| 1 | /* $NetBSD: rf_dagutils.c,v 1.54 2016/01/07 21:57:00 joerg Exp $ */ |
| 2 | /* |
| 3 | * Copyright (c) 1995 Carnegie-Mellon University. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Authors: Mark Holland, William V. Courtright II, Jim Zelenka |
| 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_dagutils.c -- utility routines for manipulating dags |
| 32 | * |
| 33 | *****************************************************************************/ |
| 34 | |
| 35 | #include <sys/cdefs.h> |
| 36 | __KERNEL_RCSID(0, "$NetBSD: rf_dagutils.c,v 1.54 2016/01/07 21:57:00 joerg Exp $" ); |
| 37 | |
| 38 | #include <dev/raidframe/raidframevar.h> |
| 39 | |
| 40 | #include "rf_archs.h" |
| 41 | #include "rf_threadstuff.h" |
| 42 | #include "rf_raid.h" |
| 43 | #include "rf_dag.h" |
| 44 | #include "rf_dagutils.h" |
| 45 | #include "rf_dagfuncs.h" |
| 46 | #include "rf_general.h" |
| 47 | #include "rf_map.h" |
| 48 | #include "rf_shutdown.h" |
| 49 | |
| 50 | #define SNUM_DIFF(_a_,_b_) (((_a_)>(_b_))?((_a_)-(_b_)):((_b_)-(_a_))) |
| 51 | |
| 52 | const RF_RedFuncs_t rf_xorFuncs = { |
| 53 | rf_RegularXorFunc, "Reg Xr" , |
| 54 | rf_SimpleXorFunc, "Simple Xr" }; |
| 55 | |
| 56 | const RF_RedFuncs_t rf_xorRecoveryFuncs = { |
| 57 | rf_RecoveryXorFunc, "Recovery Xr" , |
| 58 | rf_RecoveryXorFunc, "Recovery Xr" }; |
| 59 | |
| 60 | #if RF_DEBUG_VALIDATE_DAG |
| 61 | static void rf_RecurPrintDAG(RF_DagNode_t *, int, int); |
| 62 | static void rf_PrintDAG(RF_DagHeader_t *); |
| 63 | static int rf_ValidateBranch(RF_DagNode_t *, int *, int *, |
| 64 | RF_DagNode_t **, int); |
| 65 | static void rf_ValidateBranchVisitedBits(RF_DagNode_t *, int, int); |
| 66 | static void rf_ValidateVisitedBits(RF_DagHeader_t *); |
| 67 | #endif /* RF_DEBUG_VALIDATE_DAG */ |
| 68 | |
| 69 | /* The maximum number of nodes in a DAG is bounded by |
| 70 | |
| 71 | (2 * raidPtr->Layout->numDataCol) + (1 * layoutPtr->numParityCol) + |
| 72 | (1 * 2 * layoutPtr->numParityCol) + 3 |
| 73 | |
| 74 | which is: 2*RF_MAXCOL+1*2+1*2*2+3 |
| 75 | |
| 76 | For RF_MAXCOL of 40, this works out to 89. We use this value to provide an estimate |
| 77 | on the maximum size needed for RF_DAGPCACHE_SIZE. For RF_MAXCOL of 40, this structure |
| 78 | would be 534 bytes. Too much to have on-hand in a RF_DagNode_t, but should be ok to |
| 79 | have a few kicking around. |
| 80 | */ |
| 81 | #define RF_DAGPCACHE_SIZE ((2*RF_MAXCOL+1*2+1*2*2+3) *(RF_MAX(sizeof(RF_DagParam_t), sizeof(RF_DagNode_t *)))) |
| 82 | |
| 83 | |
| 84 | /****************************************************************************** |
| 85 | * |
| 86 | * InitNode - initialize a dag node |
| 87 | * |
| 88 | * the size of the propList array is always the same as that of the |
| 89 | * successors array. |
| 90 | * |
| 91 | *****************************************************************************/ |
| 92 | void |
| 93 | rf_InitNode(RF_DagNode_t *node, RF_NodeStatus_t initstatus, int commit, |
| 94 | int (*doFunc) (RF_DagNode_t *node), |
| 95 | int (*undoFunc) (RF_DagNode_t *node), |
| 96 | int (*wakeFunc) (RF_DagNode_t *node, int status), |
| 97 | int nSucc, int nAnte, int nParam, int nResult, |
| 98 | RF_DagHeader_t *hdr, const char *name, RF_AllocListElem_t *alist) |
| 99 | { |
| 100 | void **ptrs; |
| 101 | int nptrs; |
| 102 | |
| 103 | if (nAnte > RF_MAX_ANTECEDENTS) |
| 104 | RF_PANIC(); |
| 105 | node->status = initstatus; |
| 106 | node->commitNode = commit; |
| 107 | node->doFunc = doFunc; |
| 108 | node->undoFunc = undoFunc; |
| 109 | node->wakeFunc = wakeFunc; |
| 110 | node->numParams = nParam; |
| 111 | node->numResults = nResult; |
| 112 | node->numAntecedents = nAnte; |
| 113 | node->numAntDone = 0; |
| 114 | node->next = NULL; |
| 115 | /* node->list_next = NULL */ /* Don't touch this here! |
| 116 | It may already be |
| 117 | in use by the caller! */ |
| 118 | node->numSuccedents = nSucc; |
| 119 | node->name = name; |
| 120 | node->dagHdr = hdr; |
| 121 | node->big_dag_ptrs = NULL; |
| 122 | node->big_dag_params = NULL; |
| 123 | node->visited = 0; |
| 124 | |
| 125 | /* allocate all the pointers with one call to malloc */ |
| 126 | nptrs = nSucc + nAnte + nResult + nSucc; |
| 127 | |
| 128 | if (nptrs <= RF_DAG_PTRCACHESIZE) { |
| 129 | /* |
| 130 | * The dag_ptrs field of the node is basically some scribble |
| 131 | * space to be used here. We could get rid of it, and always |
| 132 | * allocate the range of pointers, but that's expensive. So, |
| 133 | * we pick a "common case" size for the pointer cache. Hopefully, |
| 134 | * we'll find that: |
| 135 | * (1) Generally, nptrs doesn't exceed RF_DAG_PTRCACHESIZE by |
| 136 | * only a little bit (least efficient case) |
| 137 | * (2) Generally, ntprs isn't a lot less than RF_DAG_PTRCACHESIZE |
| 138 | * (wasted memory) |
| 139 | */ |
| 140 | ptrs = (void **) node->dag_ptrs; |
| 141 | } else if (nptrs <= (RF_DAGPCACHE_SIZE / sizeof(RF_DagNode_t *))) { |
| 142 | node->big_dag_ptrs = rf_AllocDAGPCache(); |
| 143 | ptrs = (void **) node->big_dag_ptrs; |
| 144 | } else { |
| 145 | RF_MallocAndAdd(ptrs, nptrs * sizeof(void *), |
| 146 | (void **), alist); |
| 147 | } |
| 148 | node->succedents = (nSucc) ? (RF_DagNode_t **) ptrs : NULL; |
| 149 | node->antecedents = (nAnte) ? (RF_DagNode_t **) (ptrs + nSucc) : NULL; |
| 150 | node->results = (nResult) ? (void **) (ptrs + nSucc + nAnte) : NULL; |
| 151 | node->propList = (nSucc) ? (RF_PropHeader_t **) (ptrs + nSucc + nAnte + nResult) : NULL; |
| 152 | |
| 153 | if (nParam) { |
| 154 | if (nParam <= RF_DAG_PARAMCACHESIZE) { |
| 155 | node->params = (RF_DagParam_t *) node->dag_params; |
| 156 | } else if (nParam <= (RF_DAGPCACHE_SIZE / sizeof(RF_DagParam_t))) { |
| 157 | node->big_dag_params = rf_AllocDAGPCache(); |
| 158 | node->params = node->big_dag_params; |
| 159 | } else { |
| 160 | RF_MallocAndAdd(node->params, |
| 161 | nParam * sizeof(RF_DagParam_t), |
| 162 | (RF_DagParam_t *), alist); |
| 163 | } |
| 164 | } else { |
| 165 | node->params = NULL; |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | |
| 170 | |
| 171 | /****************************************************************************** |
| 172 | * |
| 173 | * allocation and deallocation routines |
| 174 | * |
| 175 | *****************************************************************************/ |
| 176 | |
| 177 | void |
| 178 | rf_FreeDAG(RF_DagHeader_t *dag_h) |
| 179 | { |
| 180 | RF_AccessStripeMapHeader_t *asmap, *t_asmap; |
| 181 | RF_PhysDiskAddr_t *pda; |
| 182 | RF_DagNode_t *tmpnode; |
| 183 | RF_DagHeader_t *nextDag; |
| 184 | |
| 185 | while (dag_h) { |
| 186 | nextDag = dag_h->next; |
| 187 | rf_FreeAllocList(dag_h->allocList); |
| 188 | for (asmap = dag_h->asmList; asmap;) { |
| 189 | t_asmap = asmap; |
| 190 | asmap = asmap->next; |
| 191 | rf_FreeAccessStripeMap(t_asmap); |
| 192 | } |
| 193 | while (dag_h->pda_cleanup_list) { |
