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freebsd-skq/sys/dev/raidframe/rf_decluster.c
Scott Long f9d186edc8 After much delay and anticipation, welcome RAIDFrame into the FreeBSD 
world.  This should be considered highly experimental.

Approved-by:	re
2002-10-20 08:17:39 +00:00

746 lines
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/* $FreeBSD$ */
/* $NetBSD: rf_decluster.c,v 1.6 2001/01/26 04:40:03 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*----------------------------------------------------------------------
*
* rf_decluster.c -- code related to the declustered layout
*
* Created 10-21-92 (MCH)
*
* Nov 93: adding support for distributed sparing. This code is a little
* complex: the basic layout used is as follows:
* let F = (v-1)/GCD(r,v-1). The spare space for each set of
* F consecutive fulltables is grouped together and placed after
* that set of tables.
* +------------------------------+
* | F fulltables |
* | Spare Space |
* | F fulltables |
* | Spare Space |
* | ... |
* +------------------------------+
*
*--------------------------------------------------------------------*/
#include <dev/raidframe/rf_archs.h>
#include <dev/raidframe/rf_types.h>
#include <dev/raidframe/rf_raid.h>
#include <dev/raidframe/rf_raidframe.h>
#include <dev/raidframe/rf_configure.h>
#include <dev/raidframe/rf_decluster.h>
#include <dev/raidframe/rf_debugMem.h>
#include <dev/raidframe/rf_utils.h>
#include <dev/raidframe/rf_alloclist.h>
#include <dev/raidframe/rf_general.h>
#include <dev/raidframe/rf_shutdown.h>
extern int rf_copyback_in_progress; /* debug only */
/* found in rf_kintf.c */
int rf_GetSpareTableFromDaemon(RF_SparetWait_t * req);
#if (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0)
/* configuration code */
int
rf_ConfigureDeclustered(
RF_ShutdownList_t ** listp,
RF_Raid_t * raidPtr,
RF_Config_t * cfgPtr)
{
RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
int b, v, k, r, lambda; /* block design params */
int i, j;
RF_RowCol_t *first_avail_slot;
RF_StripeCount_t complete_FT_count, numCompleteFullTablesPerDisk;
RF_DeclusteredConfigInfo_t *info;
RF_StripeCount_t PUsPerDisk, spareRegionDepthInPUs, numCompleteSpareRegionsPerDisk,
extraPUsPerDisk;
RF_StripeCount_t totSparePUsPerDisk;
RF_SectorNum_t diskOffsetOfLastFullTableInSUs;
RF_SectorCount_t SpareSpaceInSUs;
char *cfgBuf = (char *) (cfgPtr->layoutSpecific);
RF_StripeNum_t l, SUID;
SUID = l = 0;
numCompleteSpareRegionsPerDisk = 0;
/* 1. create layout specific structure */
RF_MallocAndAdd(info, sizeof(RF_DeclusteredConfigInfo_t), (RF_DeclusteredConfigInfo_t *), raidPtr->cleanupList);
if (info == NULL)
return (ENOMEM);
layoutPtr->layoutSpecificInfo = (void *) info;
info->SpareTable = NULL;
/* 2. extract parameters from the config structure */
if (layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) {
(void) bcopy(cfgBuf, info->sparemap_fname, RF_SPAREMAP_NAME_LEN);
}
cfgBuf += RF_SPAREMAP_NAME_LEN;
b = *((int *) cfgBuf);
cfgBuf += sizeof(int);
v = *((int *) cfgBuf);
cfgBuf += sizeof(int);
k = *((int *) cfgBuf);
cfgBuf += sizeof(int);
r = *((int *) cfgBuf);
cfgBuf += sizeof(int);
lambda = *((int *) cfgBuf);
cfgBuf += sizeof(int);
raidPtr->noRotate = *((int *) cfgBuf);
cfgBuf += sizeof(int);
/* the sparemaps are generated assuming that parity is rotated, so we
* issue a warning if both distributed sparing and no-rotate are on at
* the same time */
if ((layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) && raidPtr->noRotate) {
RF_ERRORMSG("Warning: distributed sparing specified without parity rotation.\n");
}
if (raidPtr->numCol != v) {
RF_ERRORMSG2("RAID: config error: table element count (%d) not equal to no. of cols (%d)\n", v, raidPtr->numCol);
