| 1 | /* $NetBSD: rf_dagffrd.c,v 1.19 2013/09/15 12:23:06 martin Exp $ */ |
| 2 | /* |
| 3 | * Copyright (c) 1995 Carnegie-Mellon University. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Author: Mark Holland, Daniel Stodolsky, William V. Courtright II |
| 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 | * rf_dagffrd.c |
| 31 | * |
| 32 | * code for creating fault-free read DAGs |
| 33 | * |
| 34 | */ |
| 35 | |
| 36 | #include <sys/cdefs.h> |
| 37 | __KERNEL_RCSID(0, "$NetBSD: rf_dagffrd.c,v 1.19 2013/09/15 12:23:06 martin Exp $" ); |
| 38 | |
| 39 | #include <dev/raidframe/raidframevar.h> |
| 40 | |
| 41 | #include "rf_raid.h" |
| 42 | #include "rf_dag.h" |
| 43 | #include "rf_dagutils.h" |
| 44 | #include "rf_dagfuncs.h" |
| 45 | #include "rf_debugMem.h" |
| 46 | #include "rf_general.h" |
| 47 | #include "rf_dagffrd.h" |
| 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 | void |
| 77 | rf_CreateFaultFreeReadDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap, |
| 78 | RF_DagHeader_t *dag_h, void *bp, |
| 79 | RF_RaidAccessFlags_t flags, |
| 80 | RF_AllocListElem_t *allocList) |
| 81 | { |
| 82 | rf_CreateNonredundantDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
| 83 | RF_IO_TYPE_READ); |
| 84 | } |
| 85 | |
| 86 | |
| 87 | /****************************************************************************** |
| 88 | * |
| 89 | * DAG creation code begins here |
| 90 | */ |
| 91 | |
| 92 | /****************************************************************************** |
| 93 | * |
| 94 | * creates a DAG to perform a nonredundant read or write of data within one |
| 95 | * stripe. |
| 96 | * For reads, this DAG is as follows: |
| 97 | * |
| 98 | * /---- read ----\ |
| 99 | * Header -- Block ---- read ---- Commit -- Terminate |
| 100 | * \---- read ----/ |
| 101 | * |
| 102 | * For writes, this DAG is as follows: |
| 103 | * |
| 104 | * /---- write ----\ |
| 105 | * Header -- Commit ---- write ---- Block -- Terminate |
| 106 | * \---- write ----/ |
| 107 | * |
| 108 | * There is one disk node per stripe unit accessed, and all disk nodes are in |
| 109 | * parallel. |
| 110 | * |
| 111 | * Tricky point here: The first disk node (read or write) is created |
| 112 | * normally. Subsequent disk nodes are created by copying the first one, |
| 113 | * and modifying a few params. The "succedents" and "antecedents" fields are |
| 114 | * _not_ re-created in each node, but rather left pointing to the same array |
| 115 | * that was malloc'd when the first node was created. Thus, it's essential |
| 116 | * that when this DAG is freed, the succedents and antecedents fields be freed |
| 117 | * in ONLY ONE of the read nodes. This does not apply to the "params" field |
| 118 | * because it is recreated for each READ node. |
| 119 | * |
| 120 | * Note that normal-priority accesses do not need to be tagged with their |
| 121 | * parity stripe ID, because they will never be promoted. Hence, I've |
| 122 | * commented-out the code to do this, and marked it with UNNEEDED. |
| 123 | * |
| 124 | *****************************************************************************/ |
| 125 | |
| 126 | void |