| 194 | pda = dag_h->pda_cleanup_list; |
| 195 | dag_h->pda_cleanup_list = dag_h->pda_cleanup_list->next; |
| 196 | rf_FreePhysDiskAddr(pda); |
| 197 | } |
| 198 | while (dag_h->nodes) { |
| 199 | tmpnode = dag_h->nodes; |
| 200 | dag_h->nodes = dag_h->nodes->list_next; |
| 201 | rf_FreeDAGNode(tmpnode); |
| 202 | } |
| 203 | rf_FreeDAGHeader(dag_h); |
| 204 | dag_h = nextDag; |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | #define RF_MAX_FREE_DAGH 128 |
| 209 | #define RF_MIN_FREE_DAGH 32 |
| 210 | |
| 211 | #define RF_MAX_FREE_DAGNODE 512 /* XXX Tune this... */ |
| 212 | #define RF_MIN_FREE_DAGNODE 128 /* XXX Tune this... */ |
| 213 | |
| 214 | #define RF_MAX_FREE_DAGLIST 128 |
| 215 | #define RF_MIN_FREE_DAGLIST 32 |
| 216 | |
| 217 | #define RF_MAX_FREE_DAGPCACHE 128 |
| 218 | #define RF_MIN_FREE_DAGPCACHE 8 |
| 219 | |
| 220 | #define RF_MAX_FREE_FUNCLIST 128 |
| 221 | #define RF_MIN_FREE_FUNCLIST 32 |
| 222 | |
| 223 | #define RF_MAX_FREE_BUFFERS 128 |
| 224 | #define RF_MIN_FREE_BUFFERS 32 |
| 225 | |
| 226 | static void rf_ShutdownDAGs(void *); |
| 227 | static void |
| 228 | rf_ShutdownDAGs(void *ignored) |
| 229 | { |
| 230 | pool_destroy(&rf_pools.dagh); |
| 231 | pool_destroy(&rf_pools.dagnode); |
| 232 | pool_destroy(&rf_pools.daglist); |
| 233 | pool_destroy(&rf_pools.dagpcache); |
| 234 | pool_destroy(&rf_pools.funclist); |
| 235 | } |
| 236 | |
| 237 | int |
| 238 | rf_ConfigureDAGs(RF_ShutdownList_t **listp) |
| 239 | { |
| 240 | |
| 241 | rf_pool_init(&rf_pools.dagnode, sizeof(RF_DagNode_t), |
| 242 | "rf_dagnode_pl" , RF_MIN_FREE_DAGNODE, RF_MAX_FREE_DAGNODE); |
| 243 | rf_pool_init(&rf_pools.dagh, sizeof(RF_DagHeader_t), |
| 244 | "rf_dagh_pl" , RF_MIN_FREE_DAGH, RF_MAX_FREE_DAGH); |
| 245 | rf_pool_init(&rf_pools.daglist, sizeof(RF_DagList_t), |
| 246 | "rf_daglist_pl" , RF_MIN_FREE_DAGLIST, RF_MAX_FREE_DAGLIST); |
| 247 | rf_pool_init(&rf_pools.dagpcache, RF_DAGPCACHE_SIZE, |
| 248 | "rf_dagpcache_pl" , RF_MIN_FREE_DAGPCACHE, RF_MAX_FREE_DAGPCACHE); |
| 249 | rf_pool_init(&rf_pools.funclist, sizeof(RF_FuncList_t), |
| 250 | "rf_funclist_pl" , RF_MIN_FREE_FUNCLIST, RF_MAX_FREE_FUNCLIST); |
| 251 | rf_ShutdownCreate(listp, rf_ShutdownDAGs, NULL); |
| 252 | |
| 253 | return (0); |
| 254 | } |
| 255 | |
| 256 | RF_DagHeader_t * |
| 257 | (void) |
| 258 | { |
| 259 | RF_DagHeader_t *dh; |
| 260 | |
| 261 | dh = pool_get(&rf_pools.dagh, PR_WAITOK); |
| 262 | memset((char *) dh, 0, sizeof(RF_DagHeader_t)); |
| 263 | return (dh); |
| 264 | } |
| 265 | |
| 266 | void |
| 267 | (RF_DagHeader_t * dh) |
| 268 | { |
| 269 | pool_put(&rf_pools.dagh, dh); |
| 270 | } |
| 271 | |
| 272 | RF_DagNode_t * |
| 273 | rf_AllocDAGNode(void) |
| 274 | { |
| 275 | RF_DagNode_t *node; |
| 276 | |
| 277 | node = pool_get(&rf_pools.dagnode, PR_WAITOK); |
| 278 | memset(node, 0, sizeof(RF_DagNode_t)); |
| 279 | return (node); |
| 280 | } |
| 281 | |
| 282 | void |
| 283 | rf_FreeDAGNode(RF_DagNode_t *node) |
| 284 | { |
| 285 | if (node->big_dag_ptrs) { |
| 286 | rf_FreeDAGPCache(node->big_dag_ptrs); |
| 287 | } |
| 288 | if (node->big_dag_params) { |
| 289 | rf_FreeDAGPCache(node->big_dag_params); |
| 290 | } |
| 291 | pool_put(&rf_pools.dagnode, node); |
| 292 | } |
| 293 | |
| 294 | RF_DagList_t * |
| 295 | rf_AllocDAGList(void) |
| 296 | { |
| 297 | RF_DagList_t *dagList; |
| 298 | |
| 299 | dagList = pool_get(&rf_pools.daglist, PR_WAITOK); |
| 300 | memset(dagList, 0, sizeof(RF_DagList_t)); |
| 301 | |
| 302 | return (dagList); |
| 303 | } |
| 304 | |
| 305 | void |
| 306 | rf_FreeDAGList(RF_DagList_t *dagList) |
| 307 | { |
| 308 | pool_put(&rf_pools.daglist, dagList); |
| 309 | } |
| 310 | |
| 311 | void * |
| 312 | rf_AllocDAGPCache(void) |
| 313 | { |
| 314 | void *p; |
| 315 | p = pool_get(&rf_pools.dagpcache, PR_WAITOK); |
| 316 | memset(p, 0, RF_DAGPCACHE_SIZE); |
| 317 | |
| 318 | return (p); |
| 319 | } |
| 320 | |
| 321 | void |
| 322 | rf_FreeDAGPCache(void *p) |
| 323 | { |
| 324 | pool_put(&rf_pools.dagpcache, p); |
| 325 | } |
| 326 | |
| 327 | RF_FuncList_t * |
| 328 | rf_AllocFuncList(void) |
| 329 | { |
| 330 | RF_FuncList_t *funcList; |
| 331 | |
| 332 | funcList = pool_get(&rf_pools.funclist, PR_WAITOK); |
| 333 | memset(funcList, 0, sizeof(RF_FuncList_t)); |
| 334 | |
| 335 | return (funcList); |
| 336 | } |
| 337 | |
| 338 | void |
| 339 | rf_FreeFuncList(RF_FuncList_t *funcList) |
| 340 | { |
| 341 | pool_put(&rf_pools.funclist, funcList); |
| 342 | } |
| 343 | |
| 344 | /* allocates a stripe buffer -- a buffer large enough to hold all the data |
| 345 | in an entire stripe. |
| 346 | */ |
| 347 | |
| 348 | void * |
| 349 | rf_AllocStripeBuffer(RF_Raid_t *raidPtr, RF_DagHeader_t *dag_h, |
| 350 | int size) |
| 351 | { |
| 352 | RF_VoidPointerListElem_t *vple; |
| 353 | void *p; |
| 354 | |
| 355 | RF_ASSERT((size <= (raidPtr->numCol * (raidPtr->Layout.sectorsPerStripeUnit << |
| 356 | raidPtr->logBytesPerSector)))); |
| 357 | |
| 358 | p = malloc( raidPtr->numCol * (raidPtr->Layout.sectorsPerStripeUnit << |
| 359 | raidPtr->logBytesPerSector), |
| 360 | M_RAIDFRAME, M_NOWAIT); |
| 361 | if (!p) { |
| 362 | rf_lock_mutex2(raidPtr->mutex); |
| 363 | if (raidPtr->stripebuf_count > 0) { |
| 364 | vple = raidPtr->stripebuf; |
| 365 | raidPtr->stripebuf = vple->next; |
| 366 | p = vple->p; |
| 367 | rf_FreeVPListElem(vple); |
| 368 | raidPtr->stripebuf_count--; |
| 369 | } else { |
| 370 | #ifdef DIAGNOSTIC |
| 371 | printf("raid%d: Help! Out of emergency full-stripe buffers!\n" , raidPtr->raidid); |
| 372 | #endif |
| 373 | } |
| 374 | rf_unlock_mutex2(raidPtr->mutex); |
| 375 | if (!p) { |
| 376 | /* We didn't get a buffer... not much we can do other than wait, |
| 377 | and hope that someone frees up memory for us.. */ |
| 378 | p = malloc( raidPtr->numCol * (raidPtr->Layout.sectorsPerStripeUnit << |
| 379 | raidPtr->logBytesPerSector), M_RAIDFRAME, M_WAITOK); |
| 380 | } |
| 381 | } |
| 382 | memset(p, 0, raidPtr->numCol * (raidPtr->Layout.sectorsPerStripeUnit << raidPtr->logBytesPerSector)); |
| 383 | |
| 384 | vple = rf_AllocVPListElem(); |
| 385 | vple->p = p; |
| 386 | vple->next = dag_h->desc->stripebufs; |
| 387 | dag_h->desc->stripebufs = vple; |
| 388 | |
| 389 | return (p); |
| 390 | } |
| 391 | |
| 392 | |
| 393 | void |
| 394 | rf_FreeStripeBuffer(RF_Raid_t *raidPtr, RF_VoidPointerListElem_t *vple) |
| 395 | { |
| 396 | rf_lock_mutex2(raidPtr->mutex); |
| 397 | if (raidPtr->stripebuf_count < raidPtr->numEmergencyStripeBuffers) { |
| 398 | /* just tack it in */ |
| 399 | vple->next = raidPtr->stripebuf; |
| 400 | raidPtr->stripebuf = vple; |
| 401 | raidPtr->stripebuf_count++; |
| 402 | } else { |
| 403 | free(vple->p, M_RAIDFRAME); |
| 404 | rf_FreeVPListElem(vple); |
| 405 | } |
| 406 | rf_unlock_mutex2(raidPtr->mutex); |
| 407 | } |
| 408 | |
| 409 | /* allocates a buffer big enough to hold the data described by the |
