/* $OpenBSD: rf_parityscan.c,v 1.7 2002/12/16 07:01:04 tdeval Exp $ */
/* $NetBSD: rf_parityscan.c,v 1.9 2000/05/28 03:00:31 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland
*
* 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_parityscan.c -- Misc utilities related to parity verification.
*
*****************************************************************************/
#include "rf_types.h"
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_dagfuncs.h"
#include "rf_dagutils.h"
#include "rf_mcpair.h"
#include "rf_general.h"
#include "rf_engine.h"
#include "rf_parityscan.h"
#include "rf_map.h"
/*****************************************************************************
*
* Walk through the entire arry and write new parity.
* This works by creating two DAGs, one to read a stripe of data and one to
* write new parity. The first is executed, the data is xored together, and
* then the second is executed. To avoid constantly building and tearing down
* the DAGs, we create them a priori and fill them in with the mapping
* information as we go along.
*
* There should never be more than one thread running this.
*
*****************************************************************************/
int
rf_RewriteParity(RF_Raid_t *raidPtr)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_AccessStripeMapHeader_t *asm_h;
int ret_val;
int rc;
RF_PhysDiskAddr_t pda;
RF_SectorNum_t i;
if (raidPtr->Layout.map->faultsTolerated == 0) {
/* There isn't any parity. Call it "okay." */
return (RF_PARITY_OKAY);
}
if (raidPtr->status[0] != rf_rs_optimal) {
/*
* We're in degraded mode. Don't try to verify parity now !
* XXX: This should be a "we don't want to", not a
* "we can't" error.
*/
return (RF_PARITY_COULD_NOT_VERIFY);
}
ret_val = 0;
pda.startSector = 0;
pda.numSector = raidPtr->Layout.sectorsPerStripeUnit;
rc = RF_PARITY_OKAY;
for (i = 0; i < raidPtr->totalSectors && rc <= RF_PARITY_CORRECTED;
i += layoutPtr->dataSectorsPerStripe) {
if (raidPtr->waitShutdown) {
/*
* Someone is pulling the plug on this set...
* Abort the re-write.
*/
return (1);
}
asm_h = rf_MapAccess(raidPtr, i,
layoutPtr->dataSectorsPerStripe, NULL, RF_DONT_REMAP);
raidPtr->parity_rewrite_stripes_done =
i / layoutPtr->dataSectorsPerStripe ;
rc = rf_VerifyParity(raidPtr, asm_h->stripeMap, 1, 0);
switch (rc) {
case RF_PARITY_OKAY:
case RF_PARITY_CORRECTED:
break;
case RF_PARITY_BAD:
printf("Parity bad during correction.\n");
ret_val = 1;
break;
case RF_PARITY_COULD_NOT_CORRECT:
printf("Could not correct bad parity.\n");
ret_val = 1;
break;
case RF_PARITY_COULD_NOT_VERIFY:
printf("Could not verify parity.\n");
ret_val = 1;
break;
default:
printf("Bad rc=%d from VerifyParity in"
" RewriteParity.\n", rc);
ret_val = 1;
}
rf_FreeAccessStripeMap(asm_h);
}
return (ret_val);
}
/*****************************************************************************
*
* Verify that the parity in a particular stripe is correct.
* We validate only the range of parity defined by parityPDA, since
* this is all we have locked. The way we do this is to create an asm
* that maps the whole stripe and then range-restrict it to the parity
* region defined by the parityPDA.
*
*****************************************************************************/
int
rf_VerifyParity(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *aasm, int correct_it,
RF_RaidAccessFlags_t flags)
{
RF_PhysDiskAddr_t *parityPDA;
RF_AccessStripeMap_t *doasm;
RF_LayoutSW_t *lp;
int lrc, rc;
lp = raidPtr->Layout.map;
if (lp->faultsTolerated == 0) {
/*
* There isn't any parity. Call it "okay."
*/
return (RF_PARITY_OKAY);
}
rc = RF_PARITY_OKAY;
if (lp->VerifyParity) {
for (doasm = aasm; doasm; doasm = doasm->next) {
for (parityPDA = doasm->parityInfo; parityPDA;
parityPDA = parityPDA->next) {
lrc = lp->VerifyParity(raidPtr,
doasm->raidAddress, parityPDA, correct_it,
flags);
if (lrc > rc) {
/*
* see rf_parityscan.h for why this
* works.
