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rf_interdecluster.c revision 1.10
      1 /*	$NetBSD: rf_interdecluster.c,v 1.10 2005/02/27 00:27:45 perry 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_interdecluster.c -- implements interleaved declustering
     32  *
     33  ************************************************************/
     34 
     35 #include <sys/cdefs.h>
     36 __KERNEL_RCSID(0, "$NetBSD: rf_interdecluster.c,v 1.10 2005/02/27 00:27:45 perry Exp $");
     37 
     38 #include "rf_archs.h"
     39 
     40 #if RF_INCLUDE_INTERDECLUSTER > 0
     41 
     42 #include <dev/raidframe/raidframevar.h>
     43 
     44 #include "rf_raid.h"
     45 #include "rf_interdecluster.h"
     46 #include "rf_dag.h"
     47 #include "rf_dagutils.h"
     48 #include "rf_dagfuncs.h"
     49 #include "rf_general.h"
     50 #include "rf_utils.h"
     51 #include "rf_dagffrd.h"
     52 #include "rf_dagdegrd.h"
     53 #include "rf_dagffwr.h"
     54 #include "rf_dagdegwr.h"
     55 
     56 typedef struct RF_InterdeclusterConfigInfo_s {
     57 	RF_RowCol_t **stripeIdentifier;	/* filled in at config time and used
     58 					 * by IdentifyStripe */
     59 	RF_StripeCount_t numSparingRegions;
     60 	RF_StripeCount_t stripeUnitsPerSparingRegion;
     61 	RF_SectorNum_t mirrorStripeOffset;
     62 }       RF_InterdeclusterConfigInfo_t;
     63 
     64 int
     65 rf_ConfigureInterDecluster(
     66     RF_ShutdownList_t ** listp,
     67     RF_Raid_t * raidPtr,
     68     RF_Config_t * cfgPtr)
     69 {
     70 	RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
     71 	RF_StripeCount_t num_used_stripeUnitsPerDisk;
     72 	RF_InterdeclusterConfigInfo_t *info;
     73 	RF_RowCol_t i, tmp, SUs_per_region;
     74 
     75 	/* create an Interleaved Declustering configuration structure */
     76 	RF_MallocAndAdd(info, sizeof(RF_InterdeclusterConfigInfo_t), (RF_InterdeclusterConfigInfo_t *),
     77 	    raidPtr->cleanupList);
     78 	if (info == NULL)
     79 		return (ENOMEM);
     80 	layoutPtr->layoutSpecificInfo = (void *) info;
     81 
     82 	/* fill in the config structure.  */
     83 	SUs_per_region = raidPtr->numCol * (raidPtr->numCol - 1);
     84 	info->stripeIdentifier = rf_make_2d_array(SUs_per_region, 2, raidPtr->cleanupList);
     85 	if (info->stripeIdentifier == NULL)
     86 		return (ENOMEM);
     87 	for (i = 0; i < SUs_per_region; i++) {
     88 		info->stripeIdentifier[i][0] = i / (raidPtr->numCol - 1);
     89 		tmp = i / raidPtr->numCol;
     90 		info->stripeIdentifier[i][1] = (i + 1 + tmp) % raidPtr->numCol;
     91 	}
     92 
     93 	/* no spare tables */
     94 	RF_ASSERT(raidPtr->numRow == 1);
     95 
     96 	/* fill in the remaining layout parameters */
     97 
     98 	/* total number of stripes should a multiple of 2*numCol: Each sparing
     99 	 * region consists of 2*numCol stripes: n-1 primary copy, n-1
    100 	 * secondary copy and 2 for spare .. */
    101 	num_used_stripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk - (layoutPtr->stripeUnitsPerDisk %
    102 	    (2 * raidPtr->numCol));
    103 	info->numSparingRegions = num_used_stripeUnitsPerDisk / (2 * raidPtr->numCol);
    104 	/* this is in fact the number of stripe units (that are primary data
    105 	 * copies) in the sparing region */
    106 	info->stripeUnitsPerSparingRegion = raidPtr->numCol * (raidPtr->numCol - 1);
    107 	info->mirrorStripeOffset = info->numSparingRegions * (raidPtr->numCol + 1);
    108 	layoutPtr->numStripe = info->numSparingRegions * info->stripeUnitsPerSparingRegion;
    109 	layoutPtr->numDataCol = 1;
    110 	layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;
