xref: /src/sys/dev/raidframe/rf_paritylogging.c

/*	$NetBSD: rf_paritylogging.c,v 1.19 2003/12/29 05:22:16 oster Exp $	*/
/*
 * Copyright (c) 1995 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: William V. Courtright II
 *
 * 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 (at) 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.
 */


/*
  parity logging configuration, dag selection, and mapping is implemented here
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_paritylogging.c,v 1.19 2003/12/29 05:22:16 oster Exp $");

#include "rf_archs.h"

#if RF_INCLUDE_PARITYLOGGING > 0

#include <dev/raidframe/raidframevar.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_paritylog.h"
#include "rf_paritylogDiskMgr.h"
#include "rf_paritylogging.h"
#include "rf_parityloggingdags.h"
#include "rf_general.h"
#include "rf_map.h"
#include "rf_utils.h"
#include "rf_shutdown.h"

typedef struct RF_ParityLoggingConfigInfo_s {
	RF_RowCol_t **stripeIdentifier;	/* filled in at config time & used by
					 * IdentifyStripe */
}       RF_ParityLoggingConfigInfo_t;

static void FreeRegionInfo(RF_Raid_t * raidPtr, RF_RegionId_t regionID);
static void rf_ShutdownParityLogging(RF_ThreadArg_t arg);
static void rf_ShutdownParityLoggingRegionInfo(RF_ThreadArg_t arg);
static void rf_ShutdownParityLoggingPool(RF_ThreadArg_t arg);
static void rf_ShutdownParityLoggingRegionBufferPool(RF_ThreadArg_t arg);
static void rf_ShutdownParityLoggingParityBufferPool(RF_ThreadArg_t arg);
static void rf_ShutdownParityLoggingDiskQueue(RF_ThreadArg_t arg);

int
rf_ConfigureParityLogging(
    RF_ShutdownList_t ** listp,
    RF_Raid_t * raidPtr,
    RF_Config_t * cfgPtr)
{
	int     i, j, startdisk, rc;
	RF_SectorCount_t totalLogCapacity, fragmentation, lastRegionCapacity;
	RF_SectorCount_t parityBufferCapacity, maxRegionParityRange;
	RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
	RF_ParityLoggingConfigInfo_t *info;
	RF_ParityLog_t *l = NULL, *next;
	caddr_t lHeapPtr;

	if (rf_numParityRegions <= 0)
		return(EINVAL);

	/*
         * We create multiple entries on the shutdown list here, since
         * this configuration routine is fairly complicated in and of
         * itself, and this makes backing out of a failed configuration
         * much simpler.
         */

	raidPtr->numSectorsPerLog = RF_DEFAULT_NUM_SECTORS_PER_LOG;

	/* create a parity logging configuration structure */
	RF_MallocAndAdd(info, sizeof(RF_ParityLoggingConfigInfo_t),
			(RF_ParityLoggingConfigInfo_t *),
			raidPtr->cleanupList);
	if (info == NULL)
		return (ENOMEM);
	layoutPtr->layoutSpecificInfo = (void *) info;

	/* the stripe identifier must identify the disks in each stripe, IN
	 * THE ORDER THAT THEY APPEAR IN THE STRIPE. */
	info->stripeIdentifier = rf_make_2d_array((raidPtr->numCol),
						  (raidPtr->numCol),
						  raidPtr->cleanupList);
	if (info->stripeIdentifier == NULL)
		return (ENOMEM);

	startdisk = 0;
	for (i = 0; i < (raidPtr->numCol); i++) {
		for (j = 0; j < (raidPtr->numCol); j++) {
			info->stripeIdentifier[i][j] = (startdisk + j) %
				(raidPtr->numCol - 1);
		}
		if ((--startdisk) < 0)
			startdisk = raidPtr->numCol - 1 - 1;
	}

