);
! 201:
! 202: /* Create all the nodes at once. */
! 203: nWndNodes = asmap->numStripeUnitsAccessed - 1; /*
! 204: * No access is
! 205: * generated for the
! 206: * failed pda.
! 207: */
! 208:
! 209: nRrdNodes = ((new_asm_h[0]) ?
! 210: new_asm_h[0]->stripeMap->numStripeUnitsAccessed : 0) +
! 211: ((new_asm_h[1]) ? new_asm_h[1]->stripeMap->numStripeUnitsAccessed
! 212: : 0);
! 213: /*
! 214: * XXX
! 215: *
! 216: * There's a bug with a complete stripe overwrite- that means 0 reads
! 217: * of old data, and the rest of the DAG generation code doesn't like
! 218: * that. A release is coming, and I don't wanna risk breaking a
! 219: * critical DAG generator, so here's what I'm gonna do- if there's
! 220: * no read nodes, I'm gonna fake there being a read node, and I'm
! 221: * gonna swap in a no-op node in its place (to make all the link-up
! 222: * code happy).
! 223: * This should be fixed at some point. --jimz
! 224: */
! 225: if (nRrdNodes == 0) {
! 226: nRrdNodes = 1;
! 227: rdnodesFaked = 1;
! 228: } else {
! 229: rdnodesFaked = 0;
! 230: }
! 231: /* Lock, unlock, xor, Wnd, Rrd, W(nfaults). */
! 232: nNodes = 5 + nfaults + nWndNodes + nRrdNodes;
! 233: RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t),
! 234: (RF_DagNode_t *), allocList);
! 235: i = 0;
! 236: blockNode = &nodes[i];
! 237: i += 1;
! 238: commitNode = &nodes[i];
! 239: i += 1;
! 240: unblockNode = &nodes[i];
! 241: i += 1;
! 242: termNode = &nodes[i];
! 243: i += 1;
! 244: xorNode = &nodes[i];
! 245: i += 1;
! 246: wnpNode = &nodes[i];
! 247: i += 1;
! 248: wndNodes = &nodes[i];
! 249: i += nWndNodes;
! 250: rrdNodes = &nodes[i];
! 251: i += nRrdNodes;
! 252: if (nfaults == 2) {
! 253: wnqNode = &nodes[i];
! 254: i += 1;
! 255: } else {
! 256: wnqNode = NULL;
! 257: }
! 258: RF_ASSERT(i == nNodes);
! 259:
! 260: /*
! 261: * This dag can not commit until all rrd and xor Nodes have
! 262: * completed.
! 263: */
! 264: dag_h->numCommitNodes = 1;
! 265: dag_h->numCommits = 0;
! 266: dag_h->numSuccedents = 1;
! 267:
! 268: RF_ASSERT(nRrdNodes > 0);
! 269: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 270: rf_NullNodeUndoFunc, NULL, nRrdNodes, 0, 0, 0, dag_h,
! 271: "Nil", allocList);
! 272: rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
! 273: rf_NullNodeUndoFunc, NULL, nWndNodes + nfaults, 1, 0, 0,
! 274: dag_h, "Cmt", allocList);
! 275: rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 276: rf_NullNodeUndoFunc, NULL, 1, nWndNodes + nfaults, 0, 0,
! 277: dag_h, "Nil", allocList);
! 278: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
! 279: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
! 280: rf_InitNode(xorNode, rf_wait, RF_FALSE, redFunc, rf_NullNodeUndoFunc,
! 281: NULL, 1, nRrdNodes, 2 * nXorBufs + 2, nfaults, dag_h, "Xrc",
! 282: allocList);
! 283:
! 284: /*
! 285: * Fill in the Rrd nodes. If any of the rrd buffers are the same size
! 286: * as the failed buffer, save a pointer to it so we can use it as the
! 287: * target of the XOR. The pdas in the rrd nodes have been range-
! 288: * restricted, so if a buffer is the same size as the failed buffer,
! 289: * it must also be at the same alignment within the SU.
