1 /* $NetBSD: rf_raid5_rotatedspare.c,v 1.13 2009/03/14 15:36:20 dsl 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 1.13 2009/03/14 15:36:20 dsl 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
rf_ConfigureRAID5_RS(RF_ShutdownList_t ** listp,RF_Raid_t * raidPtr,RF_Config_t * cfgPtr)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
rf_GetNumSpareRUsRAID5_RS(RF_Raid_t * raidPtr)102 rf_GetNumSpareRUsRAID5_RS(RF_Raid_t *raidPtr)
103 {
104 return (raidPtr->Layout.stripeUnitsPerDisk / raidPtr->numCol);
105 }
106
107 void
rf_MapSectorRAID5_RS(RF_Raid_t * raidPtr,RF_RaidAddr_t raidSector,RF_RowCol_t * col,RF_SectorNum_t * diskSector,int remap)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
rf_MapParityRAID5_RS(RF_Raid_t * raidPtr,RF_RaidAddr_t raidSector,RF_RowCol_t * col,RF_SectorNum_t * diskSector,int remap)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
rf_IdentifyStripeRAID5_RS(RF_Raid_t * raidPtr,RF_RaidAddr_t addr,RF_RowCol_t ** diskids)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
rf_MapSIDToPSIDRAID5_RS(RF_RaidLayout_t * layoutPtr,RF_StripeNum_t stripeID,RF_StripeNum_t * psID,RF_ReconUnitNum_t * which_ru)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 */
169