| 127 | rf_CreateNonredundantDAG(RF_Raid_t *raidPtr, |
| 128 | RF_AccessStripeMap_t *asmap, RF_DagHeader_t *dag_h, void *bp, |
| 129 | RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, |
| 130 | RF_IoType_t type) |
| 131 | { |
| 132 | RF_DagNode_t *diskNodes, *blockNode, *commitNode, *termNode; |
| 133 | RF_DagNode_t *tmpNode, *tmpdiskNode; |
| 134 | RF_PhysDiskAddr_t *pda = asmap->physInfo; |
| 135 | int (*doFunc) (RF_DagNode_t *), (*undoFunc) (RF_DagNode_t *); |
| 136 | int i, n; |
| 137 | const char *name; |
| 138 | |
| 139 | n = asmap->numStripeUnitsAccessed; |
| 140 | dag_h->creator = "NonredundantDAG" ; |
| 141 | |
| 142 | RF_ASSERT(RF_IO_IS_R_OR_W(type)); |
| 143 | switch (type) { |
| 144 | case RF_IO_TYPE_READ: |
| 145 | doFunc = rf_DiskReadFunc; |
| 146 | undoFunc = rf_DiskReadUndoFunc; |
| 147 | name = "R " ; |
| 148 | #if RF_DEBUG_DAG |
| 149 | if (rf_dagDebug) |
| 150 | printf("[Creating non-redundant read DAG]\n" ); |
| 151 | #endif |
| 152 | break; |
| 153 | case RF_IO_TYPE_WRITE: |
| 154 | doFunc = rf_DiskWriteFunc; |
| 155 | undoFunc = rf_DiskWriteUndoFunc; |
| 156 | name = "W " ; |
| 157 | #if RF_DEBUG_DAG |
| 158 | if (rf_dagDebug) |
| 159 | printf("[Creating non-redundant write DAG]\n" ); |
| 160 | #endif |
| 161 | break; |
| 162 | default: |
| 163 | RF_PANIC(); |
| 164 | } |
| 165 | |
| 166 | /* |
| 167 | * For reads, the dag can not commit until the block node is reached. |
| 168 | * for writes, the dag commits immediately. |
| 169 | */ |
| 170 | dag_h->numCommitNodes = 1; |
| 171 | dag_h->numCommits = 0; |
| 172 | dag_h->numSuccedents = 1; |
| 173 | |
| 174 | /* |
| 175 | * Node count: |
| 176 | * 1 block node |
| 177 | * n data reads (or writes) |
| 178 | * 1 commit node |
| 179 | * 1 terminator node |
| 180 | */ |
| 181 | RF_ASSERT(n > 0); |
| 182 | |
| 183 | for (i = 0; i < n; i++) { |
| 184 | tmpNode = rf_AllocDAGNode(); |
| 185 | tmpNode->list_next = dag_h->nodes; |
| 186 | dag_h->nodes = tmpNode; |
| 187 | } |
| 188 | diskNodes = dag_h->nodes; |
| 189 | |
| 190 | blockNode = rf_AllocDAGNode(); |
| 191 | blockNode->list_next = dag_h->nodes; |
| 192 | dag_h->nodes = blockNode; |
| 193 | |
| 194 | commitNode = rf_AllocDAGNode(); |
| 195 | commitNode->list_next = dag_h->nodes; |
| 196 | dag_h->nodes = commitNode; |
| 197 | |
| 198 | termNode = rf_AllocDAGNode(); |
| 199 | termNode->list_next = dag_h->nodes; |
| 200 | dag_h->nodes = termNode; |
| 201 | |
| 202 | /* initialize nodes */ |
| 203 | switch (type) { |
| 204 | case RF_IO_TYPE_READ: |
| 205 | rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
| 206 | NULL, n, 0, 0, 0, dag_h, "Nil" , allocList); |
| 207 | rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
| 208 | NULL, 1, n, 0, 0, dag_h, "Cmt" , allocList); |
| 209 | rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, |
| 210 | NULL, 0, 1, 0, 0, dag_h, "Trm" , allocList); |
| 211 | break; |
| 212 | case RF_IO_TYPE_WRITE: |
| 213 | rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
| 214 | NULL, 1, 0, 0, 0, dag_h, "Nil" , allocList); |
| 215 | rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, |
| 216 | NULL, n, 1, 0, 0, dag_h, "Cmt" , allocList); |
