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rf_parityloggingdags.c revision 1.4.6.4
      1 /*	$NetBSD: rf_parityloggingdags.c,v 1.4.6.4 2002/08/13 02:19:55 nathanw Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: 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 (at) 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   DAGs specific to parity logging are created here
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __KERNEL_RCSID(0, "$NetBSD: rf_parityloggingdags.c,v 1.4.6.4 2002/08/13 02:19:55 nathanw Exp $");
     35 
     36 #include "rf_archs.h"
     37 
     38 #if RF_INCLUDE_PARITYLOGGING > 0
     39 
     40 #include <dev/raidframe/raidframevar.h>
     41 
     42 #include "rf_raid.h"
     43 #include "rf_dag.h"
     44 #include "rf_dagutils.h"
     45 #include "rf_dagfuncs.h"
     46 #include "rf_debugMem.h"
     47 #include "rf_paritylog.h"
     48 #include "rf_general.h"
     49 
     50 #include "rf_parityloggingdags.h"
     51 
     52 /******************************************************************************
     53  *
     54  * creates a DAG to perform a large-write operation:
     55  *
     56  *         / Rod \     / Wnd \
     57  * H -- NIL- Rod - NIL - Wnd ------ NIL - T
     58  *         \ Rod /     \ Xor - Lpo /
     59  *
     60  * The writes are not done until the reads complete because if they were done in
     61  * parallel, a failure on one of the reads could leave the parity in an inconsistent
     62  * state, so that the retry with a new DAG would produce erroneous parity.
     63  *
     64  * Note:  this DAG has the nasty property that none of the buffers allocated for reading
     65  *        old data can be freed until the XOR node fires.  Need to fix this.
     66  *
     67  * The last two arguments are the number of faults tolerated, and function for the
     68  * redundancy calculation. The undo for the redundancy calc is assumed to be null
     69  *
     70  *****************************************************************************/
     71 
     72 void
     73 rf_CommonCreateParityLoggingLargeWriteDAG(
     74     RF_Raid_t * raidPtr,
     75     RF_AccessStripeMap_t * asmap,
     76     RF_DagHeader_t * dag_h,
     77     void *bp,
     78     RF_RaidAccessFlags_t flags,
     79     RF_AllocListElem_t * allocList,
     80     int nfaults,
     81     int (*redFunc) (RF_DagNode_t *))
     82 {
     83 	RF_DagNode_t *nodes, *wndNodes, *rodNodes = NULL, *syncNode, *xorNode,
     84 	       *lpoNode, *blockNode, *unblockNode, *termNode;
     85 	int     nWndNodes, nRodNodes, i;
     86 	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
     87 	RF_AccessStripeMapHeader_t *new_asm_h[2];
     88 	int     nodeNum, asmNum;
     89 	RF_ReconUnitNum_t which_ru;
     90 	char   *sosBuffer, *eosBuffer;
     91 	RF_PhysDiskAddr_t *pda;
     92 	RF_StripeNum_t parityStripeID = rf_RaidAddressToParityStripeID(&(raidPtr->Layout), asmap->raidAddress, &which_ru);
     93 
     94 	if (rf_dagDebug)
     95 		printf("[Creating parity-logging large-write DAG]\n");
     96 	RF_ASSERT(nfaults == 1);/* this arch only single fault tolerant */
     97 	dag_h->creator = "ParityLoggingLargeWriteDAG";
     98 
     99 	/* alloc the Wnd nodes, the xor node, and the Lpo node */
    100 	nWndNodes = asmap->numStripeUnitsAccessed;
    101 	RF_CallocAndAdd(nodes, nWndNodes + 6, sizeof(RF_DagNode_t), (RF_DagNode_t *), allocList);
    102 	i = 0;
    103 	wndNodes = &nodes[i];
    104 	i += nWndNodes;
    105 	xorNode = &nodes[i];
    106 	i += 1;
    107 	lpoNode = &nodes[i];
    108 	i += 1;
    109 	blockNode = &nodes[i];
    110 	i += 1;
    111 	syncNode = &nodes[i];
    112 	i += 1;
    113 	unblockNode = &nodes[i];
    114 	i += 1;
    115 	termNode = &nodes[i];
    116 	i += 1;
    117 
    118 	dag_h->numCommitNodes = nWndNodes + 1;
    119 	dag_h->numCommits = 0;
    120 	dag_h->numSuccedents = 1;
    121 
    122 	rf_MapUnaccessedPortionOfStripe(raidPtr, layoutPtr, asmap, dag_h, new_asm_h, &nRodNodes, &sosBuffer, &eosBuffer, allocList);
    123 	if (nRodNodes > 0)