*/
rc = lrc;
}
}
}
} else {
rc = RF_PARITY_COULD_NOT_VERIFY;
}
return (rc);
}
int
rf_VerifyParityBasic(RF_Raid_t *raidPtr, RF_RaidAddr_t raidAddr,
RF_PhysDiskAddr_t *parityPDA, int correct_it, RF_RaidAccessFlags_t flags)
{
RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
RF_RaidAddr_t startAddr = rf_RaidAddressOfPrevStripeBoundary(layoutPtr,
raidAddr);
RF_SectorCount_t numsector = parityPDA->numSector;
int numbytes = rf_RaidAddressToByte(raidPtr, numsector);
int bytesPerStripe = numbytes * layoutPtr->numDataCol;
RF_DagHeader_t *rd_dag_h, *wr_dag_h; /* Read, write dag. */
RF_DagNode_t *blockNode, *unblockNode, *wrBlock, *wrUnblock;
RF_AccessStripeMapHeader_t *asm_h;
RF_AccessStripeMap_t *asmap;
RF_AllocListElem_t *alloclist;
RF_PhysDiskAddr_t *pda;
char *pbuf, *buf, *end_p, *p;
int i, retcode;
RF_ReconUnitNum_t which_ru;
RF_StripeNum_t psID = rf_RaidAddressToParityStripeID(layoutPtr,
raidAddr, &which_ru);
int stripeWidth = layoutPtr->numDataCol + layoutPtr->numParityCol;
RF_AccTraceEntry_t tracerec;
RF_MCPair_t *mcpair;
retcode = RF_PARITY_OKAY;
mcpair = rf_AllocMCPair();
rf_MakeAllocList(alloclist);
RF_MallocAndAdd(buf, numbytes * (layoutPtr->numDataCol +
layoutPtr->numParityCol), (char *), alloclist);
/* Use calloc to make sure buffer is zeroed. */
RF_CallocAndAdd(pbuf, 1, numbytes, (char *), alloclist);
end_p = buf + bytesPerStripe;
rd_dag_h = rf_MakeSimpleDAG(raidPtr, stripeWidth, numbytes, buf,
rf_DiskReadFunc, rf_DiskReadUndoFunc,
"Rod", alloclist, flags, RF_IO_NORMAL_PRIORITY);
blockNode = rd_dag_h->succedents[0];
unblockNode = blockNode->succedents[0]->succedents[0];
/* Map the stripe and fill in the PDAs in the dag. */
asm_h = rf_MapAccess(raidPtr, startAddr,
layoutPtr->dataSectorsPerStripe, buf, RF_DONT_REMAP);
asmap = asm_h->stripeMap;
for (pda = asmap->physInfo, i = 0; i < layoutPtr->numDataCol;
i++, pda = pda->next) {
RF_ASSERT(pda);
rf_RangeRestrictPDA(raidPtr, parityPDA, pda, 0, 1);
RF_ASSERT(pda->numSector != 0);
if (rf_TryToRedirectPDA(raidPtr, pda, 0))
goto out; /*
* No way to verify parity if disk is
* dead. Return w/ good status.