| 410 | caller (ie. the data of the associated PDA). Glue this buffer |
| 411 | into our dag_h cleanup structure. */ |
| 412 | |
| 413 | void * |
| 414 | rf_AllocBuffer(RF_Raid_t *raidPtr, RF_DagHeader_t *dag_h, int size) |
| 415 | { |
| 416 | RF_VoidPointerListElem_t *vple; |
| 417 | void *p; |
| 418 | |
| 419 | p = rf_AllocIOBuffer(raidPtr, size); |
| 420 | vple = rf_AllocVPListElem(); |
| 421 | vple->p = p; |
| 422 | vple->next = dag_h->desc->iobufs; |
| 423 | dag_h->desc->iobufs = vple; |
| 424 | |
| 425 | return (p); |
| 426 | } |
| 427 | |
| 428 | void * |
| 429 | rf_AllocIOBuffer(RF_Raid_t *raidPtr, int size) |
| 430 | { |
| 431 | RF_VoidPointerListElem_t *vple; |
| 432 | void *p; |
| 433 | |
| 434 | RF_ASSERT((size <= (raidPtr->Layout.sectorsPerStripeUnit << |
| 435 | raidPtr->logBytesPerSector))); |
| 436 | |
| 437 | p = malloc( raidPtr->Layout.sectorsPerStripeUnit << |
| 438 | raidPtr->logBytesPerSector, |
| 439 | M_RAIDFRAME, M_NOWAIT); |
| 440 | if (!p) { |
| 441 | rf_lock_mutex2(raidPtr->mutex); |
| 442 | if (raidPtr->iobuf_count > 0) { |
| 443 | vple = raidPtr->iobuf; |
| 444 | raidPtr->iobuf = vple->next; |
| 445 | p = vple->p; |
| 446 | rf_FreeVPListElem(vple); |
| 447 | raidPtr->iobuf_count--; |
| 448 | } else { |
| 449 | #ifdef DIAGNOSTIC |
| 450 | printf("raid%d: Help! Out of emergency buffers!\n" , raidPtr->raidid); |
| 451 | #endif |
| 452 | } |
| 453 | rf_unlock_mutex2(raidPtr->mutex); |
| 454 | if (!p) { |
| 455 | /* We didn't get a buffer... not much we can do other than wait, |
| 456 | and hope that someone frees up memory for us.. */ |
| 457 | p = malloc( raidPtr->Layout.sectorsPerStripeUnit << |
| 458 | raidPtr->logBytesPerSector, |
| 459 | M_RAIDFRAME, M_WAITOK); |
| 460 | } |
| 461 | } |
| 462 | memset(p, 0, raidPtr->Layout.sectorsPerStripeUnit << raidPtr->logBytesPerSector); |
| 463 | return (p); |
| 464 | } |
| 465 | |
| 466 | void |
| 467 | rf_FreeIOBuffer(RF_Raid_t *raidPtr, RF_VoidPointerListElem_t *vple) |
| 468 | { |
| 469 | rf_lock_mutex2(raidPtr->mutex); |
| 470 | if (raidPtr->iobuf_count < raidPtr->numEmergencyBuffers) { |
| 471 | /* just tack it in */ |
| 472 | vple->next = raidPtr->iobuf; |
| 473 | raidPtr->iobuf = vple; |
| 474 | raidPtr->iobuf_count++; |
| 475 | } else { |
| 476 | free(vple->p, M_RAIDFRAME); |
| 477 | rf_FreeVPListElem(vple); |
| 478 | } |
| 479 | rf_unlock_mutex2(raidPtr->mutex); |
| 480 | } |
| 481 | |
| 482 | |
| 483 | |
| 484 | #if RF_DEBUG_VALIDATE_DAG |
| 485 | /****************************************************************************** |
| 486 | * |
| 487 | * debug routines |
| 488 | * |
| 489 | *****************************************************************************/ |
| 490 | |
| 491 | char * |
| 492 | rf_NodeStatusString(RF_DagNode_t *node) |
| 493 | { |
| 494 | switch (node->status) { |
| 495 | case rf_wait: |
| 496 | return ("wait" ); |
| 497 | case rf_fired: |
| 498 | return ("fired" ); |
| 499 | case rf_good: |
| 500 | return ("good" ); |
| 501 | case rf_bad: |
| 502 | return ("bad" ); |
| 503 | default: |
| 504 | return ("?" ); |
| 505 | } |
| 506 | } |
| 507 | |
| 508 | void |
| 509 | rf_PrintNodeInfoString(RF_DagNode_t *node) |
| 510 | { |
| 511 | RF_PhysDiskAddr_t *pda; |
| 512 | int (*df) (RF_DagNode_t *) = node->doFunc; |
| 513 | int i, lk, unlk; |
| 514 | void *bufPtr; |
| 515 | |
| 516 | if ((df == rf_DiskReadFunc) || (df == rf_DiskWriteFunc) |
| 517 | || (df == rf_DiskReadMirrorIdleFunc) |
| 518 | || (df == rf_DiskReadMirrorPartitionFunc)) { |
| 519 | pda = (RF_PhysDiskAddr_t *) node->params[0].p; |
| 520 | bufPtr = (void *) node->params[1].p; |
| 521 | lk = 0; |
| 522 | unlk = 0; |
| 523 | RF_ASSERT(!(lk && unlk)); |
| 524 | printf("c %d offs %ld nsect %d buf 0x%lx %s\n" , pda->col, |
| 525 | (long) pda->startSector, (int) pda->numSector, (long) bufPtr, |
| 526 | (lk) ? "LOCK" : ((unlk) ? "UNLK" : " " )); |
| 527 | return; |
| 528 | } |
| 529 | if ((df == rf_SimpleXorFunc) || (df == rf_RegularXorFunc) |
| 530 | || (df == rf_RecoveryXorFunc)) { |
| 531 | printf("result buf 0x%lx\n" , (long) node->results[0]); |
| 532 | for (i = 0; i < node->numParams - 1; i += 2) { |
| 533 | pda = (RF_PhysDiskAddr_t *) node->params[i].p; |
| 534 | bufPtr = (RF_PhysDiskAddr_t *) node->params[i + 1].p; |
| 535 | printf(" buf 0x%lx c%d offs %ld nsect %d\n" , |
| 536 | (long) bufPtr, pda->col, |
| 537 | (long) pda->startSector, (int) pda->numSector); |
| 538 | } |
| 539 | return; |
| 540 | } |
| 541 | #if RF_INCLUDE_PARITYLOGGING > 0 |
| 542 | if (df == rf_ParityLogOverwriteFunc || df == rf_ParityLogUpdateFunc) { |
| 543 | for (i = 0; i < node->numParams - 1; i += 2) { |
| 544 | pda = (RF_PhysDiskAddr_t *) node->params[i].p; |
| 545 | bufPtr = (RF_PhysDiskAddr_t *) node->params[i + 1].p; |
| 546 | printf(" c%d offs %ld nsect %d buf 0x%lx\n" , |
| 547 | pda->col, (long) pda->startSector, |
| 548 | (int) pda->numSector, (long) bufPtr); |
| 549 | } |
| 550 | return; |
| 551 | } |
| 552 | #endif /* RF_INCLUDE_PARITYLOGGING > 0 */ |
| 553 | |
| 554 | if ((df == rf_TerminateFunc) || (df == rf_NullNodeFunc)) { |
| 555 | printf("\n" ); |
| 556 | return; |
| 557 | } |
| 558 | printf("?\n" ); |
| 559 | } |
| 560 | #ifdef DEBUG |
| 561 | static void |
| 562 | rf_RecurPrintDAG(RF_DagNode_t *node, int depth, int unvisited) |
| 563 | { |
| 564 | char *anttype; |
| 565 | int i; |
| 566 | |
| 567 | node->visited = (unvisited) ? 0 : 1; |
| 568 | printf("(%d) %d C%d %s: %s,s%d %d/%d,a%d/%d,p%d,r%d S{" , depth, |
| 569 | node->nodeNum, node->commitNode, node->name, rf_NodeStatusString(node), |
| 570 | node->numSuccedents, node->numSuccFired, node->numSuccDone, |
| 571 | node->numAntecedents, node->numAntDone, node->numParams, node->numResults); |
| 572 | for (i = 0; i < node->numSuccedents; i++) { |
| 573 | printf("%d%s" , node->succedents[i]->nodeNum, |
| 574 | ((i == node->numSuccedents - 1) ? "\0" : " " )); |
| 575 | } |
| 576 | printf("} A{" ); |
| 577 | for (i = 0; i < node->numAntecedents; i++) { |
| 578 | switch (node->antType[i]) { |
| 579 | case rf_trueData: |
| 580 | anttype = "T" ; |
| 581 | break; |
| 582 | case rf_antiData: |
| 583 | anttype = "A" ; |
| 584 | break; |
| 585 | case rf_outputData: |
| 586 | anttype = "O" ; |
| 587 | break; |
| 588 | case rf_control: |
| 589 | anttype = "C" ; |
| 590 | break; |
| 591 | default: |
| 592 | anttype = "?" ; |
| 593 | break; |
| 594 | } |
| 595 | printf("%d(%s)%s" , node->antecedents[i]->nodeNum, anttype, (i == node->numAntecedents - 1) ? "\0" : " " ); |
| 596 | } |
| 597 | printf("}; " ); |
| 598 | rf_PrintNodeInfoString(node); |
| 599 | for (i = 0; i < node->numSuccedents; i++) { |
| 600 | if (node->succedents[i]->visited == unvisited) |
| 601 | rf_RecurPrintDAG(node->succedents[i], depth + 1, unvisited); |
| 602 | } |
| 603 | } |
| 604 | |
| 605 | static void |
| 606 | rf_PrintDAG(RF_DagHeader_t *dag_h) |
| 607 | { |
| 608 | int unvisited, i; |
| 609 | char *status; |
| 610 | |
