/* $OpenBSD: rf_dagdegwr.c,v 1.2 1999/02/16 00:02:29 niklas Exp $ */ /* $NetBSD: rf_dagdegwr.c,v 1.3 1999/02/05 00:06:07 oster Exp $ */ /* * Copyright (c) 1995 Carnegie-Mellon University. * All rights reserved. * * Author: Mark Holland, Daniel Stodolsky, William V. Courtright II * * Permission to use, copy, modify and distribute this software and * its documentation is hereby granted, provided that both the copyright * notice and this permission notice appear in all copies of the * software, derivative works or modified versions, and any portions * thereof, and that both notices appear in supporting documentation. * * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. * * Carnegie Mellon requests users of this software to return to * * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU * School of Computer Science * Carnegie Mellon University * Pittsburgh PA 15213-3890 * * any improvements or extensions that they make and grant Carnegie the * rights to redistribute these changes. */ /* * rf_dagdegwr.c * * code for creating degraded write DAGs * */ #include "rf_types.h" #include "rf_raid.h" #include "rf_dag.h" #include "rf_dagutils.h" #include "rf_dagfuncs.h" #include "rf_threadid.h" #include "rf_debugMem.h" #include "rf_memchunk.h" #include "rf_general.h" #include "rf_dagdegwr.h" #include "rf_sys.h" /****************************************************************************** * * General comments on DAG creation: * * All DAGs in this file use roll-away error recovery. Each DAG has a single * commit node, usually called "Cmt." If an error occurs before the Cmt node * is reached, the execution engine will halt forward execution and work * backward through the graph, executing the undo functions. Assuming that * each node in the graph prior to the Cmt node are undoable and atomic - or - * does not make changes to permanent state, the graph will fail atomically. * If an error occurs after the Cmt node executes, the engine will roll-forward * through the graph, blindly executing nodes until it reaches the end. * If a graph reaches the end, it is assumed to have completed successfully. * * A graph has only 1 Cmt node. * */ /****************************************************************************** * * The following wrappers map the standard DAG creation interface to the * DAG creation routines. Additionally, these wrappers enable experimentation * with new DAG structures by providing an extra level of indirection, allowing * the DAG creation routines to be replaced at this single point. */ static RF_CREATE_DAG_FUNC_DECL(rf_CreateSimpleDegradedWriteDAG) { rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList, 1, rf_RecoveryXorFunc, RF_TRUE); } void rf_CreateDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList) RF_Raid_t *raidPtr; RF_AccessStripeMap_t *asmap; RF_DagHeader_t *dag_h; void *bp; RF_RaidAccessFlags_t flags; RF_AllocListElem_t *allocList; { RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); RF_PhysDiskAddr_t *failedPDA = asmap->failedPDAs[0]; RF_ASSERT(asmap->numDataFailed == 1); dag_h->creator = "DegradedWriteDAG"; /* if the access writes only a portion of the failed unit, and also * writes some portion of at least one surviving unit, we create two * DAGs, one for the failed component and one for the non-failed * component, and do them sequentially. Note that the fact that we're * accessing only a portion of the failed unit indicates that the * access either starts or ends in the failed unit, and hence we need * create only two dags. This is inefficient in that the same data or * parity can get read and written twice using this structure. I need * to fix this to do the access all at once. */ RF_ASSERT(!