| 217 | rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, |
| 218 | NULL, 0, n, 0, 0, dag_h, "Trm" , allocList); |
| 219 | break; |
| 220 | default: |
| 221 | RF_PANIC(); |
| 222 | } |
| 223 | |
| 224 | tmpdiskNode = diskNodes; |
| 225 | for (i = 0; i < n; i++) { |
| 226 | RF_ASSERT(pda != NULL); |
| 227 | rf_InitNode(tmpdiskNode, rf_wait, RF_FALSE, doFunc, undoFunc, rf_GenericWakeupFunc, |
| 228 | 1, 1, 4, 0, dag_h, name, allocList); |
| 229 | tmpdiskNode->params[0].p = pda; |
| 230 | tmpdiskNode->params[1].p = pda->bufPtr; |
| 231 | /* parity stripe id is not necessary */ |
| 232 | tmpdiskNode->params[2].v = 0; |
| 233 | tmpdiskNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0); |
| 234 | pda = pda->next; |
| 235 | tmpdiskNode = tmpdiskNode->list_next; |
| 236 | } |
| 237 | |
| 238 | /* |
| 239 | * Connect nodes. |
| 240 | */ |
| 241 | |
| 242 | /* connect hdr to block node */ |
| 243 | RF_ASSERT(blockNode->numAntecedents == 0); |
| 244 | dag_h->succedents[0] = blockNode; |
| 245 | |
| 246 | if (type == RF_IO_TYPE_READ) { |
| 247 | /* connecting a nonredundant read DAG */ |
| 248 | RF_ASSERT(blockNode->numSuccedents == n); |
| 249 | RF_ASSERT(commitNode->numAntecedents == n); |
| 250 | tmpdiskNode = diskNodes; |
| 251 | for (i = 0; i < n; i++) { |
| 252 | /* connect block node to each read node */ |
| 253 | RF_ASSERT(tmpdiskNode->numAntecedents == 1); |
| 254 | blockNode->succedents[i] = tmpdiskNode; |
| 255 | tmpdiskNode->antecedents[0] = blockNode; |
| 256 | tmpdiskNode->antType[0] = rf_control; |
| 257 | |
| 258 | /* connect each read node to the commit node */ |
| 259 | RF_ASSERT(tmpdiskNode->numSuccedents == 1); |
| 260 | tmpdiskNode->succedents[0] = commitNode; |
| 261 | commitNode->antecedents[i] = tmpdiskNode; |
| 262 | commitNode->antType[i] = rf_control; |
| 263 | tmpdiskNode = tmpdiskNode->list_next; |
| 264 | } |
| 265 | /* connect the commit node to the term node */ |
| 266 | RF_ASSERT(commitNode->numSuccedents == 1); |
| 267 | RF_ASSERT(termNode->numAntecedents == 1); |
| 268 | RF_ASSERT(termNode->numSuccedents == 0); |
| 269 | commitNode->succedents[0] = termNode; |
| 270 | termNode->antecedents[0] = commitNode; |
| 271 | termNode->antType[0] = rf_control; |
| 272 | } else { |
| 273 | /* connecting a nonredundant write DAG */ |
| 274 | /* connect the block node to the commit node */ |
| 275 | RF_ASSERT(blockNode->numSuccedents == 1); |
| 276 | RF_ASSERT(commitNode->numAntecedents == 1); |
| 277 | blockNode->succedents[0] = commitNode; |
| 278 | commitNode->antecedents[0] = blockNode; |
| 279 | commitNode->antType[0] = rf_control; |
| 280 | |
| 281 | RF_ASSERT(commitNode->numSuccedents == n); |
| 282 | RF_ASSERT(termNode->numAntecedents == n); |
| 283 | RF_ASSERT(termNode->numSuccedents == 0); |
| 284 | tmpdiskNode = diskNodes; |
| 285 | for (i = 0; i < n; i++) { |
| 286 | /* connect the commit node to each write node */ |
| 287 | RF_ASSERT(tmpdiskNode->numAntecedents == 1); |
| 288 | commitNode->succedents[i] = tmpdiskNode; |
| 289 | tmpdiskNode->antecedents[0] = commitNode; |
| 290 | tmpdiskNode->antType[0] = rf_control; |
| 291 | |
| 292 | /* connect each write node to the term node */ |
