/* $NetBSD: rf_dagdegwr.c,v 1.37 2023/10/15 18:15:19 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
[email protected]
* 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_dagdegwr.c,v 1.37 2023/10/15 18:15:19 oster Exp $");
#include <dev/raidframe/raidframevar.h>
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_dagutils.h"
#include "rf_dagfuncs.h"
#include "rf_debugMem.h"
#include "rf_general.h"
#include "rf_dagdegwr.h"
#include "rf_map.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(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
RF_DagHeader_t *dag_h, void *bp,
RF_RaidAccessFlags_t flags,
RF_AllocListElem_t *allocList)
{
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 &&
asmap->failedPDAs[0]->numSector !=
raidPtr->Layout.sectorsPerStripeUnit));
rf_CreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags,
allocList);
}
/******************************************************************************
*
* DAG creation code begins here
*/
#define BUF_ALLOC(num) \
RF_MallocAndAdd(rf_RaidAddressToByte(raidPtr, num), allocList)
/******************************************************************************
*
* 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(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,
void (*redFunc) (RF_DagNode_t *),
int allowBufferRecycle)
{
int nRrdNodes, nWndNodes, nXorBufs, i, j, paramNum,
rdnodesFaked;
RF_DagNode_t *blockNode, *unblockNode, *wnpNode, *termNode;
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
RF_DagNode_t *wnqNode;
#endif
RF_DagNode_t *wndNodes, *rrdNodes, *xorNode, *commitNode;
RF_DagNode_t *tmpNode, *tmpwndNode, *tmprrdNode;
RF_SectorCount_t sectorsPerSU;
RF_ReconUnitNum_t which_ru;
char *xorTargetBuf = NULL; /* the target buffer for the XOR
* operation */
char overlappingPDAs[RF_MAXCOL];/* 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_DEBUG_DAG
if (rf_dagDebug)
printf("[Creating degraded-write DAG]\n");
#endif
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 */
memset(overlappingPDAs, 0, RF_MAXCOL);
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;
}
blockNode = rf_AllocDAGNode(raidPtr);
blockNode->list_next = dag_h->nodes;
dag_h->nodes = blockNode;
commitNode = rf_AllocDAGNode(raidPtr);
commitNode->list_next = dag_h->nodes;
dag_h->nodes = commitNode;
unblockNode = rf_AllocDAGNode(raidPtr);
unblockNode->list_next = dag_h->nodes;
dag_h->nodes = unblockNode;
termNode = rf_AllocDAGNode(raidPtr);
termNode->list_next = dag_h->nodes;
dag_h->nodes = termNode;
xorNode = rf_AllocDAGNode(raidPtr);
xorNode->list_next = dag_h->nodes;
dag_h->nodes = xorNode;
wnpNode = rf_AllocDAGNode(raidPtr);
wnpNode->list_next = dag_h->nodes;
dag_h->nodes = wnpNode;
for (i = 0; i < nWndNodes; i++) {
tmpNode = rf_AllocDAGNode(raidPtr);
tmpNode->list_next = dag_h->nodes;
dag_h->nodes = tmpNode;
}
wndNodes = dag_h->nodes;
for (i = 0; i < nRrdNodes; i++) {
tmpNode = rf_AllocDAGNode(raidPtr);
tmpNode->list_next = dag_h->nodes;
dag_h->nodes = tmpNode;
}
rrdNodes = dag_h->nodes;
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
if (nfaults == 2) {
wnqNode = rf_AllocDAGNode(raidPtr);
wnqNode->list_next = dag_h->nodes;
dag_h->nodes = wnqNode;
} else {
wnqNode = NULL;
}
#endif
/* 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;
tmprrdNode = rrdNodes;
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(tmprrdNode, rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc,
rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Rrd", allocList);
RF_ASSERT(pda);
tmprrdNode->params[0].p = pda;
tmprrdNode->params[1].p = pda->bufPtr;
tmprrdNode->params[2].v = parityStripeID;
tmprrdNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, which_ru);
tmprrdNode = tmprrdNode->list_next;
}
}
/* i now equals the number of stripe units accessed in new_asm_h[0] */
/* Note that for tmprrdNode, this means a continuation from above, so no need to
assign it anything.. */
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(tmprrdNode, rf_wait, RF_FALSE, rf_DiskReadFunc, rf_DiskReadUndoFunc,
rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Rrd", allocList);
RF_ASSERT(pda);
tmprrdNode->params[0].p = pda;
tmprrdNode->params[1].p = pda->bufPtr;
tmprrdNode->params[2].v = parityStripeID;
tmprrdNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, which_ru);
if (allowBufferRecycle && (pda->numSector == failedPDA->numSector))
xorTargetBuf = pda->bufPtr;
tmprrdNode = tmprrdNode->list_next;
}
}
if (rdnodesFaked) {
/*
* This is where we'll init that fake noop read node
* (XXX should the wakeup func be different?)
