NetBSD/sys/dev/raidframe/rf_raid0.c

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Fix the "We panic if we can't create a DAG" problem that's existed ~forever. This requires a number of things: 1) If we can't create a DAG, set desc->numStripes to 0 in rf_SelectAlgorithm. This will ensure that we don't attempt to free any dagArray[] elements in rf_StateCleanup. 2) Modify rf_State_CreateDAG() to not panic in the event of a DAG failure. Instead, set the bp->b_flags and bp->b_error, and set things up to skip to rf_State_Cleanup(). 3) Need to mark desc->status as "bad" so that we actually stop looking for a different DAG. (which we won't find... no matter how many times we try). 4) rf_State_LastState() will then do the biodone(), and return EIO for the IO in question. 5) Remove some " || 1 "'s from ProcessNode(). These were for debugging, and we don't need the failure notices spewing over and over again as the failing DAGs are processed. 6) Needed to change if (asmap->numDataFailed + asmap->numParityFailed > 1) to if ((asmap->numDataFailed + asmap->numParityFailed > 1) || (raidPtr->numFailures > 1)){ in rf_raid5.c so that it doesn't try to return rf_CreateNonRedundantWriteDAG as the creation function. 7) Note that we can't apply the above change to the RAID 1 code as with the silly "fake 2-D" RAID 1 sets, it is possible to have 2 failed components in the RAID 1 set, and that would stop them from working. (I really don't know why/how those "fake 2-D" RAID 1 sets even work with all the "single-fault" assumptions present in the rest of the code.) 8) Needed to protect rf_RAID0DagSelect() in a similar way -- it should return NULL as the createFunc. 9) No point printing out "Multiple disks failed..." a zillion times.
2004-01-03 00:41:08 +03:00
/* $NetBSD: rf_raid0.c,v 1.10 2004/01/02 21:41:08 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_raid0.c -- implements RAID Level 0
*
***************************************/
2001-11-13 10:11:12 +03:00
#include <sys/cdefs.h>
Fix the "We panic if we can't create a DAG" problem that's existed ~forever. This requires a number of things: 1) If we can't create a DAG, set desc->numStripes to 0 in rf_SelectAlgorithm. This will ensure that we don't attempt to free any dagArray[] elements in rf_StateCleanup. 2) Modify rf_State_CreateDAG() to not panic in the event of a DAG failure. Instead, set the bp->b_flags and bp->b_error, and set things up to skip to rf_State_Cleanup(). 3) Need to mark desc->status as "bad" so that we actually stop looking for a different DAG. (which we won't find... no matter how many times we try). 4) rf_State_LastState() will then do the biodone(), and return EIO for the IO in question. 5) Remove some " || 1 "'s from ProcessNode(). These were for debugging, and we don't need the failure notices spewing over and over again as the failing DAGs are processed. 6) Needed to change if (asmap->numDataFailed + asmap->numParityFailed > 1) to if ((asmap->numDataFailed + asmap->numParityFailed > 1) || (raidPtr->numFailures > 1)){ in rf_raid5.c so that it doesn't try to return rf_CreateNonRedundantWriteDAG as the creation function. 7) Note that we can't apply the above change to the RAID 1 code as with the silly "fake 2-D" RAID 1 sets, it is possible to have 2 failed components in the RAID 1 set, and that would stop them from working. (I really don't know why/how those "fake 2-D" RAID 1 sets even work with all the "single-fault" assumptions present in the rest of the code.) 8) Needed to protect rf_RAID0DagSelect() in a similar way -- it should return NULL as the createFunc. 9) No point printing out "Multiple disks failed..." a zillion times.