| 611 | /* set dag status */ |
| 612 | switch (dag_h->status) { |
| 613 | case rf_enable: |
| 614 | status = "enable" ; |
| 615 | break; |
| 616 | case rf_rollForward: |
| 617 | status = "rollForward" ; |
| 618 | break; |
| 619 | case rf_rollBackward: |
| 620 | status = "rollBackward" ; |
| 621 | break; |
| 622 | default: |
| 623 | status = "illegal!" ; |
| 624 | break; |
| 625 | } |
| 626 | /* find out if visited bits are currently set or clear */ |
| 627 | unvisited = dag_h->succedents[0]->visited; |
| 628 | |
| 629 | printf("DAG type: %s\n" , dag_h->creator); |
| 630 | printf("format is (depth) num commit type: status,nSucc nSuccFired/nSuccDone,nAnte/nAnteDone,nParam,nResult S{x} A{x(type)}; info\n" ); |
| 631 | printf("(0) %d Hdr: %s, s%d, (commit %d/%d) S{" , dag_h->nodeNum, |
| 632 | status, dag_h->numSuccedents, dag_h->numCommitNodes, dag_h->numCommits); |
| 633 | for (i = 0; i < dag_h->numSuccedents; i++) { |
| 634 | printf("%d%s" , dag_h->succedents[i]->nodeNum, |
| 635 | ((i == dag_h->numSuccedents - 1) ? "\0" : " " )); |
| 636 | } |
| 637 | printf("};\n" ); |
| 638 | for (i = 0; i < dag_h->numSuccedents; i++) { |
| 639 | if (dag_h->succedents[i]->visited == unvisited) |
| 640 | rf_RecurPrintDAG(dag_h->succedents[i], 1, unvisited); |
| 641 | } |
| 642 | } |
| 643 | #endif |
| 644 | /* assigns node numbers */ |
| 645 | int |
| 646 | rf_AssignNodeNums(RF_DagHeader_t * dag_h) |
| 647 | { |
| 648 | int unvisited, i, nnum; |
| 649 | RF_DagNode_t *node; |
| 650 | |
| 651 | nnum = 0; |
| 652 | unvisited = dag_h->succedents[0]->visited; |
| 653 | |
| 654 | dag_h->nodeNum = nnum++; |
| 655 | for (i = 0; i < dag_h->numSuccedents; i++) { |
| 656 | node = dag_h->succedents[i]; |
| 657 | if (node->visited == unvisited) { |
| 658 | nnum = rf_RecurAssignNodeNums(dag_h->succedents[i], nnum, unvisited); |
| 659 | } |
| 660 | } |
| 661 | return (nnum); |
| 662 | } |
| 663 | |
| 664 | int |
| 665 | rf_RecurAssignNodeNums(RF_DagNode_t *node, int num, int unvisited) |
| 666 | { |
| 667 | int i; |
| 668 | |
| 669 | node->visited = (unvisited) ? 0 : 1; |
| 670 | |
| 671 | node->nodeNum = num++; |
| 672 | for (i = 0; i < node->numSuccedents; i++) { |
| 673 | if (node->succedents[i]->visited == unvisited) { |
| 674 | num = rf_RecurAssignNodeNums(node->succedents[i], num, unvisited); |
| 675 | } |
| 676 | } |
| 677 | return (num); |
| 678 | } |
| 679 | /* set the header pointers in each node to "newptr" */ |
| 680 | void |
| 681 | rf_ResetDAGHeaderPointers(RF_DagHeader_t *dag_h, RF_DagHeader_t *newptr) |
| 682 | { |
| 683 | int i; |
| 684 | for (i = 0; i < dag_h->numSuccedents; i++) |
| 685 | if (dag_h->succedents[i]->dagHdr != newptr) |
| 686 | rf_RecurResetDAGHeaderPointers(dag_h->succedents[i], newptr); |
| 687 | } |
| 688 | |
| 689 | void |
| 690 | rf_RecurResetDAGHeaderPointers(RF_DagNode_t *node, RF_DagHeader_t *newptr) |
| 691 | { |
| 692 | int i; |
| 693 | node->dagHdr = newptr; |
| 694 | for (i = 0; i < node->numSuccedents; i++) |
| 695 | if (node->succedents[i]->dagHdr != newptr) |
| 696 | rf_RecurResetDAGHeaderPointers(node->succedents[i], newptr); |
| 697 | } |
| 698 | |
| 699 | |
| 700 | void |
| 701 | rf_PrintDAGList(RF_DagHeader_t * dag_h) |
| 702 | { |
| 703 | int i = 0; |
| 704 | |
| 705 | for (; dag_h; dag_h = dag_h->next) { |
| 706 | rf_AssignNodeNums(dag_h); |
| 707 | printf("\n\nDAG %d IN LIST:\n" , i++); |
| 708 | rf_PrintDAG(dag_h); |
| 709 | } |
| 710 | } |
| 711 | |
| 712 | static int |
| 713 | rf_ValidateBranch(RF_DagNode_t *node, int *scount, int *acount, |
| 714 | RF_DagNode_t **nodes, int unvisited) |
| 715 | { |
| 716 | int i, retcode = 0; |
| 717 | |
| 718 | /* construct an array of node pointers indexed by node num */ |
| 719 | node->visited = (unvisited) ? 0 : 1; |
| 720 | nodes[node->nodeNum] = node; |
| 721 | |
| 722 | if (node->next != NULL) { |
| 723 | printf("INVALID DAG: next pointer in node is not NULL\n" ); |
| 724 | retcode = 1; |
| 725 | } |
| 726 | if (node->status != rf_wait) { |
| 727 | printf("INVALID DAG: Node status is not wait\n" ); |
| 728 | retcode = 1; |
| 729 | } |
| 730 | if (node->numAntDone != 0) { |
| 731 | printf("INVALID DAG: numAntDone is not zero\n" ); |
| 732 | retcode = 1; |
| 733 | } |
| 734 | if (node->doFunc == rf_TerminateFunc) { |
| 735 | if (node->numSuccedents != 0) { |
| 736 | printf("INVALID DAG: Terminator node has succedents\n" ); |
| 737 | retcode = 1; |
| 738 | } |
| 739 | } else { |
| 740 | if (node->numSuccedents == 0) { |
| 741 | printf("INVALID DAG: Non-terminator node has no succedents\n" ); |
| 742 | retcode = 1; |
| 743 | } |
| 744 | } |
| 745 | for (i = 0; i < node->numSuccedents; i++) { |
| 746 | if (!node->succedents[i]) { |
| 747 | printf("INVALID DAG: succedent %d of node %s is NULL\n" , i, node->name); |
| 748 | retcode = 1; |
| 749 | } |
| 750 | scount[node->succedents[i]->nodeNum]++; |
| 751 | } |
| 752 | for (i = 0; i < node->numAntecedents; i++) { |
| 753 | if (!node->antecedents[i]) { |
| 754 | printf("INVALID DAG: antecedent %d of node %s is NULL\n" , i, node->name); |
| 755 | retcode = 1; |
| 756 | } |
| 757 | acount[node->antecedents[i]->nodeNum]++; |
| 758 | } |
| 759 | for (i = 0; i < node->numSuccedents; i++) { |
| 760 | if (node->succedents[i]->visited == unvisited) { |
| 761 | if (rf_ValidateBranch(node->succedents[i], scount, |
| 762 | acount, nodes, unvisited)) { |
| 763 | retcode = 1; |
| 764 | } |
| 765 | } |
| 766 | } |
| 767 | return (retcode); |
| 768 | } |
| 769 | |
| 770 | static void |
| 771 | rf_ValidateBranchVisitedBits(RF_DagNode_t *node, int unvisited, int rl) |
| 772 | { |
| 773 | int i; |
| 774 | |
| 775 | RF_ASSERT(node->visited == unvisited); |
| 776 | for (i = 0; i < node->numSuccedents; i++) { |
| 777 | if (node->succedents[i] == NULL) { |
| 778 | printf("node=%lx node->succedents[%d] is NULL\n" , (long) node, i); |
| 779 | RF_ASSERT(0); |
| 780 | } |
| 781 | rf_ValidateBranchVisitedBits(node->succedents[i], unvisited, rl + 1); |
| 782 | } |
| 783 | } |
| 784 | /* NOTE: never call this on a big dag, because it is exponential |
| 785 | * in execution time |
| 786 | */ |
| 787 | static void |
| 788 | rf_ValidateVisitedBits(RF_DagHeader_t *dag) |
| 789 | { |
| 790 | int i, unvisited; |
| 791 | |
| 792 | unvisited = dag->succedents[0]->visited; |
| 793 | |
| 794 | for (i = 0; i < dag->numSuccedents; i++) { |
| 795 | if (dag->succedents[i] == NULL) { |
| 796 | printf("dag=%lx dag->succedents[%d] is NULL\n" , (long) dag, i); |
| 797 | RF_ASSERT(0); |
| 798 | } |
| 799 | rf_ValidateBranchVisitedBits(dag->succedents[i], unvisited, 0); |
| 800 | } |
| 801 | } |
| 802 | /* validate a DAG. _at entry_ verify that: |
| 803 | * -- numNodesCompleted is zero |
| 804 | * -- node queue is null |
| 805 | * -- dag status is rf_enable |
| 806 | * -- next pointer is null on every node |
| 807 | * -- all nodes have status wait |
| 808 | * -- numAntDone is zero in all nodes |