return (EINVAL);
}
/* 3. set up the values used in the mapping code */
info->BlocksPerTable = b;
info->Lambda = lambda;
info->NumParityReps = info->groupSize = k;
info->SUsPerTable = b * (k - 1) * layoutPtr->SUsPerPU; /* b blks, k-1 SUs each */
info->SUsPerFullTable = k * info->SUsPerTable; /* rot k times */
info->PUsPerBlock = k - 1;
info->SUsPerBlock = info->PUsPerBlock * layoutPtr->SUsPerPU;
info->TableDepthInPUs = (b * k) / v;
info->FullTableDepthInPUs = info->TableDepthInPUs * k; /* k repetitions */
/* used only in distributed sparing case */
info->FullTablesPerSpareRegion = (v - 1) / rf_gcd(r, v - 1); /* (v-1)/gcd fulltables */
info->TablesPerSpareRegion = k * info->FullTablesPerSpareRegion;
info->SpareSpaceDepthPerRegionInSUs = (r * info->TablesPerSpareRegion / (v - 1)) * layoutPtr->SUsPerPU;
/* check to make sure the block design is sufficiently small */
if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
if (info->FullTableDepthInPUs * layoutPtr->SUsPerPU + info->SpareSpaceDepthPerRegionInSUs > layoutPtr->stripeUnitsPerDisk) {
RF_ERRORMSG3("RAID: config error: Full Table depth (%d) + Spare Space (%d) larger than disk size (%d) (BD too big)\n",
(int) info->FullTableDepthInPUs,
(int) info->SpareSpaceDepthPerRegionInSUs,
(int) layoutPtr->stripeUnitsPerDisk);
return (EINVAL);
}
} else {
if (info->TableDepthInPUs * layoutPtr->SUsPerPU > layoutPtr->stripeUnitsPerDisk) {
RF_ERRORMSG2("RAID: config error: Table depth (%d) larger than disk size (%d) (BD too big)\n",
(int) (info->TableDepthInPUs * layoutPtr->SUsPerPU), \
(int) layoutPtr->stripeUnitsPerDisk);
return (EINVAL);
}
}
/* compute the size of each disk, and the number of tables in the last
* fulltable (which need not be complete) */
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
PUsPerDisk = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU;
spareRegionDepthInPUs = (info->TablesPerSpareRegion * info->TableDepthInPUs +
(info->TablesPerSpareRegion * info->TableDepthInPUs) / (v - 1));
info->SpareRegionDepthInSUs = spareRegionDepthInPUs * layoutPtr->SUsPerPU;
numCompleteSpareRegionsPerDisk = PUsPerDisk / spareRegionDepthInPUs;
info->NumCompleteSRs = numCompleteSpareRegionsPerDisk;
extraPUsPerDisk = PUsPerDisk % spareRegionDepthInPUs;
/* assume conservatively that we need the full amount of spare
* space in one region in order to provide spares for the
* partial spare region at the end of the array. We set "i"
* to the number of tables in the partial spare region. This
* may actually include some fulltables. */
extraPUsPerDisk -= (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
if (extraPUsPerDisk <= 0)
i = 0;
else
i = extraPUsPerDisk / info->TableDepthInPUs;
complete_FT_count = raidPtr->numRow * (numCompleteSpareRegionsPerDisk * (info->TablesPerSpareRegion / k) + i / k);
info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
info->ExtraTablesPerDisk = i % k;
/* note that in the last spare region, the spare space is
* complete even though data/parity space is not */
totSparePUsPerDisk = (numCompleteSpareRegionsPerDisk + 1) * (info->SpareSpaceDepthPerRegionInSUs / layoutPtr->SUsPerPU);
info->TotSparePUsPerDisk = totSparePUsPerDisk;
layoutPtr->stripeUnitsPerDisk =
((complete_FT_count / raidPtr->numRow) * info->FullTableDepthInPUs + /* data & parity space */
info->ExtraTablesPerDisk * info->TableDepthInPUs +
totSparePUsPerDisk /* spare space */
) * layoutPtr->SUsPerPU;
layoutPtr->dataStripeUnitsPerDisk =
(complete_FT_count * info->FullTableDepthInPUs + info->ExtraTablesPerDisk * info->TableDepthInPUs)
* layoutPtr->SUsPerPU * (k - 1) / k;
} else {
/* non-dist spare case: force each disk to contain an
