1 | /* $NetBSD: rf_chaindecluster.c,v 1.15 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_chaindecluster.c -- implements chained declustering |
32 | * |
33 | *****************************************************************************/ |
34 | |
35 | #include <sys/cdefs.h> |
36 | __KERNEL_RCSID(0, "$NetBSD: rf_chaindecluster.c,v 1.15 2006/11/16 01:33:23 christos Exp $" ); |
37 | |
38 | #include "rf_archs.h" |
39 | |
40 | #if (RF_INCLUDE_CHAINDECLUSTER > 0) |
41 | |
42 | #include <dev/raidframe/raidframevar.h> |
43 | |
44 | #include "rf_raid.h" |
45 | #include "rf_chaindecluster.h" |
46 | #include "rf_dag.h" |
47 | #include "rf_dagutils.h" |
48 | #include "rf_dagffrd.h" |
49 | #include "rf_dagffwr.h" |
50 | #include "rf_dagdegrd.h" |
51 | #include "rf_dagfuncs.h" |
52 | #include "rf_general.h" |
53 | #include "rf_utils.h" |
54 | |
55 | typedef struct RF_ChaindeclusterConfigInfo_s { |
56 | RF_RowCol_t **stripeIdentifier; /* filled in at config time and used |
57 | * by IdentifyStripe */ |
58 | RF_StripeCount_t numSparingRegions; |
59 | RF_StripeCount_t stripeUnitsPerSparingRegion; |
60 | RF_SectorNum_t mirrorStripeOffset; |
61 | } RF_ChaindeclusterConfigInfo_t; |
62 | |
63 | int |
64 | rf_ConfigureChainDecluster(RF_ShutdownList_t **listp, |
65 | RF_Raid_t *raidPtr, RF_Config_t *cfgPtr) |
66 | { |
67 | RF_RaidLayout_t *layoutPtr = &raidPtr->Layout; |
68 | RF_StripeCount_t num_used_stripeUnitsPerDisk; |
69 | RF_ChaindeclusterConfigInfo_t *info; |
70 | RF_RowCol_t i; |
71 | |
72 | /* create a Chained Declustering configuration structure */ |
73 | RF_MallocAndAdd(info, sizeof(RF_ChaindeclusterConfigInfo_t), (RF_ChaindeclusterConfigInfo_t *), raidPtr->cleanupList); |
74 | if (info == NULL) |
75 | return (ENOMEM); |
76 | layoutPtr->layoutSpecificInfo = (void *) info; |
77 | |
78 | /* fill in the config structure. */ |
79 | info->stripeIdentifier = rf_make_2d_array(raidPtr->numCol, 2, raidPtr->cleanupList); |
80 | if (info->stripeIdentifier == NULL) |
81 | return (ENOMEM); |
82 | for (i = 0; i < raidPtr->numCol; i++) { |
83 | info->stripeIdentifier[i][0] = i % raidPtr->numCol; |
84 | info->stripeIdentifier[i][1] = (i + 1) % raidPtr->numCol; |
85 | } |
86 | |
87 | /* fill in the remaining layout parameters */ |
88 | num_used_stripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk - (layoutPtr->stripeUnitsPerDisk % |
89 | (2 * raidPtr->numCol - 2)); |
90 | info->numSparingRegions = num_used_stripeUnitsPerDisk / (2 * raidPtr->numCol - 2); |
91 | info->stripeUnitsPerSparingRegion = raidPtr->numCol * (raidPtr->numCol - 1); |
92 | info->mirrorStripeOffset = info->numSparingRegions * (raidPtr->numCol - 1); |
93 | layoutPtr->numStripe = info->numSparingRegions * info->stripeUnitsPerSparingRegion; |
94 | layoutPtr->numDataCol = 1; |
95 | layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit; |
96 | layoutPtr->numParityCol = 1; |
97 | |
98 | layoutPtr->dataStripeUnitsPerDisk = num_used_stripeUnitsPerDisk; |
99 | |
100 | raidPtr->sectorsPerDisk = |
101 | num_used_stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit; |
102 | |
103 | raidPtr->totalSectors = |
104 | (layoutPtr->numStripe) * layoutPtr->sectorsPerStripeUnit; |
105 | |
106 | layoutPtr->stripeUnitsPerDisk = raidPtr->sectorsPerDisk / layoutPtr->sectorsPerStripeUnit; |
107 | |
108 | return (0); |
109 | } |
110 | |
111 | RF_ReconUnitCount_t |
112 | rf_GetNumSpareRUsChainDecluster(RF_Raid_t *raidPtr) |
113 | { |
114 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
115 | |
116 | /* |
117 | * The layout uses two stripe units per disk as spare within each |
118 | * sparing region. |
119 | */ |
120 | return (2 * info->numSparingRegions); |
121 | } |
122 | |
123 | |
124 | /* Maps to the primary copy of the data, i.e. the first mirror pair */ |
125 | void |
126 | rf_MapSectorChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector, |
127 | RF_RowCol_t *col, RF_SectorNum_t *diskSector, |
128 | int remap) |
129 | { |
130 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
131 | RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; |
132 | RF_SectorNum_t index_within_region, index_within_disk; |
133 | RF_StripeNum_t sparing_region_id; |
134 | int col_before_remap; |
135 | |
136 | sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; |
137 | index_within_region = SUID % info->stripeUnitsPerSparingRegion; |
138 | index_within_disk = index_within_region / raidPtr->numCol; |
139 | col_before_remap = SUID % raidPtr->numCol; |
140 | |
141 | if (!remap) { |
142 | *col = col_before_remap; |
143 | *diskSector = (index_within_disk + ((raidPtr->numCol - 1) * sparing_region_id)) * |
144 | raidPtr->Layout.sectorsPerStripeUnit; |
145 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
146 | } else { |
147 | /* remap sector to spare space... */ |
148 | *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; |
149 | *diskSector += (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit; |
150 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
151 | index_within_disk = index_within_region / raidPtr->numCol; |