| 809 | * -- terminator node has zero successors |
| 810 | * -- no other node besides terminator has zero successors |
| 811 | * -- no successor or antecedent pointer in a node is NULL |
| 812 | * -- number of times that each node appears as a successor of another node |
| 813 | * is equal to the antecedent count on that node |
| 814 | * -- number of times that each node appears as an antecedent of another node |
| 815 | * is equal to the succedent count on that node |
| 816 | * -- what else? |
| 817 | */ |
| 818 | int |
| 819 | rf_ValidateDAG(RF_DagHeader_t *dag_h) |
| 820 | { |
| 821 | int i, nodecount; |
| 822 | int *scount, *acount;/* per-node successor and antecedent counts */ |
| 823 | RF_DagNode_t **nodes; /* array of ptrs to nodes in dag */ |
| 824 | int retcode = 0; |
| 825 | int unvisited; |
| 826 | int commitNodeCount = 0; |
| 827 | |
| 828 | if (rf_validateVisitedDebug) |
| 829 | rf_ValidateVisitedBits(dag_h); |
| 830 | |
| 831 | if (dag_h->numNodesCompleted != 0) { |
| 832 | printf("INVALID DAG: num nodes completed is %d, should be 0\n" , dag_h->numNodesCompleted); |
| 833 | retcode = 1; |
| 834 | goto validate_dag_bad; |
| 835 | } |
| 836 | if (dag_h->status != rf_enable) { |
| 837 | printf("INVALID DAG: not enabled\n" ); |
| 838 | retcode = 1; |
| 839 | goto validate_dag_bad; |
| 840 | } |
| 841 | if (dag_h->numCommits != 0) { |
| 842 | printf("INVALID DAG: numCommits != 0 (%d)\n" , dag_h->numCommits); |
| 843 | retcode = 1; |
| 844 | goto validate_dag_bad; |
| 845 | } |
| 846 | if (dag_h->numSuccedents != 1) { |
| 847 | /* currently, all dags must have only one succedent */ |
| 848 | printf("INVALID DAG: numSuccedents !1 (%d)\n" , dag_h->numSuccedents); |
| 849 | retcode = 1; |
| 850 | goto validate_dag_bad; |
| 851 | } |
| 852 | nodecount = rf_AssignNodeNums(dag_h); |
| 853 | |
| 854 | unvisited = dag_h->succedents[0]->visited; |
| 855 | |
| 856 | RF_Malloc(scount, nodecount * sizeof(int), (int *)); |
| 857 | RF_Malloc(acount, nodecount * sizeof(int), (int *)); |
| 858 | RF_Malloc(nodes, nodecount * sizeof(RF_DagNode_t *), |
| 859 | (RF_DagNode_t **)); |
| 860 | for (i = 0; i < dag_h->numSuccedents; i++) { |
| 861 | if ((dag_h->succedents[i]->visited == unvisited) |
| 862 | && rf_ValidateBranch(dag_h->succedents[i], scount, |
| 863 | acount, nodes, unvisited)) { |
| 864 | retcode = 1; |
| 865 | } |
| 866 | } |
| 867 | /* start at 1 to skip the header node */ |
| 868 | for (i = 1; i < nodecount; i++) { |
| 869 | if (nodes[i]->commitNode) |
| 870 | commitNodeCount++; |
| 871 | if (nodes[i]->doFunc == NULL) { |
| 872 | printf("INVALID DAG: node %s has an undefined doFunc\n" , nodes[i]->name); |
| 873 | retcode = 1; |
| 874 | goto validate_dag_out; |
| 875 | } |
| 876 | if (nodes[i]->undoFunc == NULL) { |
| 877 | printf("INVALID DAG: node %s has an undefined doFunc\n" , nodes[i]->name); |
| 878 | retcode = 1; |
| 879 | goto validate_dag_out; |
| 880 | } |
| 881 | if (nodes[i]->numAntecedents != scount[nodes[i]->nodeNum]) { |
| 882 | printf("INVALID DAG: node %s has %d antecedents but appears as a succedent %d times\n" , |
| 883 | nodes[i]->name, nodes[i]->numAntecedents, scount[nodes[i]->nodeNum]); |
| 884 | retcode = 1; |
| 885 | goto validate_dag_out; |
| 886 | } |
| 887 | if (nodes[i]->numSuccedents != acount[nodes[i]->nodeNum]) { |
| 888 | printf("INVALID DAG: node %s has %d succedents but appears as an antecedent %d times\n" , |
| 889 | nodes[i]->name, nodes[i]->numSuccedents, acount[nodes[i]->nodeNum]); |
| 890 | retcode = 1; |
| 891 | goto validate_dag_out; |
| 892 | } |
| 893 | } |
| 894 | |
| 895 | if (dag_h->numCommitNodes != commitNodeCount) { |
| 896 | printf("INVALID DAG: incorrect commit node count. hdr->numCommitNodes (%d) found (%d) commit nodes in graph\n" , |
| 897 | dag_h->numCommitNodes, commitNodeCount); |
| 898 | retcode = 1; |
| 899 | goto validate_dag_out; |
| 900 | } |
| 901 | validate_dag_out: |
| 902 | RF_Free(scount, nodecount * sizeof(int)); |
| 903 | RF_Free(acount, nodecount * sizeof(int)); |
| 904 | RF_Free(nodes, nodecount * sizeof(RF_DagNode_t *)); |
| 905 | if (retcode) |
| 906 | rf_PrintDAGList(dag_h); |
| 907 | |
| 908 | if (rf_validateVisitedDebug) |
| 909 | rf_ValidateVisitedBits(dag_h); |
| 910 | |
| 911 | return (retcode); |
| 912 | |
| 913 | validate_dag_bad: |
| 914 | rf_PrintDAGList(dag_h); |
| 915 | return (retcode); |
| 916 | } |
| 917 | |
| 918 | #endif /* RF_DEBUG_VALIDATE_DAG */ |
| 919 | |
| 920 | /****************************************************************************** |
| 921 | * |
| 922 | * misc construction routines |
| 923 | * |
| 924 | *****************************************************************************/ |
| 925 | |
| 926 | void |
| 927 | rf_redirect_asm(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap) |
| 928 | { |
| 929 | int ds = (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) ? 1 : 0; |
| 930 | int fcol = raidPtr->reconControl->fcol; |
| 931 | int scol = raidPtr->reconControl->spareCol; |
| 932 | RF_PhysDiskAddr_t *pda; |
| 933 | |
| 934 | RF_ASSERT(raidPtr->status == rf_rs_reconstructing); |
| 935 | for (pda = asmap->physInfo; pda; pda = pda->next) { |
| 936 | if (pda->col == fcol) { |
| 937 | #if RF_DEBUG_DAG |
| 938 | if (rf_dagDebug) { |
| 939 | if (!rf_CheckRUReconstructed(raidPtr->reconControl->reconMap, |
| 940 | pda->startSector)) { |
| 941 | RF_PANIC(); |
| 942 | } |
| 943 | } |
| 944 | #endif |
| 945 | /* printf("Remapped data for large write\n"); */ |
| 946 | if (ds) { |
| 947 | raidPtr->Layout.map->MapSector(raidPtr, pda->raidAddress, |
| 948 | &pda->col, &pda->startSector, RF_REMAP); |
| 949 | } else { |
| 950 | pda->col = scol; |
| 951 | } |
| 952 | } |
| 953 | } |
| 954 | for (pda = asmap->parityInfo; pda; pda = pda->next) { |
| 955 | if (pda->col == fcol) { |
| 956 | #if RF_DEBUG_DAG |
| 957 | if (rf_dagDebug) { |
| 958 | if (!rf_CheckRUReconstructed(raidPtr->reconControl->reconMap, pda->startSector)) { |
| 959 | RF_PANIC(); |
| 960 | } |
| 961 | } |
| 962 | #endif |
| 963 | } |
| 964 | if (ds) { |
| 965 | (raidPtr->Layout.map->MapParity) (raidPtr, pda->raidAddress, &pda->col, &pda->startSector, RF_REMAP); |
| 966 | } else { |
| 967 | pda->col = scol; |
| 968 | } |
| 969 | } |
| 970 | } |
| 971 | |
| 972 | |
| 973 | /* this routine allocates read buffers and generates stripe maps for the |
| 974 | * regions of the array from the start of the stripe to the start of the |
| 975 | * access, and from the end of the access to the end of the stripe. It also |
| 976 | * computes and returns the number of DAG nodes needed to read all this data. |
| 977 | * Note that this routine does the wrong thing if the access is fully |
| 978 | * contained within one stripe unit, so we RF_ASSERT against this case at the |
| 979 | * start. |
| 980 | * |
| 981 | * layoutPtr - in: layout information |
| 982 | * asmap - in: access stripe map |
| 983 | * dag_h - in: header of the dag to create |