* integral number of tables */
layoutPtr->stripeUnitsPerDisk /= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
layoutPtr->stripeUnitsPerDisk *= (info->TableDepthInPUs * layoutPtr->SUsPerPU);
/* compute the number of tables in the last fulltable, which
* need not be complete */
complete_FT_count =
((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->FullTableDepthInPUs) * raidPtr->numRow;
info->FullTableLimitSUID = complete_FT_count * info->SUsPerFullTable;
info->ExtraTablesPerDisk =
((layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerPU) / info->TableDepthInPUs) % k;
}
raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit;
/* find the disk offset of the stripe unit where the last fulltable
* starts */
numCompleteFullTablesPerDisk = complete_FT_count / raidPtr->numRow;
diskOffsetOfLastFullTableInSUs = numCompleteFullTablesPerDisk * info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
SpareSpaceInSUs = numCompleteSpareRegionsPerDisk * info->SpareSpaceDepthPerRegionInSUs;
diskOffsetOfLastFullTableInSUs += SpareSpaceInSUs;
info->DiskOffsetOfLastSpareSpaceChunkInSUs =
diskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU;
}
info->DiskOffsetOfLastFullTableInSUs = diskOffsetOfLastFullTableInSUs;
info->numCompleteFullTablesPerDisk = numCompleteFullTablesPerDisk;
/* 4. create and initialize the lookup tables */
info->LayoutTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
if (info->LayoutTable == NULL)
return (ENOMEM);
info->OffsetTable = rf_make_2d_array(b, k, raidPtr->cleanupList);
if (info->OffsetTable == NULL)
return (ENOMEM);
info->BlockTable = rf_make_2d_array(info->TableDepthInPUs * layoutPtr->SUsPerPU, raidPtr->numCol, raidPtr->cleanupList);
if (info->BlockTable == NULL)
return (ENOMEM);
first_avail_slot = rf_make_1d_array(v, NULL);
if (first_avail_slot == NULL)
return (ENOMEM);
for (i = 0; i < b; i++)
for (j = 0; j < k; j++)
info->LayoutTable[i][j] = *cfgBuf++;
/* initialize offset table */
for (i = 0; i < b; i++)
for (j = 0; j < k; j++) {
info->OffsetTable[i][j] = first_avail_slot[info->LayoutTable[i][j]];
first_avail_slot[info->LayoutTable[i][j]]++;
}
/* initialize block table */
for (SUID = l = 0; l < layoutPtr->SUsPerPU; l++) {
for (i = 0; i < b; i++) {
for (j = 0; j < k; j++) {
info->BlockTable[(info->OffsetTable[i][j] * layoutPtr->SUsPerPU) + l]
[info->LayoutTable[i][j]] = SUID;
}
SUID++;
}
}
rf_free_1d_array(first_avail_slot, v);
/* 5. set up the remaining redundant-but-useful parameters */
raidPtr->totalSectors = (k * complete_FT_count + raidPtr->numRow * info->ExtraTablesPerDisk) *
info->SUsPerTable * layoutPtr->sectorsPerStripeUnit;
layoutPtr->numStripe = (raidPtr->totalSectors / layoutPtr->sectorsPerStripeUnit) / (k - 1);
/* strange evaluation order below to try and minimize overflow
* problems */
layoutPtr->dataSectorsPerStripe = (k - 1) * layoutPtr->sectorsPerStripeUnit;
layoutPtr->bytesPerStripeUnit = layoutPtr->sectorsPerStripeUnit << raidPtr->logBytesPerSector;
layoutPtr->numDataCol = k - 1;
layoutPtr->numParityCol = 1;
return (0);
}
/* declustering with distributed sparing */
static void rf_ShutdownDeclusteredDS(RF_ThreadArg_t);
static void
rf_ShutdownDeclusteredDS(arg)
RF_ThreadArg_t arg;
{
RF_DeclusteredConfigInfo_t *info;
RF_Raid_t *raidPtr;
raidPtr = (RF_Raid_t *) arg;
info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
if (info->SpareTable)
rf_FreeSpareTable(raidPtr);
}
int
rf_ConfigureDeclusteredDS(
RF_ShutdownList_t ** listp,
RF_Raid_t * raidPtr,
RF_Config_t * cfgPtr)
{
int rc;
rc = rf_ConfigureDeclustered(listp, raidPtr, cfgPtr);
if (rc)
return (rc);
rc = rf_ShutdownCreate(listp, rf_ShutdownDeclusteredDS, raidPtr);
if (rc) {
RF_ERRORMSG1("Got %d adding shutdown event for DeclusteredDS\n", rc);
