Home | History | Annotate | Line # | Download | only in raidframe
rf_raid5_rotatedspare.c revision 1.7 
      1 /*	$NetBSD: rf_raid5_rotatedspare.c,v 1.7 2002/09/23 02:40:09 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 <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "$NetBSD: rf_raid5_rotatedspare.c,v 1.7 2002/09/23 02:40:09 oster 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->numRow == 1);
     73 	RF_ASSERT(raidPtr->numCol >= 3);
     74 
     75 	/* the stripe identifier must identify the disks in each stripe, IN
     76 	 * THE ORDER THAT THEY APPEAR IN THE STRIPE. */
     77 	info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, raidPtr->numCol, raidPtr->cleanupList);
     78 	if (info->stripeIdentifier == NULL)
     79 		return (ENOMEM);
     80 	startdisk = 0;
     81 	for (i = 0; i < raidPtr->numCol; i++) {
     82 		for (j = 0; j < raidPtr->numCol; j++) {
     83 			info->stripeIdentifier[i][j] = (startdisk + j) % raidPtr->numCol;
     84 		}
     85 		if ((--startdisk) < 0)
     86 			startdisk = raidPtr->numCol - 1;
     87 	}
     88 
     89 	/* fill in the remaining layout parameters */
     90 	layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
     91 	layoutPtr->numDataCol = raidPtr->numCol - 2;
     92 	layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
     93 	layoutPtr->numParityCol = 1;
     94 	layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
     95 	raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
     96 
     97 	raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk * layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
     98 
     99 	return (0);
    100 }
    101 
    102 RF_ReconUnitCount_t
    103 rf_GetNumSpareRUsRAID5_RS(raidPtr)
    104 	RF_Raid_t *raidPtr;
    105 {
    106 	return (raidPtr->Layout.stripeUnitsPerDisk / raidPtr->numCol);
    107 }
    108 
    109 void
    110 rf_MapSectorRAID5_RS(
    111     RF_Raid_t * raidPtr,
    112     RF_RaidAddr_t raidSector,
    113     RF_RowCol_t * row,
    114     RF_RowCol_t * col,
    115     RF_SectorNum_t * diskSector,
    116     int remap)
    117 {
    118 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
    119 
    120 	*row = 0;
    121 	if (remap) {
    122 		*col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
    123 		*col = (*col + 1) % raidPtr->numCol;	/* spare unit is rotated
    124 							 * with parity; line
    125 							 * above maps to parity */
    126 	} else {
    127 		*col = (SUID + (SUID / raidPtr->Layout.numDataCol)) % raidPtr->numCol;
    128 	}
    129 	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
    130 	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    131 }
    132 
    133 void
    134 rf_MapParityRAID5_RS(
    135     RF_Raid_t * raidPtr,
    136     RF_RaidAddr_t raidSector,
    137     RF_RowCol_t * row,
    138     RF_RowCol_t * col,
    139     RF_SectorNum_t * diskSector,
    140     int remap)
    141 {
    142 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
    143 
    144 	*row = 0;
    145 	*col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
    146 	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) * raidPtr->Layout.sectorsPerStripeUnit +
    147 	    (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    148 	if (remap)
    149 		*col = (*col + 1) % raidPtr->numCol;
    150 }
    151 
    152 void
    153 rf_IdentifyStripeRAID5_RS(
    154     RF_Raid_t * raidPtr,
    155     RF_RaidAddr_t addr,
    156     RF_RowCol_t ** diskids,
    157     RF_RowCol_t * outRow)
    158 {
    159 	RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
    160 	RF_Raid5RSConfigInfo_t *info = (RF_Raid5RSConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    161 	*outRow = 0;
    162 	*diskids = info->stripeIdentifier[stripeID % raidPtr->numCol];
    163 
    164 }
    165 
    166 void
    167 rf_MapSIDToPSIDRAID5_RS(
    168     RF_RaidLayout_t * layoutPtr,
    169     RF_StripeNum_t stripeID,
    170     RF_StripeNum_t * psID,
    171     RF_ReconUnitNum_t * which_ru)
    172 {
    173 	*which_ru = 0;
    174 	*psID = stripeID;
    175 }
    176 #endif /* RF_INCLUDE_RAID5_RS > 0 */
    177