| 984 | * new_asm_h - in: ptr to array of 2 headers. to be filled in |
| 985 | * nRodNodes - out: num nodes to be generated to read unaccessed data |
| 986 | * sosBuffer, eosBuffer - out: pointers to newly allocated buffer |
| 987 | */ |
| 988 | void |
| 989 | rf_MapUnaccessedPortionOfStripe(RF_Raid_t *raidPtr, |
| 990 | RF_RaidLayout_t *layoutPtr, |
| 991 | RF_AccessStripeMap_t *asmap, |
| 992 | RF_DagHeader_t *dag_h, |
| 993 | RF_AccessStripeMapHeader_t **new_asm_h, |
| 994 | int *nRodNodes, |
| 995 | char **sosBuffer, char **eosBuffer, |
| 996 | RF_AllocListElem_t *allocList) |
| 997 | { |
| 998 | RF_RaidAddr_t sosRaidAddress, eosRaidAddress; |
| 999 | RF_SectorNum_t sosNumSector, eosNumSector; |
| 1000 | |
| 1001 | RF_ASSERT(asmap->numStripeUnitsAccessed > (layoutPtr->numDataCol / 2)); |
| 1002 | /* generate an access map for the region of the array from start of |
| 1003 | * stripe to start of access */ |
| 1004 | new_asm_h[0] = new_asm_h[1] = NULL; |
| 1005 | *nRodNodes = 0; |
| 1006 | if (!rf_RaidAddressStripeAligned(layoutPtr, asmap->raidAddress)) { |
| 1007 | sosRaidAddress = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, asmap->raidAddress); |
| 1008 | sosNumSector = asmap->raidAddress - sosRaidAddress; |
| 1009 | *sosBuffer = rf_AllocStripeBuffer(raidPtr, dag_h, rf_RaidAddressToByte(raidPtr, sosNumSector)); |
| 1010 | new_asm_h[0] = rf_MapAccess(raidPtr, sosRaidAddress, sosNumSector, *sosBuffer, RF_DONT_REMAP); |
| 1011 | new_asm_h[0]->next = dag_h->asmList; |
| 1012 | dag_h->asmList = new_asm_h[0]; |
| 1013 | *nRodNodes += new_asm_h[0]->stripeMap->numStripeUnitsAccessed; |
| 1014 | |
| 1015 | RF_ASSERT(new_asm_h[0]->stripeMap->next == NULL); |
| 1016 | /* we're totally within one stripe here */ |
| 1017 | if (asmap->flags & RF_ASM_REDIR_LARGE_WRITE) |
| 1018 | rf_redirect_asm(raidPtr, new_asm_h[0]->stripeMap); |
| 1019 | } |
| 1020 | /* generate an access map for the region of the array from end of |
| 1021 | * access to end of stripe */ |
| 1022 | if (!rf_RaidAddressStripeAligned(layoutPtr, asmap->endRaidAddress)) { |
| 1023 | eosRaidAddress = asmap->endRaidAddress; |
| 1024 | eosNumSector = rf_RaidAddressOfNextStripeBoundary(layoutPtr, eosRaidAddress) - eosRaidAddress; |
| 1025 | *eosBuffer = rf_AllocStripeBuffer(raidPtr, dag_h, rf_RaidAddressToByte(raidPtr, eosNumSector)); |
| 1026 | new_asm_h[1] = rf_MapAccess(raidPtr, eosRaidAddress, eosNumSector, *eosBuffer, RF_DONT_REMAP); |
| 1027 | new_asm_h[1]->next = dag_h->asmList; |
| 1028 | dag_h->asmList = new_asm_h[1]; |
| 1029 | *nRodNodes += new_asm_h[1]->stripeMap->numStripeUnitsAccessed; |
| 1030 | |
| 1031 | RF_ASSERT(new_asm_h[1]->stripeMap->next == NULL); |
| 1032 | /* we're totally within one stripe here */ |
| 1033 | if (asmap->flags & RF_ASM_REDIR_LARGE_WRITE) |
| 1034 | rf_redirect_asm(raidPtr, new_asm_h[1]->stripeMap); |
| 1035 | } |
| 1036 | } |
| 1037 | |
| 1038 | |
| 1039 | |
| 1040 | /* returns non-zero if the indicated ranges of stripe unit offsets overlap */ |
| 1041 | int |
| 1042 | rf_PDAOverlap(RF_RaidLayout_t *layoutPtr, |
| 1043 | RF_PhysDiskAddr_t *src, RF_PhysDiskAddr_t *dest) |
| 1044 | { |
| 1045 | RF_SectorNum_t soffs = rf_StripeUnitOffset(layoutPtr, src->startSector); |
| 1046 | RF_SectorNum_t doffs = rf_StripeUnitOffset(layoutPtr, dest->startSector); |
| 1047 | /* use -1 to be sure we stay within SU */ |
| 1048 | RF_SectorNum_t send = rf_StripeUnitOffset(layoutPtr, src->startSector + src->numSector - 1); |
| 1049 | RF_SectorNum_t dend = rf_StripeUnitOffset(layoutPtr, dest->startSector + dest->numSector - 1); |
| 1050 | return ((RF_MAX(soffs, doffs) <= RF_MIN(send, dend)) ? 1 : 0); |
| 1051 | } |
| 1052 | |
| 1053 | |
| 1054 | /* GenerateFailedAccessASMs |
| 1055 | * |
| 1056 | * this routine figures out what portion of the stripe needs to be read |
| 1057 | * to effect the degraded read or write operation. It's primary function |
| 1058 | * is to identify everything required to recover the data, and then |
| 1059 | * eliminate anything that is already being accessed by the user. |
| 1060 | * |
| 1061 | * The main result is two new ASMs, one for the region from the start of the |
| 1062 | * stripe to the start of the access, and one for the region from the end of |
| 1063 | * the access to the end of the stripe. These ASMs describe everything that |
| 1064 | * needs to be read to effect the degraded access. Other results are: |
| 1065 | * nXorBufs -- the total number of buffers that need to be XORed together to |
| 1066 | * recover the lost data, |
| 1067 | * rpBufPtr -- ptr to a newly-allocated buffer to hold the parity. If NULL |
| 1068 | * at entry, not allocated. |
| 1069 | * overlappingPDAs -- |
| 1070 | * describes which of the non-failed PDAs in the user access |
| 1071 | * overlap data that needs to be read to effect recovery. |
| 1072 | * overlappingPDAs[i]==1 if and only if, neglecting the failed |
| 1073 | * PDA, the ith pda in the input asm overlaps data that needs |
| 1074 | * to be read for recovery. |
| 1075 | */ |
| 1076 | /* in: asm - ASM for the actual access, one stripe only */ |
| 1077 | /* in: failedPDA - which component of the access has failed */ |
| 1078 | /* in: dag_h - header of the DAG we're going to create */ |
| 1079 | /* out: new_asm_h - the two new ASMs */ |
| 1080 | /* out: nXorBufs - the total number of xor bufs required */ |
| 1081 | /* out: rpBufPtr - a buffer for the parity read */ |
| 1082 | void |
| 1083 | rf_GenerateFailedAccessASMs(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap, |
| 1084 | RF_PhysDiskAddr_t *failedPDA, |
| 1085 | RF_DagHeader_t *dag_h, |
| 1086 | RF_AccessStripeMapHeader_t **new_asm_h, |
| 1087 | int *nXorBufs, char **rpBufPtr, |
| 1088 | char *overlappingPDAs, |
| 1089 | RF_AllocListElem_t *allocList) |
| 1090 | { |
| 1091 | RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); |
| 1092 | |
| 1093 | /* s=start, e=end, s=stripe, a=access, f=failed, su=stripe unit */ |
| 1094 | RF_RaidAddr_t sosAddr, sosEndAddr, eosStartAddr, eosAddr; |
| 1095 | RF_PhysDiskAddr_t *pda; |
| 1096 | int foundit, i; |
| 1097 | |
| 1098 | foundit = 0; |
| 1099 | /* first compute the following raid addresses: start of stripe, |
| 1100 | * (sosAddr) MIN(start of access, start of failed SU), (sosEndAddr) |
| 1101 | * MAX(end of access, end of failed SU), (eosStartAddr) end of |
| 1102 | * stripe (i.e. start of next stripe) (eosAddr) */ |
| 1103 | sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, asmap->raidAddress); |
| 1104 | sosEndAddr = RF_MIN(asmap->raidAddress, rf_RaidAddressOfPrevStripeUnitBoundary(layoutPtr, failedPDA->raidAddress)); |
| 1105 | eosStartAddr = RF_MAX(asmap->endRaidAddress, rf_RaidAddressOfNextStripeUnitBoundary(layoutPtr, failedPDA->raidAddress)); |
| 1106 | eosAddr = rf_RaidAddressOfNextStripeBoundary(layoutPtr, asmap->raidAddress); |
| 1107 | |