    111 	layoutPtr->numParityCol = 1;
    112 
    113 	layoutPtr->dataStripeUnitsPerDisk = num_used_stripeUnitsPerDisk;
    114 
    115 	raidPtr->sectorsPerDisk =
    116 	    num_used_stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
    117 
    118 	raidPtr->totalSectors =
    119 	    (layoutPtr->numStripe) * layoutPtr->sectorsPerStripeUnit;
    120 
    121 	layoutPtr->stripeUnitsPerDisk = raidPtr->sectorsPerDisk / layoutPtr->sectorsPerStripeUnit;
    122 
    123 	return (0);
    124 }
    125 
    126 int
    127 rf_GetDefaultNumFloatingReconBuffersInterDecluster(RF_Raid_t * raidPtr)
    128 {
    129 	return (30);
    130 }
    131 
    132 RF_HeadSepLimit_t
    133 rf_GetDefaultHeadSepLimitInterDecluster(RF_Raid_t * raidPtr)
    134 {
    135 	return (raidPtr->sectorsPerDisk);
    136 }
    137 
    138 RF_ReconUnitCount_t
    139 rf_GetNumSpareRUsInterDecluster(
    140     RF_Raid_t * raidPtr)
    141 {
    142 	RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    143 
    144 	return (2 * ((RF_ReconUnitCount_t) info->numSparingRegions));
    145 	/* the layout uses two stripe units per disk as spare within each
    146 	 * sparing region */
    147 }
    148 /* Maps to the primary copy of the data, i.e. the first mirror pair */
    149 void
    150 rf_MapSectorInterDecluster(
    151     RF_Raid_t * raidPtr,
    152     RF_RaidAddr_t raidSector,
    153     RF_RowCol_t * row,
    154     RF_RowCol_t * col,
    155     RF_SectorNum_t * diskSector,
    156     int remap)
    157 {
    158 	RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    159 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
    160 	RF_StripeNum_t su_offset_into_disk, mirror_su_offset_into_disk;
    161 	RF_StripeNum_t sparing_region_id, index_within_region;
    162 	int     col_before_remap;
    163 
    164 	*row = 0;
    165 	sparing_region_id = SUID / info->stripeUnitsPerSparingRegion;
    166 	index_within_region = SUID % info->stripeUnitsPerSparingRegion;
    167 	su_offset_into_disk = index_within_region % (raidPtr->numCol - 1);
    168 	mirror_su_offset_into_disk = index_within_region / raidPtr->numCol;
    169 	col_before_remap = index_within_region / (raidPtr->numCol - 1);
    170 
    171 	if (!remap) {
    172 		*col = col_before_remap;
    173 		*diskSector = (su_offset_into_disk + ((raidPtr->numCol - 1) * sparing_region_id)) *
    174 		    raidPtr->Layout.sectorsPerStripeUnit;
    175 		*diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    176 	} else {
    177 		/* remap sector to spare space... */
    178 		*diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit;
    179 		*diskSector += (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit;
    180 		*diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    181 		*col = (index_within_region + 1 + mirror_su_offset_into_disk) % raidPtr->numCol;
    182 		*col = (*col + 1) % raidPtr->numCol;
    183 		if (*col == col_before_remap)
    184 			*col = (*col + 1) % raidPtr->numCol;
    185 	}
    186 }
    187 /* Maps to the second copy of the mirror pair. */
    188 void
    189 rf_MapParityInterDecluster(
    190     RF_Raid_t * raidPtr,
    191     RF_RaidAddr_t raidSector,
    192     RF_RowCol_t * row,
    193     RF_RowCol_t * col,
    194     RF_SectorNum_t * diskSector,
    195     int remap)
    196 {
    197 	RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    198 	RF_StripeNum_t sparing_region_id, index_within_region, mirror_su_offset_into_disk;
    199 	RF_StripeNum_t SUID = raidSector / raidPtr->Layout.sectorsPerStripeUnit;
    200 	int     col_before_remap;
    201 
    202 	sparing_region_id = SUID / info->stripeUnitsPerSparingRegion;