    124 		RF_CallocAndAdd(rodNodes, nRodNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *), allocList);
    125 
    126 	/* begin node initialization */
    127 	rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nRodNodes + 1, 0, 0, 0, dag_h, "Nil", allocList);
    128 	rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, nWndNodes + 1, 0, 0, dag_h, "Nil", allocList);
    129 	rf_InitNode(syncNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nWndNodes + 1, nRodNodes + 1, 0, 0, dag_h, "Nil", allocList);
    130 	rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
    131 
    132 	/* initialize the Rod nodes */
    133 	for (nodeNum = asmNum = 0; asmNum < 2; asmNum++) {
    134 		if (new_asm_h[asmNum]) {
    135 			pda = new_asm_h[asmNum]->stripeMap->physInfo;
    136 			while (pda) {
    137 				rf_InitNode(&rodNodes[nodeNum], rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Rod", allocList);
    138 				rodNodes[nodeNum].params[0].p = pda;
    139 				rodNodes[nodeNum].params[1].p = pda->bufPtr;
    140 				rodNodes[nodeNum].params[2].v = parityStripeID;
    141 				rodNodes[nodeNum].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
    142 				nodeNum++;
    143 				pda = pda->next;
    144 			}
    145 		}
    146 	}
    147 	RF_ASSERT(nodeNum == nRodNodes);
    148 
    149 	/* initialize the wnd nodes */
    150 	pda = asmap->physInfo;
    151 	for (i = 0; i < nWndNodes; i++) {
    152 		rf_InitNode(&wndNodes[i], rf_wait, RF_TRUE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Wnd", allocList);
    153 		RF_ASSERT(pda != NULL);
    154 		wndNodes[i].params[0].p = pda;
    155 		wndNodes[i].params[1].p = pda->bufPtr;
    156 		wndNodes[i].params[2].v = parityStripeID;
    157 		wndNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
    158 		pda = pda->next;
    159 	}
    160 
    161 	/* initialize the redundancy node */
    162 	rf_InitNode(xorNode, rf_wait, RF_TRUE, redFunc, rf_NullNodeUndoFunc, NULL, 1, 1, 2 * (nWndNodes + nRodNodes) + 1, 1, dag_h, "Xr ", allocList);
    163 	xorNode->flags |= RF_DAGNODE_FLAG_YIELD;
    164 	for (i = 0; i < nWndNodes; i++) {
    165 		xorNode->params[2 * i + 0] = wndNodes[i].params[0];	/* pda */
    166 		xorNode->params[2 * i + 1] = wndNodes[i].params[1];	/* buf ptr */
    167 	}
    168 	for (i = 0; i < nRodNodes; i++) {
    169 		xorNode->params[2 * (nWndNodes + i) + 0] = rodNodes[i].params[0];	/* pda */
    170 		xorNode->params[2 * (nWndNodes + i) + 1] = rodNodes[i].params[1];	/* buf ptr */
    171 	}
    172 	xorNode->params[2 * (nWndNodes + nRodNodes)].p = raidPtr;	/* xor node needs to get
    173 									 * at RAID information */
    174 
    175 	/* look for an Rod node that reads a complete SU.  If none, alloc a
    176 	 * buffer to receive the parity info. Note that we can't use a new
    177 	 * data buffer because it will not have gotten written when the xor
    178 	 * occurs. */
    179 	for (i = 0; i < nRodNodes; i++)
    180 		if (((RF_PhysDiskAddr_t *) rodNodes[i].params[0].p)->numSector == raidPtr->Layout.sectorsPerStripeUnit)
    181 			break;
    182 	if (i == nRodNodes) {
    183 		RF_CallocAndAdd(xorNode->results[0], 1, rf_RaidAddressToByte(raidPtr, raidPtr->Layout.sectorsPerStripeUnit), (void *), allocList);
    184 	} else {
    185 		xorNode->results[0] = rodNodes[i].params[1].p;
    186 	}
    187 
    188 	/* initialize the Lpo node */
    189 	rf_InitNode(lpoNode, rf_wait, RF_FALSE, rf_ParityLogOverwriteFunc, rf_ParityLogOverwriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 2, 0, dag_h, "Lpo", allocList);
    190 
    191 	lpoNode->params[0].p = asmap->parityInfo;
    192 	lpoNode->params[1].p = xorNode->results[0];
    193 	RF_ASSERT(asmap->parityInfo->next == NULL);	/* parityInfo must
    194 							 * describe entire
    195 							 * parity unit */
    196 
    197 	/* connect nodes to form graph */
    198 
    199 	/* connect dag header to block node */
    200 	RF_ASSERT(dag_h->numSuccedents == 1);
    201 	RF_ASSERT(blockNode->numAntecedents == 0);
    202 	dag_h->succedents[0] = blockNode;
    203 
    204 	/* connect the block node to the Rod nodes */