| 1108 | /* now generate access stripe maps for each of the above regions of |
| 1109 | * the stripe. Use a dummy (NULL) buf ptr for now */ |
| 1110 | |
| 1111 | new_asm_h[0] = (sosAddr != sosEndAddr) ? rf_MapAccess(raidPtr, sosAddr, sosEndAddr - sosAddr, NULL, RF_DONT_REMAP) : NULL; |
| 1112 | new_asm_h[1] = (eosStartAddr != eosAddr) ? rf_MapAccess(raidPtr, eosStartAddr, eosAddr - eosStartAddr, NULL, RF_DONT_REMAP) : NULL; |
| 1113 | |
| 1114 | /* walk through the PDAs and range-restrict each SU to the region of |
| 1115 | * the SU touched on the failed PDA. also compute total data buffer |
| 1116 | * space requirements in this step. Ignore the parity for now. */ |
| 1117 | /* Also count nodes to find out how many bufs need to be xored together */ |
| 1118 | (*nXorBufs) = 1; /* in read case, 1 is for parity. In write |
| 1119 | * case, 1 is for failed data */ |
| 1120 | |
| 1121 | if (new_asm_h[0]) { |
| 1122 | new_asm_h[0]->next = dag_h->asmList; |
| 1123 | dag_h->asmList = new_asm_h[0]; |
| 1124 | for (pda = new_asm_h[0]->stripeMap->physInfo; pda; pda = pda->next) { |
| 1125 | rf_RangeRestrictPDA(raidPtr, failedPDA, pda, RF_RESTRICT_NOBUFFER, 0); |
| 1126 | pda->bufPtr = rf_AllocBuffer(raidPtr, dag_h, pda->numSector << raidPtr->logBytesPerSector); |
| 1127 | } |
| 1128 | (*nXorBufs) += new_asm_h[0]->stripeMap->numStripeUnitsAccessed; |
| 1129 | } |
| 1130 | if (new_asm_h[1]) { |
| 1131 | new_asm_h[1]->next = dag_h->asmList; |
| 1132 | dag_h->asmList = new_asm_h[1]; |
| 1133 | for (pda = new_asm_h[1]->stripeMap->physInfo; pda; pda = pda->next) { |
| 1134 | rf_RangeRestrictPDA(raidPtr, failedPDA, pda, RF_RESTRICT_NOBUFFER, 0); |
| 1135 | pda->bufPtr = rf_AllocBuffer(raidPtr, dag_h, pda->numSector << raidPtr->logBytesPerSector); |
| 1136 | } |
| 1137 | (*nXorBufs) += new_asm_h[1]->stripeMap->numStripeUnitsAccessed; |
| 1138 | } |
| 1139 | |
| 1140 | /* allocate a buffer for parity */ |
| 1141 | if (rpBufPtr) |
| 1142 | *rpBufPtr = rf_AllocBuffer(raidPtr, dag_h, failedPDA->numSector << raidPtr->logBytesPerSector); |
| 1143 | |
| 1144 | /* the last step is to figure out how many more distinct buffers need |
| 1145 | * to get xor'd to produce the missing unit. there's one for each |
| 1146 | * user-data read node that overlaps the portion of the failed unit |
| 1147 | * being accessed */ |
| 1148 | |
| 1149 | for (foundit = i = 0, pda = asmap->physInfo; pda; i++, pda = pda->next) { |
| 1150 | if (pda == failedPDA) { |
| 1151 | i--; |
| 1152 | foundit = 1; |
| 1153 | continue; |
| 1154 | } |
| 1155 | if (rf_PDAOverlap(layoutPtr, pda, failedPDA)) { |
| 1156 | overlappingPDAs[i] = 1; |
| 1157 | (*nXorBufs)++; |
| 1158 | } |
| 1159 | } |
| 1160 | if (!foundit) { |
| 1161 | RF_ERRORMSG("GenerateFailedAccessASMs: did not find failedPDA in asm list\n" ); |
| 1162 | RF_ASSERT(0); |
| 1163 | } |
| 1164 | #if RF_DEBUG_DAG |
| 1165 | if (rf_degDagDebug) { |
| 1166 | if (new_asm_h[0]) { |
| 1167 | printf("First asm:\n" ); |
| 1168 | rf_PrintFullAccessStripeMap(new_asm_h[0], 1); |
| 1169 | } |
| 1170 | if (new_asm_h[1]) { |
| 1171 | printf("Second asm:\n" ); |
| 1172 | rf_PrintFullAccessStripeMap(new_asm_h[1], 1); |
| 1173 | } |
| 1174 | } |
| 1175 | #endif |
| 1176 | } |
| 1177 | |
| 1178 | |
| 1179 | /* adjusts the offset and number of sectors in the destination pda so that |
| 1180 | * it covers at most the region of the SU covered by the source PDA. This |
| 1181 | * is exclusively a restriction: the number of sectors indicated by the |
| 1182 | * target PDA can only shrink. |
| 1183 | * |
| 1184 | * For example: s = sectors within SU indicated by source PDA |
| 1185 | * d = sectors within SU indicated by dest PDA |
| 1186 | * r = results, stored in dest PDA |
| 1187 | * |
| 1188 | * |--------------- one stripe unit ---------------------| |
| 1189 | * | sssssssssssssssssssssssssssssssss | |
| 1190 | * | ddddddddddddddddddddddddddddddddddddddddddddd | |
| 1191 | * | rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr | |
| 1192 | * |
| 1193 | * Another example: |
| 1194 | * |
| 1195 | * |--------------- one stripe unit ---------------------| |
| 1196 | * | sssssssssssssssssssssssssssssssss | |
| 1197 | * | ddddddddddddddddddddddd | |
| 1198 | * | rrrrrrrrrrrrrrrr | |
| 1199 | * |
| 1200 | */ |
| 1201 | void |
| 1202 | rf_RangeRestrictPDA(RF_Raid_t *raidPtr, RF_PhysDiskAddr_t *src, |
| 1203 | RF_PhysDiskAddr_t *dest, int dobuffer, int doraidaddr) |
| 1204 | { |
| 1205 | RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; |
| 1206 | RF_SectorNum_t soffs = rf_StripeUnitOffset(layoutPtr, src->startSector); |
| 1207 | RF_SectorNum_t doffs = rf_StripeUnitOffset(layoutPtr, dest->startSector); |
| 1208 | RF_SectorNum_t send = rf_StripeUnitOffset(layoutPtr, src->startSector + src->numSector - 1); /* use -1 to be sure we |
| 1209 | * stay within SU */ |
| 1210 | RF_SectorNum_t dend = rf_StripeUnitOffset(layoutPtr, dest->startSector + dest->numSector - 1); |
| 1211 | RF_SectorNum_t subAddr = rf_RaidAddressOfPrevStripeUnitBoundary(layoutPtr, dest->startSector); /* stripe unit boundary */ |
| 1212 | |
| 1213 | dest->startSector = subAddr + RF_MAX(soffs, doffs); |
| 1214 | dest->numSector = subAddr + RF_MIN(send, dend) + 1 - dest->startSector; |
| 1215 | |
| 1216 | if (dobuffer) |
| 1217 | dest->bufPtr = (char *)(dest->bufPtr) + ((soffs > doffs) ? rf_RaidAddressToByte(raidPtr, soffs - doffs) : 0); |
| 1218 | if (doraidaddr) { |
| 1219 | dest->raidAddress = rf_RaidAddressOfPrevStripeUnitBoundary(layoutPtr, dest->raidAddress) + |
| 1220 | rf_StripeUnitOffset(layoutPtr, dest->startSector); |
| 1221 | } |
| 1222 | } |
| 1223 | |
| 1224 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) |
| 1225 | |
| 1226 | /* |
| 1227 | * Want the highest of these primes to be the largest one |
| 1228 | * less than the max expected number of columns (won't hurt |
| 1229 | * to be too small or too large, but won't be optimal, either) |
| 1230 | * --jimz |
| 1231 | */ |
| 1232 | #define NLOWPRIMES 8 |
| 1233 | static int lowprimes[NLOWPRIMES] = {2, 3, 5, 7, 11, 13, 17, 19}; |
| 1234 | /***************************************************************************** |
| 1235 | * compute the workload shift factor. (chained declustering) |
| 1236 | * |
| 1237 | * return nonzero if access should shift to secondary, otherwise, |
| 1238 | * access is to primary |
| 1239 | *****************************************************************************/ |
| 1240 | int |
| 1241 | rf_compute_workload_shift(RF_Raid_t *raidPtr, RF_PhysDiskAddr_t *pda) |
| 1242 | { |
| 1243 | /* |
| 1244 | * variables: |
| 1245 | * d = column of disk containing primary |
| 1246 | * f = column of failed disk |
| 1247 | * n = number of disks in array |
| 1248 | * sd = "shift distance" (number of columns that d is to the right of f) |
| 1249 | * v = numerator of redirection ratio |
| 1250 | * k = denominator of redirection ratio |
| 1251 | */ |
| 1252 | RF_RowCol_t d, f, sd, n; |
