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/* $OpenBSD: rf_pqdeg.c,v 1.1 1999/01/11 14:29:39 niklas Exp $ */
/* $NetBSD: rf_pqdeg.c,v 1.1 1998/11/13 04:20:32 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.
*/
/*
* Log: rf_pqdeg.c,v
* Revision 1.19 1996/11/05 21:10:40 jimz
* failed pda generalization
*
* Revision 1.18 1996/07/31 16:30:01 jimz
* asm/asmap fix
*
* Revision 1.17 1996/07/31 15:35:09 jimz
* evenodd changes; bugfixes for double-degraded archs, generalize
* some formerly PQ-only functions
*
* Revision 1.16 1996/07/27 23:36:08 jimz
* Solaris port of simulator
*
* Revision 1.15 1996/07/22 19:52:16 jimz
* switched node params to RF_DagParam_t, a union of
* a 64-bit int and a void *, for better portability
* attempted hpux port, but failed partway through for
* lack of a single C compiler capable of compiling all
* source files
*
* Revision 1.14 1996/06/02 17:31:48 jimz
* Moved a lot of global stuff into array structure, where it belongs.
* Fixed up paritylogging, pss modules in this manner. Some general
* code cleanup. Removed lots of dead code, some dead files.
*
* Revision 1.13 1996/05/31 22:26:54 jimz
* fix a lot of mapping problems, memory allocation problems
* found some weird lock issues, fixed 'em
* more code cleanup
*
* Revision 1.12 1996/05/27 18:56:37 jimz
* more code cleanup
* better typing
* compiles in all 3 environments
*
* Revision 1.11 1996/05/24 22:17:04 jimz
* continue code + namespace cleanup
* typed a bunch of flags
*
* Revision 1.10 1996/05/24 04:28:55 jimz
* release cleanup ckpt
*
* Revision 1.9 1996/05/18 19:51:34 jimz
* major code cleanup- fix syntax, make some types consistent,
* add prototypes, clean out dead code, et cetera
*
* Revision 1.8 1996/05/03 19:41:07 wvcii
* added includes for dag library
*
* Revision 1.7 1995/11/30 16:19:36 wvcii
* added copyright info
*
* Revision 1.6 1995/11/07 16:15:08 wvcii
* updated/added prototyping for dag creation
*
* Revision 1.5 1995/03/01 20:25:48 holland
* kernelization changes
*
* Revision 1.4 1995/02/03 22:31:36 holland
* many changes related to kernelization
*
* Revision 1.3 1995/02/01 15:13:05 holland
* moved #include of general.h out of raid.h and into each file
*
* Revision 1.2 1994/12/05 04:50:26 danner
* additional pq support
*
* Revision 1.1 1994/11/29 20:36:02 danner
* Initial revision
*
*/
#include "rf_archs.h"
#if (RF_INCLUDE_DECL_PQ > 0) || (RF_INCLUDE_RAID6 > 0)
#include "rf_types.h"
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_dagutils.h"
#include "rf_dagfuncs.h"
#include "rf_dagffrd.h"
#include "rf_dagffwr.h"
#include "rf_dagdegrd.h"
#include "rf_dagdegwr.h"
#include "rf_threadid.h"
#include "rf_etimer.h"
#include "rf_pqdeg.h"
#include "rf_general.h"
#include "rf_pqdegdags.h"
#include "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_PQ_DoubleDegRead(raidPtr, asmap, dag_h, bp, flags, allocList);
}
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)
{
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_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_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) */
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