    205 	RF_ASSERT(blockNode->numSuccedents == nRodNodes + 1);
    206 	for (i = 0; i < nRodNodes; i++) {
    207 		RF_ASSERT(rodNodes[i].numAntecedents == 1);
    208 		blockNode->succedents[i] = &rodNodes[i];
    209 		rodNodes[i].antecedents[0] = blockNode;
    210 		rodNodes[i].antType[0] = rf_control;
    211 	}
    212 
    213 	/* connect the block node to the sync node */
    214 	/* necessary if nRodNodes == 0 */
    215 	RF_ASSERT(syncNode->numAntecedents == nRodNodes + 1);
    216 	blockNode->succedents[nRodNodes] = syncNode;
    217 	syncNode->antecedents[0] = blockNode;
    218 	syncNode->antType[0] = rf_control;
    219 
    220 	/* connect the Rod nodes to the syncNode */
    221 	for (i = 0; i < nRodNodes; i++) {
    222 		rodNodes[i].succedents[0] = syncNode;
    223 		syncNode->antecedents[1 + i] = &rodNodes[i];
    224 		syncNode->antType[1 + i] = rf_control;
    225 	}
    226 
    227 	/* connect the sync node to the xor node */
    228 	RF_ASSERT(syncNode->numSuccedents == nWndNodes + 1);
    229 	RF_ASSERT(xorNode->numAntecedents == 1);
    230 	syncNode->succedents[0] = xorNode;
    231 	xorNode->antecedents[0] = syncNode;
    232 	xorNode->antType[0] = rf_trueData;	/* carry forward from sync */
    233 
    234 	/* connect the sync node to the Wnd nodes */
    235 	for (i = 0; i < nWndNodes; i++) {
    236 		RF_ASSERT(wndNodes->numAntecedents == 1);
    237 		syncNode->succedents[1 + i] = &wndNodes[i];
    238 		wndNodes[i].antecedents[0] = syncNode;
    239 		wndNodes[i].antType[0] = rf_control;
    240 	}
    241 
    242 	/* connect the xor node to the Lpo node */
    243 	RF_ASSERT(xorNode->numSuccedents == 1);
    244 	RF_ASSERT(lpoNode->numAntecedents == 1);
    245 	xorNode->succedents[0] = lpoNode;
    246 	lpoNode->antecedents[0] = xorNode;
    247 	lpoNode->antType[0] = rf_trueData;
    248 
    249 	/* connect the Wnd nodes to the unblock node */
    250 	RF_ASSERT(unblockNode->numAntecedents == nWndNodes + 1);
    251 	for (i = 0; i < nWndNodes; i++) {
    252 		RF_ASSERT(wndNodes->numSuccedents == 1);
    253 		wndNodes[i].succedents[0] = unblockNode;
    254 		unblockNode->antecedents[i] = &wndNodes[i];
    255 		unblockNode->antType[i] = rf_control;
    256 	}
    257 
    258 	/* connect the Lpo node to the unblock node */
    259 	RF_ASSERT(lpoNode->numSuccedents == 1);
    260 	lpoNode->succedents[0] = unblockNode;
    261 	unblockNode->antecedents[nWndNodes] = lpoNode;
    262 	unblockNode->antType[nWndNodes] = rf_control;
    263 
    264 	/* connect unblock node to terminator */
    265 	RF_ASSERT(unblockNode->numSuccedents == 1);
    266 	RF_ASSERT(termNode->numAntecedents == 1);
    267 	RF_ASSERT(termNode->numSuccedents == 0);
    268 	unblockNode->succedents[0] = termNode;
    269 	termNode->antecedents[0] = unblockNode;
    270 	termNode->antType[0] = rf_control;
    271 }
    272 
    273 
    274 
    275 
    276 /******************************************************************************
    277  *
    278  * creates a DAG to perform a small-write operation (either raid 5 or pq), which is as follows:
    279  *
    280  *                                     Header
    281  *                                       |
    282  *                                     Block
    283  *                                 / |  ... \   \
    284  *                                /  |       \   \
    285  *                             Rod  Rod      Rod  Rop
    286  *                             | \ /| \    / |  \/ |
    287  *                             |    |        |  /\ |
    288  *                             Wnd  Wnd      Wnd   X
    289  *                              |    \       /     |
    290  *                              |     \     /      |
    291  *                               \     \   /      Lpo
    292  *                                \     \ /       /
    293  *                                 +-> Unblock <-+
    294  *                                       |
    295  *                                       T
    296  *
    297  *
    298  * R = Read, W = Write, X = Xor, o = old, n = new, d = data, p = parity.