*/
blockNode->succedents[i]->params[0].p = pda;
blockNode->succedents[i]->params[2].v = psID;
blockNode->succedents[i]->params[3].v =
RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
}
RF_ASSERT(!asmap->parityInfo->next);
rf_RangeRestrictPDA(raidPtr, parityPDA, asmap->parityInfo, 0, 1);
RF_ASSERT(asmap->parityInfo->numSector != 0);
if (rf_TryToRedirectPDA(raidPtr, asmap->parityInfo, 1))
goto out;
blockNode->succedents[layoutPtr->numDataCol]->params[0].p =
asmap->parityInfo;
/* Fire off the DAG. */
bzero((char *) &tracerec, sizeof(tracerec));
rd_dag_h->tracerec = &tracerec;
if (rf_verifyParityDebug) {
printf("Parity verify read dag:\n");
rf_PrintDAGList(rd_dag_h);
}
RF_LOCK_MUTEX(mcpair->mutex);
mcpair->flag = 0;
rf_DispatchDAG(rd_dag_h, (void (*) (void *)) rf_MCPairWakeupFunc,
(void *) mcpair);
while (!mcpair->flag)
RF_WAIT_COND(mcpair->cond, mcpair->mutex);
RF_UNLOCK_MUTEX(mcpair->mutex);
if (rd_dag_h->status != rf_enable) {
RF_ERRORMSG("Unable to verify parity: can't read the"
" stripe.\n");
retcode = RF_PARITY_COULD_NOT_VERIFY;
goto out;
}
for (p = buf; p < end_p; p += numbytes) {
rf_bxor(p, pbuf, numbytes, NULL);
}
for (i = 0; i < numbytes; i++) {
#if 0
if (pbuf[i] != 0 || buf[bytesPerStripe + i] != 0) {
printf("Bytes: %d %d %d\n", i, pbuf[i],
buf[bytesPerStripe + i]);
}
#endif
if (pbuf[i] != buf[bytesPerStripe + i]) {
if (!correct_it)
RF_ERRORMSG3("Parity verify error: byte %d of"
" parity is 0x%x should be 0x%x.\n", i,
(u_char) buf[bytesPerStripe + i],
(u_char) pbuf[i]);
retcode = RF_PARITY_BAD;
break;
}
}
if (retcode && correct_it) {
wr_dag_h = rf_MakeSimpleDAG(raidPtr, 1, numbytes, pbuf,
rf_DiskWriteFunc, rf_DiskWriteUndoFunc,
"Wnp", alloclist, flags, RF_IO_NORMAL_PRIORITY);
wrBlock = wr_dag_h->succedents[0];
wrUnblock = wrBlock->succedents[0]->succedents[0];
wrBlock->succedents[0]->params[0].p = asmap->parityInfo;
wrBlock->succedents[0]->params[2].v = psID;
wrBlock->succedents[0]->params[3].v =
RF_CREATE_PARAM3(RF_IO_NORMAL_PRIORITY, 0, 0, which_ru);
bzero((char *) &tracerec, sizeof(tracerec));
wr_dag_h->tracerec = &tracerec;
if (rf_verifyParityDebug) {
printf("Parity verify write dag:\n");
rf_PrintDAGList(wr_dag_h);
}
RF_LOCK_MUTEX(mcpair->mutex);
mcpair->flag = 0;
rf_DispatchDAG(wr_dag_h, (void (*) (void *))
rf_MCPairWakeupFunc, (void *) mcpair);
while (!mcpair->flag)
RF_WAIT_COND(mcpair->cond, mcpair->mutex);
RF_UNLOCK_MUTEX(mcpair->mutex);
if (wr_dag_h->status != rf_enable) {
RF_ERRORMSG("Unable to correct parity in VerifyParity:"
" can't write the stripe.\n");
retcode = RF_PARITY_COULD_NOT_CORRECT;
}
rf_FreeDAG(wr_dag_h);
if (retcode == RF_PARITY_BAD)
retcode = RF_PARITY_CORRECTED;
}
out:
rf_FreeAccessStripeMap(asm_h);
rf_FreeAllocList(alloclist);
rf_FreeDAG(rd_dag_h);
rf_FreeMCPair(mcpair);
return (retcode);
}
int
rf_TryToRedirectPDA(RF_Raid_t *raidPtr, RF_PhysDiskAddr_t *pda, int parity)
{
if (raidPtr->Disks[pda->row][pda->col].status == rf_ds_reconstructing) {
if (rf_CheckRUReconstructed(raidPtr->reconControl[pda->row]
->reconMap, pda->startSector)) {
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
RF_RowCol_t or = pda->row, oc = pda->col;
RF_SectorNum_t os = pda->startSector;
if (parity) {
(raidPtr->Layout.map->MapParity)
(raidPtr, pda->raidAddress,
&pda->row, &pda->col,
&pda->startSector, RF_REMAP);
if (rf_verifyParityDebug)
printf("VerifyParity: Redir P"
" r %d c %d sect %ld ->"
" r %d c %d sect %ld.\n",
or, oc, (long) os,
pda->row, pda->col,
(long) pda->startSector);
} else {
(raidPtr->Layout.map->MapSector)
(raidPtr, pda->raidAddress,
&pda->row, &pda->col,
&pda->startSector, RF_REMAP);
if (rf_verifyParityDebug)
printf("VerifyParity: Redir D"
" r %d c %d sect %ld ->"
" r %d c %d sect %ld.\n",
or, oc, (long) os,
pda->row, pda->col,
(long) pda->startSector);
}
} else {
RF_RowCol_t spRow =
raidPtr->Disks[pda->row][pda->col].spareRow;
RF_RowCol_t spCol =
raidPtr->Disks[pda->row][pda->col].spareCol;
pda->row = spRow;
pda->col = spCol;
}
}
}
if (RF_DEAD_DISK(raidPtr->Disks[pda->row][pda->col].status))
return (1);
return (0);
}
/*****************************************************************************
*
* Currently a stub.