	/* fill in the remaining layout parameters */
	layoutPtr->numStripe = layoutPtr->stripeUnitsPerDisk;
	layoutPtr->numParityCol = 1;
	layoutPtr->numParityLogCol = 1;
	layoutPtr->numDataCol = raidPtr->numCol - layoutPtr->numParityCol -
		layoutPtr->numParityLogCol;
	layoutPtr->dataSectorsPerStripe = layoutPtr->numDataCol *
		layoutPtr->sectorsPerStripeUnit;
	layoutPtr->dataStripeUnitsPerDisk = layoutPtr->stripeUnitsPerDisk;
	raidPtr->sectorsPerDisk = layoutPtr->stripeUnitsPerDisk *
		layoutPtr->sectorsPerStripeUnit;

	raidPtr->totalSectors = layoutPtr->stripeUnitsPerDisk *
		layoutPtr->numDataCol * layoutPtr->sectorsPerStripeUnit;

	/* configure parity log parameters
	 *
	 * parameter               comment/constraints
	 * -------------------------------------------
	 * numParityRegions*       all regions (except possibly last)
	 *                         of equal size
	 * totalInCoreLogCapacity* amount of memory in bytes available
	 *                         for in-core logs (default 1 MB)
	 * numSectorsPerLog#       capacity of an in-core log in sectors
	 *                         (1 * disk track)
	 * numParityLogs           total number of in-core logs,
	 *                         should be at least numParityRegions
	 * regionLogCapacity       size of a region log (except possibly
	 *                         last one) in sectors
	 * totalLogCapacity        total amount of log space in sectors
	 *
	 * where '*' denotes a user settable parameter.
	 * Note that logs are fixed to be the size of a disk track,
	 * value #defined in rf_paritylog.h
	 *
	 */

	totalLogCapacity = layoutPtr->stripeUnitsPerDisk * layoutPtr->sectorsPerStripeUnit * layoutPtr->numParityLogCol;
	raidPtr->regionLogCapacity = totalLogCapacity / rf_numParityRegions;
	if (rf_parityLogDebug)
		printf("bytes per sector %d\n", raidPtr->bytesPerSector);

	/* reduce fragmentation within a disk region by adjusting the number
	 * of regions in an attempt to allow an integral number of logs to fit
	 * into a disk region */
	fragmentation = raidPtr->regionLogCapacity % raidPtr->numSectorsPerLog;
	if (fragmentation > 0)
		for (i = 1; i < (raidPtr->numSectorsPerLog / 2); i++) {
			if (((totalLogCapacity / (rf_numParityRegions + i)) %
			     raidPtr->numSectorsPerLog) < fragmentation) {
				rf_numParityRegions++;
				raidPtr->regionLogCapacity = totalLogCapacity /
					rf_numParityRegions;
				fragmentation = raidPtr->regionLogCapacity %
					raidPtr->numSectorsPerLog;
			}
			if (((totalLogCapacity / (rf_numParityRegions - i)) %
			     raidPtr->numSectorsPerLog) < fragmentation) {
				rf_numParityRegions--;
				raidPtr->regionLogCapacity = totalLogCapacity /
					rf_numParityRegions;
				fragmentation = raidPtr->regionLogCapacity %
					raidPtr->numSectorsPerLog;
			}
		}
	/* ensure integral number of regions per log */
	raidPtr->regionLogCapacity = (raidPtr->regionLogCapacity /
				      raidPtr->numSectorsPerLog) *
		raidPtr->numSectorsPerLog;

	raidPtr->numParityLogs = rf_totalInCoreLogCapacity /
		(raidPtr->bytesPerSector * raidPtr->numSectorsPerLog);
	/* to avoid deadlock, must ensure that enough logs exist for each
	 * region to have one simultaneously */
	if (raidPtr->numParityLogs < rf_numParityRegions)
		raidPtr->numParityLogs = rf_numParityRegions;

