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/* $OpenBSD: rf_chaindecluster.c,v 1.4 2002/12/16 07:01:03 tdeval Exp $ */
/* $NetBSD: rf_chaindecluster.c,v 1.4 2000/01/07 03:40:56 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Khalil Amiri
*
* 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_chaindecluster.c -- implements chained declustering
*
*****************************************************************************/
#include "rf_archs.h"
#include "rf_types.h"
#include "rf_raid.h"
#include "rf_chaindecluster.h"
#include "rf_dag.h"
#include "rf_dagutils.h"
#include "rf_dagffrd.h"
#include "rf_dagffwr.h"
#include "rf_dagdegrd.h"
#include "rf_dagfuncs.h"
#include "rf_general.h"
#include "rf_utils.h"
typedef struct RF_ChaindeclusterConfigInfo_s {
RF_RowCol_t **stripeIdentifier; /*
* Filled in at config time and
* used by IdentifyStripe.
*/
RF_StripeCount_t numSparingRegions;
RF_StripeCount_t stripeUnitsPerSparingRegion;
RF_SectorNum_t mirrorStripeOffset;
} RF_ChaindeclusterConfigInfo_t;
int
rf_ConfigureChainDecluster(RF_ShutdownList_t **listp, RF_Raid_t *raidPtr,
RF_Config_t *cfgPtr)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_StripeCount_t num_used_stripeUnitsPerDisk;
RF_ChaindeclusterConfigInfo_t *info;
RF_RowCol_t i;
/* Create a Chained Declustering configuration structure. */
RF_MallocAndAdd(info, sizeof(RF_ChaindeclusterConfigInfo_t),
(RF_ChaindeclusterConfigInfo_t *), raidPtr->cleanupList);
if (info == NULL)
return (ENOMEM);
layoutPtr->layoutSpecificInfo = (void *) info;
/* Fill in the config structure. */
info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, 2,
raidPtr->cleanupList);
if (info->stripeIdentifier == NULL)
return (ENOMEM);
for (i = 0; i < raidPtr->numCol; i++) {
info->stripeIdentifier[i][0] = i % raidPtr->numCol;
info->stripeIdentifier[i][1] = (i + 1) % raidPtr->numCol;
}
RF_ASSERT(raidPtr->numRow == 1);
/* Fill in the remaining layout parameters. */
num_used_stripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk -
(layoutPtr->stripeUnitsPerDisk % (2 * raidPtr->numCol - 2));
info->numSparingRegions = num_used_stripeUnitsPerDisk /
(2 * raidPtr->numCol - 2);
info->stripeUnitsPerSparingRegion = raidPtr->numCol *
(raidPtr->numCol - 1);
info->mirrorStripeOffset = info->numSparingRegions *
(raidPtr->numCol - 1);
layoutPtr->numStripe = info->numSparingRegions *
info->stripeUnitsPerSparingRegion;
layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit <<
raidPtr->logBytesPerSector;
layoutPtr->numDataCol = 1;
layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol *
layoutPtr->sectorsPerStripeUnit;
layoutPtr->numParityCol = 1;
layoutPtr->dataStripeUnitsPerDisk = num_used_stripeUnitsPerDisk;
raidPtr->sectorsPerDisk = num_used_stripeUnitsPerDisk *
layoutPtr->sectorsPerStripeUnit;
raidPtr->totalSectors = (layoutPtr->numStripe) *
layoutPtr->sectorsPerStripeUnit;
layoutPtr->stripeUnitsPerDisk = raidPtr->sectorsPerDisk /
layoutPtr->sectorsPerStripeUnit;
return (0);
}
RF_ReconUnitCount_t
rf_GetNumSpareRUsChainDecluster(RF_Raid_t *raidPtr)
{
RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *)
raidPtr->Layout.layoutSpecificInfo;
/*
* The layout uses two stripe units per disk as spare within each
* sparing region.
*/
return (2 * info->numSparingRegions);
}
/* Maps to the primary copy of the data, i.e. the first mirror pair. */
void
rf_MapSectorChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
RF_RowCol_t *row, RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
{
RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *)
raidPtr->Layout.layoutSpecificInfo;
RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
RF_SectorNum_t index_within_region, index_within_disk;
RF_StripeNum_t sparing_region_id;
int col_before_remap;
*row = 0;
sparing_region_id = SUID / info->stripeUnitsPerSparingRegion;
index_within_region = SUID % info->stripeUnitsPerSparingRegion;
index_within_disk = index_within_region / raidPtr->numCol;
col_before_remap = SUID % raidPtr->numCol;
if (!remap) {
*col = col_before_remap;
*diskSector = (index_within_disk + ((raidPtr->numCol - 1) *
sparing_region_id)) * raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidSector %
raidPtr->Layout.sectorsPerStripeUnit);
} else {
/* Remap sector to spare space... */
*diskSector = sparing_region_id * (raidPtr->numCol + 1) *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidPtr->numCol - 1) *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidSector %
raidPtr->Layout.sectorsPerStripeUnit);
index_within_disk = index_within_region / raidPtr->numCol;
if (index_within_disk < col_before_remap)
*col = index_within_disk;
else
if (index_within_disk == raidPtr->numCol - 2) {
*col = (col_before_remap + raidPtr->numCol - 1)
% raidPtr->numCol;
*diskSector +=
raidPtr->Layout.sectorsPerStripeUnit;
} else
*col = (index_within_disk + 2) %
raidPtr->numCol;
}
}
/*
* Maps to the second copy of the mirror pair, which is chain declustered.