rf_ShutdownDeclusteredDS(raidPtr);
return (rc);
}
return (0);
}
void
rf_MapSectorDeclustered(raidPtr, raidSector, row, col, diskSector, remap)
RF_Raid_t *raidPtr;
RF_RaidAddr_t raidSector;
RF_RowCol_t *row;
RF_RowCol_t *col;
RF_SectorNum_t *diskSector;
int remap;
{
RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
RF_StripeNum_t BlockID, BlockOffset, RepIndex;
RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0;
rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
FullTableID = SUID / sus_per_fulltable; /* fulltable ID within array
* (across rows) */
if (raidPtr->numRow == 1)
*row = 0; /* avoid a mod and a div in the common case */
else {
*row = FullTableID % raidPtr->numRow;
FullTableID /= raidPtr->numRow; /* convert to fulltable ID on
* this disk */
}
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
}
FullTableOffset = SUID % sus_per_fulltable;
TableID = FullTableOffset / info->SUsPerTable;
TableOffset = FullTableOffset - TableID * info->SUsPerTable;
BlockID = TableOffset / info->PUsPerBlock;
BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
BlockID %= info->BlocksPerTable;
RepIndex = info->PUsPerBlock - TableID;
if (!raidPtr->noRotate)
BlockOffset += ((BlockOffset >= RepIndex) ? 1 : 0);
*col = info->LayoutTable[BlockID][BlockOffset];
/* remap to distributed spare space if indicated */
if (remap) {
RF_ASSERT(raidPtr->Disks[*row][*col].status == rf_ds_reconstructing || raidPtr->Disks[*row][*col].status == rf_ds_dist_spared ||
(rf_copyback_in_progress && raidPtr->Disks[*row][*col].status == rf_ds_optimal));
rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU);
} else {
outSU = base_suid;
outSU += FullTableID * fulltable_depth; /* offs to strt of FT */
outSU += SpareSpace; /* skip rsvd spare space */
outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU; /* offs to strt of tble */
outSU += info->OffsetTable[BlockID][BlockOffset] * layoutPtr->SUsPerPU; /* offs to the PU */
}
outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock); /* offs to the SU within
* a PU */
/* convert SUs to sectors, and, if not aligned to SU boundary, add in
* offset to sector. */
*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
RF_ASSERT(*col != -1);
}
/* prototyping this inexplicably causes the compile of the layout table (rf_layout.c) to fail */
void
rf_MapParityDeclustered(
RF_Raid_t * raidPtr,
RF_RaidAddr_t raidSector,
RF_RowCol_t * row,
RF_RowCol_t * col,
RF_SectorNum_t * diskSector,
int remap)
{
RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
RF_StripeNum_t SUID = raidSector / layoutPtr->sectorsPerStripeUnit;
RF_StripeNum_t FullTableID, FullTableOffset, TableID, TableOffset;
RF_StripeNum_t BlockID, BlockOffset, RepIndex;
RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
RF_StripeNum_t base_suid = 0, outSU, SpareRegion = 0, SpareSpace = 0;
rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
/* compute row & (possibly) spare space exactly as before */
FullTableID = SUID / sus_per_fulltable;
if (raidPtr->numRow == 1)
*row = 0; /* avoid a mod and a div in the common case */
else {
*row = FullTableID % raidPtr->numRow;
FullTableID /= raidPtr->numRow; /* convert to fulltable ID on
* this disk */
}
if ((raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE)) {
SpareRegion = FullTableID / info->FullTablesPerSpareRegion;
SpareSpace = SpareRegion * info->SpareSpaceDepthPerRegionInSUs;
}
/* compute BlockID and RepIndex exactly as before */
FullTableOffset = SUID % sus_per_fulltable;
TableID = FullTableOffset / info->SUsPerTable;
TableOffset = FullTableOffset - TableID * info->SUsPerTable;
/* TableOffset = FullTableOffset % info->SUsPerTable; */
