/* $OpenBSD: rf_dagdegwr.c,v 1.6 2006/07/09 22:10:05 mk Exp $ */
/* $NetBSD: rf_dagdegwr.c,v 1.5 2000/01/07 03:40:57 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_debugMem.h"
#include "rf_memchunk.h"
#include "rf_general.h"
#include "rf_dagdegwr.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.
*
*****************************************************************************/
RF_CREATE_DAG_FUNC_DECL(rf_CreateSimpleDegradedWriteDAG)
{
rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
flags, allocList, 1, rf_RecoveryXorFunc, RF_TRUE);
}
void
rf_CreateDegradedWriteDAG(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 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(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) do { \
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); \
} while (0)
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];
RF_PhysDiskAddr_t *ftwo = asmap->failedPDAs[1];
RF_PhysDiskAddr_t *pda_p;
RF_RaidAddr_t sosAddr;
/*
* Determine how many pda's we will have to generate per unaccessed
* stripe. If there is only one failed data unit, it is one; if two,
* possibly two, depending whether 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;
/* Link them 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_) do { \
(_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); \
} while (0)
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) do { \
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; \
} while (0)
/* 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) do { \
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; \
} while (0)
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);
}
}
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