(asmap->numStripeUnitsAccessed != 1 && failedPDA->numSector != layoutPtr->sectorsPerStripeUnit)); rf_CreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList); } /****************************************************************************** * * DAG creation code begins here */ /****************************************************************************** * * CommonCreateSimpleDegradedWriteDAG -- creates a DAG to do a degraded-mode * write, which is as follows * * / {Wnq} --\ * hdr -> blockNode -> Rod -> Xor -> Cmt -> Wnp ----> unblock -> term * \ {Rod} / \ Wnd ---/ * \ {Wnd} -/ * * commit nodes: Xor, Wnd * * IMPORTANT: * This DAG generator does not work for double-degraded archs since it does not * generate Q * * This dag is essentially identical to the large-write dag, except that the * write to the failed data unit is suppressed. * * IMPORTANT: this dag does not work in the case where the access writes only * a portion of the failed unit, and also writes some portion of at least one * surviving SU. this case is handled in CreateDegradedWriteDAG above. * * The block & unblock nodes are leftovers from a previous version. They * do nothing, but I haven't deleted them because it would be a tremendous * effort to put them back in. * * This dag is used whenever a one of the data units in a write has failed. * If it is the parity unit that failed, the nonredundant write dag (below) * is used. *****************************************************************************/ void rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList, nfaults, redFunc, allowBufferRecycle) RF_Raid_t *raidPtr; RF_AccessStripeMap_t *asmap; RF_DagHeader_t *dag_h; void *bp; RF_RaidAccessFlags_t flags; RF_AllocListElem_t *allocList; int nfaults; int (*redFunc) (RF_DagNode_t *); int allowBufferRecycle; { int nNodes, nRrdNodes, nWndNodes, nXorBufs, i, j, paramNum, rdnodesFaked; RF_DagNode_t *blockNode, *unblockNode, *wnpNode, *wnqNode, *termNode; RF_DagNode_t *nodes, *wndNodes, *rrdNodes, *xorNode, *commitNode; RF_SectorCount_t sectorsPerSU; RF_ReconUnitNum_t which_ru; char *xorTargetBuf = NULL; /* the target buffer for the XOR * operation */ char *overlappingPDAs;/* a temporary array of flags */ RF_AccessStripeMapHeader_t *new_asm_h[2]; RF_PhysDiskAddr_t *pda, *parityPDA; RF_StripeNum_t parityStripeID; RF_PhysDiskAddr_t *failedPDA; RF_RaidLayout_t *layoutPtr; layoutPtr = &(raidPtr->Layout); parityStripeID = rf_RaidAddressToParityStripeID(layoutPtr, asmap->raidAddress, &which_ru); sectorsPerSU = layoutPtr->sectorsPerStripeUnit; /* failedPDA points to the pda within the asm that targets the failed * disk */ failedPDA = asmap->failedPDAs[0]; if (rf_dagDebug) printf("[Creating degraded-write DAG]\n"); RF_ASSERT(asmap->numDataFailed == 1); dag_h->creator = "SimpleDegradedWriteDAG"; /* * Generate two ASMs identifying the surviving data * we need in order to recover the lost data. */ /* overlappingPDAs array must be zero'd */ RF_Calloc(overlappingPDAs, asmap->numStripeUnitsAccessed, sizeof(char), (char *)); rf_GenerateFailedAccessASMs(raidPtr, asmap, failedPDA, dag_h, new_asm_h, &nXorBufs, NULL, overlappingPDAs, allocList); /* create all the nodes at once */ nWndNodes = asmap->numStripeUnitsAccessed - 1; /* no access is * generated for the * failed pda */ nRrdNodes = ((new_asm_h[0]) ? new_asm_h[0]->stripeMap->numStripeUnitsAccessed : 0) + ((new_asm_h[1]) ? new_asm_h[1]->stripeMap->numStripeUnitsAccessed : 0); /* * XXX * * There's a bug with a complete stripe overwrite- that means 0 reads * of old data, and the rest of the DAG generation code doesn't like * that. A release is coming, and I don't wanna risk breaking a critical * DAG generator, so here's what I'm gonna do- if there's no read nodes, * I'm gonna fake there being a read node, and I'm gonna swap in a * no-op node in its place (to make all the link-up code happy). * This should be fixed at some point. --jimz */ if (nRrdNodes == 0) { nRrdNodes = 1; rdnodesFaked = 1; } else { rdnodesFaked = 0; } /* lock, unlock, xor, Wnd, Rrd, W(nfaults) */ nNodes = 5 + nfaults + nWndNodes + nRrdNodes; RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *), allocList); i = 0; blockNode = &nodes[i]; i += 1; commitNode = &nodes[i]; i += 1; unblockNode = &nodes[i]; i += 1; termNode = &nodes[i]; i += 1; xorNode = &nodes[i]; i += 1; wnpNode = &nodes[i]; i += 1; wndNodes = &nodes[i]; i += nWndNodes; rrdNodes = &nodes[i]; i += nRrdNodes; if (nfaults == 2) { wnqNode = &nodes[i]; i += 1; } else { wnqNode = NULL; } RF_ASSERT(i == nNodes); /* this dag can not commit until all rrd and xor Nodes have completed */ dag_h->numCommitNodes = 1; dag_h->numCommits = 0; dag_h->numSuccedents = 1; RF_ASSERT(nRrdNodes > 0); rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nRrdNodes, 0, 0, 0, dag_h, "Nil", allocList); rf_InitNode(commitNode, rf_wait, RF_TRUE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nWndNodes + nfaults, 1, 0, 0, dag_h, "Cmt", allocList); rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, nWndNodes + nfaults, 0, 0, dag_h, "Nil", allocList); rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList); rf_InitNode(xorNode, rf_wait, RF_FALSE, redFunc, rf_NullNodeUndoFunc, NULL, 1, nRrdNodes, 2 * nXorBufs + 2, nfaults, dag_h, "Xrc", allocList); /* * Fill in the Rrd nodes. If any of the rrd buffers are the same size as * the failed buffer, save a pointer to it so we can use it as the target * of the XOR. The pdas in the rrd nodes have been range-restricted, so if * a buffer is the same size as the failed buffer, it must also be at the * same alignment within the SU. */ i = 0; if (new_asm_h[0]) { for (i = 0, pda = new_asm_h[0]->stripeMap->physInfo; i < new_asm_h[0]->stripeMap->numStripeUnitsAccessed; i++, pda = pda->next) { rf_InitNode(&rrdNodes[i], rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Rrd", allocList); RF_ASSERT(pda); rrdNodes[i].params[0].p = pda; rrdNodes[i].params[1].p = pda->bufPtr; rrdNodes[i].params[2].v = parityStripeID; rrdNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); } } /* i now equals the number of stripe units accessed in new_asm_h[0] */ if (new_asm_h[1]) { for (j = 0, pda = new_asm_h[1]->stripeMap->physInfo; j < new_asm_h[1]->stripeMap->numStripeUnitsAccessed; j++, pda = pda->next) { rf_InitNode(&rrdNodes[i + j], rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Rrd", allocList); RF_ASSERT(pda); rrdNodes[i + j].params[0].p = pda; rrdNodes[i + j].params[1].p = pda->bufPtr; rrdNodes[i + j].params[2].v = parityStripeID; rrdNodes[i + j].