* The second copy is contained in the next disk (mod numCol) after the disk
* containing the primary copy.
* The offset into the disk is one-half disk down.
*/
void
rf_MapParityChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
RF_RowCol_t *row, RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
{
RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *)
raidPtr->Layout.layoutSpecificInfo;
RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
RF_SectorNum_t index_within_region, index_within_disk;
RF_StripeNum_t sparing_region_id;
int col_before_remap;
*row = 0;
if (!remap) {
*col = SUID % raidPtr->numCol;
*col = (*col + 1) % raidPtr->numCol;
*diskSector = info->mirrorStripeOffset *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (SUID / raidPtr->numCol) *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidSector %
raidPtr->Layout.sectorsPerStripeUnit);
} else {
/* Remap parity to spare space... */
sparing_region_id = SUID / info->stripeUnitsPerSparingRegion;
index_within_region = SUID % info->stripeUnitsPerSparingRegion;
index_within_disk = index_within_region / raidPtr->numCol;
*diskSector = sparing_region_id * (raidPtr->numCol + 1) *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidPtr->numCol) *
raidPtr->Layout.sectorsPerStripeUnit;
*diskSector += (raidSector %
raidPtr->Layout.sectorsPerStripeUnit);
col_before_remap = SUID % raidPtr->numCol;
if (index_within_disk < col_before_remap)
*col = index_within_disk;
else
if (index_within_disk == raidPtr->numCol - 2) {
*col = (col_before_remap + 2) % raidPtr->numCol;
*diskSector -=
raidPtr->Layout.sectorsPerStripeUnit;
} else
*col = (index_within_disk + 2) %
raidPtr->numCol;
}
}
void
rf_IdentifyStripeChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t addr,
RF_RowCol_t **diskids, RF_RowCol_t *outRow)
{
RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *)
raidPtr->Layout.layoutSpecificInfo;
RF_StripeNum_t SUID;
RF_RowCol_t col;
SUID = addr / raidPtr->Layout.sectorsPerStripeUnit;
col = SUID % raidPtr->numCol;
*outRow = 0;
*diskids = info->stripeIdentifier[col];
}
void
rf_MapSIDToPSIDChainDecluster(RF_RaidLayout_t *layoutPtr,
RF_StripeNum_t stripeID, RF_StripeNum_t *psID, RF_ReconUnitNum_t *which_ru)
{
*which_ru = 0;
*psID = stripeID;
}
/****************************************************************************
* Select a graph to perform a single-stripe access.
*
* Parameters: raidPtr - description of the physical array
* type - type of operation (read or write) requested
* asmap - logical & physical addresses for this access
* createFunc - function to use to create the graph (return value)
*****************************************************************************/
void
rf_RAIDCDagSelect(RF_Raid_t *raidPtr, RF_IoType_t type,
RF_AccessStripeMap_t *asmap, RF_VoidFuncPtr *createFunc)
{
RF_ASSERT(RF_IO_IS_R_OR_W(type));
RF_ASSERT(raidPtr->numRow == 1);
if (asmap->numDataFailed + asmap->numParityFailed > 1) {
RF_ERRORMSG("Multiple disks failed in a single group !"
" Aborting I/O operation.\n");
*createFunc = NULL;
return;
}
*createFunc = (type == RF_IO_TYPE_READ) ?
(RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG :
(RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG;
if (type == RF_IO_TYPE_READ) {
if ((raidPtr->status[0] == rf_rs_degraded) ||
(raidPtr->status[0] == rf_rs_reconstructing))
/*
* Array status is degraded,
* implement workload shifting.
*/
*createFunc = (RF_VoidFuncPtr)
rf_CreateRaidCDegradedReadDAG;
else
/*
* Array status not degraded,
* so use mirror partition dag.
*/
*createFunc = (RF_VoidFuncPtr)
rf_CreateMirrorPartitionReadDAG;
} else
*createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG;
}
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