    299  * When the access spans a stripe unit boundary and is less than one SU in size, there will
    300  * be two Rop -- X -- Wnp branches.  I call this the "double-XOR" case.
    301  * The second output from each Rod node goes to the X node.  In the double-XOR
    302  * case, there are exactly 2 Rod nodes, and each sends one output to one X node.
    303  * There is one Rod -- Wnd -- T branch for each stripe unit being updated.
    304  *
    305  * The block and unblock nodes are unused.  See comment above CreateFaultFreeReadDAG.
    306  *
    307  * Note:  this DAG ignores all the optimizations related to making the RMWs atomic.
    308  *        it also has the nasty property that none of the buffers allocated for reading
    309  *        old data & parity can be freed until the XOR node fires.  Need to fix this.
    310  *
    311  * A null qfuncs indicates single fault tolerant
    312  *****************************************************************************/
    313 
    314 void
    315 rf_CommonCreateParityLoggingSmallWriteDAG(
    316     RF_Raid_t * raidPtr,
    317     RF_AccessStripeMap_t * asmap,
    318     RF_DagHeader_t * dag_h,
    319     void *bp,
    320     RF_RaidAccessFlags_t flags,
    321     RF_AllocListElem_t * allocList,
    322     RF_RedFuncs_t * pfuncs,
    323     RF_RedFuncs_t * qfuncs)
    324 {
    325 	RF_DagNode_t *xorNodes, *blockNode, *unblockNode, *nodes;
    326 	RF_DagNode_t *readDataNodes, *readParityNodes;
    327 	RF_DagNode_t *writeDataNodes, *lpuNodes;
    328 	RF_DagNode_t *unlockDataNodes = NULL, *termNode;
    329 	RF_PhysDiskAddr_t *pda = asmap->physInfo;
    330 	int     numDataNodes = asmap->numStripeUnitsAccessed;
    331 	int     numParityNodes = (asmap->parityInfo->next) ? 2 : 1;
    332 	int     i, j, nNodes, totalNumNodes;
    333 	RF_ReconUnitNum_t which_ru;
    334 	int     (*func) (RF_DagNode_t * node), (*undoFunc) (RF_DagNode_t * node);
    335 	int     (*qfunc) (RF_DagNode_t * node);
    336 	char   *name, *qname;
    337 	RF_StripeNum_t parityStripeID = rf_RaidAddressToParityStripeID(&(raidPtr->Layout), asmap->raidAddress, &which_ru);
    338 #ifdef RAID_DIAGNOSTIC
    339 	long    nfaults = qfuncs ? 2 : 1;
    340 #endif /* RAID_DIAGNOSTIC */
    341 	int     lu_flag = (rf_enableAtomicRMW) ? 1 : 0;	/* lock/unlock flag */
    342 
    343 	if (rf_dagDebug)
    344 		printf("[Creating parity-logging small-write DAG]\n");
    345 	RF_ASSERT(numDataNodes > 0);
    346 	RF_ASSERT(nfaults == 1);
    347 	dag_h->creator = "ParityLoggingSmallWriteDAG";
    348 
    349 	/* DAG creation occurs in three steps: 1. count the number of nodes in
    350 	 * the DAG 2. create the nodes 3. initialize the nodes 4. connect the
    351 	 * nodes */
    352 
    353 	/* Step 1. compute number of nodes in the graph */
    354 
    355 	/* number of nodes: a read and write for each data unit a redundancy
    356 	 * computation node for each parity node a read and Lpu for each
    357 	 * parity unit a block and unblock node (2) a terminator node if
    358 	 * atomic RMW an unlock node for each data unit, redundancy unit */
    359 	totalNumNodes = (2 * numDataNodes) + numParityNodes + (2 * numParityNodes) + 3;
    360 	if (lu_flag)
    361 		totalNumNodes += numDataNodes;
    362 
    363 	nNodes = numDataNodes + numParityNodes;
    364 
    365 	dag_h->numCommitNodes = numDataNodes + numParityNodes;
    366 	dag_h->numCommits = 0;
    367 	dag_h->numSuccedents = 1;
    368 
    369 	/* Step 2. create the nodes */
    370 	RF_CallocAndAdd(nodes, totalNumNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *), allocList);
