218 lines
6.7 KiB
C
218 lines
6.7 KiB
C
/* $FreeBSD$ */
|
|
/* $NetBSD: rf_pqdeg.c,v 1.5 2000/01/07 03:41:04 oster Exp $ */
|
|
/*
|
|
* Copyright (c) 1995 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Author: Daniel Stodolsky
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <dev/raidframe/rf_archs.h>
|
|
|
|
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
|
|
|
|
#include <dev/raidframe/rf_types.h>
|
|
#include <dev/raidframe/rf_raid.h>
|
|
#include <dev/raidframe/rf_dag.h>
|
|
#include <dev/raidframe/rf_dagutils.h>
|
|
#include <dev/raidframe/rf_dagfuncs.h>
|
|
#include <dev/raidframe/rf_dagffrd.h>
|
|
#include <dev/raidframe/rf_dagffwr.h>
|
|
#include <dev/raidframe/rf_dagdegrd.h>
|
|
#include <dev/raidframe/rf_dagdegwr.h>
|
|
#include <dev/raidframe/rf_etimer.h>
|
|
#include <dev/raidframe/rf_pqdeg.h>
|
|
#include <dev/raidframe/rf_general.h>
|
|
#include <dev/raidframe/rf_pqdegdags.h>
|
|
#include <dev/raidframe/rf_pq.h>
|
|
|
|
/*
|
|
Degraded mode dag functions for P+Q calculations.
|
|
|
|
The following nomenclature is used.
|
|
|
|
PQ_<D><P><Q>_Create{Large,Small}<Write|Read>DAG
|
|
|
|
where <D><P><Q> are single digits representing the number of failed
|
|
data units <D> (0,1,2), parity units <P> (0,1), and Q units <Q>, effecting
|
|
the I/O. The reads have only PQ_<D><P><Q>_CreateReadDAG variants, while
|
|
the single fault writes have both large and small write versions. (Single fault
|
|
PQ is equivalent to normal mode raid 5 in many aspects.
|
|
|
|
Some versions degenerate into the same case, and are grouped together below.
|
|
*/
|
|
|
|
/* Reads, single failure
|
|
|
|
we have parity, so we can do a raid 5
|
|
reconstruct read.
|
|
*/
|
|
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_100_CreateReadDAG)
|
|
{
|
|
rf_CreateDegradedReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, &rf_pRecoveryFuncs);
|
|
}
|
|
/* Reads double failure */
|
|
|
|
/*
|
|
Q is lost, but not parity
|
|
so we can a raid 5 reconstruct read.
|
|
*/
|
|
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_101_CreateReadDAG)
|
|
{
|
|
rf_CreateDegradedReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, &rf_pRecoveryFuncs);
|
|
}
|
|
/*
|
|
parity is lost, so we need to
|
|
do a reconstruct read and recompute
|
|
the data with Q.
|
|
*/
|
|
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_110_CreateReadDAG)
|
|
{
|
|
RF_PhysDiskAddr_t *temp;
|
|
/* swap P and Q pointers to fake out the DegradedReadDAG code */
|
|
temp = asmap->parityInfo;
|
|
asmap->parityInfo = asmap->qInfo;
|
|
asmap->qInfo = temp;
|
|
rf_CreateDegradedReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList, &rf_qRecoveryFuncs);
|
|
}
|
|
/*
|
|
Two data units are dead in this stripe, so we will need read
|
|
both P and Q to reconstruct the data. Note that only
|
|
one data unit we are reading may actually be missing.