! 290: */
! 291: i = 0;
! 292: if (new_asm_h[0]) {
! 293: for (i = 0, pda = new_asm_h[0]->stripeMap->physInfo;
! 294: i < new_asm_h[0]->stripeMap->numStripeUnitsAccessed;
! 295: i++, pda = pda->next) {
! 296: rf_InitNode(&rrdNodes[i], rf_wait, RF_FALSE,
! 297: rf_DiskReadFunc, rf_DiskReadUndoFunc,
! 298: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
! 299: "Rrd", allocList);
! 300: RF_ASSERT(pda);
! 301: rrdNodes[i].params[0].p = pda;
! 302: rrdNodes[i].params[1].p = pda->bufPtr;
! 303: rrdNodes[i].params[2].v = parityStripeID;
! 304: rrdNodes[i].params[3].v = RF_CREATE_PARAM3(
! 305: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
! 306: }
! 307: }
! 308: /* i now equals the number of stripe units accessed in new_asm_h[0]. */
! 309: if (new_asm_h[1]) {
! 310: for (j = 0, pda = new_asm_h[1]->stripeMap->physInfo;
! 311: j < new_asm_h[1]->stripeMap->numStripeUnitsAccessed;
! 312: j++, pda = pda->next) {
! 313: rf_InitNode(&rrdNodes[i + j], rf_wait, RF_FALSE,
! 314: rf_DiskReadFunc, rf_DiskReadUndoFunc,
! 315: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
! 316: "Rrd", allocList);
! 317: RF_ASSERT(pda);
! 318: rrdNodes[i + j].params[0].p = pda;
! 319: rrdNodes[i + j].params[1].p = pda->bufPtr;
! 320: rrdNodes[i + j].params[2].v = parityStripeID;
! 321: rrdNodes[i + j].params[3].v = RF_CREATE_PARAM3(
! 322: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
! 323: if (allowBufferRecycle &&
! 324: (pda->numSector == failedPDA->numSector))
! 325: xorTargetBuf = pda->bufPtr;
! 326: }
! 327: }
! 328: if (rdnodesFaked) {
! 329: /*
! 330: * This is where we'll init that fake noop read node.
! 331: * (XXX should the wakeup func be different ?)
! 332: */
! 333: rf_InitNode(&rrdNodes[0], rf_wait, RF_FALSE, rf_NullNodeFunc,
! 334: rf_NullNodeUndoFunc, NULL, 1, 1, 0, 0, dag_h, "RrN",
! 335: allocList);
! 336: }
! 337: /*
! 338: * Make a PDA for the parity unit. The parity PDA should start at
! 339: * the same offset into the SU as the failed PDA.
! 340: */
! 341: /*
! 342: * Danner comment: I don't think this copy is really necessary. We are
! 343: * in one of two cases here.
! 344: * (1) The entire failed unit is written. Then asmap->parityInfo will
! 345: * describe the entire parity.
! 346: * (2) We are only writing a subset of the failed unit and nothing else.
! 347: * Then the asmap->parityInfo describes the failed unit and the copy
! 348: * can also be avoided.
! 349: */
! 350:
! 351: RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t),
! 352: (RF_PhysDiskAddr_t *), allocList);
! 353: parityPDA->row = asmap->parityInfo->row;
! 354: parityPDA->col = asmap->parityInfo->col;
! 355: parityPDA->startSector = ((asmap->parityInfo->startSector /
! 356: sectorsPerSU) * sectorsPerSU) + (failedPDA->startSector %
! 357: sectorsPerSU);
! 358: parityPDA->numSector = failedPDA->numSector;
! 359:
! 360: if (!xorTargetBuf) {
! 361: RF_CallocAndAdd(xorTargetBuf, 1, rf_RaidAddressToByte(raidPtr,
! 362: failedPDA->numSector), (char *), allocList);
! 363: }
! 364: /* Init the Wnp node. */
! 365: rf_InitNode(wnpNode, rf_wait, RF_FALSE, rf_DiskWriteFunc,
! 366: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0,
! 367: dag_h, "Wnp", allocList);
! 368: wnpNode->params[0].p = parityPDA;
! 369: wnpNode->params[1].p = xorTargetBuf;
! 370: wnpNode->params[2].v = parityStripeID;
! 371: wnpNode->params[3].v = RF_CREATE_PARAM3(
! 372: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
! 373:
! 374: /* Fill in the Wnq Node. */