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); if (allowBufferRecycle && (pda->numSector == failedPDA->numSector)) xorTargetBuf = pda->bufPtr; } } if (rdnodesFaked) { /* * This is where we'll init that fake noop read node * (XXX should the wakeup func be different?) */ rf_InitNode(&rrdNodes[0], rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, 1, 0, 0, dag_h, "RrN", allocList); } /* * Make a PDA for the parity unit. The parity PDA should start at * the same offset into the SU as the failed PDA. */ /* Danner comment: I don't think this copy is really necessary. We are * in one of two cases here. (1) The entire failed unit is written. * Then asmap->parityInfo will describe the entire parity. (2) We are * only writing a subset of the failed unit and nothing else. Then the * asmap->parityInfo describes the failed unit and the copy can also * be avoided. */ RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); parityPDA->row = asmap->parityInfo->row; parityPDA->col = asmap->parityInfo->col; parityPDA->startSector = ((asmap->parityInfo->startSector / sectorsPerSU) * sectorsPerSU) + (failedPDA->startSector % sectorsPerSU); parityPDA->numSector = failedPDA->numSector; if (!xorTargetBuf) { RF_CallocAndAdd(xorTargetBuf, 1, rf_RaidAddressToByte(raidPtr, failedPDA->numSector), (char *), allocList); } /* init the Wnp node */ rf_InitNode(wnpNode, rf_wait, RF_FALSE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Wnp", allocList); wnpNode->params[0].p = parityPDA; wnpNode->params[1].p = xorTargetBuf; wnpNode->params[2].v = parityStripeID; wnpNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); /* fill in the Wnq Node */ if (nfaults == 2) { { RF_MallocAndAdd(parityPDA, sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); parityPDA->row = asmap->qInfo->row; parityPDA->col = asmap->qInfo->col; parityPDA->startSector = ((asmap->qInfo->startSector / sectorsPerSU) * sectorsPerSU) + (failedPDA->startSector % sectorsPerSU); parityPDA->numSector = failedPDA->numSector; rf_InitNode(wnqNode, rf_wait, RF_FALSE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Wnq", allocList); wnqNode->params[0].p = parityPDA; RF_CallocAndAdd(xorNode->results[1], 1, rf_RaidAddressToByte(raidPtr, failedPDA->numSector), (char *), allocList); wnqNode->params[1].p = xorNode->results[1]; wnqNode->params[2].v = parityStripeID; wnqNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); } } /* fill in the Wnd nodes */ for (pda = asmap->physInfo, i = 0; i < nWndNodes; i++, pda = pda->next) { if (pda == failedPDA) { i--; continue; } rf_InitNode(&wndNodes[i], rf_wait, RF_FALSE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Wnd", allocList); RF_ASSERT(pda); wndNodes[i].params[0].p = pda; wndNodes[i].params[1].p = pda->bufPtr; wndNodes[i].params[2].v = parityStripeID; wndNodes[i].params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru); } /* fill in the results of the xor node */ xorNode->results[0] = xorTargetBuf; /* fill in the params of the xor node */ paramNum = 0; if (rdnodesFaked == 0) { for (i = 0; i < nRrdNodes; i++) { /* all the Rrd nodes need to be xored together */ xorNode->params[paramNum++] = rrdNodes[i].params[0]; xorNode->params[paramNum++] = rrdNodes[i].params[1]; } } for (i = 0; i < nWndNodes; i++) { /* any Wnd nodes that overlap the failed access need to be * xored in */ if (overlappingPDAs[i]) { RF_MallocAndAdd(pda, sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); bcopy((char *) wndNodes[i].params[0].p, (char *) pda, sizeof(RF_PhysDiskAddr_t)); rf_RangeRestrictPDA(raidPtr, failedPDA, pda, RF_RESTRICT_DOBUFFER, 0); xorNode->params[paramNum++].p = pda; xorNode->params[paramNum++].p = pda->bufPtr; } } RF_Free(overlappingPDAs, asmap->numStripeUnitsAccessed * sizeof(char)); /* * Install the failed PDA into the xor param list so that the * new data gets xor'd in. */ xorNode->params[paramNum++].p = failedPDA; xorNode->params[paramNum++].p = failedPDA->bufPtr; /* * The last 2 params to the recovery xor node are always the failed * PDA and the raidPtr. install the failedPDA even though we have just * done so above. This allows us to use the same XOR function for both * degraded reads and degraded writes. */ xorNode->params[paramNum++].p = failedPDA; xorNode->params[paramNum++].p = raidPtr; RF_ASSERT(paramNum == 2 * nXorBufs + 2); /* * Code to link nodes begins here */ /* link header to block node */ RF_ASSERT(blockNode->numAntecedents == 0); dag_h->succedents[0] = blockNode; /* link block node to rd nodes */ RF_ASSERT(blockNode->numSuccedents == nRrdNodes); for (i = 0; i < nRrdNodes; i++) { RF_ASSERT(rrdNodes[i].numAntecedents == 1); blockNode->succedents[i] = &rrdNodes[i]; rrdNodes[i].antecedents[0] = blockNode; rrdNodes[i].antType[0] = rf_control; } /* link read nodes to xor node */ RF_ASSERT(xorNode->numAntecedents == nRrdNodes); for (i = 0; i < nRrdNodes; i++) { RF_ASSERT(rrdNodes[i].numSuccedents == 1); rrdNodes[i].succedents[0] = xorNode; xorNode->antecedents[i] = &rrdNodes[i]; xorNode->antType[i] = rf_trueData; } /* link xor node to commit node */ RF_ASSERT(xorNode->numSuccedents == 1); RF_ASSERT(commitNode->numAntecedents == 1); xorNode->succedents[0] = commitNode; commitNode->antecedents[0] = xorNode; commitNode->antType[0] = rf_control; /* link commit node to wnd nodes */ RF_ASSERT(commitNode->numSuccedents == nfaults + nWndNodes); for (i = 0; i < nWndNodes; i++) { RF_ASSERT(wndNodes[i].numAntecedents == 1); commitNode->succedents[i] = &wndNodes[i]; wndNodes[i].antecedents[0] = commitNode; wndNodes[i].antType[0] = rf_control; } /* link the commit node to wnp, wnq nodes */ RF_ASSERT(wnpNode->numAntecedents == 1); commitNode->succedents[nWndNodes] = wnpNode; wnpNode->antecedents[0] = commitNode; wnpNode->antType[0] = rf_control; if (nfaults == 2) { RF_ASSERT(wnqNode->numAntecedents == 1); commitNode->succedents[nWndNodes + 1] = wnqNode; wnqNode->antecedents[0] = commitNode; wnqNode->antType[0] = rf_control; } /* link write new data nodes to unblock node */ RF_ASSERT(unblockNode->numAntecedents == (nWndNodes + nfaults)); for (i = 0; i < nWndNodes; i++) { RF_ASSERT(wndNodes[i].numSuccedents == 1); wndNodes[i].succedents[0] = unblockNode; unblockNode->antecedents[i] = &wndNodes[i]; unblockNode->antType[i] = rf_control; } /* link write new parity node to unblock node */ RF_ASSERT(wnpNode->numSuccedents == 1); wnpNode->succedents[0] = unblockNode; unblockNode->antecedents[nWndNodes] = wnpNode; unblockNode->antType[nWndNodes] = rf_control; /* link write new q node to unblock node */ if (nfaults == 2) { RF_ASSERT(wnqNode->numSuccedents == 1); wnqNode->succedents[0] = unblockNode; unblockNode->antecedents[nWndNodes + 1] = wnqNode; unblockNode->antType[nWndNodes + 1] = rf_control; } /* link unblock node to term node */ RF_ASSERT(unblockNode->numSuccedents == 1); RF_ASSERT(termNode->numAntecedents == 1); RF_ASSERT(termNode->numSuccedents == 0); unblockNode->succedents[0] = termNode; termNode->antecedents[0] = unblockNode; termNode->antType[0] = rf_control; } #define CONS_PDA(if,start,num) \ pda_p->row = asmap->if->row; pda_p->col = asmap->if->col; \ pda_p->startSector = ((asmap->if->startSector / secPerSU) * secPerSU) + start; \ pda_p->numSector = num; \ pda_p->next = NULL; \ RF_MallocAndAdd(pda_p->bufPtr,rf_RaidAddressToByte(raidPtr,num),(char *), allocList) void rf_WriteGenerateFailedAccessASMs( RF_Raid_t * raidPtr, RF_AccessStripeMap_t * asmap, RF_PhysDiskAddr_t ** pdap, int *nNodep, RF_PhysDiskAddr_t ** pqpdap, int *nPQNodep, RF_AllocListElem_t * allocList) { RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); int PDAPerDisk, i; RF_SectorCount_t secPerSU = layoutPtr->sectorsPerStripeUnit; int numDataCol = layoutPtr->numDataCol; int state; unsigned napdas; RF_SectorNum_t fone_start, fone_end, ftwo_start = 0, ftwo_end; RF_PhysDiskAddr_t *fone = asmap->failedPDAs[0], *ftwo = asmap->failedPDAs[1]; RF_PhysDiskAddr_t *pda_p; RF_RaidAddr_t sosAddr; /* determine how many pda's we will have to generate per unaccess * stripe. If there is only one failed data unit, it is one; if two, * possibly two, depending wether they overlap. */ fone_start = rf_StripeUnitOffset(layoutPtr, fone->startSector); fone_end = fone_start + fone->numSector; if (asmap->numDataFailed == 1) { PDAPerDisk = 1; state = 1; RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); pda_p = *pqpdap; /* build p */ CONS_PDA(parityInfo, fone_start, fone->numSector); pda_p->type = RF_PDA_TYPE_PARITY; pda_p++; /* build q */ CONS_PDA(qInfo, fone_start, fone->numSector); pda_p->type = RF_PDA_TYPE_Q; } else { ftwo_start = rf_StripeUnitOffset(layoutPtr, ftwo->startSector); ftwo_end = ftwo_start + ftwo->numSector; if (fone->numSector + ftwo->numSector > secPerSU) { PDAPerDisk = 1; state = 2; RF_MallocAndAdd(*pqpdap, 2 * sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); pda_p = *pqpdap; CONS_PDA(parityInfo, 0, secPerSU); pda_p->type = RF_PDA_TYPE_PARITY; pda_p++; CONS_PDA(qInfo, 0, secPerSU); pda_p->type = RF_PDA_TYPE_Q; } else { PDAPerDisk = 2; state = 3; /* four of them, fone, then ftwo */ RF_MallocAndAdd(*pqpdap, 4 * sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); pda_p = *pqpdap; CONS_PDA(parityInfo, fone_start, fone->numSector); pda_p->type = RF_PDA_TYPE_PARITY; pda_p++; CONS_PDA(qInfo, fone_start, fone->numSector); pda_p->type = RF_PDA_TYPE_Q; pda_p++; CONS_PDA(parityInfo, ftwo_start, ftwo->numSector); pda_p->type = RF_PDA_TYPE_PARITY; pda_p++; CONS_PDA(qInfo, ftwo_start, ftwo->numSector); pda_p->type = RF_PDA_TYPE_Q; } } /* figure out number of nonaccessed pda */ napdas = PDAPerDisk * (numDataCol - 2); *nPQNodep = PDAPerDisk; *nNodep = napdas; if (napdas == 0) return; /* short circuit */ /* allocate up our list of pda's */ RF_CallocAndAdd(pda_p, napdas, sizeof(RF_PhysDiskAddr_t), (RF_PhysDiskAddr_t *), allocList); *pdap = pda_p; /* linkem together */ for (i = 0; i < (napdas - 1); i++) pda_p[i].next = pda_p + (i + 1); sosAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr, asmap->raidAddress); for (i = 0; i < numDataCol; i++) { if ((pda_p - (*pdap)) == napdas) continue; pda_p->type = RF_PDA_TYPE_DATA; pda_p->raidAddress = sosAddr + (i * secPerSU); (raidPtr->Layout.map->MapSector) (raidPtr, pda_p->raidAddress, &(pda_p->row), &(pda_p->col), &(pda_p->startSector), 0); /* skip over dead disks */ if (RF_DEAD_DISK(raidPtr->Disks[pda_p->row][pda_p->col].status)) continue; switch (state) { case 1: /* fone */ pda_p->numSector = fone->numSector; pda_p->raidAddress += fone_start; pda_p->startSector += fone_start; RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(raidPtr, pda_p->numSector), (char *), allocList); break; case 2: /* full stripe */ pda_p->numSector = secPerSU; RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(raidPtr, secPerSU), (char *), allocList); break; case 3: /* two slabs */ pda_p->numSector = fone->numSector; pda_p->raidAddress += fone_start; pda_p->startSector += fone_start; RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(raidPtr, pda_p->numSector), (char *), allocList); pda_p++; pda_p->type = RF_PDA_TYPE_DATA; pda_p->raidAddress = sosAddr + (i * secPerSU); (raidPtr->Layout.map->MapSector) (raidPtr, pda_p->raidAddress, &(pda_p->row), &(pda_p->col), &(pda_p->startSector), 0); pda_p->numSector = ftwo->numSector; pda_p->raidAddress += ftwo_start; pda_p->startSector += ftwo_start; RF_MallocAndAdd(pda_p->bufPtr, rf_RaidAddressToByte(raidPtr, pda_p->numSector), (char *), allocList); break; default: RF_PANIC(); } pda_p++; } RF_ASSERT(pda_p - *pdap == napdas); return; } #define DISK_NODE_PDA(node) ((node)->params[0].p) #define DISK_NODE_PARAMS(_node_,_p_) \ (_node_).params[0].p = _p_ ; \ (_node_).params[1].p = (_p_)->bufPtr; \ (_node_).params[2].v = parityStripeID; \ (_node_).params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru) void rf_DoubleDegSmallWrite( RF_Raid_t * raidPtr, RF_AccessStripeMap_t * asmap, RF_DagHeader_t * dag_h, void *bp, RF_RaidAccessFlags_t flags, RF_AllocListElem_t * allocList, char *redundantReadNodeName, char *redundantWriteNodeName, char *recoveryNodeName, int (*recovFunc) (RF_DagNode_t *)) { RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout); RF_DagNode_t *nodes, *wudNodes, *rrdNodes, *recoveryNode, *blockNode, *unblockNode, *rpNodes, *rqNodes, *wpNodes, *wqNodes, *termNode; RF_PhysDiskAddr_t *pda, *pqPDAs; RF_PhysDiskAddr_t *npdas; int nWriteNodes, nNodes, nReadNodes, nRrdNodes, nWudNodes, i; RF_ReconUnitNum_t which_ru; int nPQNodes; RF_StripeNum_t parityStripeID = rf_RaidAddressToParityStripeID(layoutPtr, asmap->raidAddress, &which_ru); /* simple small write case - First part looks like a reconstruct-read * of the failed data units. Then a write of all data units not * failed. */ /* Hdr | ------Block- / / \ Rrd Rrd ... Rrd Rp Rq \ \ * / -------PQ----- / \ \ Wud Wp WQ \ | / * --Unblock- | T * * Rrd = read recovery data (potentially none) Wud = write user data * (not incl. failed disks) Wp = Write P (could be two) Wq = Write Q * (could be two) * */ rf_WriteGenerateFailedAccessASMs(raidPtr, asmap, &npdas, &nRrdNodes, &pqPDAs, &nPQNodes, allocList); RF_ASSERT(asmap->numDataFailed == 1); nWudNodes = asmap->numStripeUnitsAccessed - (asmap->numDataFailed); nReadNodes = nRrdNodes + 2 * nPQNodes; nWriteNodes = nWudNodes + 2 * nPQNodes; nNodes = 4 + nReadNodes + nWriteNodes; RF_CallocAndAdd(nodes, nNodes, sizeof(RF_DagNode_t), (RF_DagNode_t *), allocList); blockNode = nodes; unblockNode = blockNode + 1; termNode = unblockNode + 1; recoveryNode = termNode + 1; rrdNodes = recoveryNode + 1; rpNodes = rrdNodes + nRrdNodes; rqNodes = rpNodes + nPQNodes; wudNodes = rqNodes + nPQNodes; wpNodes = wudNodes + nWudNodes; wqNodes = wpNodes + nPQNodes; dag_h->creator = "PQ_DDSimpleSmallWrite"; dag_h->numSuccedents = 1; dag_h->succedents[0] = blockNode; rf_InitNode(termNode, rf_wait, RF_FALSE, rf_TerminateFunc, rf_TerminateUndoFunc, NULL, 0, 1, 0, 0, dag_h, "Trm", allocList); termNode->antecedents[0] = unblockNode; termNode->antType[0] = rf_control; /* init the block and unblock nodes */ /* The block node has all the read nodes as successors */ rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, nReadNodes, 0, 0, 0, dag_h, "Nil", allocList); for (i = 0; i < nReadNodes; i++) blockNode->succedents[i] = rrdNodes + i; /* The unblock node has all the writes as successors */ rf_InitNode(unblockNode, rf_wait, RF_FALSE, rf_NullNodeFunc, rf_NullNodeUndoFunc, NULL, 1, nWriteNodes, 0, 0, dag_h, "Nil", allocList); for (i = 0; i < nWriteNodes; i++) { unblockNode->antecedents[i] = wudNodes + i; unblockNode->antType[i] = rf_control; } unblockNode->succedents[0] = termNode; #define INIT_READ_NODE(node,name) \ rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, name, allocList); \ (node)->succedents[0] = recoveryNode; \ (node)->antecedents[0] = blockNode; \ (node)->antType[0] = rf_control; /* build the read nodes */ pda = npdas; for (i = 0; i < nRrdNodes; i++, pda = pda->next) { INIT_READ_NODE(rrdNodes + i, "rrd"); DISK_NODE_PARAMS(rrdNodes[i], pda); } /* read redundancy pdas */ pda = pqPDAs; INIT_READ_NODE(rpNodes, "Rp"); RF_ASSERT(pda); DISK_NODE_PARAMS(rpNodes[0], pda); pda++; INIT_READ_NODE(rqNodes, redundantReadNodeName); RF_ASSERT(pda); DISK_NODE_PARAMS(rqNodes[0], pda); if (nPQNodes == 2) { pda++; INIT_READ_NODE(rpNodes + 1, "Rp"); RF_ASSERT(pda); DISK_NODE_PARAMS(rpNodes[1], pda); pda++; INIT_READ_NODE(rqNodes + 1, redundantReadNodeName); RF_ASSERT(pda); DISK_NODE_PARAMS(rqNodes[1], pda); } /* the recovery node has all reads as precedessors and all writes as * successors. It generates a result for every write P or write Q * node. As parameters, it takes a pda per read and a pda per stripe * of user data written. It also takes as the last params the raidPtr * and asm. For results, it takes PDA for P & Q. */ rf_InitNode(recoveryNode, rf_wait, RF_FALSE, recovFunc, rf_NullNodeUndoFunc, NULL, nWriteNodes, /* succesors */ nReadNodes, /* preds */ nReadNodes + nWudNodes + 3, /* params */ 2 * nPQNodes, /* results */ dag_h, recoveryNodeName, allocList); for (i = 0; i < nReadNodes; i++) { recoveryNode->antecedents[i] = rrdNodes + i; recoveryNode->antType[i] = rf_control; recoveryNode->params[i].p = DISK_NODE_PDA(rrdNodes + i); } for (i = 0; i < nWudNodes; i++) { recoveryNode->succedents[i] = wudNodes + i; } recoveryNode->params[nReadNodes + nWudNodes].p = asmap->failedPDAs[0]; recoveryNode->params[nReadNodes + nWudNodes + 1].p = raidPtr; recoveryNode->params[nReadNodes + nWudNodes + 2].p = asmap; for (; i < nWriteNodes; i++) recoveryNode->succedents[i] = wudNodes + i; pda = pqPDAs; recoveryNode->results[0] = pda; pda++; recoveryNode->results[1] = pda; if (nPQNodes == 2) { pda++; recoveryNode->results[2] = pda; pda++; recoveryNode->results[3] = pda; } /* fill writes */ #define INIT_WRITE_NODE(node,name) \ rf_InitNode(node, rf_wait, RF_FALSE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc, rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, name, allocList); \ (node)->succedents[0] = unblockNode; \ (node)->antecedents[0] = recoveryNode; \ (node)->antType[0] = rf_control; pda = asmap->physInfo; for (i = 0; i < nWudNodes; i++) { INIT_WRITE_NODE(wudNodes + i, "Wd"); DISK_NODE_PARAMS(wudNodes[i], pda); recoveryNode->params[nReadNodes + i].p = DISK_NODE_PDA(wudNodes + i); pda = pda->next; } /* write redundancy pdas */ pda = pqPDAs; INIT_WRITE_NODE(wpNodes, "Wp"); RF_ASSERT(pda); DISK_NODE_PARAMS(wpNodes[0], pda); pda++; INIT_WRITE_NODE(wqNodes, "Wq"); RF_ASSERT(pda); DISK_NODE_PARAMS(wqNodes[0], pda); if (nPQNodes == 2) { pda++; INIT_WRITE_NODE(wpNodes + 1, "Wp"); RF_ASSERT(pda); DISK_NODE_PARAMS(wpNodes[1], pda); pda++; INIT_WRITE_NODE(wqNodes + 1, "Wq"); RF_ASSERT(pda); DISK_NODE_PARAMS(wqNodes[1], pda); } }