2004-01-03 00:41:08 +03:00
__KERNEL_RCSID(0, "$NetBSD: rf_raid0.c,v 1.10 2004/01/02 21:41:08 oster Exp $");
2001-11-13 10:11:12 +03:00
#include <dev/raidframe/raidframevar.h>
#include "rf_raid.h"
#include "rf_raid0.h"
#include "rf_dag.h"
#include "rf_dagffrd.h"
#include "rf_dagffwr.h"
#include "rf_dagutils.h"
#include "rf_dagfuncs.h"
#include "rf_general.h"
#include "rf_parityscan.h"
typedef struct RF_Raid0ConfigInfo_s {
RF_RowCol_t *stripeIdentifier;
} RF_Raid0ConfigInfo_t;
int
rf_ConfigureRAID0(RF_ShutdownList_t **listp, RF_Raid_t *raidPtr,
RF_Config_t *cfgPtr)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_Raid0ConfigInfo_t *info;
RF_RowCol_t i;
/* create a RAID level 0 configuration structure */
RF_MallocAndAdd(info, sizeof(RF_Raid0ConfigInfo_t), (RF_Raid0ConfigInfo_t *), raidPtr->cleanupList);
if (info == NULL)
return (ENOMEM);
layoutPtr->layoutSpecificInfo = (void *) info;
RF_MallocAndAdd(info->stripeIdentifier, raidPtr->numCol * sizeof(RF_RowCol_t), (RF_RowCol_t *), raidPtr->cleanupList);
if (info->stripeIdentifier == NULL)
return (ENOMEM);
for (i = 0; i < raidPtr->numCol; i++)
info->stripeIdentifier[i] = i;
RF_ASSERT(raidPtr->numRow == 1);
raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * raidPtr->numCol * layoutPtr->sectorsPerStripeUnit;
layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
layoutPtr->dataSectorsPerStripe = raidPtr->numCol * layoutPtr->sectorsPerStripeUnit;
layoutPtr->numDataCol = raidPtr->numCol;
layoutPtr->numParityCol = 0;
return (0);
}
void
rf_MapSectorRAID0(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
{
RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
*col = SUID % raidPtr->numCol;
*diskSector = (SUID / raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit +
(raidSector % raidPtr->Layout.sectorsPerStripeUnit);
}
void
rf_MapParityRAID0(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
{
*col = 0;
*diskSector = 0;
}
void
rf_IdentifyStripeRAID0(RF_Raid_t *raidPtr, RF_RaidAddr_t addr,
RF_RowCol_t **diskids)
{
RF_Raid0ConfigInfo_t *info;
info = raidPtr->Layout.layoutSpecificInfo;
*diskids = info->stripeIdentifier;
}
void
rf_MapSIDToPSIDRAID0(RF_RaidLayout_t *layoutPtr, RF_StripeNum_t stripeID,
RF_StripeNum_t *psID, RF_ReconUnitNum_t *which_ru)
{
*which_ru = 0;
*psID = stripeID;
}
void
rf_RAID0DagSelect(
RF_Raid_t * raidPtr,
RF_IoType_t type,
RF_AccessStripeMap_t * asmap,
RF_VoidFuncPtr * createFunc)
{
Fix the "We panic if we can't create a DAG" problem that's existed ~forever. This requires a number of things: 1) If we can't create a DAG, set desc->numStripes to 0 in rf_SelectAlgorithm. This will ensure that we don't attempt to free any dagArray[] elements in rf_StateCleanup. 2) Modify rf_State_CreateDAG() to not panic in the event of a DAG failure. Instead, set the bp->b_flags and bp->b_error, and set things up to skip to rf_State_Cleanup(). 3) Need to mark desc->status as "bad" so that we actually stop looking for a different DAG. (which we won't find... no matter how many times we try). 4) rf_State_LastState() will then do the biodone(), and return EIO for the IO in question. 5) Remove some " || 1 "'s from ProcessNode(). These were for debugging, and we don't need the failure notices spewing over and over again as the failing DAGs are processed. 6) Needed to change if (asmap->numDataFailed + asmap->numParityFailed > 1) to if ((asmap->numDataFailed + asmap->numParityFailed > 1) || (raidPtr->numFailures > 1)){ in rf_raid5.c so that it doesn't try to return rf_CreateNonRedundantWriteDAG as the creation function. 7) Note that we can't apply the above change to the RAID 1 code as with the silly "fake 2-D" RAID 1 sets, it is possible to have 2 failed components in the RAID 1 set, and that would stop them from working. (I really don't know why/how those "fake 2-D" RAID 1 sets even work with all the "single-fault" assumptions present in the rest of the code.) 8) Needed to protect rf_RAID0DagSelect() in a similar way -- it should return NULL as the createFunc. 9) No point printing out "Multiple disks failed..." a zillion times.
2004-01-03 00:41:08 +03:00
if (raidPtr->numFailures > 0) {
*createFunc = NULL;
return;
}
*createFunc = ((type == RF_IO_TYPE_READ) ?
(RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG : (RF_VoidFuncPtr) rf_CreateRAID0WriteDAG);
}
int
rf_VerifyParityRAID0(RF_Raid_t *raidPtr, RF_RaidAddr_t raidAddr,
RF_PhysDiskAddr_t *parityPDA, int correct_it,
RF_RaidAccessFlags_t flags)
{
/*
* No parity is always okay.
*/
return (RF_PARITY_OKAY);
}