! 375: if (nfaults == 2) {
! 376: {
! 377: RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t),
! 378: (RF_PhysDiskAddr_t *), allocList);
! 379: parityPDA->row = asmap->qInfo->row;
! 380: parityPDA->col = asmap->qInfo->col;
! 381: parityPDA->startSector = ((asmap->qInfo->startSector /
! 382: sectorsPerSU) * sectorsPerSU) +
! 383: (failedPDA->startSector % sectorsPerSU);
! 384: parityPDA->numSector = failedPDA->numSector;
! 385:
! 386: rf_InitNode(wnqNode, rf_wait, RF_FALSE,
! 387: rf_DiskWriteFunc, rf_DiskWriteUndoFunc,
! 388: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h,
! 389: "Wnq", allocList);
! 390: wnqNode->params[0].p = parityPDA;
! 391: RF_CallocAndAdd(xorNode->results[1], 1,
! 392: rf_RaidAddressToByte(raidPtr, failedPDA->numSector),
! 393: (char *), allocList);
! 394: wnqNode->params[1].p = xorNode->results[1];
! 395: wnqNode->params[2].v = parityStripeID;
! 396: wnqNode->params[3].v = RF_CREATE_PARAM3(
! 397: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
! 398: }
! 399: }
! 400: /* Fill in the Wnd nodes. */
! 401: for (pda = asmap->physInfo, i = 0; i < nWndNodes;
! 402: i++, pda = pda->next) {
! 403: if (pda == failedPDA) {
! 404: i--;
! 405: continue;
! 406: }
! 407: rf_InitNode(&wndNodes[i], rf_wait, RF_FALSE, rf_DiskWriteFunc,
! 408: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0,
! 409: dag_h, "Wnd", allocList);
! 410: RF_ASSERT(pda);
! 411: wndNodes[i].params[0].p = pda;
! 412: wndNodes[i].params[1].p = pda->bufPtr;
! 413: wndNodes[i].params[2].v = parityStripeID;
! 414: wndNodes[i].params[3].v = RF_CREATE_PARAM3(
! 415: RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
! 416: }
! 417:
! 418: /* Fill in the results of the xor node. */
! 419: xorNode->results[0] = xorTargetBuf;
! 420:
! 421: /* Fill in the params of the xor node. */
! 422:
! 423: paramNum = 0;
! 424: if (rdnodesFaked == 0) {
! 425: for (i = 0; i < nRrdNodes; i++) {
! 426: /* All the Rrd nodes need to be xored together. */
! 427: xorNode->params[paramNum++] = rrdNodes[i].params[0];
! 428: xorNode->params[paramNum++] = rrdNodes[i].params[1];
! 429: }
! 430: }
! 431: for (i = 0; i < nWndNodes; i++) {
! 432: /*
! 433: * Any Wnd nodes that overlap the failed access need to be
! 434: * xored in.
! 435: */
! 436: if (overlappingPDAs[i]) {
! 437: RF_MallocAndAdd(pda, sizeof(RF_PhysDiskAddr_t),
! 438: (RF_PhysDiskAddr_t *), allocList);
! 439: bcopy((char *) wndNodes[i].params[0].p, (char *) pda,
! 440: sizeof(RF_PhysDiskAddr_t));
! 441: rf_RangeRestrictPDA(raidPtr, failedPDA, pda,
! 442: RF_RESTRICT_DOBUFFER, 0);
! 443: xorNode->params[paramNum++].p = pda;
! 444: xorNode->params[paramNum++].p = pda->bufPtr;
! 445: }
! 446: }
! 447: RF_Free(overlappingPDAs, asmap->numStripeUnitsAccessed * sizeof(char));
! 448:
! 449: /*
! 450: * Install the failed PDA into the xor param list so that the
! 451: * new data gets xor'd in.
! 452: */
! 453: xorNode->params[paramNum++].p = failedPDA;
! 454: xorNode->params[paramNum++].p = failedPDA->bufPtr;
! 455:
! 456: /*
! 457: * The last 2 params to the recovery xor node are always the failed
! 458: * PDA and the raidPtr. Install the failedPDA even though we have just
! 459: * done so above. This allows us to use the same XOR function for both
! 460: * degraded reads and degraded writes.
! 461: */
! 462: xorNode->params[paramNum++].p = failedPDA;
! 463: xorNode->params[paramNum++].p = raidPtr;
! 464: RF_ASSERT(paramNum == 2 * nXorBufs + 2);
! 465:
! 466: /*
! 467: * Code to link nodes begins here.
