sys/dev/raidframe/rf_raid5_rotatedspare.c

   1 /*      $NetBSD: rf_raid5_rotatedspare.c,v 1.12 2006/11/16 01:33:23 christos Exp $      */
   2 /*
   3  * Copyright (c) 1995 Carnegie-Mellon University.
   4  * All rights reserved.
   5  *
   6  * Author: Khalil Amiri
   7  *
   8  * Permission to use, copy, modify and distribute this software and
   9  * its documentation is hereby granted, provided that both the copyright
  10  * notice and this permission notice appear in all copies of the
  11  * software, derivative works or modified versions, and any portions
  12  * thereof, and that both notices appear in supporting documentation.
  13  *
  14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
  16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  17  *
  18  * Carnegie Mellon requests users of this software to return to
  19  *
  20  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  21  *  School of Computer Science
  22  *  Carnegie Mellon University
  23  *  Pittsburgh PA 15213-3890
  24  *
  25  * any improvements or extensions that they make and grant Carnegie the
  26  * rights to redistribute these changes.
  27  */
  28
  29 /**************************************************************************
  30  *
  31  * rf_raid5_rotated_spare.c -- implements RAID Level 5 with rotated sparing
  32  *
  33  **************************************************************************/
  34
  35 #include <sys/cdefs.h>
  36 __KERNEL_RCSID(0, "$NetBSD: rf_raid5_rotatedspare.c,v 1.12 2006/11/16 01:33:23 christos Exp $");
  37
  38 #include "rf_archs.h"
  39
  40 #if RF_INCLUDE_RAID5_RS > 0
  41
  42 #include "rf_raid.h"
  43 #include "rf_raid5.h"
  44 #include "rf_dag.h"
  45 #include "rf_dagutils.h"
  46 #include "rf_dagfuncs.h"
  47 #include "rf_general.h"
  48 #include "rf_utils.h"
  49 #include "rf_raid5_rotatedspare.h"
  50
  51 typedef struct RF_Raid5RSConfigInfo_s {
  52         RF_RowCol_t **stripeIdentifier; /* filled in at config time & used by
  53                                          * IdentifyStripe */
  54 }       RF_Raid5RSConfigInfo_t;
  55
  56 int
  57 rf_ConfigureRAID5_RS(
  58     RF_ShutdownList_t ** listp,
  59     RF_Raid_t * raidPtr,
  60     RF_Config_t * cfgPtr)
  61 {
  62         RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
  63         RF_Raid5RSConfigInfo_t *info;
  64         RF_RowCol_t i, j, startdisk;
  65
  66         /* create a RAID level 5 configuration structure */
  67         RF_MallocAndAdd(info, sizeof(RF_Raid5RSConfigInfo_t), (RF_Raid5RSConfigInfo_t *), raidPtr->cleanupList);
  68         if (info == NULL)
  69                 return (ENOMEM);
  70         layoutPtr->layoutSpecificInfo = (void *) info;
  71
  72         RF_ASSERT(raidPtr->numCol >= 3);
  73
  74         /* the stripe identifier must identify the disks in each stripe, IN
  75          * THE ORDER THAT THEY APPEAR IN THE STRIPE. */
  76         info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, raidPtr->numCol, raidPtr->cleanupList);
  77         if (info->stripeIdentifier == NULL)
  78                 return (ENOMEM);
  79         startdisk = 0;
  80         for (i = 0; i < raidPtr->numCol; i++) {
  81                 for (j = 0; j < raidPtr->numCol; j++) {
  82                         info->stripeIdentifier[i][j] = (startdisk + j) % raidPtr->numCol;
  83                 }
  84                 if ((--startdisk) < 0)
  85                         startdisk = raidPtr->numCol - 1;
  86         }
  87
  88         /* fill in the remaining layout parameters */
  89         layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
  90         layoutPtr->numDataCol = raidPtr->numCol - 2;
  91         layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
  92         layoutPtr->numParityCol = 1;
  93         layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
  94         raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
  95
  96         raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
  97
  98         return (0);
  99 }
 100
 101 RF_ReconUnitCount_t
 102 rf_GetNumSpareRUsRAID5_RS(RF_Raid_t *raidPtr)
 103 {
 104         return (raidPtr->Layout.stripeUnitsPerDisk / raidPtr->numCol);
 105 }
 106
 107 void
 108 rf_MapSectorRAID5_RS(
 109     RF_Raid_t * raidPtr,
 110     RF_RaidAddr_t raidSector,
 111     RF_RowCol_t * col,
 112     RF_SectorNum_t * diskSector,
 113     int remap)
 114 {
 115         RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
 116
 117         if (remap) {
 118                 *col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
 119                 *col = (*col + 1) % raidPtr->numCol;    /* spare unit is rotated
 120                                                          * with parity; line
 121                                                          * above maps to parity */
 122         } else {
 123                 *col = (SUID + (SUID / raidPtr->Layout.numDataCol)) % raidPtr->numCol;
 124         }
 125         *diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
 126             (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
 127 }
 128
 129 void
 130 rf_MapParityRAID5_RS(
 131     RF_Raid_t * raidPtr,
 132     RF_RaidAddr_t raidSector,
 133     RF_RowCol_t * col,
 134     RF_SectorNum_t * diskSector,
 135     int remap)
 136 {
 137         RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
 138
 139         *col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
 140         *diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
 141             (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
 142         if (remap)
 143                 *col = (*col + 1) % raidPtr->numCol;
 144 }
 145
 146 void
 147 rf_IdentifyStripeRAID5_RS(
 148     RF_Raid_t * raidPtr,
 149     RF_RaidAddr_t addr,
 150     RF_RowCol_t ** diskids)
 151 {
 152         RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
 153         RF_Raid5RSConfigInfo_t *info = (RF_Raid5RSConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
 154         *diskids = info->stripeIdentifier[stripeID % raidPtr->numCol];
 155
 156 }
 157
 158 void
 159 rf_MapSIDToPSIDRAID5_RS(
 160     RF_RaidLayout_t * layoutPtr,
 161     RF_StripeNum_t stripeID,
 162     RF_StripeNum_t * psID,
 163     RF_ReconUnitNum_t * which_ru)
 164 {
 165         *which_ru = 0;
 166         *psID = stripeID;
 167 }
 168 #endif /* RF_INCLUDE_RAID5_RS > 0 */