/* BlockID = (TableOffset / info->PUsPerBlock) %
* info->BlocksPerTable; */
BlockID = TableOffset / info->PUsPerBlock;
/* BlockOffset = TableOffset % info->PUsPerBlock; */
BlockOffset = TableOffset - BlockID * info->PUsPerBlock;
BlockID %= info->BlocksPerTable;
/* the parity block is in the position indicated by RepIndex */
RepIndex = (raidPtr->noRotate) ? info->PUsPerBlock : info->PUsPerBlock - TableID;
*col = info->LayoutTable[BlockID][RepIndex];
if (remap) {
RF_ASSERT(raidPtr->Disks[*row][*col].status == rf_ds_reconstructing || raidPtr->Disks[*row][*col].status == rf_ds_dist_spared ||
(rf_copyback_in_progress && raidPtr->Disks[*row][*col].status == rf_ds_optimal));
rf_remap_to_spare_space(layoutPtr, info, *row, FullTableID, TableID, BlockID, (base_suid) ? 1 : 0, SpareRegion, col, &outSU);
} else {
/* compute sector as before, except use RepIndex instead of
* BlockOffset */
outSU = base_suid;
outSU += FullTableID * fulltable_depth;
outSU += SpareSpace; /* skip rsvd spare space */
outSU += TableID * info->TableDepthInPUs * layoutPtr->SUsPerPU;
outSU += info->OffsetTable[BlockID][RepIndex] * layoutPtr->SUsPerPU;
}
outSU += TableOffset / (info->BlocksPerTable * info->PUsPerBlock);
*diskSector = outSU * layoutPtr->sectorsPerStripeUnit + (raidSector % layoutPtr->sectorsPerStripeUnit);
RF_ASSERT(*col != -1);
}
/* returns an array of ints identifying the disks that comprise the stripe containing the indicated address.
* the caller must _never_ attempt to modify this array.
*/
void
rf_IdentifyStripeDeclustered(
RF_Raid_t * raidPtr,
RF_RaidAddr_t addr,
RF_RowCol_t ** diskids,
RF_RowCol_t * outRow)
{
RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
RF_StripeCount_t sus_per_fulltable = info->SUsPerFullTable;
RF_StripeCount_t fulltable_depth = info->FullTableDepthInPUs * layoutPtr->SUsPerPU;
RF_StripeNum_t base_suid = 0;
RF_StripeNum_t SUID = rf_RaidAddressToStripeUnitID(layoutPtr, addr);
RF_StripeNum_t stripeID, FullTableID;
int tableOffset;
rf_decluster_adjust_params(layoutPtr, &SUID, &sus_per_fulltable, &fulltable_depth, &base_suid);
FullTableID = SUID / sus_per_fulltable; /* fulltable ID within array
* (across rows) */
*outRow = FullTableID % raidPtr->numRow;
stripeID = rf_StripeUnitIDToStripeID(layoutPtr, SUID); /* find stripe offset
* into array */
tableOffset = (stripeID % info->BlocksPerTable); /* find offset into
* block design table */
*diskids = info->LayoutTable[tableOffset];
}
/* This returns the default head-separation limit, which is measured
* in "required units for reconstruction". Each time a disk fetches
* a unit, it bumps a counter. The head-sep code prohibits any disk
* from getting more than headSepLimit counter values ahead of any
* other.
*
* We assume here that the number of floating recon buffers is already
* set. There are r stripes to be reconstructed in each table, and so
* if we have a total of B buffers, we can have at most B/r tables
* under recon at any one time. In each table, lambda units are required
* from each disk, so given B buffers, the head sep limit has to be
* (lambda*B)/r units. We subtract one to avoid weird boundary cases.
*
* for example, suppose were given 50 buffers, r=19, and lambda=4 as in
* the 20.5 design. There are 19 stripes/table to be reconstructed, so
* we can have 50/19 tables concurrently under reconstruction, which means
* we can allow the fastest disk to get 50/19 tables ahead of the slower
* disk. There are lambda "required units" for each disk, so the fastest
* disk can get 4*50/19 = 10 counter values ahead of the slowest.
*
* If numBufsToAccumulate is not 1, we need to limit the head sep further
* because multiple bufs will be required for each stripe under recon.