! 468: */
! 469:
! 470: /* Link header to block node. */
! 471: RF_ASSERT(blockNode->numAntecedents == 0);
! 472: dag_h->succedents[0] = blockNode;
! 473:
! 474: /* Link block node to rd nodes. */
! 475: RF_ASSERT(blockNode->numSuccedents == nRrdNodes);
! 476: for (i = 0; i < nRrdNodes; i++) {
! 477: RF_ASSERT(rrdNodes[i].numAntecedents == 1);
! 478: blockNode->succedents[i] = &rrdNodes[i];
! 479: rrdNodes[i].antecedents[0] = blockNode;
! 480: rrdNodes[i].antType[0] = rf_control;
! 481: }
! 482:
! 483: /* Link read nodes to xor node. */
! 484: RF_ASSERT(xorNode->numAntecedents == nRrdNodes);
! 485: for (i = 0; i < nRrdNodes; i++) {
! 486: RF_ASSERT(rrdNodes[i].numSuccedents == 1);
! 487: rrdNodes[i].succedents[0] = xorNode;
! 488: xorNode->antecedents[i] = &rrdNodes[i];
! 489: xorNode->antType[i] = rf_trueData;
! 490: }
! 491:
! 492: /* Link xor node to commit node. */
! 493: RF_ASSERT(xorNode->numSuccedents == 1);
! 494: RF_ASSERT(commitNode->numAntecedents == 1);
! 495: xorNode->succedents[0] = commitNode;
! 496: commitNode->antecedents[0] = xorNode;
! 497: commitNode->antType[0] = rf_control;
! 498:
! 499: /* Link commit node to wnd nodes. */
! 500: RF_ASSERT(commitNode->numSuccedents == nfaults + nWndNodes);
! 501: for (i = 0; i < nWndNodes; i++) {
! 502: RF_ASSERT(wndNodes[i].numAntecedents == 1);
! 503: commitNode->succedents[i] = &wndNodes[i];
! 504: wndNodes[i].antecedents[0] = commitNode;
! 505: wndNodes[i].antType[0] = rf_control;
! 506: }
! 507:
! 508: /* Link the commit node to wnp, wnq nodes. */
! 509: RF_ASSERT(wnpNode->numAntecedents == 1);
! 510: commitNode->succedents[nWndNodes] = wnpNode;
! 511: wnpNode->antecedents[0] = commitNode;
! 512: wnpNode->antType[0] = rf_control;
! 513: if (nfaults == 2) {
! 514: RF_ASSERT(wnqNode->numAntecedents == 1);
! 515: commitNode->succedents[nWndNodes + 1] = wnqNode;
! 516: wnqNode->antecedents[0] = commitNode;
! 517: wnqNode->antType[0] = rf_control;
! 518: }
! 519: /* Link write new data nodes to unblock node. */
! 520: RF_ASSERT(unblockNode->numAntecedents == (nWndNodes + nfaults));
! 521: for (i = 0; i < nWndNodes; i++) {
! 522: RF_ASSERT(wndNodes[i].numSuccedents == 1);
! 523: wndNodes[i].succedents[0] = unblockNode;
! 524: unblockNode->antecedents[i] = &wndNodes[i];
! 525: unblockNode->antType[i] = rf_control;
! 526: }
! 527:
! 528: /* Link write new parity node to unblock node. */
! 529: RF_ASSERT(wnpNode->numSuccedents == 1);
! 530: wnpNode->succedents[0] = unblockNode;
! 531: unblockNode->antecedents[nWndNodes] = wnpNode;
! 532: unblockNode->antType[nWndNodes] = rf_control;
! 533:
! 534: /* Link write new q node to unblock node. */
! 535: if (nfaults == 2) {
! 536: RF_ASSERT(wnqNode->numSuccedents == 1);
! 537: wnqNode->succedents[0] = unblockNode;
! 538: unblockNode->antecedents[nWndNodes + 1] = wnqNode;
! 539: unblockNode->antType[nWndNodes + 1] = rf_control;
! 540: }
! 541: /* Link unblock node to term node. */
! 542: RF_ASSERT(unblockNode->numSuccedents == 1);
! 543: RF_ASSERT(termNode->numAntecedents == 1);
! 544: RF_ASSERT(termNode->numSuccedents == 0);
! 545: unblockNode->succedents[0] = termNode;
! 546: termNode->antecedents[0] = unblockNode;
! 547: termNode->antType[0] = rf_control;
! 548: }
! 549:
! 550: #define CONS_PDA(if,start,num) do { \
! 551: pda_p->row = asmap->if->row; \
! 552: pda_p->col = asmap->if->col; \
! 553: pda_p->startSector = ((asmap->if->startSector / secPerSU) * \
! 554: secPerSU) + start; \
