Annotation of sys/dev/raidframe/rf_dagffrd.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: rf_dagffrd.c,v 1.4 2002/12/16 07:01:03 tdeval Exp $ */
! 2: /* $NetBSD: rf_dagffrd.c,v 1.4 2000/01/07 03:40:58 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_dagffrd.c
! 33: *
! 34: * Code for creating fault-free read 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_dagffrd.h"
! 47:
! 48: void rf_CreateMirrorReadDAG( RF_Raid_t *, RF_AccessStripeMap_t *,
! 49: RF_DagHeader_t *, void *, RF_RaidAccessFlags_t, RF_AllocListElem_t *,
! 50: int (*) (RF_DagNode_t *));
! 51:
! 52: /*****************************************************************************
! 53: *
! 54: * General comments on DAG creation:
! 55: *
! 56: * All DAGs in this file use roll-away error recovery. Each DAG has a single
! 57: * commit node, usually called "Cmt." If an error occurs before the Cmt node
! 58: * is reached, the execution engine will halt forward execution and work
! 59: * backward through the graph, executing the undo functions. Assuming that
! 60: * each node in the graph prior to the Cmt node are undoable and atomic - or -
! 61: * does not make changes to permanent state, the graph will fail atomically.
! 62: * If an error occurs after the Cmt node executes, the engine will roll-forward
! 63: * through the graph, blindly executing nodes until it reaches the end.
! 64: * If a graph reaches the end, it is assumed to have completed successfully.
! 65: *
! 66: * A graph has only 1 Cmt node.
! 67: *
! 68: *****************************************************************************/
! 69:
! 70:
! 71: /*****************************************************************************
! 72: *
! 73: * The following wrappers map the standard DAG creation interface to the
! 74: * DAG creation routines. Additionally, these wrappers enable experimentation
! 75: * with new DAG structures by providing an extra level of indirection, allowing
! 76: * the DAG creation routines to be replaced at this single point.
! 77: *
! 78: *****************************************************************************/
! 79:
! 80: void
! 81: rf_CreateFaultFreeReadDAG(
! 82: RF_Raid_t *raidPtr,
! 83: RF_AccessStripeMap_t *asmap,
! 84: RF_DagHeader_t *dag_h,
! 85: void *bp,
! 86: RF_RaidAccessFlags_t flags,
! 87: RF_AllocListElem_t *allocList
! 88: )
! 89: {
! 90: rf_CreateNonredundantDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
! 91: RF_IO_TYPE_READ);
! 92: }
! 93:
! 94:
! 95: /*****************************************************************************
! 96: *
! 97: * DAG creation code begins here.
! 98: *
! 99: *****************************************************************************/
! 100:
! 101: /*****************************************************************************
! 102: *
! 103: * Creates a DAG to perform a nonredundant read or write of data within one
! 104: * stripe.
! 105: * For reads, this DAG is as follows:
! 106: *
! 107: * /---- read ----\
! 108: * Header -- Block ---- read ---- Commit -- Terminate
! 109: * \---- read ----/
! 110: *
! 111: * For writes, this DAG is as follows:
! 112: *
! 113: * /---- write ----\
! 114: * Header -- Commit ---- write ---- Block -- Terminate
! 115: * \---- write ----/
! 116: *
! 117: * There is one disk node per stripe unit accessed, and all disk nodes are in
! 118: * parallel.
! 119: *
! 120: * Tricky point here: The first disk node (read or write) is created
! 121: * normally. Subsequent disk nodes are created by copying the first one,
! 122: * and modifying a few params. The "succedents" and "antecedents" fields are
! 123: * _not_ re-created in each node, but rather left pointing to the same array
! 124: * that was malloc'd when the first node was created. Thus, it's essential
! 125: * that when this DAG is freed, the succedents and antecedents fields be freed
! 126: * in ONLY ONE of the read nodes. This does not apply to the "params" field
! 127: * because it is recreated for each READ node.
! 128: *
! 129: * Note that normal-priority accesses do not need to be tagged with their
! 130: * parity stripe ID, because they will never be promoted. Hence, I've
! 131: * commented-out the code to do this, and marked it with UNNEEDED.