| 1253 | int k, v, ret, i; |
| 1254 | |
| 1255 | n = raidPtr->numCol; |
| 1256 | |
| 1257 | /* assign column of primary copy to d */ |
| 1258 | d = pda->col; |
| 1259 | |
| 1260 | /* assign column of dead disk to f */ |
| 1261 | for (f = 0; ((!RF_DEAD_DISK(raidPtr->Disks[f].status)) && (f < n)); f++) |
| 1262 | continue; |
| 1263 | |
| 1264 | RF_ASSERT(f < n); |
| 1265 | RF_ASSERT(f != d); |
| 1266 | |
| 1267 | sd = (f > d) ? (n + d - f) : (d - f); |
| 1268 | RF_ASSERT(sd < n); |
| 1269 | |
| 1270 | /* |
| 1271 | * v of every k accesses should be redirected |
| 1272 | * |
| 1273 | * v/k := (n-1-sd)/(n-1) |
| 1274 | */ |
| 1275 | v = (n - 1 - sd); |
| 1276 | k = (n - 1); |
| 1277 | |
| 1278 | #if 1 |
| 1279 | /* |
| 1280 | * XXX |
| 1281 | * Is this worth it? |
| 1282 | * |
| 1283 | * Now reduce the fraction, by repeatedly factoring |
| 1284 | * out primes (just like they teach in elementary school!) |
| 1285 | */ |
| 1286 | for (i = 0; i < NLOWPRIMES; i++) { |
| 1287 | if (lowprimes[i] > v) |
| 1288 | break; |
| 1289 | while (((v % lowprimes[i]) == 0) && ((k % lowprimes[i]) == 0)) { |
| 1290 | v /= lowprimes[i]; |
| 1291 | k /= lowprimes[i]; |
| 1292 | } |
| 1293 | } |
| 1294 | #endif |
| 1295 | |
| 1296 | raidPtr->hist_diskreq[d]++; |
| 1297 | if (raidPtr->hist_diskreq[d] > v) { |
| 1298 | ret = 0; /* do not redirect */ |
| 1299 | } else { |
| 1300 | ret = 1; /* redirect */ |
| 1301 | } |
| 1302 | |
| 1303 | #if 0 |
| 1304 | printf("d=%d f=%d sd=%d v=%d k=%d ret=%d h=%d\n" , d, f, sd, v, k, ret, |
| 1305 | raidPtr->hist_diskreq[d]); |
| 1306 | #endif |
| 1307 | |
| 1308 | if (raidPtr->hist_diskreq[d] >= k) { |
| 1309 | /* reset counter */ |
| 1310 | raidPtr->hist_diskreq[d] = 0; |
| 1311 | } |
| 1312 | return (ret); |
| 1313 | } |
| 1314 | #endif /* (RF_INCLUDE_CHAINDECLUSTER > 0) */ |
| 1315 | |
| 1316 | /* |
| 1317 | * Disk selection routines |
| 1318 | */ |
| 1319 | |
| 1320 | /* |
| 1321 | * Selects the disk with the shortest queue from a mirror pair. |
| 1322 | * Both the disk I/Os queued in RAIDframe as well as those at the physical |
| 1323 | * disk are counted as members of the "queue" |
| 1324 | */ |
| 1325 | void |
| 1326 | rf_SelectMirrorDiskIdle(RF_DagNode_t * node) |
| 1327 | { |
| 1328 | RF_Raid_t *raidPtr = (RF_Raid_t *) node->dagHdr->raidPtr; |
| 1329 | RF_RowCol_t colData, colMirror; |
| 1330 | int dataQueueLength, mirrorQueueLength, usemirror; |
| 1331 | RF_PhysDiskAddr_t *data_pda = (RF_PhysDiskAddr_t *) node->params[0].p; |
| 1332 | RF_PhysDiskAddr_t *mirror_pda = (RF_PhysDiskAddr_t *) node->params[4].p; |
| 1333 | RF_PhysDiskAddr_t *tmp_pda; |
| 1334 | RF_RaidDisk_t *disks = raidPtr->Disks; |
| 1335 | RF_DiskQueue_t *dqs = raidPtr->Queues, *dataQueue, *mirrorQueue; |
| 1336 | |
| 1337 | /* return the [row col] of the disk with the shortest queue */ |
| 1338 | colData = data_pda->col; |
| 1339 | colMirror = mirror_pda->col; |
| 1340 | dataQueue = &(dqs[colData]); |
| 1341 | mirrorQueue = &(dqs[colMirror]); |
| 1342 | |
| 1343 | #ifdef RF_LOCK_QUEUES_TO_READ_LEN |
| 1344 | RF_LOCK_QUEUE_MUTEX(dataQueue, "SelectMirrorDiskIdle" ); |
| 1345 | #endif /* RF_LOCK_QUEUES_TO_READ_LEN */ |
| 1346 | dataQueueLength = dataQueue->queueLength + dataQueue->numOutstanding; |
| 1347 | #ifdef RF_LOCK_QUEUES_TO_READ_LEN |
| 1348 | RF_UNLOCK_QUEUE_MUTEX(dataQueue, "SelectMirrorDiskIdle" ); |
| 1349 | RF_LOCK_QUEUE_MUTEX(mirrorQueue, "SelectMirrorDiskIdle" ); |
| 1350 | #endif /* RF_LOCK_QUEUES_TO_READ_LEN */ |
| 1351 | mirrorQueueLength = mirrorQueue->queueLength + mirrorQueue->numOutstanding; |
| 1352 | #ifdef RF_LOCK_QUEUES_TO_READ_LEN |
| 1353 | RF_UNLOCK_QUEUE_MUTEX(mirrorQueue, "SelectMirrorDiskIdle" ); |
| 1354 | #endif /* RF_LOCK_QUEUES_TO_READ_LEN */ |
| 1355 | |
| 1356 | usemirror = 0; |
| 1357 | if (RF_DEAD_DISK(disks[colMirror].status)) { |
| 1358 | usemirror = 0; |
| 1359 | } else |
| 1360 | if (RF_DEAD_DISK(disks[colData].status)) { |
| 1361 | usemirror = 1; |
| 1362 | } else |
| 1363 | if (raidPtr->parity_good == RF_RAID_DIRTY) { |
| 1364 | /* Trust only the main disk */ |
| 1365 | usemirror = 0; |
| 1366 | } else |
| 1367 | if (dataQueueLength < mirrorQueueLength) { |
| 1368 | usemirror = 0; |
| 1369 | } else |
| 1370 | if (mirrorQueueLength < dataQueueLength) { |
| 1371 | usemirror = 1; |
| 1372 | } else { |
| 1373 | /* queues are equal length. attempt |
| 1374 | * cleverness. */ |
| 1375 | if (SNUM_DIFF(dataQueue->last_deq_sector, data_pda->startSector) |
| 1376 | <= SNUM_DIFF(mirrorQueue->last_deq_sector, mirror_pda->startSector)) { |
| 1377 | usemirror = 0; |
| 1378 | } else { |
| 1379 | usemirror = 1; |
| 1380 | } |
| 1381 | } |
| 1382 | |
| 1383 | if (usemirror) { |
| 1384 | /* use mirror (parity) disk, swap params 0 & 4 */ |
| 1385 | tmp_pda = data_pda; |
| 1386 | node->params[0].p = mirror_pda; |
| 1387 | node->params[4].p = tmp_pda; |
| 1388 | } else { |
| 1389 | /* use data disk, leave param 0 unchanged */ |
| 1390 | } |
| 1391 | /* printf("dataQueueLength %d, mirrorQueueLength |
| 1392 | * %d\n",dataQueueLength, mirrorQueueLength); */ |
| 1393 | } |
| 1394 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) || (RF_INCLUDE_INTERDECLUSTER > 0) || (RF_DEBUG_VALIDATE_DAG > 0) |
| 1395 | /* |
| 1396 | * Do simple partitioning. This assumes that |
| 1397 | * the data and parity disks are laid out identically. |
| 1398 | */ |
| 1399 | void |
| 1400 | rf_SelectMirrorDiskPartition(RF_DagNode_t * node) |
| 1401 | { |
| 1402 | RF_Raid_t *raidPtr = (RF_Raid_t *) node->dagHdr->raidPtr; |
| 1403 | RF_RowCol_t colData, colMirror; |
| 1404 | RF_PhysDiskAddr_t *data_pda = (RF_PhysDiskAddr_t *) node->params[0].p; |
| 1405 | RF_PhysDiskAddr_t *mirror_pda = (RF_PhysDiskAddr_t *) node->params[4].p; |
| 1406 | RF_PhysDiskAddr_t *tmp_pda; |
| 1407 | RF_RaidDisk_t *disks = raidPtr->Disks; |
| 1408 | int usemirror; |
| 1409 | |
| 1410 | /* return the [row col] of the disk with the shortest queue */ |
| 1411 | colData = data_pda->col; |
| 1412 | colMirror = mirror_pda->col; |
| 1413 | |
| 1414 | usemirror = 0; |
| 1415 | if (RF_DEAD_DISK(disks[colMirror].status)) { |
| 1416 | usemirror = 0; |
| 1417 | } else |
| 1418 | if (RF_DEAD_DISK(disks[colData].status)) { |
| 1419 | usemirror = 1; |
| 1420 | } else |
| 1421 | if (raidPtr->parity_good == RF_RAID_DIRTY) { |
| 1422 | /* Trust only the main disk */ |
| 1423 | usemirror = 0; |
| 1424 | } else |
| 1425 | if (data_pda->startSector < |
| 1426 | (disks[colData].numBlocks / 2)) { |
| 1427 | usemirror = 0; |
| 1428 | } else { |
| 1429 | usemirror = 1; |
| 1430 | } |
| 1431 | |
| 1432 | if (usemirror) { |
| 1433 | /* use mirror (parity) disk, swap params 0 & 4 */ |
| 1434 | tmp_pda = data_pda; |
| 1435 | node->params[0].p = mirror_pda; |
| 1436 | node->params[4].p = tmp_pda; |
| 1437 | } else { |
| 1438 | /* use data disk, leave param 0 unchanged */ |
| 1439 | } |
| 1440 | } |
| 1441 | #endif |
| 1442 | |