! 555: pda_p->numSector = num; \
! 556: pda_p->next = NULL; \
! 557: RF_MallocAndAdd(pda_p->bufPtr, \
! 558: rf_RaidAddressToByte(raidPtr,num),(char *), allocList); \
! 559: } while (0)
! 560:
! 561: void
! 562: rf_WriteGenerateFailedAccessASMs(RF_Raid_t *raidPtr,
! 563: RF_AccessStripeMap_t *asmap, RF_PhysDiskAddr_t **pdap, int *nNodep,
! 564: RF_PhysDiskAddr_t **pqpdap, int *nPQNodep, RF_AllocListElem_t *allocList)
! 565: {
! 566: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
! 567: int PDAPerDisk, i;
! 568: RF_SectorCount_t secPerSU = layoutPtr->sectorsPerStripeUnit;
! 569: int numDataCol = layoutPtr->numDataCol;
! 570: int state;
! 571: unsigned napdas;
! 572: RF_SectorNum_t fone_start, fone_end, ftwo_start = 0, ftwo_end;
! 573: RF_PhysDiskAddr_t *fone = asmap->failedPDAs[0];
! 574: RF_PhysDiskAddr_t *ftwo = asmap->failedPDAs[1];
! 575: RF_PhysDiskAddr_t *pda_p;
! 576: RF_RaidAddr_t sosAddr;
! 577:
! 578: /*
! 579: * Determine how many pda's we will have to generate per unaccessed
! 580: * stripe. If there is only one failed data unit, it is one; if two,
! 581: * possibly two, depending whether they overlap.
! 582: */
! 583:
! 584: fone_start = rf_StripeUnitOffset(layoutPtr, fone->startSector);
! 585: fone_end = fone_start + fone->numSector;
! 586:
! 587: if (asmap->numDataFailed == 1) {
! 588: PDAPerDisk = 1;
! 589: state = 1;
! 590: RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t),
! 591: (RF_PhysDiskAddr_t *), allocList);
! 592: pda_p = *pqpdap;
! 593: /* Build p. */
! 594: CONS_PDA(parityInfo, fone_start, fone->numSector);
! 595: pda_p->type = RF_PDA_TYPE_PARITY;
! 596: pda_p++;
! 597: /* Build q. */
! 598: CONS_PDA(qInfo, fone_start, fone->numSector);
! 599: pda_p->type = RF_PDA_TYPE_Q;
! 600: } else {
! 601: ftwo_start = rf_StripeUnitOffset(layoutPtr, ftwo->startSector);
! 602: ftwo_end = ftwo_start + ftwo->numSector;
! 603: if (fone->numSector + ftwo->numSector > secPerSU) {
! 604: PDAPerDisk = 1;
! 605: state = 2;
! 606: RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t),
! 607: (RF_PhysDiskAddr_t *), allocList);
! 608: pda_p = *pqpdap;
! 609: CONS_PDA(parityInfo, 0, secPerSU);
! 610: pda_p->type = RF_PDA_TYPE_PARITY;
! 611: pda_p++;
! 612: CONS_PDA(qInfo, 0, secPerSU);
! 613: pda_p->type = RF_PDA_TYPE_Q;
! 614: } else {
! 615: PDAPerDisk = 2;
! 616: state = 3;
! 617: /* Four of them, fone, then ftwo. */
! 618: RF_MallocAndAdd(*pqpdap, 4 * sizeof(RF_PhysDiskAddr_t),
! 619: (RF_PhysDiskAddr_t *), allocList);
! 620: pda_p = *pqpdap;
! 621: CONS_PDA(parityInfo, fone_start, fone->numSector);
! 622: pda_p->type = RF_PDA_TYPE_PARITY;
! 623: pda_p++;
! 624: CONS_PDA(qInfo, fone_start, fone->numSector);
! 625: pda_p->type = RF_PDA_TYPE_Q;
! 626: pda_p++;
! 627: CONS_PDA(parityInfo, ftwo_start, ftwo->numSector);
! 628: pda_p->type = RF_PDA_TYPE_PARITY;
! 629: pda_p++;
! 630: CONS_PDA(qInfo, ftwo_start, ftwo->numSector);
! 631: pda_p->type = RF_PDA_TYPE_Q;
! 632: }
! 633: }
! 634: /* Figure out number of nonaccessed pda. */
! 635: napdas = PDAPerDisk * (numDataCol - 2);
! 636: *nPQNodep = PDAPerDisk;
! 637:
! 638: *nNodep = napdas;
! 639: if (napdas == 0)
! 640: return; /* Short circuit. */
! 641:
! 642: /* Allocate up our list of pda's. */
! 643:
! 644: RF_CallocAndAdd(pda_p, napdas, sizeof(RF_PhysDiskAddr_t),
! 645: (RF_PhysDiskAddr_t *), allocList);
! 646: *pdap = pda_p;
! 647:
! 648: /* Link them together. */
! 649: for (i = 0; i < (napdas - 1); i++)