152 | if (index_within_disk < col_before_remap) |
153 | *col = index_within_disk; |
154 | else |
155 | if (index_within_disk == raidPtr->numCol - 2) { |
156 | *col = (col_before_remap + raidPtr->numCol - 1) % raidPtr->numCol; |
157 | *diskSector += raidPtr->Layout.sectorsPerStripeUnit; |
158 | } else |
159 | *col = (index_within_disk + 2) % raidPtr->numCol; |
160 | } |
161 | |
162 | } |
163 | |
164 | |
165 | |
166 | /* Maps to the second copy of the mirror pair, which is chain declustered. The second copy is contained |
167 | in the next disk (mod numCol) after the disk containing the primary copy. |
168 | The offset into the disk is one-half disk down */ |
169 | void |
170 | rf_MapParityChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t raidSector, |
171 | RF_RowCol_t *col, RF_SectorNum_t *diskSector, |
172 | int remap) |
173 | { |
174 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
175 | RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit; |
176 | RF_SectorNum_t index_within_region, index_within_disk; |
177 | RF_StripeNum_t sparing_region_id; |
178 | int col_before_remap; |
179 | |
180 | if (!remap) { |
181 | *col = SUID % raidPtr->numCol; |
182 | *col = (*col + 1) % raidPtr->numCol; |
183 | *diskSector = info->mirrorStripeOffset * raidPtr->Layout.sectorsPerStripeUnit; |
184 | *diskSector += (SUID / raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit; |
185 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
186 | } else { |
187 | /* remap parity to spare space ... */ |
188 | sparing_region_id = SUID / info->stripeUnitsPerSparingRegion; |
189 | index_within_region = SUID % info->stripeUnitsPerSparingRegion; |
190 | index_within_disk = index_within_region / raidPtr->numCol; |
191 | *diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit; |
192 | *diskSector += (raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit; |
193 | *diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit); |
194 | col_before_remap = SUID % raidPtr->numCol; |
195 | if (index_within_disk < col_before_remap) |
196 | *col = index_within_disk; |
197 | else |
198 | if (index_within_disk == raidPtr->numCol - 2) { |
199 | *col = (col_before_remap + 2) % raidPtr->numCol; |
200 | *diskSector -= raidPtr->Layout.sectorsPerStripeUnit; |
201 | } else |
202 | *col = (index_within_disk + 2) % raidPtr->numCol; |
203 | } |
204 | |
205 | } |
206 | |
207 | void |
208 | rf_IdentifyStripeChainDecluster(RF_Raid_t *raidPtr, RF_RaidAddr_t addr, |
209 | RF_RowCol_t **diskids) |
210 | { |
211 | RF_ChaindeclusterConfigInfo_t *info = (RF_ChaindeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo; |
212 | RF_StripeNum_t SUID; |
213 | RF_RowCol_t col; |
214 | |
215 | SUID = addr / raidPtr->Layout.sectorsPerStripeUnit; |
216 | col = SUID % raidPtr->numCol; |
217 | *diskids = info->stripeIdentifier[col]; |
218 | } |
219 | |
220 | void |
221 | rf_MapSIDToPSIDChainDecluster(RF_RaidLayout_t *layoutPtr, |
222 | RF_StripeNum_t stripeID, |
223 | RF_StripeNum_t *psID, |
224 | RF_ReconUnitNum_t *which_ru) |
225 | { |
226 | *which_ru = 0; |
227 | *psID = stripeID; |
228 | } |
229 | /****************************************************************************** |
230 | * select a graph to perform a single-stripe access |
231 | * |
232 | * Parameters: raidPtr - description of the physical array |
233 | * type - type of operation (read or write) requested |
234 | * asmap - logical & physical addresses for this access |
235 | * createFunc - function to use to create the graph (return value) |
236 | *****************************************************************************/ |
237 | |
238 | void |
239 | rf_RAIDCDagSelect(RF_Raid_t *raidPtr, RF_IoType_t type, |
240 | RF_AccessStripeMap_t *asmap, RF_VoidFuncPtr *createFunc) |
241 | #if 0 |
242 | void (**createFunc) (RF_Raid_t *, RF_AccessStripeMap_t *, |
243 | RF_DagHeader_t *, void *, RF_RaidAccessFlags_t, |
244 | RF_AllocListElem_t *) |
245 | #endif |
246 | { |
247 | RF_ASSERT(RF_IO_IS_R_OR_W(type)); |
248 | |
249 | if (asmap->numDataFailed + asmap->numParityFailed > 1) { |
250 | RF_ERRORMSG("Multiple disks failed in a single group! Aborting I/O operation.\n" ); |
251 | *createFunc = NULL; |
252 | return; |
253 | } |
254 | *createFunc = (type == RF_IO_TYPE_READ) ? (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG : (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; |
255 | |
256 | if (type == RF_IO_TYPE_READ) { |
257 | if ((raidPtr->status == rf_rs_degraded) || (raidPtr->status == rf_rs_reconstructing)) |
258 | *createFunc = (RF_VoidFuncPtr) rf_CreateRaidCDegradedReadDAG; /* array status is |
259 | * degraded, implement |
260 | * workload shifting */ |
261 | else |
262 | *createFunc = (RF_VoidFuncPtr) rf_CreateMirrorPartitionReadDAG; /* array status not |
263 | * degraded, so use |
264 | * mirror partition dag */ |
265 | } else |
266 | *createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG; |
267 | } |
268 | #endif /* (RF_INCLUDE_CHAINDECLUSTER > 0) */ |
269 | |