| 293 | RF_ASSERT(tmpdiskNode->numSuccedents == 1); |
| 294 | tmpdiskNode->succedents[0] = termNode; |
| 295 | termNode->antecedents[i] = tmpdiskNode; |
| 296 | termNode->antType[i] = rf_control; |
| 297 | tmpdiskNode = tmpdiskNode->list_next; |
| 298 | } |
| 299 | } |
| 300 | } |
| 301 | /****************************************************************************** |
| 302 | * Create a fault-free read DAG for RAID level 1 |
| 303 | * |
| 304 | * Hdr -> Nil -> Rmir -> Cmt -> Trm |
| 305 | * |
| 306 | * The "Rmir" node schedules a read from the disk in the mirror pair with the |
| 307 | * shortest disk queue. the proper queue is selected at Rmir execution. this |
| 308 | * deferred mapping is unlike other archs in RAIDframe which generally fix |
| 309 | * mapping at DAG creation time. |
| 310 | * |
| 311 | * Parameters: raidPtr - description of the physical array |
| 312 | * asmap - logical & physical addresses for this access |
| 313 | * bp - buffer ptr (for holding read data) |
| 314 | * flags - general flags (e.g. disk locking) |
| 315 | * allocList - list of memory allocated in DAG creation |
| 316 | *****************************************************************************/ |
| 317 | |
| 318 | static void |
| 319 | CreateMirrorReadDAG(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap, |
| 320 | RF_DagHeader_t *dag_h, void *bp, |
| 321 | RF_RaidAccessFlags_t flags, RF_AllocListElem_t *allocList, |
| 322 | int (*readfunc) (RF_DagNode_t * node)) |
| 323 | { |
| 324 | RF_DagNode_t *readNodes, *blockNode, *commitNode, *termNode; |
| 325 | RF_DagNode_t *tmpNode, *tmpreadNode; |
| 326 | RF_PhysDiskAddr_t *data_pda = asmap->physInfo; |
| 327 | RF_PhysDiskAddr_t *parity_pda = asmap->parityInfo; |
| 328 | int i, n; |
| 329 | |
| 330 | n = asmap->numStripeUnitsAccessed; |
| 331 | dag_h->creator = "RaidOneReadDAG" ; |
| 332 | #if RF_DEBUG_DAG |
| 333 | if (rf_dagDebug) { |
| 334 | printf("[Creating RAID level 1 read DAG]\n" ); |
| 335 | } |
| 336 | #endif |
| 337 | /* |
| 338 | * This dag can not commit until the commit node is reached |
| 339 | * errors prior to the commit point imply the dag has failed. |
| 340 | */ |
| 341 | dag_h->numCommitNodes = 1; |
| 342 | dag_h->numCommits = 0; |
| 343 | dag_h->numSuccedents = 1; |
| 344 | |
| 345 | /* |
| 346 | * Node count: |
| 347 | * n data reads |
| 348 | * 1 block node |
| 349 | * 1 commit node |
| 350 | * 1 terminator node |
| 351 | */ |
| 352 | RF_ASSERT(n > 0); |
| 353 | |
| 354 | for (i = 0; i < n; i++) { |
| 355 | tmpNode = rf_AllocDAGNode(); |
| 356 | tmpNode->list_next = dag_h->nodes; |
| 357 | dag_h->nodes = tmpNode; |
| 358 | } |
| 359 | readNodes = dag_h->nodes; |
| 360 | |
| 361 | blockNode = rf_AllocDAGNode(); |
| 362 | blockNode->list_next = dag_h->nodes; |
| 363 | dag_h->nodes = blockNode; |
| 364 | |
| 365 | commitNode = rf_AllocDAGNode(); |
| 366 | commitNode->list_next = dag_h->nodes; |
| 367 | dag_h->nodes = commitNode; |
| 368 | |
| 369 | termNode = rf_AllocDAGNode(); |
| 370 | termNode->list_next = dag_h->nodes; |
| 371 | dag_h->nodes = termNode; |
| 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 | tmpreadNode = readNodes; |