*/
RF_HeadSepLimit_t
rf_GetDefaultHeadSepLimitDeclustered(
RF_Raid_t * raidPtr)
{
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
return (info->Lambda * raidPtr->numFloatingReconBufs / info->TableDepthInPUs / rf_numBufsToAccumulate);
}
/* returns the default number of recon buffers to use. The value
* is somewhat arbitrary...it's intended to be large enough to allow
* for a reasonably large head-sep limit, but small enough that you
* don't use up all your system memory with buffers.
*/
int
rf_GetDefaultNumFloatingReconBuffersDeclustered(RF_Raid_t * raidPtr)
{
return (100 * rf_numBufsToAccumulate);
}
/* sectors in the last fulltable of the array need to be handled
* specially since this fulltable can be incomplete. this function
* changes the values of certain params to handle this.
*
* the idea here is that MapSector et. al. figure out which disk the
* addressed unit lives on by computing the modulos of the unit number
* with the number of units per fulltable, table, etc. In the last
* fulltable, there are fewer units per fulltable, so we need to adjust
* the number of user data units per fulltable to reflect this.
*
* so, we (1) convert the fulltable size and depth parameters to
* the size of the partial fulltable at the end, (2) compute the
* disk sector offset where this fulltable starts, and (3) convert
* the users stripe unit number from an offset into the array to
* an offset into the last fulltable.
*/
void
rf_decluster_adjust_params(
RF_RaidLayout_t * layoutPtr,
RF_StripeNum_t * SUID,
RF_StripeCount_t * sus_per_fulltable,
RF_StripeCount_t * fulltable_depth,
RF_StripeNum_t * base_suid)
{
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
if (*SUID >= info->FullTableLimitSUID) {
/* new full table size is size of last full table on disk */
*sus_per_fulltable = info->ExtraTablesPerDisk * info->SUsPerTable;
/* new full table depth is corresponding depth */
*fulltable_depth = info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU;
/* set up the new base offset */
*base_suid = info->DiskOffsetOfLastFullTableInSUs;
/* convert users array address to an offset into the last
* fulltable */
*SUID -= info->FullTableLimitSUID;
}
}
/*
* map a stripe ID to a parity stripe ID.
* See comment above RaidAddressToParityStripeID in layout.c.
*/
void
rf_MapSIDToPSIDDeclustered(
RF_RaidLayout_t * layoutPtr,
RF_StripeNum_t stripeID,
RF_StripeNum_t * psID,
RF_ReconUnitNum_t * which_ru)
{
RF_DeclusteredConfigInfo_t *info;
info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
*psID = (stripeID / (layoutPtr->SUsPerPU * info->BlocksPerTable))
* info->BlocksPerTable + (stripeID % info->BlocksPerTable);
*which_ru = (stripeID % (info->BlocksPerTable * layoutPtr->SUsPerPU))
/ info->BlocksPerTable;
RF_ASSERT((*which_ru) < layoutPtr->SUsPerPU / layoutPtr->SUsPerRU);
}
/*
* Called from MapSector and MapParity to retarget an access at the spare unit.
* Modifies the "col" and "outSU" parameters only.
*/
void
rf_remap_to_spare_space(
RF_RaidLayout_t * layoutPtr,
RF_DeclusteredConfigInfo_t * info,
RF_RowCol_t row,
RF_StripeNum_t FullTableID,
RF_StripeNum_t TableID,
RF_SectorNum_t BlockID,
RF_StripeNum_t base_suid,
RF_StripeNum_t SpareRegion,
RF_RowCol_t * outCol,
RF_StripeNum_t * outSU)
{
RF_StripeNum_t ftID, spareTableStartSU, TableInSpareRegion, lastSROffset,
which_ft;
/*
* note that FullTableID and hence SpareRegion may have gotten
* tweaked by rf_decluster_adjust_params. We detect this by
* noticing that base_suid is not 0.
*/
if (base_suid == 0) {
ftID = FullTableID;
} else {
/*
* There may be > 1.0 full tables in the last (i.e. partial)
* spare region. find out which of these we're in.