|
|
*/
|
|
RF_CREATE_DAG_FUNC_DECL(rf_CreateDoubleDegradedReadDAG);
|
|
RF_CREATE_DAG_FUNC_DECL(rf_CreateDoubleDegradedReadDAG)
|
|
{
|
|
rf_PQ_DoubleDegRead(raidPtr, asmap, dag_h, bp, flags, allocList);
|
|
}
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_200_CreateReadDAG);
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_200_CreateReadDAG)
|
|
{
|
|
rf_CreateDoubleDegradedReadDAG(raidPtr, asmap, dag_h, bp, flags, allocList);
|
|
}
|
|
/* Writes, single failure */
|
|
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_100_CreateWriteDAG);
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_100_CreateWriteDAG)
|
|
{
|
|
if (asmap->numStripeUnitsAccessed != 1 &&
|
|
asmap->failedPDAs[0]->numSector !=
|
|
raidPtr->Layout.sectorsPerStripeUnit)
|
|
RF_PANIC();
|
|
rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp,
|
|
flags, allocList, 2,
|
|
(int (*) (RF_DagNode_t *)) rf_Degraded_100_PQFunc,
|
|
RF_FALSE);
|
|
}
|
|
/* Dead P - act like a RAID 5 small write with parity = Q */
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_010_CreateSmallWriteDAG)
|
|
{
|
|
RF_PhysDiskAddr_t *temp;
|
|
/* swap P and Q pointers to fake out the DegradedReadDAG code */
|
|
temp = asmap->parityInfo;
|
|
asmap->parityInfo = asmap->qInfo;
|
|
asmap->qInfo = temp;
|
|
rf_CommonCreateSmallWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, &rf_qFuncs, NULL);
|
|
}
|
|
/* Dead Q - act like a RAID 5 small write */
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_001_CreateSmallWriteDAG)
|
|
{
|
|
rf_CommonCreateSmallWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, &rf_pFuncs, NULL);
|
|
}
|
|
/* Dead P - act like a RAID 5 large write but for Q */
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_010_CreateLargeWriteDAG)
|
|
{
|
|
RF_PhysDiskAddr_t *temp;
|
|
/* swap P and Q pointers to fake out the code */
|
|
temp = asmap->parityInfo;
|
|
asmap->parityInfo = asmap->qInfo;
|
|
asmap->qInfo = temp;
|
|
rf_CommonCreateLargeWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, 1, rf_RegularQFunc, RF_FALSE);
|
|
}
|
|
/* Dead Q - act like a RAID 5 large write */
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_001_CreateLargeWriteDAG)
|
|
{
|
|
rf_CommonCreateLargeWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, 1, rf_RegularPFunc, RF_FALSE);
|
|
}
|
|
|
|
|
|
/*
|
|
* writes, double failure
|
|
*/
|
|
|
|
/*
|
|
* Lost P & Q - do a nonredundant write
|
|
*/
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_011_CreateWriteDAG)
|
|
{
|
|
rf_CreateNonRedundantWriteDAG(raidPtr, asmap, dag_h, bp, flags, allocList,
|
|
RF_IO_TYPE_WRITE);
|
|
}
|
|
/*
|
|
In the two cases below,
|
|
A nasty case arises when the write a (strict) portion of a failed stripe unit
|
|
and parts of another su. For now, we do not support this.
|
|
*/
|
|
|
|
/*
|
|
Lost Data and P - do a Q write.
|
|
*/
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_110_CreateWriteDAG)
|
|
{
|
|
RF_PhysDiskAddr_t *temp;
|
|
|
|
if (asmap->numStripeUnitsAccessed != 1 &&
|
|
asmap->failedPDAs[0]->numSector != raidPtr->Layout.sectorsPerStripeUnit) {
|
|
RF_PANIC();
|
|
}
|
|
/* swap P and Q to fake out parity code */
|
|
temp = asmap->parityInfo;
|
|
asmap->parityInfo = asmap->qInfo;
|
|
asmap->qInfo = temp;
|
|
rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, 1,
|
|
(int (*) (RF_DagNode_t *)) rf_PQ_DegradedWriteQFunc,
|
|
RF_FALSE);
|
|
/* is the regular Q func the right one to call? */
|
|
}
|
|
/*
|
|
Lost Data and Q - do degraded mode P write
|
|
*/
|
|
RF_CREATE_DAG_FUNC_DECL(rf_PQ_101_CreateWriteDAG)
|
|
{
|
|
if (asmap->numStripeUnitsAccessed != 1 &&
|
|
asmap->failedPDAs[0]->numSector != raidPtr->Layout.sectorsPerStripeUnit)
|
|
RF_PANIC();
|
|
rf_CommonCreateSimpleDegradedWriteDAG(raidPtr, asmap, dag_h, bp, flags,
|
|
allocList, 1, rf_RecoveryXorFunc, RF_FALSE);
|
|
}
|
|
#endif /* (RF_INCLUDE_DECL_PQ > 0) ||
|
|
* (RF_INCLUDE_RAID6 > 0) */
|