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rf_raid5_rotatedspare.c revision 1.3 
      1 /*	$NetBSD: rf_raid5_rotatedspare.c,v 1.3 1999/02/05 00:06:16 oster 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 (at) 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 "rf_raid.h"
     36 #include "rf_raid5.h"
     37 #include "rf_dag.h"
     38 #include "rf_dagutils.h"
     39 #include "rf_dagfuncs.h"
     40 #include "rf_threadid.h"
     41 #include "rf_general.h"
     42 #include "rf_utils.h"
     43 #include "rf_raid5_rotatedspare.h"
     44 
     45 typedef struct RF_Raid5RSConfigInfo_s {
     46 	RF_RowCol_t **stripeIdentifier;	/* filled in at config time & used by
     47 					 * IdentifyStripe */
     48 }       RF_Raid5RSConfigInfo_t;
     49 
     50 int
     51 rf_ConfigureRAID5_RS(
     52     RF_ShutdownList_t ** listp,
     53     RF_Raid_t * raidPtr,
     54     RF_Config_t * cfgPtr)
     55 {
     56 	RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
     57 	RF_Raid5RSConfigInfo_t *info;
     58 	RF_RowCol_t i, j, startdisk;
     59 
     60 	/* create a RAID level 5 configuration structure */
     61 	RF_MallocAndAdd(info, sizeof(RF_Raid5RSConfigInfo_t), (RF_Raid5RSConfigInfo_t *), raidPtr->cleanupList);
     62 	if (info == NULL)
     63 		return (ENOMEM);
     64 	layoutPtr->layoutSpecificInfo = (void *) info;
     65 
     66 	RF_ASSERT(raidPtr->numRow == 1);
     67 	RF_ASSERT(raidPtr->numCol >= 3);
     68 
     69 	/* the stripe identifier must identify the disks in each stripe, IN
     70 	 * THE ORDER THAT THEY APPEAR IN THE STRIPE. */
     71 	info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, raidPtr->numCol, raidPtr->cleanupList);
     72 	if (info->stripeIdentifier == NULL)
     73 		return (ENOMEM);
     74 	startdisk = 0;
     75 	for (i = 0; i < raidPtr->numCol; i++) {
     76 		for (j = 0; j < raidPtr->numCol; j++) {
     77 			info->stripeIdentifier[i][j] = (startdisk + j) % raidPtr->numCol;
     78 		}
     79 		if ((--startdisk) < 0)
     80 			startdisk = raidPtr->numCol - 1;
     81 	}
     82 
     83 	/* fill in the remaining layout parameters */
     84 	layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
     85 	layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
     86 	layoutPtr->numDataCol = raidPtr->numCol - 2;
     87 	layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
     88 	layoutPtr->numParityCol = 1;
     89 	layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
     90 	raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
     91 
     92 	raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
     93 
     94 	return (0);
     95 }
     96 
     97 RF_ReconUnitCount_t
     98 rf_GetNumSpareRUsRAID5_RS(raidPtr)
     99 	RF_Raid_t *raidPtr;
    100 {
    101 	return (raidPtr->Layout.stripeUnitsPerDisk / raidPtr->numCol);
    102 }
    103 
    104 void
    105 rf_MapSectorRAID5_RS(
    106     RF_Raid_t * raidPtr,
    107     RF_RaidAddr_t raidSector,
    108     RF_RowCol_t * row,
    109     RF_RowCol_t * col,
    110     RF_SectorNum_t * diskSector,
    111     int remap)
    112 {
    113 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
    114 
    115 	*row = 0;
    116 	if (remap) {
    117 		*col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
    118 		*col = (*col + 1) % raidPtr->numCol;	/* spare unit is rotated
    119 							 * with parity; line
    120 							 * above maps to parity */
    121 	} else {
    122 		*col = (SUID + (SUID / raidPtr->Layout.numDataCol)) % raidPtr->numCol;
    123 	}
    124 	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
    125 	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    126 }
    127 
    128 void
    129 rf_MapParityRAID5_RS(
    130     RF_Raid_t * raidPtr,
    131     RF_RaidAddr_t raidSector,
    132     RF_RowCol_t * row,
    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 	*row = 0;
    140 	*col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
    141 	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
    142 	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    143 	if (remap)
    144 		*col = (*col + 1) % raidPtr->numCol;
    145 }
    146 
    147 void
    148 rf_IdentifyStripeRAID5_RS(
    149     RF_Raid_t * raidPtr,
    150     RF_RaidAddr_t addr,
    151     RF_RowCol_t ** diskids,
    152     RF_RowCol_t * outRow)
    153 {
    154 	RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
    155 	RF_Raid5RSConfigInfo_t *info = (RF_Raid5RSConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    156 	*outRow = 0;
    157 	*diskids = info->stripeIdentifier[stripeID % raidPtr->numCol];
    158 
    159 }
    160 
    161 void
    162 rf_MapSIDToPSIDRAID5_RS(
    163     RF_RaidLayout_t * layoutPtr,
    164     RF_StripeNum_t stripeID,
    165     RF_StripeNum_t * psID,
    166     RF_ReconUnitNum_t * which_ru)
    167 {
    168 	*which_ru = 0;
    169 	*psID = stripeID;
    170 }
    171