*/
lastSROffset = info->NumCompleteSRs * info->SpareRegionDepthInSUs;
which_ft = (info->DiskOffsetOfLastFullTableInSUs - lastSROffset) / (info->FullTableDepthInPUs * layoutPtr->SUsPerPU);
/* compute the actual full table ID */
ftID = info->DiskOffsetOfLastFullTableInSUs / (info->FullTableDepthInPUs * layoutPtr->SUsPerPU) + which_ft;
SpareRegion = info->NumCompleteSRs;
}
TableInSpareRegion = (ftID * info->NumParityReps + TableID) % info->TablesPerSpareRegion;
*outCol = info->SpareTable[TableInSpareRegion][BlockID].spareDisk;
RF_ASSERT(*outCol != -1);
spareTableStartSU = (SpareRegion == info->NumCompleteSRs) ?
info->DiskOffsetOfLastFullTableInSUs + info->ExtraTablesPerDisk * info->TableDepthInPUs * layoutPtr->SUsPerPU :
(SpareRegion + 1) * info->SpareRegionDepthInSUs - info->SpareSpaceDepthPerRegionInSUs;
*outSU = spareTableStartSU + info->SpareTable[TableInSpareRegion][BlockID].spareBlockOffsetInSUs;
if (*outSU >= layoutPtr->stripeUnitsPerDisk) {
printf("rf_remap_to_spare_space: invalid remapped disk SU offset %ld\n", (long) *outSU);
}
}
#endif /* (RF_INCLUDE_PARITY_DECLUSTERING > 0) || (RF_INCLUDE_PARITY_DECLUSTERING_PQ > 0) */
int
rf_InstallSpareTable(
RF_Raid_t * raidPtr,
RF_RowCol_t frow,
RF_RowCol_t fcol)
{
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
RF_SparetWait_t *req;
int retcode;
RF_Malloc(req, sizeof(*req), (RF_SparetWait_t *));
req->C = raidPtr->numCol;
req->G = raidPtr->Layout.numDataCol + raidPtr->Layout.numParityCol;
req->fcol = fcol;
req->SUsPerPU = raidPtr->Layout.SUsPerPU;
req->TablesPerSpareRegion = info->TablesPerSpareRegion;
req->BlocksPerTable = info->BlocksPerTable;
req->TableDepthInPUs = info->TableDepthInPUs;
req->SpareSpaceDepthPerRegionInSUs = info->SpareSpaceDepthPerRegionInSUs;
retcode = rf_GetSpareTableFromDaemon(req);
RF_ASSERT(!retcode); /* XXX -- fix this to recover gracefully --
* XXX */
return (retcode);
}
/*
* Invoked via ioctl to install a spare table in the kernel.
*/
int
rf_SetSpareTable(raidPtr, data)
RF_Raid_t *raidPtr;
void *data;
{
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) raidPtr->Layout.layoutSpecificInfo;
RF_SpareTableEntry_t **ptrs;
int i, retcode;
/* what we need to copyin is a 2-d array, so first copyin the user
* pointers to the rows in the table */
RF_Malloc(ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *), (RF_SpareTableEntry_t **));
retcode = copyin((caddr_t) data, (caddr_t) ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *));
if (retcode)
return (retcode);
/* now allocate kernel space for the row pointers */
RF_Malloc(info->SpareTable, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *), (RF_SpareTableEntry_t **));
/* now allocate kernel space for each row in the table, and copy it in
* from user space */
for (i = 0; i < info->TablesPerSpareRegion; i++) {
RF_Malloc(info->SpareTable[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t), (RF_SpareTableEntry_t *));
retcode = copyin(ptrs[i], info->SpareTable[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t));
if (retcode) {
info->SpareTable = NULL; /* blow off the memory
* we've allocated */
return (retcode);
}
}
/* free up the temporary array we used */
RF_Free(ptrs, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *));
return (0);
}
RF_ReconUnitCount_t
rf_GetNumSpareRUsDeclustered(raidPtr)
RF_Raid_t *raidPtr;
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
return (((RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo)->TotSparePUsPerDisk);
}
void
rf_FreeSpareTable(raidPtr)
RF_Raid_t *raidPtr;
{
long i;
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_DeclusteredConfigInfo_t *info = (RF_DeclusteredConfigInfo_t *) layoutPtr->layoutSpecificInfo;
RF_SpareTableEntry_t **table = info->SpareTable;
for (i = 0; i < info->TablesPerSpareRegion; i++) {
RF_Free(table[i], info->BlocksPerTable * sizeof(RF_SpareTableEntry_t));
}
RF_Free(table, info->TablesPerSpareRegion * sizeof(RF_SpareTableEntry_t *));
info->SpareTable = (RF_SpareTableEntry_t **) NULL;
}
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