! 132: *
! 133: *****************************************************************************/
! 134:
! 135: void
! 136: rf_CreateNonredundantDAG(
! 137: RF_Raid_t *raidPtr,
! 138: RF_AccessStripeMap_t *asmap,
! 139: RF_DagHeader_t *dag_h,
! 140: void *bp,
! 141: RF_RaidAccessFlags_t flags,
! 142: RF_AllocListElem_t *allocList,
! 143: RF_IoType_t type
! 144: )
! 145: {
! 146: RF_DagNode_t *nodes, *diskNodes, *blockNode, *commitNode, *termNode;
! 147: RF_PhysDiskAddr_t *pda = asmap->physInfo;
! 148: int (*doFunc) (RF_DagNode_t *), (*undoFunc) (RF_DagNode_t *);
! 149: int i, n, totalNumNodes;
! 150: char *name;
! 151:
! 152: n = asmap->numStripeUnitsAccessed;
! 153: dag_h->creator = "NonredundantDAG";
! 154:
! 155: RF_ASSERT(RF_IO_IS_R_OR_W(type));
! 156: switch (type) {
! 157: case RF_IO_TYPE_READ:
! 158: doFunc = rf_DiskReadFunc;
! 159: undoFunc = rf_DiskReadUndoFunc;
! 160: name = "R ";
! 161: if (rf_dagDebug)
! 162: printf("[Creating non-redundant read DAG]\n");
! 163: break;
! 164: case RF_IO_TYPE_WRITE:
! 165: doFunc = rf_DiskWriteFunc;
! 166: undoFunc = rf_DiskWriteUndoFunc;
! 167: name = "W ";
! 168: if (rf_dagDebug)
! 169: printf("[Creating non-redundant write DAG]\n");
! 170: break;
! 171: default:
! 172: RF_PANIC();
! 173: }
! 174:
! 175: /*
! 176: * For reads, the dag can not commit until the block node is reached.
! 177: * For writes, the dag commits immediately.
! 178: */
! 179: dag_h->numCommitNodes = 1;
! 180: dag_h->numCommits = 0;
! 181: dag_h->numSuccedents = 1;
! 182:
! 183: /*
! 184: * Node count:
! 185: * 1 block node
! 186: * n data reads (or writes)
! 187: * 1 commit node
! 188: * 1 terminator node
! 189: */
! 190: RF_ASSERT(n > 0);
! 191: totalNumNodes = n + 3;
! 192: RF_CallocAndAdd(nodes, totalNumNodes, sizeof(RF_DagNode_t),
! 193: (RF_DagNode_t *), allocList);
! 194: i = 0;
! 195: diskNodes = &nodes[i];
! 196: i += n;
! 197: blockNode = &nodes[i];
! 198: i += 1;
! 199: commitNode = &nodes[i];
! 200: i += 1;
! 201: termNode = &nodes[i];
! 202: i += 1;
! 203: RF_ASSERT(i == totalNumNodes);
! 204:
! 205: /* Initialize nodes. */
! 206: switch (type) {
! 207: case RF_IO_TYPE_READ:
! 208: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 209: rf_NullNodeUndoFunc, NULL, n, 0, 0, 0, dag_h, "Nil",
! 210: allocList);
! 211: rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
! 212: rf_NullNodeUndoFunc, NULL, 1, n, 0, 0, dag_h, "Cmt",
! 213: allocList);
! 214: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
! 215: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm",
! 216: allocList);
! 217: break;
! 218: case RF_IO_TYPE_WRITE:
! 219: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 220: rf_NullNodeUndoFunc, NULL, 1, 0, 0, 0, dag_h, "Nil",
! 221: allocList);
! 222: rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
! 223: rf_NullNodeUndoFunc, NULL, n, 1, 0, 0, dag_h, "Cmt",
! 224: allocList);
! 225: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
! 226: rf_TerminateUndoFunc, NULL, 0, n, 0, 0, dag_h, "Trm",
! 227: allocList);
! 228: break;
! 229: default:
! 230: RF_PANIC();
! 231: }
! 232:
! 233: for (i = 0; i < n; i++) {
! 234: RF_ASSERT(pda != NULL);
! 235: rf_InitNode(&diskNodes[i], rf_wait, RF_FALSE, doFunc, undoFunc,
! 236: rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, name, allocList);
! 237: diskNodes[i].params[0].p = pda;
! 238: diskNodes[i].params[1].p = pda->bufPtr;
! 239: /* Parity stripe id is not necessary. */
! 240: diskNodes[i].params[2].v = 0;
! 241: diskNodes[i].params[3].v =
! 242: RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, 0);
! 243: pda = pda->next;
! 244: }
! 245:
! 246: /*
! 247: * Connect nodes.