! 650: pda_p[i].next = pda_p + (i + 1);
! 651:
! 652: sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr,
! 653: asmap->raidAddress);
! 654: for (i = 0; i < numDataCol; i++) {
! 655: if ((pda_p - (*pdap)) == napdas)
! 656: continue;
! 657: pda_p->type = RF_PDA_TYPE_DATA;
! 658: pda_p->raidAddress = sosAddr + (i * secPerSU);
! 659: (raidPtr->Layout.map->MapSector) (raidPtr, pda_p->raidAddress,
! 660: &(pda_p->row), &(pda_p->col), &(pda_p->startSector), 0);
! 661: /* Skip over dead disks. */
! 662: if (RF_DEAD_DISK(raidPtr->Disks[pda_p->row][pda_p->col].status))
! 663: continue;
! 664: switch (state) {
! 665: case 1: /* Fone. */
! 666: pda_p->numSector = fone->numSector;
! 667: pda_p->raidAddress += fone_start;
! 668: pda_p->startSector += fone_start;
! 669: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
! 670: raidPtr, pda_p->numSector), (char *), allocList);
! 671: break;
! 672: case 2: /* Full stripe. */
! 673: pda_p->numSector = secPerSU;
! 674: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
! 675: raidPtr, secPerSU), (char *), allocList);
! 676: break;
! 677: case 3: /* Two slabs. */
! 678: pda_p->numSector = fone->numSector;
! 679: pda_p->raidAddress += fone_start;
! 680: pda_p->startSector += fone_start;
! 681: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
! 682: raidPtr, pda_p->numSector), (char *), allocList);
! 683: pda_p++;
! 684: pda_p->type = RF_PDA_TYPE_DATA;
! 685: pda_p->raidAddress = sosAddr + (i * secPerSU);
! 686: (raidPtr->Layout.map->MapSector) (raidPtr,
! 687: pda_p->raidAddress, &(pda_p->row), &(pda_p->col),
! 688: &(pda_p->startSector), 0);
! 689: pda_p->numSector = ftwo->numSector;
! 690: pda_p->raidAddress += ftwo_start;
! 691: pda_p->startSector += ftwo_start;
! 692: RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(
! 693: raidPtr, pda_p->numSector), (char *), allocList);
! 694: break;
! 695: default:
! 696: RF_PANIC();
! 697: }
! 698: pda_p++;
! 699: }
! 700:
! 701: RF_ASSERT(pda_p - *pdap == napdas);
! 702: return;
! 703: }
! 704:
! 705: #define DISK_NODE_PDA(node) ((node)->params[0].p)
! 706:
! 707: #define DISK_NODE_PARAMS(_node_,_p_) do { \
! 708: (_node_).params[0].p = _p_ ; \
! 709: (_node_).params[1].p = (_p_)->bufPtr; \
! 710: (_node_).params[2].v = parityStripeID; \
! 711: (_node_).params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, \
! 712: 0, 0, which_ru); \
! 713: } while (0)
! 714:
! 715: void
! 716: rf_DoubleDegSmallWrite(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
! 717: RF_DagHeader_t *dag_h, void *bp, RF_RaidAccessFlags_t flags,
! 718: RF_AllocListElem_t *allocList, char *redundantReadNodeName,
! 719: char *redundantWriteNodeName, char *recoveryNodeName,
! 720: int (*recovFunc) (RF_DagNode_t *))
! 721: {
! 722: RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
! 723: RF_DagNode_t *nodes, *wudNodes, *rrdNodes, *recoveryNode, *blockNode,
! 724: *unblockNode, *rpNodes, *rqNodes, *wpNodes, *wqNodes, *termNode;
! 725: RF_PhysDiskAddr_t *pda, *pqPDAs;
! 726: RF_PhysDiskAddr_t *npdas;
! 727: int nWriteNodes, nNodes, nReadNodes, nRrdNodes, nWudNodes, i;
! 728: RF_ReconUnitNum_t which_ru;
! 729: int nPQNodes;
! 730: RF_StripeNum_t parityStripeID = rf_RaidAddressToParityStripeID(
! 731: layoutPtr, asmap->raidAddress, &which_ru);
! 732:
! 733: /*
! 734: * Simple small write case - First part looks like a reconstruct-read
! 735: * of the failed data units. Then a write of all data units not
! 736: * failed.