*
* Takes as input an ASM describing a write operation and containing one
* failure, and verifies that the parity was correctly updated to reflect the
* write.
*
* If it's a data unit that has failed, we read the other data units in the
* stripe and the parity unit, XOR them together, and verify that we get the
* data intended for the failed disk. Since it's easy, we also validate that
* the right data got written to the surviving data disks.
*
* If it's the parity that failed, there's really no validation we can do
* except the above verification that the right data got written to all disks.
* This is because the new data intended for the failed disk is supplied in
* the ASM, but this is of course not the case for the new parity.
*
*****************************************************************************/
int
rf_VerifyDegrModeWrite(RF_Raid_t *raidPtr, RF_AccessStripeMapHeader_t *asmh)
{
return (0);
}
/*
* Creates a simple DAG with a header, a block-recon node at level 1,
* nNodes nodes at level 2, an unblock-recon node at level 3, and
* a terminator node at level 4. The stripe address field in
* the block and unblock nodes are not touched, nor are the pda
* fields in the second-level nodes, so they must be filled in later.
*
* Commit point is established at unblock node - this means that any
* failure during dag execution causes the dag to fail.
*/
RF_DagHeader_t *
rf_MakeSimpleDAG(RF_Raid_t *raidPtr, int nNodes, int bytesPerSU, char *databuf,
int (*doFunc) (RF_DagNode_t * node), int (*undoFunc) (RF_DagNode_t * node),
char *name /* Node names at the second level. */,
RF_AllocListElem_t *alloclist, RF_RaidAccessFlags_t flags, int priority)
{
RF_DagHeader_t *dag_h;
RF_DagNode_t *nodes, *termNode, *blockNode, *unblockNode;
int i;
/*
* Create the nodes, the block & unblock nodes, and the terminator
* node.
*/
RF_CallocAndAdd(nodes, nNodes + 3, sizeof(RF_DagNode_t),
(RF_DagNode_t *), alloclist);
blockNode = &nodes[nNodes];
unblockNode = blockNode + 1;
termNode = unblockNode + 1;
dag_h = rf_AllocDAGHeader();
dag_h->raidPtr = (void *) raidPtr;
dag_h->allocList = NULL; /* We won't use this alloc list. */
dag_h->status = rf_enable;
dag_h->numSuccedents = 1;
dag_h->creator = "SimpleDAG";
/*
* This dag can not commit until the unblock node is reached.
* Errors prior to the commit point imply the dag has failed.
*/
dag_h->numCommitNodes = 1;
dag_h->numCommits = 0;
dag_h->succedents[0] = blockNode;
rf_InitNode(blockNode, rf_wait, RF_FALSE, rf_NullNodeFunc,
rf_NullNodeUndoFunc, NULL, nNodes, 0, 0, 0, dag_h,
"Nil", alloclist);
rf_InitNode(unblockNode, rf_wait, RF_TRUE, rf_NullNodeFunc,
rf_NullNodeUndoFunc, NULL, 1, nNodes, 0, 0, dag_h,
"Nil", alloclist);
unblockNode->succedents[0] = termNode;
for (i = 0; i < nNodes; i++) {
blockNode->succedents[i] = unblockNode->antecedents[i]
= &nodes[i];
unblockNode->antType[i] = rf_control;
rf_InitNode(&nodes[i], rf_wait, RF_FALSE, doFunc, undoFunc,
rf_GenericWakeupFunc, 1, 1, 4, 0, dag_h, name, alloclist);
nodes[i].succedents[0] = unblockNode;
nodes[i].antecedents[0] = blockNode;
nodes[i].antType[0] = rf_control;
nodes[i].params[1].p = (databuf + (i * bytesPerSU));
}
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;
return (dag_h);
}
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