! 248: */
! 249:
! 250: /* Connect hdr to block node. */
! 251: RF_ASSERT(blockNode->numAntecedents == 0);
! 252: dag_h->succedents[0] = blockNode;
! 253:
! 254: if (type == RF_IO_TYPE_READ) {
! 255: /* Connecting a nonredundant read DAG. */
! 256: RF_ASSERT(blockNode->numSuccedents == n);
! 257: RF_ASSERT(commitNode->numAntecedents == n);
! 258: for (i = 0; i < n; i++) {
! 259: /* Connect block node to each read node. */
! 260: RF_ASSERT(diskNodes[i].numAntecedents == 1);
! 261: blockNode->succedents[i] = &diskNodes[i];
! 262: diskNodes[i].antecedents[0] = blockNode;
! 263: diskNodes[i].antType[0] = rf_control;
! 264:
! 265: /* Connect each read node to the commit node. */
! 266: RF_ASSERT(diskNodes[i].numSuccedents == 1);
! 267: diskNodes[i].succedents[0] = commitNode;
! 268: commitNode->antecedents[i] = &diskNodes[i];
! 269: commitNode->antType[i] = rf_control;
! 270: }
! 271: /* Connect the commit node to the term node. */
! 272: RF_ASSERT(commitNode->numSuccedents == 1);
! 273: RF_ASSERT(termNode->numAntecedents == 1);
! 274: RF_ASSERT(termNode->numSuccedents == 0);
! 275: commitNode->succedents[0] = termNode;
! 276: termNode->antecedents[0] = commitNode;
! 277: termNode->antType[0] = rf_control;
! 278: } else {
! 279: /* Connecting a nonredundant write DAG. */
! 280: /* Connect the block node to the commit node. */
! 281: RF_ASSERT(blockNode->numSuccedents == 1);
! 282: RF_ASSERT(commitNode->numAntecedents == 1);
! 283: blockNode->succedents[0] = commitNode;
! 284: commitNode->antecedents[0] = blockNode;
! 285: commitNode->antType[0] = rf_control;
! 286:
! 287: RF_ASSERT(commitNode->numSuccedents == n);
! 288: RF_ASSERT(termNode->numAntecedents == n);
! 289: RF_ASSERT(termNode->numSuccedents == 0);
! 290: for (i = 0; i < n; i++) {
! 291: /* Connect the commit node to each write node. */
! 292: RF_ASSERT(diskNodes[i].numAntecedents == 1);
! 293: commitNode->succedents[i] = &diskNodes[i];
! 294: diskNodes[i].antecedents[0] = commitNode;
! 295: diskNodes[i].antType[0] = rf_control;
! 296:
! 297: /* Connect each write node to the term node. */
! 298: RF_ASSERT(diskNodes[i].numSuccedents == 1);
! 299: diskNodes[i].succedents[0] = termNode;
! 300: termNode->antecedents[i] = &diskNodes[i];
! 301: termNode->antType[i] = rf_control;
! 302: }
! 303: }
! 304: }
! 305: /*****************************************************************************
! 306: * Create a fault-free read DAG for RAID level 1.
! 307: *
! 308: * Hdr -> Nil -> Rmir -> Cmt -> Trm
! 309: *
! 310: * The "Rmir" node schedules a read from the disk in the mirror pair with the
! 311: * shortest disk queue. The proper queue is selected at Rmir execution. This
! 312: * deferred mapping is unlike other archs in RAIDframe which generally fix
! 313: * mapping at DAG creation time.
! 314: *
! 315: * Parameters: raidPtr - description of the physical array
! 316: * asmap - logical & physical addresses for this access
! 317: * bp - buffer ptr (for holding read data)
! 318: * flags - general flags (e.g. disk locking)
! 319: * allocList - list of memory allocated in DAG creation
! 320: *****************************************************************************/
! 321:
! 322: void
! 323: rf_CreateMirrorReadDAG(
! 324: RF_Raid_t *raidPtr,
! 325: RF_AccessStripeMap_t *asmap,
! 326: RF_DagHeader_t *dag_h,
! 327: void *bp,
! 328: RF_RaidAccessFlags_t flags,
! 329: RF_AllocListElem_t *allocList,
! 330: int (*readfunc) (RF_DagNode_t *)
! 331: )
! 332: {
! 333: RF_DagNode_t *readNodes, *nodes, *blockNode, *commitNode, *termNode;
! 334: RF_PhysDiskAddr_t *data_pda = asmap->physInfo;
! 335: RF_PhysDiskAddr_t *parity_pda = asmap->parityInfo;
! 336: int i, n, totalNumNodes;
! 337:
! 338: n = asmap->numStripeUnitsAccessed;
! 339: dag_h->creator = "RaidOneReadDAG";
! 340: if (rf_dagDebug) {
! 341: printf("[Creating RAID level 1 read DAG]\n");
! 342: }
! 343: /*
! 344: * This dag can not commit until the commit node is reached.
! 345: * Errors prior to the commit point imply the dag has failed.