*/
/* node that rrdNodes will just be a single node... */
rf_InitNode(rrdNodes, 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. */
parityPDA = rf_AllocPhysDiskAddr(raidPtr);
parityPDA->next = dag_h->pda_cleanup_list;
dag_h->pda_cleanup_list = parityPDA;
parityPDA->col = asmap->parityInfo->col;
parityPDA->startSector = ((asmap->parityInfo->startSector / sectorsPerSU)
* sectorsPerSU) + (failedPDA->startSector % sectorsPerSU);
parityPDA->numSector = failedPDA->numSector;
if (!xorTargetBuf) {
xorTargetBuf = rf_AllocBuffer(raidPtr, dag_h, rf_RaidAddressToByte(raidPtr, failedPDA->numSector));
}
/* 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, which_ru);
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
/* fill in the Wnq Node */
if (nfaults == 2) {
{
parityPDA = RF_MallocAndAdd(sizeof(*parityPDA), allocList);
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;
xorNode->results[1] = BUF_ALLOC(failedPDA->numSector);
wnqNode->params[1].p = xorNode->results[1];
wnqNode->params[2].v = parityStripeID;
wnqNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, which_ru);
}
}
#endif
/* fill in the Wnd nodes */
tmpwndNode = wndNodes;
for (pda = asmap->physInfo, i = 0; i < nWndNodes; i++, pda = pda->next) {
if (pda == failedPDA) {
i--;
continue;
}
rf_InitNode(tmpwndNode, rf_wait, RF_FALSE, rf_DiskWriteFunc, rf_DiskWriteUndoFunc,
rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, "Wnd", allocList);
RF_ASSERT(pda);
tmpwndNode->params[0].p = pda;
tmpwndNode->params[1].p = pda->bufPtr;
tmpwndNode->params[2].v = parityStripeID;
tmpwndNode->params[3].v = RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, which_ru);
tmpwndNode = tmpwndNode->list_next;
}
/* 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) {
tmprrdNode = rrdNodes;
for (i = 0; i < nRrdNodes; i++) {
/* all the Rrd nodes need to be xored together */
xorNode->params[paramNum++] = tmprrdNode->params[0];
xorNode->params[paramNum++] = tmprrdNode->params[1];
tmprrdNode = tmprrdNode->list_next;
}
}
tmpwndNode = wndNodes;
for (i = 0; i < nWndNodes; i++) {
/* any Wnd nodes that overlap the failed access need to be
* xored in */
if (overlappingPDAs[i]) {
pda = rf_AllocPhysDiskAddr(raidPtr);
memcpy((char *) pda, (char *) tmpwndNode->params[0].p, sizeof(RF_PhysDiskAddr_t));
/* add it into the pda_cleanup_list *after* the copy, TYVM */
pda->next = dag_h->pda_cleanup_list;
dag_h->pda_cleanup_list = pda;
rf_RangeRestrictPDA(raidPtr, failedPDA, pda, RF_RESTRICT_DOBUFFER, 0);
xorNode->params[paramNum++].p = pda;
xorNode->params[paramNum++].p = pda->bufPtr;
}
tmpwndNode = tmpwndNode->list_next;
}
/*
* 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);
tmprrdNode = rrdNodes;
for (i = 0; i < nRrdNodes; i++) {
RF_ASSERT(tmprrdNode->numAntecedents == 1);
blockNode->succedents[i] = tmprrdNode;
tmprrdNode->antecedents[0] = blockNode;
tmprrdNode->antType[0] = rf_control;
tmprrdNode = tmprrdNode->list_next;
}
/* link read nodes to xor node */
RF_ASSERT(xorNode->numAntecedents == nRrdNodes);
tmprrdNode = rrdNodes;
for (i = 0; i < nRrdNodes; i++) {
RF_ASSERT(tmprrdNode->numSuccedents == 1);
tmprrdNode->succedents[0] = xorNode;
xorNode->antecedents[i] = tmprrdNode;
xorNode->antType[i] = rf_trueData;
tmprrdNode = tmprrdNode->list_next;
}
/* 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);
tmpwndNode = wndNodes;