	/* create region information structs */
	printf("Allocating %d bytes for in-core parity region info\n",
	       (int) (rf_numParityRegions * sizeof(RF_RegionInfo_t)));
	RF_Malloc(raidPtr->regionInfo,
		  (rf_numParityRegions * sizeof(RF_RegionInfo_t)),
		  (RF_RegionInfo_t *));
	if (raidPtr->regionInfo == NULL)
		return (ENOMEM);

	/* last region may not be full capacity */
	lastRegionCapacity = raidPtr->regionLogCapacity;
	while ((rf_numParityRegions - 1) * raidPtr->regionLogCapacity +
	       lastRegionCapacity > totalLogCapacity)
		lastRegionCapacity = lastRegionCapacity -
			raidPtr->numSectorsPerLog;

	raidPtr->regionParityRange = raidPtr->sectorsPerDisk /
		rf_numParityRegions;
	maxRegionParityRange = raidPtr->regionParityRange;

/* i can't remember why this line is in the code -wvcii 6/30/95 */
/*  if (raidPtr->sectorsPerDisk % rf_numParityRegions > 0)
    regionParityRange++; */

	/* build pool of unused parity logs */
	printf("Allocating %d bytes for %d parity logs\n",
	       raidPtr->numParityLogs * raidPtr->numSectorsPerLog *
	       raidPtr->bytesPerSector,
	       raidPtr->numParityLogs);
	RF_Malloc(raidPtr->parityLogBufferHeap, raidPtr->numParityLogs *
		  raidPtr->numSectorsPerLog * raidPtr->bytesPerSector,
		  (caddr_t));
	if (raidPtr->parityLogBufferHeap == NULL)
		return (ENOMEM);
	lHeapPtr = raidPtr->parityLogBufferHeap;
	rc = rf_mutex_init(&raidPtr->parityLogPool.mutex);
	if (rc) {
		rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
		RF_Free(raidPtr->parityLogBufferHeap, raidPtr->numParityLogs *
			raidPtr->numSectorsPerLog * raidPtr->bytesPerSector);
		return (ENOMEM);
	}
	for (i = 0; i < raidPtr->numParityLogs; i++) {
		if (i == 0) {
			RF_Malloc(raidPtr->parityLogPool.parityLogs,
				  sizeof(RF_ParityLog_t), (RF_ParityLog_t *));
			if (raidPtr->parityLogPool.parityLogs == NULL) {
				RF_Free(raidPtr->parityLogBufferHeap,
					raidPtr->numParityLogs *
					raidPtr->numSectorsPerLog *
					raidPtr->bytesPerSector);
				return (ENOMEM);
			}
			l = raidPtr->parityLogPool.parityLogs;
		} else {
			RF_Malloc(l->next, sizeof(RF_ParityLog_t),
				  (RF_ParityLog_t *));
			if (l->next == NULL) {
				RF_Free(raidPtr->parityLogBufferHeap,
					raidPtr->numParityLogs *
					raidPtr->numSectorsPerLog *
					raidPtr->bytesPerSector);
				for (l = raidPtr->parityLogPool.parityLogs;
				     l;
				     l = next) {
					next = l->next;
					if (l->records)
						RF_Free(l->records, (raidPtr->numSectorsPerLog * sizeof(RF_ParityLogRecord_t)));
					RF_Free(l, sizeof(RF_ParityLog_t));
				}
				return (ENOMEM);
			}
			l = l->next;
		}
		l->bufPtr = lHeapPtr;
		lHeapPtr += raidPtr->numSectorsPerLog *
			raidPtr->bytesPerSector;
		RF_Malloc(l->records, (raidPtr->numSectorsPerLog *
				       sizeof(RF_ParityLogRecord_t)),
			  (RF_ParityLogRecord_t *));
		if (l->records == NULL) {
			RF_Free(raidPtr->parityLogBufferHeap,
				raidPtr->numParityLogs *
				raidPtr->numSectorsPerLog *
				raidPtr->bytesPerSector);
			for (l = raidPtr->parityLogPool.parityLogs;
			     l;
			     l = next) {
				next = l->next;
				if (l->records)
					RF_Free(l->records,
						(raidPtr->numSectorsPerLog *
						 sizeof(RF_ParityLogRecord_t)));
				RF_Free(l, sizeof(RF_ParityLog_t));
			}
			return (ENOMEM);
		}
	}
	rc = rf_ShutdownCreate(listp, rf_ShutdownParityLoggingPool, raidPtr);
	if (rc) {
		RF_ERRORMSG3("Unable to create shutdown entry file %s line %d rc=%d\n", __FILE__,
		    __LINE__, rc);
		rf_ShutdownParityLoggingPool(raidPtr);
		return (rc);
	}
	/* build pool of region buffers */
	rc = rf_mutex_init(&raidPtr->regionBufferPool.mutex);
	if (rc) {
		rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
		return (ENOMEM);
	}
	rc = rf_cond_init(&raidPtr->regionBufferPool.cond);
	if (rc) {
		rf_print_unable_to_init_cond(__FILE__, __LINE__, rc);
		return (ENOMEM);
	}
	raidPtr->regionBufferPool.bufferSize = raidPtr->regionLogCapacity *
		raidPtr->bytesPerSector;
	printf("regionBufferPool.bufferSize %d\n",
	       raidPtr->regionBufferPool.bufferSize);