    203 	index_within_region = SUID % info->stripeUnitsPerSparingRegion;
    204 	mirror_su_offset_into_disk = index_within_region / raidPtr->numCol;
    205 	col_before_remap = (index_within_region + 1 + mirror_su_offset_into_disk) % raidPtr->numCol;
    206 
    207 	*row = 0;
    208 	if (!remap) {
    209 		*col = col_before_remap;
    210 		*diskSector = info->mirrorStripeOffset * raidPtr->Layout.sectorsPerStripeUnit;
    211 		*diskSector += sparing_region_id * (raidPtr->numCol - 1) * raidPtr->Layout.sectorsPerStripeUnit;
    212 		*diskSector += mirror_su_offset_into_disk * raidPtr->Layout.sectorsPerStripeUnit;
    213 		*diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    214 	} else {
    215 		/* remap parity to spare space ... */
    216 		*diskSector = sparing_region_id * (raidPtr->numCol + 1) * raidPtr->Layout.sectorsPerStripeUnit;
    217 		*diskSector += (raidPtr->numCol) * raidPtr->Layout.sectorsPerStripeUnit;
    218 		*diskSector += (raidSector % raidPtr->Layout.sectorsPerStripeUnit);
    219 		*col = index_within_region / (raidPtr->numCol - 1);
    220 		*col = (*col + 1) % raidPtr->numCol;
    221 		if (*col == col_before_remap)
    222 			*col = (*col + 1) % raidPtr->numCol;
    223 	}
    224 }
    225 
    226 void
    227 rf_IdentifyStripeInterDecluster(
    228     RF_Raid_t * raidPtr,
    229     RF_RaidAddr_t addr,
    230     RF_RowCol_t ** diskids,
    231     RF_RowCol_t * outRow)
    232 {
    233 	RF_InterdeclusterConfigInfo_t *info = (RF_InterdeclusterConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
    234 	RF_StripeNum_t SUID;
    235 
    236 	SUID = addr / raidPtr->Layout.sectorsPerStripeUnit;
    237 	SUID = SUID % info->stripeUnitsPerSparingRegion;
    238 
    239 	*outRow = 0;
    240 	*diskids = info->stripeIdentifier[SUID];
    241 }
    242 
    243 void
    244 rf_MapSIDToPSIDInterDecluster(
    245     RF_RaidLayout_t * layoutPtr,
    246     RF_StripeNum_t stripeID,
    247     RF_StripeNum_t * psID,
    248     RF_ReconUnitNum_t * which_ru)
    249 {
    250 	*which_ru = 0;
    251 	*psID = stripeID;
    252 }
    253 /******************************************************************************
    254  * select a graph to perform a single-stripe access
    255  *
    256  * Parameters:  raidPtr    - description of the physical array
    257  *              type       - type of operation (read or write) requested
    258  *              asmap      - logical & physical addresses for this access
    259  *              createFunc - name of function to use to create the graph
    260  *****************************************************************************/
    261 
    262 void
    263 rf_RAIDIDagSelect(
    264     RF_Raid_t * raidPtr,
    265     RF_IoType_t type,
    266     RF_AccessStripeMap_t * asmap,
    267     RF_VoidFuncPtr * createFunc)
    268 {
    269 	RF_ASSERT(RF_IO_IS_R_OR_W(type));
    270 
    271 	if (asmap->numDataFailed + asmap->numParityFailed > 1) {
    272 		RF_ERRORMSG("Multiple disks failed in a single group!  Aborting I/O operation.\n");
    273 		*createFunc = NULL;
    274 		return;
    275 	}
    276 	*createFunc = (type == RF_IO_TYPE_READ) ? (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG : (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG;
    277 	if (type == RF_IO_TYPE_READ) {
    278 		if (asmap->numDataFailed == 0)
    279 			*createFunc = (RF_VoidFuncPtr) rf_CreateMirrorPartitionReadDAG;
    280 		else
    281 			*createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneDegradedReadDAG;
    282 	} else
    283 		*createFunc = (RF_VoidFuncPtr) rf_CreateRaidOneWriteDAG;
    284 }
    285 #endif /* RF_INCLUDE_INTERDECLUSTER > 0 */
    286