| 382 | for (i = 0; i < n; i++) { |
| 383 | RF_ASSERT(data_pda != NULL); |
| 384 | RF_ASSERT(parity_pda != NULL); |
| 385 | rf_InitNode(tmpreadNode, rf_wait, RF_FALSE, readfunc, |
| 386 | rf_DiskReadMirrorUndoFunc, rf_GenericWakeupFunc, 1, 1, 5, 0, dag_h, |
| 387 | "Rmir" , allocList); |
| 388 | tmpreadNode->params[0].p = data_pda; |
| 389 | tmpreadNode->params[1].p = data_pda->bufPtr; |
| 390 | /* parity stripe id is not necessary */ |
| 391 | tmpreadNode->params[2].p = 0; |
| 392 | tmpreadNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0); |
| 393 | tmpreadNode->params[4].p = parity_pda; |
| 394 | data_pda = data_pda->next; |
| 395 | parity_pda = parity_pda->next; |
| 396 | tmpreadNode = tmpreadNode->list_next; |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * Connect nodes |
| 401 | */ |
| 402 | |
| 403 | /* connect hdr to block node */ |
| 404 | RF_ASSERT(blockNode->numAntecedents == 0); |
| 405 | dag_h->succedents[0] = blockNode; |
| 406 | |
| 407 | /* connect block node to read nodes */ |
| 408 | RF_ASSERT(blockNode->numSuccedents == n); |
| 409 | tmpreadNode = readNodes; |
| 410 | for (i = 0; i < n; i++) { |
| 411 | RF_ASSERT(tmpreadNode->numAntecedents == 1); |
| 412 | blockNode->succedents[i] = tmpreadNode; |
| 413 | tmpreadNode->antecedents[0] = blockNode; |
| 414 | tmpreadNode->antType[0] = rf_control; |
| 415 | tmpreadNode = tmpreadNode->list_next; |
| 416 | } |
| 417 | |
| 418 | /* connect read nodes to commit node */ |
| 419 | RF_ASSERT(commitNode->numAntecedents == n); |
| 420 | tmpreadNode = readNodes; |
| 421 | for (i = 0; i < n; i++) { |
| 422 | RF_ASSERT(tmpreadNode->numSuccedents == 1); |
| 423 | tmpreadNode->succedents[0] = commitNode; |
| 424 | commitNode->antecedents[i] = tmpreadNode; |
| 425 | commitNode->antType[i] = rf_control; |
| 426 | tmpreadNode = tmpreadNode->list_next; |
| 427 | } |
| 428 | |
| 429 | /* connect commit node to term node */ |
| 430 | RF_ASSERT(commitNode->numSuccedents == 1); |
| 431 | RF_ASSERT(termNode->numAntecedents == 1); |
| 432 | RF_ASSERT(termNode->numSuccedents == 0); |
| 433 | commitNode->succedents[0] = termNode; |
| 434 | termNode->antecedents[0] = commitNode; |
| 435 | termNode->antType[0] = rf_control; |
| 436 | } |
| 437 | |
| 438 | void |
| 439 | rf_CreateMirrorIdleReadDAG( |
| 440 | RF_Raid_t * raidPtr, |
| 441 | RF_AccessStripeMap_t * asmap, |
| 442 | RF_DagHeader_t * dag_h, |
| 443 | void *bp, |
| 444 | RF_RaidAccessFlags_t flags, |
| 445 | RF_AllocListElem_t * allocList) |
| 446 | { |
| 447 | CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
| 448 | rf_DiskReadMirrorIdleFunc); |
| 449 | } |
| 450 | |
| 451 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) || (RF_INCLUDE_INTERDECLUSTER > 0) |
| 452 | |
| 453 | void |
| 454 | rf_CreateMirrorPartitionReadDAG(RF_Raid_t *raidPtr, |
| 455 | RF_AccessStripeMap_t *asmap, |
| 456 | RF_DagHeader_t *dag_h, void *bp, |
| 457 | RF_RaidAccessFlags_t flags, |
| 458 | RF_AllocListElem_t *allocList) |
| 459 | { |
| 460 | CreateMirrorReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, |
| 461 | rf_DiskReadMirrorPartitionFunc); |
| 462 | } |
| 463 | #endif |
| 464 | |