Annotation of sys/dev/raidframe/rf_raid5_rotatedspare.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: rf_raid5_rotatedspare.c,v 1.4 2002/12/16 07:01:04 tdeval Exp $ */
2: /* $NetBSD: rf_raid5_rotatedspare.c,v 1.4 2000/01/07 03:41:03 oster Exp $ */
3:
4: /*
5: * Copyright (c) 1995 Carnegie-Mellon University.
6: * All rights reserved.
7: *
8: * Author: Khalil Amiri
9: *
10: * Permission to use, copy, modify and distribute this software and
11: * its documentation is hereby granted, provided that both the copyright
12: * notice and this permission notice appear in all copies of the
13: * software, derivative works or modified versions, and any portions
14: * thereof, and that both notices appear in supporting documentation.
15: *
16: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
18: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19: *
20: * Carnegie Mellon requests users of this software to return to
21: *
22: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
23: * School of Computer Science
24: * Carnegie Mellon University
25: * Pittsburgh PA 15213-3890
26: *
27: * any improvements or extensions that they make and grant Carnegie the
28: * rights to redistribute these changes.
29: */
30:
31: /*****************************************************************************
32: *
33: * rf_raid5_rotated_spare.c -- Implements RAID Level 5 with rotated sparing.
34: *
35: *****************************************************************************/
36:
37: #include "rf_raid.h"
38: #include "rf_raid5.h"
39: #include "rf_dag.h"
40: #include "rf_dagutils.h"
41: #include "rf_dagfuncs.h"
42: #include "rf_general.h"
43: #include "rf_utils.h"
44: #include "rf_raid5_rotatedspare.h"
45:
46: typedef struct RF_Raid5RSConfigInfo_s {
47: RF_RowCol_t **stripeIdentifier; /*
48: * Filled in at config time & used by
49: * IdentifyStripe.
50: */
51: } RF_Raid5RSConfigInfo_t;
52:
53: int
54: rf_ConfigureRAID5_RS(RF_ShutdownList_t **listp, RF_Raid_t *raidPtr,
55: RF_Config_t *cfgPtr)
56: {
57: RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
58: RF_Raid5RSConfigInfo_t *info;
59: RF_RowCol_t i, j, startdisk;
60:
61: /* Create a RAID level 5 configuration structure. */
62: RF_MallocAndAdd(info, sizeof(RF_Raid5RSConfigInfo_t),
63: (RF_Raid5RSConfigInfo_t *), raidPtr->cleanupList);
64: if (info == NULL)
65: return (ENOMEM);
66: layoutPtr->layoutSpecificInfo = (void *) info;
67:
68: RF_ASSERT(raidPtr->numRow == 1);
69: RF_ASSERT(raidPtr->numCol >= 3);
70:
71: /*
72: * The stripe identifier must identify the disks in each stripe, IN
73: * THE ORDER THAT THEY APPEAR IN THE STRIPE.
74: */
75: info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol,
76: 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) %
83: 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->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit <<
92: raidPtr->logBytesPerSector;
93: layoutPtr->numDataCol = raidPtr->numCol - 2;
94: layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol *
95: layoutPtr->sectorsPerStripeUnit;
96: layoutPtr->numParityCol = 1;
97: layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
98: raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk *
99: layoutPtr->sectorsPerStripeUnit;
100:
101: raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk *
102: layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
103:
104: return (0);
105: }
106:
107: RF_ReconUnitCount_t
108: rf_GetNumSpareRUsRAID5_RS(RF_Raid_t *raidPtr)
109: {
110: return (raidPtr->Layout.stripeUnitsPerDisk / raidPtr->numCol);
111: }
112:
113: void
114: rf_MapSectorRAID5_RS(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
115: RF_RowCol_t *row, RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
116: {
117: RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
118:
119: *row = 0;
120: if (remap) {
121: *col = raidPtr->numCol - 1 -
122: (1 + SUID / raidPtr->Layout.numDataCol) % raidPtr->numCol;
123: *col = (*col + 1) % raidPtr->numCol; /*
124: * Spare unit is rotated
125: * with parity; line
126: * above maps to parity.
127: */
128: } else {
129: *col = (SUID + (SUID / raidPtr->Layout.numDataCol)) %
130: raidPtr->numCol;
131: }
132: *diskSector = (SUID / (raidPtr->Layout.numDataCol)) *
133: raidPtr->Layout.sectorsPerStripeUnit +
134: (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
135: }
136:
137: void
138: rf_MapParityRAID5_RS(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector,
139: RF_RowCol_t *row, RF_RowCol_t *col, RF_SectorNum_t *diskSector, int remap)
140: {
141: RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
142:
143: *row = 0;
144: *col = raidPtr->numCol - 1 - (1 + SUID / raidPtr->Layout.numDataCol) %
145: raidPtr->numCol;
146: *diskSector = (SUID / (raidPtr->Layout.numDataCol)) *
147: raidPtr->Layout.sectorsPerStripeUnit +
148: (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
149: if (remap)
150: *col = (*col + 1) % raidPtr->numCol;
151: }
152:
153: void
154: rf_IdentifyStripeRAID5_RS(RF_Raid_t *raidPtr, RF_RaidAddr_t addr,
155: RF_RowCol_t **diskids, RF_RowCol_t *outRow)
156: {
157: RF_StripeNum_t stripeID =
158: rf_RaidAddressToStripeID(&raidPtr->Layout, addr);
159: RF_Raid5RSConfigInfo_t *info =
160: (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(RF_RaidLayout_t *layoutPtr, RF_StripeNum_t stripeID,
168: RF_StripeNum_t *psID, RF_ReconUnitNum_t *which_ru)
169: {
170: *which_ru = 0;
171: *psID = stripeID;
172: }
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