! 737: */
! 738:
! 739:
! 740: /*
! 741: * Hdr | ------Block- / / \ Rrd Rrd ... Rrd Rp Rq \ \
! 742: * / -------PQ----- / \ \ Wud Wp WQ \ | /
! 743: * --Unblock- | T
! 744: *
! 745: * Rrd = read recovery data (potentially none)
! 746: * Wud = write user data (not incl. failed disks)
! 747: * Wp = Write P (could be two)
! 748: * Wq = Write Q (could be two)
! 749: *
! 750: */
! 751:
! 752: rf_WriteGenerateFailedAccessASMs(raidPtr, asmap, &npdas, &nRrdNodes,
! 753: &pqPDAs, &nPQNodes, allocList);
! 754:
! 755: RF_ASSERT(asmap->numDataFailed == 1);
! 756:
! 757: nWudNodes = asmap->numStripeUnitsAccessed - (asmap->numDataFailed);
! 758: nReadNodes = nRrdNodes + 2 * nPQNodes;
! 759: nWriteNodes = nWudNodes + 2 * nPQNodes;
! 760: nNodes = 4 + nReadNodes + nWriteNodes;
! 761:
! 762: RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *),
! 763: allocList);
! 764: blockNode = nodes;
! 765: unblockNode = blockNode + 1;
! 766: termNode = unblockNode + 1;
! 767: recoveryNode = termNode + 1;
! 768: rrdNodes = recoveryNode + 1;
! 769: rpNodes = rrdNodes + nRrdNodes;
! 770: rqNodes = rpNodes + nPQNodes;
! 771: wudNodes = rqNodes + nPQNodes;
! 772: wpNodes = wudNodes + nWudNodes;
! 773: wqNodes = wpNodes + nPQNodes;
! 774:
! 775: dag_h->creator = "PQ_DDSimpleSmallWrite";
! 776: dag_h->numSuccedents = 1;
! 777: dag_h->succedents[0] = blockNode;
! 778: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
! 779: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
! 780: termNode->antecedents[0] = unblockNode;
! 781: termNode->antType[0] = rf_control;
! 782:
! 783: /* Init the block and unblock nodes. */
! 784: /* The block node has all the read nodes as successors. */
! 785: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 786: rf_NullNodeUndoFunc, NULL, nReadNodes, 0, 0, 0, dag_h,
! 787: "Nil", allocList);
! 788: for (i = 0; i < nReadNodes; i++)
! 789: blockNode->succedents[i] = rrdNodes + i;
! 790:
! 791: /* The unblock node has all the writes as successors. */
! 792: rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 793: rf_NullNodeUndoFunc, NULL, 1, nWriteNodes, 0, 0, dag_h,
! 794: "Nil", allocList);
! 795: for (i = 0; i < nWriteNodes; i++) {
! 796: unblockNode->antecedents[i] = wudNodes + i;
! 797: unblockNode->antType[i] = rf_control;
! 798: }
! 799: unblockNode->succedents[0] = termNode;
! 800:
! 801: #define INIT_READ_NODE(node,name) do { \
! 802: rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskReadFunc, \
! 803: rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, \
! 804: dag_h, name, allocList); \
! 805: (node)->succedents[0] = recoveryNode; \
! 806: (node)->antecedents[0] = blockNode; \
! 807: (node)->antType[0] = rf_control; \
! 808: } while (0)
! 809:
! 810: /* Build the read nodes. */
! 811: pda = npdas;
! 812: for (i = 0; i < nRrdNodes; i++, pda = pda->next) {
! 813: INIT_READ_NODE(rrdNodes + i, "rrd");
! 814: DISK_NODE_PARAMS(rrdNodes[i], pda);
! 815: }
! 816:
! 817: /* Read redundancy pdas. */
! 818: pda = pqPDAs;
! 819: INIT_READ_NODE(rpNodes, "Rp");
! 820: RF_ASSERT(pda);
! 821: DISK_NODE_PARAMS(rpNodes[0], pda);
! 822: pda++;
! 823: INIT_READ_NODE(rqNodes, redundantReadNodeName);
! 824: RF_ASSERT(pda);
! 825: DISK_NODE_PARAMS(rqNodes[0], pda);
! 826: if (nPQNodes == 2) {
! 827: pda++;
! 828: INIT_READ_NODE(rpNodes + 1, "Rp");
! 829: RF_ASSERT(pda);
! 830: DISK_NODE_PARAMS(rpNodes[1], pda);
! 831: pda++;
! 832: INIT_READ_NODE(rqNodes + 1, redundantReadNodeName);
! 833: RF_ASSERT(pda);
! 834: DISK_NODE_PARAMS(rqNodes[1], pda);
! 835: }
! 836: /*
! 837: * The recovery node has all reads as precedessors and all writes as
! 838: * successors. It generates a result for every write P or write Q
! 839: * node. As parameters, it takes a pda per read and a pda per stripe
! 840: * of user data written. It also takes as the last params the raidPtr
! 841: * and asm. For results, it takes PDA for P & Q.