for (i = 0; i < nWndNodes; i++) {
RF_ASSERT(tmpwndNode->numAntecedents == 1);
commitNode->succedents[i] = tmpwndNode;
tmpwndNode->antecedents[0] = commitNode;
tmpwndNode->antType[0] = rf_control;
tmpwndNode = tmpwndNode->list_next;
}
/* 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 (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
if (nfaults == 2) {
RF_ASSERT(wnqNode->numAntecedents == 1);
commitNode->succedents[nWndNodes + 1] = wnqNode;
wnqNode->antecedents[0] = commitNode;
wnqNode->antType[0] = rf_control;
}
#endif
/* link write new data nodes to unblock node */
RF_ASSERT(unblockNode->numAntecedents == (nWndNodes + nfaults));
tmpwndNode = wndNodes;
for (i = 0; i < nWndNodes; i++) {
RF_ASSERT(tmpwndNode->numSuccedents == 1);
tmpwndNode->succedents[0] = unblockNode;
unblockNode->antecedents[i] = tmpwndNode;
unblockNode->antType[i] = rf_control;
tmpwndNode = tmpwndNode->list_next;
}
/* 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;
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
/* 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;
}
#endif
/* 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->col = asmap->if->col; \
pda_p->startSector = ((asmap->if->startSector / secPerSU) * secPerSU) + start; \
pda_p->numSector = num; \
pda_p->next = NULL; \
pda_p->bufPtr = BUF_ALLOC(num)
#if (RF_INCLUDE_RAID6 > 0) || (RF_INCLUDE_PQ > 0) || (RF_INCLUDE_EVENODD > 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, ftwo_start = 0;
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 whether they overlap. */
fone_start = rf_StripeUnitOffset(layoutPtr, fone->startSector);
if (asmap->numDataFailed == 1) {
PDAPerDisk = 1;
state = 1;
*pqpdap = RF_MallocAndAdd(2 * sizeof(**pqpdap), 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);
if (fone->numSector + ftwo->numSector > secPerSU) {
PDAPerDisk = 1;
state = 2;
*pqpdap = RF_MallocAndAdd(2 * sizeof(**pqpdap),
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 */
*pqpdap = RF_MallocAndAdd(4 * sizeof(*pqpdap),
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 */
pda_p = RF_MallocAndAdd(napdas * sizeof(*pda_p), 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->col), &(pda_p->startSector), 0);
/* skip over dead disks */
if (RF_DEAD_DISK(raidPtr->Disks[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;
pda_p->bufPtr = BUF_ALLOC(pda_p->numSector);
break;
case 2: /* full stripe */
pda_p->numSector = secPerSU;
pda_p->bufPtr = BUF_ALLOC(secPerSU);
break;
case 3: /* two slabs */
pda_p->numSector = fone->numSector;
pda_p->raidAddress += fone_start;
pda_p->startSector += fone_start;
pda_p->bufPtr = BUF_ALLOC(pda_p->numSector);
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->col), &(pda_p->startSector), 0);
pda_p->numSector = ftwo->numSector;
pda_p->raidAddress += ftwo_start;
pda_p->startSector += ftwo_start;
pda_p->bufPtr = BUF_ALLOC(pda_p->numSector);
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, 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,
const char *redundantReadNodeName,
const char *redundantWriteNodeName,
const char *recoveryNodeName,
void (*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;
nodes = RF_MallocAndAdd(nNodes * sizeof(*nodes), 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);
}
}
#endif /* (RF_INCLUDE_PQ > 0) || (RF_INCLUDE_EVENODD > 0) */