    371 	i = 0;
    372 	blockNode = &nodes[i];
    373 	i += 1;
    374 	unblockNode = &nodes[i];
    375 	i += 1;
    376 	readDataNodes = &nodes[i];
    377 	i += numDataNodes;
    378 	readParityNodes = &nodes[i];
    379 	i += numParityNodes;
    380 	writeDataNodes = &nodes[i];
    381 	i += numDataNodes;
    382 	lpuNodes = &nodes[i];
    383 	i += numParityNodes;
    384 	xorNodes = &nodes[i];
    385 	i += numParityNodes;
    386 	termNode = &nodes[i];
    387 	i += 1;
    388 	if (lu_flag) {
    389 		unlockDataNodes = &nodes[i];
    390 		i += numDataNodes;
    391 	}
    392 	RF_ASSERT(i == totalNumNodes);
    393 
    394 	/* Step 3. initialize the nodes */
    395 	/* initialize block node (Nil) */
    396 	rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nNodes, 0, 0, 0, dag_h, "Nil", allocList);
    397 
    398 	/* initialize unblock node (Nil) */
    399 	rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, nNodes, 0, 0, dag_h, "Nil", allocList);
    400 
    401 	/* initialize terminatory node (Trm) */
    402 	rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList);
    403 
    404 	/* initialize nodes which read old data (Rod) */
    405 	for (i = 0; i < numDataNodes; i++) {
    406 		rf_InitNode(&readDataNodes[i], rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, nNodes, 1, 4, 0, dag_h, "Rod", allocList);
    407 		RF_ASSERT(pda != NULL);
    408 		readDataNodes[i].params[0].p = pda;	/* physical disk addr
    409 							 * desc */
    410 		readDataNodes[i].params[1].p = rf_AllocBuffer(raidPtr, dag_h, pda, allocList);	/* buffer to hold old
    411 												 * data */
    412 		readDataNodes[i].params[2].v = parityStripeID;
    413 		readDataNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, lu_flag, 0, which_ru);
    414 		pda = pda->next;
    415 		readDataNodes[i].propList[0] = NULL;
    416 		readDataNodes[i].propList[1] = NULL;
    417 	}
    418 
    419 	/* initialize nodes which read old parity (Rop) */
    420 	pda = asmap->parityInfo;
    421 	i = 0;
    422 	for (i = 0; i < numParityNodes; i++) {
    423 		RF_ASSERT(pda != NULL);
    424 		rf_InitNode(&readParityNodes[i], rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, nNodes, 1, 4, 0, dag_h, "Rop", allocList);
    425 		readParityNodes[i].params[0].p = pda;
    426 		readParityNodes[i].params[1].p = rf_AllocBuffer(raidPtr, dag_h, pda, allocList);	/* buffer to hold old
    427 													 * parity */
    428 		readParityNodes[i].params[2].v = parityStripeID;
    429 		readParityNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
    430 		readParityNodes[i].propList[0] = NULL;
    431 		pda = pda->next;
    432 	}
    433 
    434 	/* initialize nodes which write new data (Wnd) */
    435 	pda = asmap->physInfo;
    436 	for (i = 0; i < numDataNodes; i++) {
    437 		RF_ASSERT(pda != NULL);
    438 		rf_InitNode(&writeDataNodes[i], rf_wait, RF_TRUE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, nNodes, 4, 0, dag_h, "Wnd", allocList);
    439 		writeDataNodes[i].params[0].p = pda;	/* physical disk addr
    440 							 * desc */
    441 		writeDataNodes[i].params[1].p = pda->bufPtr;	/* buffer holding new
    442 								 * data to be written */
    443 		writeDataNodes[i].params[2].v = parityStripeID;
    444 		writeDataNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
    445 
    446 		if (lu_flag) {
    447 			/* initialize node to unlock the disk queue */
    448 			rf_InitNode(&unlockDataNodes[i], rf_wait, RF_FALSE, rf_DiskUnlockFunc, rf_DiskUnlockUndoFunc, rf_GenericWakeupFunc, 1, 1, 2, 0, dag_h, "Und", allocList);