	/* for now, only one region at a time may be reintegrated */
	raidPtr->regionBufferPool.totalBuffers = 1;

	raidPtr->regionBufferPool.availableBuffers =
		raidPtr->regionBufferPool.totalBuffers;
	raidPtr->regionBufferPool.availBuffersIndex = 0;
	raidPtr->regionBufferPool.emptyBuffersIndex = 0;
	printf("Allocating %d bytes for regionBufferPool\n",
	       (int) (raidPtr->regionBufferPool.totalBuffers *
		      sizeof(caddr_t)));
	RF_Malloc(raidPtr->regionBufferPool.buffers,
		  raidPtr->regionBufferPool.totalBuffers * sizeof(caddr_t),
		  (caddr_t *));
	if (raidPtr->regionBufferPool.buffers == NULL) {
		rf_cond_destroy(&raidPtr->regionBufferPool.cond);
		return (ENOMEM);
	}
	for (i = 0; i < raidPtr->regionBufferPool.totalBuffers; i++) {
		printf("Allocating %d bytes for regionBufferPool#%d\n",
		       (int) (raidPtr->regionBufferPool.bufferSize *
			      sizeof(char)), i);
		RF_Malloc(raidPtr->regionBufferPool.buffers[i],
			  raidPtr->regionBufferPool.bufferSize * sizeof(char),
			  (caddr_t));
		if (raidPtr->regionBufferPool.buffers[i] == NULL) {
			rf_cond_destroy(&raidPtr->regionBufferPool.cond);
			for (j = 0; j < i; j++) {
				RF_Free(raidPtr->regionBufferPool.buffers[i],
					raidPtr->regionBufferPool.bufferSize *
					sizeof(char));
			}
			RF_Free(raidPtr->regionBufferPool.buffers,
				raidPtr->regionBufferPool.totalBuffers *
				sizeof(caddr_t));
			return (ENOMEM);
		}
		printf("raidPtr->regionBufferPool.buffers[%d] = %lx\n", i,
		    (long) raidPtr->regionBufferPool.buffers[i]);
	}
	rc = rf_ShutdownCreate(listp,
			       rf_ShutdownParityLoggingRegionBufferPool,
			       raidPtr);
	if (rc) {
		RF_ERRORMSG3("Unable to create shutdown entry file %s line %d rc=%d\n", __FILE__,
		    __LINE__, rc);
		rf_ShutdownParityLoggingRegionBufferPool(raidPtr);
		return (rc);
	}
	/* build pool of parity buffers */
	parityBufferCapacity = maxRegionParityRange;
	rc = rf_mutex_init(&raidPtr->parityBufferPool.mutex);
	if (rc) {
		rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
		return (rc);
	}
	rc = rf_cond_init(&raidPtr->parityBufferPool.cond);
	if (rc) {
		rf_print_unable_to_init_cond(__FILE__, __LINE__, rc);
		return (ENOMEM);
	}
	raidPtr->parityBufferPool.bufferSize = parityBufferCapacity *
		raidPtr->bytesPerSector;
	printf("parityBufferPool.bufferSize %d\n",
	       raidPtr->parityBufferPool.bufferSize);