! 346: */
! 347: dag_h->numCommitNodes = 1;
! 348: dag_h->numCommits = 0;
! 349: dag_h->numSuccedents = 1;
! 350:
! 351: /*
! 352: * Node count:
! 353: * n data reads
! 354: * 1 block node
! 355: * 1 commit node
! 356: * 1 terminator node
! 357: */
! 358: RF_ASSERT(n > 0);
! 359: totalNumNodes = n + 3;
! 360: RF_CallocAndAdd(nodes, totalNumNodes, sizeof(RF_DagNode_t),
! 361: (RF_DagNode_t *), allocList);
! 362: i = 0;
! 363: readNodes = &nodes[i];
! 364: i += n;
! 365: blockNode = &nodes[i];
! 366: i += 1;
! 367: commitNode = &nodes[i];
! 368: i += 1;
! 369: termNode = &nodes[i];
! 370: i += 1;
! 371: RF_ASSERT(i == totalNumNodes);
! 372:
! 373: /* Initialize nodes. */
! 374: rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
! 375: rf_NullNodeUndoFunc, NULL, n, 0, 0, 0, dag_h, "Nil", allocList);
! 376: rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
! 377: rf_NullNodeUndoFunc, NULL, 1, n, 0, 0, dag_h, "Cmt", allocList);
! 378: rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc,
! 379: rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
! 380:
! 381: for (i = 0; i < n; i++) {
! 382: RF_ASSERT(data_pda != NULL);
! 383: RF_ASSERT(parity_pda != NULL);
! 384: rf_InitNode(&readNodes[i], rf_wait, RF_FALSE, readfunc,
! 385: rf_DiskReadMirrorUndoFunc, rf_GenericWakeupFunc, 1, 1, 5,
! 386: 0, dag_h, "Rmir", allocList);
! 387: readNodes[i].params[0].p = data_pda;
! 388: readNodes[i].params[1].p = data_pda->bufPtr;
! 389: /* Parity stripe id is not necessary. */
! 390: readNodes[i].params[2].p = 0;
! 391: readNodes[i].params[3].v =
! 392: RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, 0);
! 393: readNodes[i].params[4].p = parity_pda;
! 394: data_pda = data_pda->next;
! 395: parity_pda = parity_pda->next;
! 396: }
! 397:
! 398: /*
! 399: * Connect nodes.
! 400: */
! 401:
! 402: /* Connect hdr to block node. */
! 403: RF_ASSERT(blockNode->numAntecedents == 0);
! 404: dag_h->succedents[0] = blockNode;
! 405:
! 406: /* Connect block node to read nodes. */
! 407: RF_ASSERT(blockNode->numSuccedents == n);
! 408: for (i = 0; i < n; i++) {
! 409: RF_ASSERT(readNodes[i].numAntecedents == 1);
! 410: blockNode->succedents[i] = &readNodes[i];
! 411: readNodes[i].antecedents[0] = blockNode;
! 412: readNodes[i].antType[0] = rf_control;
! 413: }
! 414:
! 415: /* Connect read nodes to commit node. */
! 416: RF_ASSERT(commitNode->numAntecedents == n);
! 417: for (i = 0; i < n; i++) {
! 418: RF_ASSERT(readNodes[i].numSuccedents == 1);
! 419: readNodes[i].succedents[0] = commitNode;
! 420: commitNode->antecedents[i] = &readNodes[i];
! 421: commitNode->antType[i] = rf_control;
! 422: }
! 423:
! 424: /* Connect commit node to term node. */
! 425: RF_ASSERT(commitNode->numSuccedents == 1);
! 426: RF_ASSERT(termNode->numAntecedents == 1);
! 427: RF_ASSERT(termNode->numSuccedents == 0);
! 428: commitNode->succedents[0] = termNode;
! 429: termNode->antecedents[0] = commitNode;
! 430: termNode->antType[0] = rf_control;
! 431: }
! 432:
! 433: void
! 434: rf_CreateMirrorIdleReadDAG(
! 435: RF_Raid_t *raidPtr,
! 436: RF_AccessStripeMap_t *asmap,
! 437: RF_DagHeader_t *dag_h,
! 438: void *bp,
! 439: RF_RaidAccessFlags_t flags,
! 440: RF_AllocListElem_t *allocList
! 441: )
! 442: {
! 443: rf_CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
! 444: rf_DiskReadMirrorIdleFunc);
! 445: }
! 446:
! 447: void
! 448: rf_CreateMirrorPartitionReadDAG(
! 449: RF_Raid_t *raidPtr,
! 450: RF_AccessStripeMap_t *asmap,
! 451: RF_DagHeader_t *dag_h,
! 452: void *bp,
! 453: RF_RaidAccessFlags_t flags,
! 454: RF_AllocListElem_t *allocList
! 455: )
! 456: {
! 457: rf_CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
! 458: rf_DiskReadMirrorPartitionFunc);
! 459: }
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