! 842: */
! 843:
! 844: rf_InitNode(recoveryNode, rf_wait, RF_FALSE, recovFunc,
! 845: rf_NullNodeUndoFunc, NULL,
! 846: nWriteNodes, /* succesors */
! 847: nReadNodes, /* preds */
! 848: nReadNodes + nWudNodes + 3, /* params */
! 849: 2 * nPQNodes, /* results */
! 850: dag_h, recoveryNodeName, allocList);
! 851:
! 852:
! 853:
! 854: for (i = 0; i < nReadNodes; i++) {
! 855: recoveryNode->antecedents[i] = rrdNodes + i;
! 856: recoveryNode->antType[i] = rf_control;
! 857: recoveryNode->params[i].p = DISK_NODE_PDA(rrdNodes + i);
! 858: }
! 859: for (i = 0; i < nWudNodes; i++) {
! 860: recoveryNode->succedents[i] = wudNodes + i;
! 861: }
! 862: recoveryNode->params[nReadNodes + nWudNodes].p = asmap->failedPDAs[0];
! 863: recoveryNode->params[nReadNodes + nWudNodes + 1].p = raidPtr;
! 864: recoveryNode->params[nReadNodes + nWudNodes + 2].p = asmap;
! 865:
! 866: for (; i < nWriteNodes; i++)
! 867: recoveryNode->succedents[i] = wudNodes + i;
! 868:
! 869: pda = pqPDAs;
! 870: recoveryNode->results[0] = pda;
! 871: pda++;
! 872: recoveryNode->results[1] = pda;
! 873: if (nPQNodes == 2) {
! 874: pda++;
! 875: recoveryNode->results[2] = pda;
! 876: pda++;
! 877: recoveryNode->results[3] = pda;
! 878: }
! 879: /* Fill writes. */
! 880: #define INIT_WRITE_NODE(node,name) do { \
! 881: rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskWriteFunc, \
! 882: rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, \
! 883: dag_h, name, allocList); \
! 884: (node)->succedents[0] = unblockNode; \
! 885: (node)->antecedents[0] = recoveryNode; \
! 886: (node)->antType[0] = rf_control; \
! 887: } while (0)
! 888:
! 889: pda = asmap->physInfo;
! 890: for (i = 0; i < nWudNodes; i++) {
! 891: INIT_WRITE_NODE(wudNodes + i, "Wd");
! 892: DISK_NODE_PARAMS(wudNodes[i], pda);
! 893: recoveryNode->params[nReadNodes + i].p =
! 894: DISK_NODE_PDA(wudNodes + i);
! 895: pda = pda->next;
! 896: }
! 897: /* Write redundancy pdas. */
! 898: pda = pqPDAs;
! 899: INIT_WRITE_NODE(wpNodes, "Wp");
! 900: RF_ASSERT(pda);
! 901: DISK_NODE_PARAMS(wpNodes[0], pda);
! 902: pda++;
! 903: INIT_WRITE_NODE(wqNodes, "Wq");
! 904: RF_ASSERT(pda);
! 905: DISK_NODE_PARAMS(wqNodes[0], pda);
! 906: if (nPQNodes == 2) {
! 907: pda++;
! 908: INIT_WRITE_NODE(wpNodes + 1, "Wp");
! 909: RF_ASSERT(pda);
! 910: DISK_NODE_PARAMS(wpNodes[1], pda);
! 911: pda++;
! 912: INIT_WRITE_NODE(wqNodes + 1, "Wq");
! 913: RF_ASSERT(pda);
! 914: DISK_NODE_PARAMS(wqNodes[1], pda);
! 915: }
! 916: }
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