    449 			unlockDataNodes[i].params[0].p = pda;	/* physical disk addr
    450 								 * desc */
    451 			unlockDataNodes[i].params[1].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, lu_flag, which_ru);
    452 		}
    453 		pda = pda->next;
    454 	}
    455 
    456 
    457 	/* initialize nodes which compute new parity */
    458 	/* we use the simple XOR func in the double-XOR case, and when we're
    459 	 * accessing only a portion of one stripe unit. the distinction
    460 	 * between the two is that the regular XOR func assumes that the
    461 	 * targbuf is a full SU in size, and examines the pda associated with
    462 	 * the buffer to decide where within the buffer to XOR the data,
    463 	 * whereas the simple XOR func just XORs the data into the start of
    464 	 * the buffer. */
    465 	if ((numParityNodes == 2) || ((numDataNodes == 1) && (asmap->totalSectorsAccessed < raidPtr->Layout.sectorsPerStripeUnit))) {
    466 		func = pfuncs->simple;
    467 		undoFunc = rf_NullNodeUndoFunc;
    468 		name = pfuncs->SimpleName;
    469 		if (qfuncs) {
    470 			qfunc = qfuncs->simple;
    471 			qname = qfuncs->SimpleName;
    472 		}
    473 	} else {
    474 		func = pfuncs->regular;
    475 		undoFunc = rf_NullNodeUndoFunc;
    476 		name = pfuncs->RegularName;
    477 		if (qfuncs) {
    478 			qfunc = qfuncs->regular;
    479 			qname = qfuncs->RegularName;
    480 		}
    481 	}
    482 	/* initialize the xor nodes: params are {pda,buf} from {Rod,Wnd,Rop}
    483 	 * nodes, and raidPtr  */
    484 	if (numParityNodes == 2) {	/* double-xor case */
    485 		for (i = 0; i < numParityNodes; i++) {
    486 			rf_InitNode(&xorNodes[i], rf_wait, RF_TRUE, func, undoFunc, NULL, 1, nNodes, 7, 1, dag_h, name, allocList);	/* no wakeup func for
    487 																	 * xor */
    488 			xorNodes[i].flags |= RF_DAGNODE_FLAG_YIELD;
    489 			xorNodes[i].params[0] = readDataNodes[i].params[0];
    490 			xorNodes[i].params[1] = readDataNodes[i].params[1];
    491 			xorNodes[i].params[2] = readParityNodes[i].params[0];
    492 			xorNodes[i].params[3] = readParityNodes[i].params[1];
    493 			xorNodes[i].params[4] = writeDataNodes[i].params[0];
    494 			xorNodes[i].params[5] = writeDataNodes[i].params[1];
    495 			xorNodes[i].params[6].p = raidPtr;
    496 			xorNodes[i].results[0] = readParityNodes[i].params[1].p;	/* use old parity buf as
    497 											 * target buf */
    498 		}
    499 	} else {
    500 		/* there is only one xor node in this case */
    501 		rf_InitNode(&xorNodes[0], rf_wait, RF_TRUE, func, undoFunc, NULL, 1, nNodes, (2 * (numDataNodes + numDataNodes + 1) + 1), 1, dag_h, name, allocList);
    502 		xorNodes[0].flags |= RF_DAGNODE_FLAG_YIELD;
    503 		for (i = 0; i < numDataNodes + 1; i++) {
    504 			/* set up params related to Rod and Rop nodes */
    505 			xorNodes[0].params[2 * i + 0] = readDataNodes[i].params[0];	/* pda */
    506 			xorNodes[0].params[2 * i + 1] = readDataNodes[i].params[1];	/* buffer pointer */
    507 		}
    508 		for (i = 0; i < numDataNodes; i++) {
    509 			/* set up params related to Wnd and Wnp nodes */
    510 			xorNodes[0].params[2 * (numDataNodes + 1 + i) + 0] = writeDataNodes[i].params[0];	/* pda */
    511 			xorNodes[0].params[2 * (numDataNodes + 1 + i) + 1] = writeDataNodes[i].params[1];	/* buffer pointer */
    512 		}
    513 		xorNodes[0].params[2 * (numDataNodes + numDataNodes + 1)].p = raidPtr;	/* xor node needs to get
    514 											 * at RAID information */
    515 		xorNodes[0].results[0] = readParityNodes[0].params[1].p;
    516 	}
    517 
    518 	/* initialize the log node(s) */
    519 	pda = asmap->parityInfo;
    520 	for (i = 0; i < numParityNodes; i++) {
    521 		RF_ASSERT(pda);
    522 		rf_InitNode(&lpuNodes[i], rf_wait, RF_FALSE, rf_ParityLogUpdateFunc, rf_ParityLogUpdateUndoFunc, rf_GenericWakeupFunc, 1, 1, 2, 0, dag_h, "Lpu", allocList);
    523 		lpuNodes[i].params[0].p = pda;	/* PhysDiskAddr of parity */
    524 		lpuNodes[i].params[1].p = xorNodes[i].results[0];	/* buffer pointer to
    525 									 * parity */
    526 		pda = pda->next;
    527 	}
    528 
    529 
    530 	/* Step 4. connect the nodes */
    531 
    532 	/* connect header to block node */
    533 	RF_ASSERT(dag_h->numSuccedents == 1);
    534 	RF_ASSERT(blockNode->numAntecedents == 0);
    535 	dag_h->succedents[0] = blockNode;
    536 
    537 	/* connect block node to read old data nodes */
    538 	RF_ASSERT(blockNode->numSuccedents == (numDataNodes + numParityNodes));
    539 	for (i = 0; i < numDataNodes; i++) {
    540 		blockNode->succedents[i] = &readDataNodes[i];
    541 		RF_ASSERT(readDataNodes[i].numAntecedents == 1);
    542 		readDataNodes[i].antecedents[0] = blockNode;
    543 		readDataNodes[i].antType[0] = rf_control;
    544 	}
    545 
    546 	/* connect block node to read old parity nodes */
    547 	for (i = 0; i < numParityNodes; i++) {
    548 		blockNode->succedents[numDataNodes + i] = &readParityNodes[i];
    549 		RF_ASSERT(readParityNodes[i].numAntecedents == 1);
    550 		readParityNodes[i].antecedents[0] = blockNode;
    551 		readParityNodes[i].antType[0] = rf_control;
    552 	}
    553 
    554 	/* connect read old data nodes to write new data nodes */
    555 	for (i = 0; i < numDataNodes; i++) {
    556 		RF_ASSERT(readDataNodes[i].numSuccedents == numDataNodes + numParityNodes);
    557 		for (j = 0; j < numDataNodes; j++) {
    558 			RF_ASSERT(writeDataNodes[j].numAntecedents == numDataNodes + numParityNodes);
    559 			readDataNodes[i].succedents[j] = &writeDataNodes[j];
    560 			writeDataNodes[j].antecedents[i] = &readDataNodes[i];
    561 			if (i == j)
    562 				writeDataNodes[j].antType[i] = rf_antiData;
    563 			else
    564 				writeDataNodes[j].antType[i] = rf_control;
    565 		}
    566 	}
    567 
    568 	/* connect read old data nodes to xor nodes */
    569 	for (i = 0; i < numDataNodes; i++)
    570 		for (j = 0; j < numParityNodes; j++) {
    571 			RF_ASSERT(xorNodes[j].numAntecedents == numDataNodes + numParityNodes);
    572 			readDataNodes[i].succedents[numDataNodes + j] = &xorNodes[j];
    573 			xorNodes[j].antecedents[i] = &readDataNodes[i];
    574 			xorNodes[j].antType[i] = rf_trueData;
    575 		}
    576 
    577 	/* connect read old parity nodes to write new data nodes */
    578 	for (i = 0; i < numParityNodes; i++) {
    579 		RF_ASSERT(readParityNodes[i].numSuccedents == numDataNodes + numParityNodes);
    580 		for (j = 0; j < numDataNodes; j++) {
    581 			readParityNodes[i].succedents[j] = &writeDataNodes[j];
    582 			writeDataNodes[j].antecedents[numDataNodes + i] = &readParityNodes[i];
    583 			writeDataNodes[j].antType[numDataNodes + i] = rf_control;
    584 		}
    585 	}
    586 
    587 	/* connect read old parity nodes to xor nodes */
    588 	for (i = 0; i < numParityNodes; i++)
    589 		for (j = 0; j < numParityNodes; j++) {
    590 			readParityNodes[i].succedents[numDataNodes + j] = &xorNodes[j];
    591 			xorNodes[j].antecedents[numDataNodes + i] = &readParityNodes[i];
    592 			xorNodes[j].antType[numDataNodes + i] = rf_trueData;
    593 		}
    594 
    595 	/* connect xor nodes to write new parity nodes */
    596 	for (i = 0; i < numParityNodes; i++) {
    597 		RF_ASSERT(xorNodes[i].numSuccedents == 1);
    598 		RF_ASSERT(lpuNodes[i].numAntecedents == 1);
    599 		xorNodes[i].succedents[0] = &lpuNodes[i];
    600 		lpuNodes[i].antecedents[0] = &xorNodes[i];
    601 		lpuNodes[i].antType[0] = rf_trueData;
    602 	}
    603 
    604 	for (i = 0; i < numDataNodes; i++) {
    605 		if (lu_flag) {
    606 			/* connect write new data nodes to unlock nodes */
    607 			RF_ASSERT(writeDataNodes[i].numSuccedents == 1);
    608 			RF_ASSERT(unlockDataNodes[i].numAntecedents == 1);
    609 			writeDataNodes[i].succedents[0] = &unlockDataNodes[i];
    610 			unlockDataNodes[i].antecedents[0] = &writeDataNodes[i];
    611 			unlockDataNodes[i].antType[0] = rf_control;
    612 
    613 			/* connect unlock nodes to unblock node */
    614 			RF_ASSERT(unlockDataNodes[i].numSuccedents == 1);
    615 			RF_ASSERT(unblockNode->numAntecedents == (numDataNodes + (nfaults * numParityNodes)));
    616 			unlockDataNodes[i].succedents[0] = unblockNode;
    617 			unblockNode->antecedents[i] = &unlockDataNodes[i];
    618 			unblockNode->antType[i] = rf_control;
    619 		} else {
    620 			/* connect write new data nodes to unblock node */
    621 			RF_ASSERT(writeDataNodes[i].numSuccedents == 1);
    622 			RF_ASSERT(unblockNode->numAntecedents == (numDataNodes + (nfaults * numParityNodes)));
    623 			writeDataNodes[i].succedents[0] = unblockNode;
    624 			unblockNode->antecedents[i] = &writeDataNodes[i];
    625 			unblockNode->antType[i] = rf_control;
    626 		}
    627 	}
    628 
    629 	/* connect write new parity nodes to unblock node */
    630 	for (i = 0; i < numParityNodes; i++) {
    631 		RF_ASSERT(lpuNodes[i].numSuccedents == 1);
    632 		lpuNodes[i].succedents[0] = unblockNode;
    633 		unblockNode->antecedents[numDataNodes + i] = &lpuNodes[i];
    634 		unblockNode->antType[numDataNodes + i] = rf_control;
    635 	}
    636 
    637 	/* connect unblock node to terminator */
    638 	RF_ASSERT(unblockNode->numSuccedents == 1);
    639 	RF_ASSERT(termNode->numAntecedents == 1);
    640 	RF_ASSERT(termNode->numSuccedents == 0);
    641 	unblockNode->succedents[0] = termNode;
    642 	termNode->antecedents[0] = unblockNode;
    643 	termNode->antType[0] = rf_control;
    644 }
    645 
    646 
    647 void
    648 rf_CreateParityLoggingSmallWriteDAG(
    649     RF_Raid_t * raidPtr,
    650     RF_AccessStripeMap_t * asmap,
    651     RF_DagHeader_t * dag_h,
    652     void *bp,
    653     RF_RaidAccessFlags_t flags,
    654     RF_AllocListElem_t * allocList,
    655     RF_RedFuncs_t * pfuncs,
    656     RF_RedFuncs_t * qfuncs)
    657 {
    658 	dag_h->creator = "ParityLoggingSmallWriteDAG";
    659 	rf_CommonCreateParityLoggingSmallWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList, &rf_xorFuncs, NULL);
    660 }
    661 
    662 
    663 void
    664 rf_CreateParityLoggingLargeWriteDAG(
    665     RF_Raid_t * raidPtr,
    666     RF_AccessStripeMap_t * asmap,
    667     RF_DagHeader_t * dag_h,
    668     void *bp,
    669     RF_RaidAccessFlags_t flags,
    670     RF_AllocListElem_t * allocList,
    671     int nfaults,
    672     int (*redFunc) (RF_DagNode_t *))
    673 {
    674 	dag_h->creator = "ParityLoggingSmallWriteDAG";
    675 	rf_CommonCreateParityLoggingLargeWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList, 1, rf_RegularXorFunc);
    676 }
    677 #endif				/* RF_INCLUDE_PARITYLOGGING > 0 */
    678