	/* for now, only one region at a time may be reintegrated */
	raidPtr->parityBufferPool.totalBuffers = 1;

	raidPtr->parityBufferPool.availableBuffers =
		raidPtr->parityBufferPool.totalBuffers;
	raidPtr->parityBufferPool.availBuffersIndex = 0;
	raidPtr->parityBufferPool.emptyBuffersIndex = 0;
	printf("Allocating %d bytes for parityBufferPool of %d units\n",
	       (int) (raidPtr->parityBufferPool.totalBuffers *
		      sizeof(caddr_t)),
	       raidPtr->parityBufferPool.totalBuffers );
	RF_Malloc(raidPtr->parityBufferPool.buffers,
		  raidPtr->parityBufferPool.totalBuffers * sizeof(caddr_t),
		  (caddr_t *));
	if (raidPtr->parityBufferPool.buffers == NULL) {
		rf_cond_destroy(&raidPtr->parityBufferPool.cond);
		return (ENOMEM);
	}
	for (i = 0; i < raidPtr->parityBufferPool.totalBuffers; i++) {
		printf("Allocating %d bytes for parityBufferPool#%d\n",
		       (int) (raidPtr->parityBufferPool.bufferSize *
			      sizeof(char)),i);
		RF_Malloc(raidPtr->parityBufferPool.buffers[i],
			  raidPtr->parityBufferPool.bufferSize * sizeof(char),
			  (caddr_t));
		if (raidPtr->parityBufferPool.buffers == NULL) {
			rf_cond_destroy(&raidPtr->parityBufferPool.cond);
			for (j = 0; j < i; j++) {
				RF_Free(raidPtr->parityBufferPool.buffers[i],
					raidPtr->regionBufferPool.bufferSize *
					sizeof(char));
			}
			RF_Free(raidPtr->parityBufferPool.buffers,
				raidPtr->regionBufferPool.totalBuffers *
				sizeof(caddr_t));
			return (ENOMEM);
		}
		printf("parityBufferPool.buffers[%d] = %lx\n", i,
		    (long) raidPtr->parityBufferPool.buffers[i]);
	}
	rc = rf_ShutdownCreate(listp,
			       rf_ShutdownParityLoggingParityBufferPool,
			       raidPtr);
	if (rc) {
		RF_ERRORMSG3("Unable to create shutdown entry file %s line %d rc=%d\n", __FILE__,
		    __LINE__, rc);
		rf_ShutdownParityLoggingParityBufferPool(raidPtr);
		return (rc);
	}
	/* initialize parityLogDiskQueue */
	rf_mutex_init(&raidPtr->parityLogDiskQueue.mutex);
	rc = rf_create_managed_cond(listp, &raidPtr->parityLogDiskQueue.cond);
	if (rc) {
		rf_print_unable_to_init_cond(__FILE__, __LINE__, rc);
		return (rc);
	}
	raidPtr->parityLogDiskQueue.flushQueue = NULL;
	raidPtr->parityLogDiskQueue.reintQueue = NULL;
	raidPtr->parityLogDiskQueue.bufHead = NULL;
	raidPtr->parityLogDiskQueue.bufTail = NULL;
	raidPtr->parityLogDiskQueue.reintHead = NULL;
	raidPtr->parityLogDiskQueue.reintTail = NULL;
	raidPtr->parityLogDiskQueue.logBlockHead = NULL;
	raidPtr->parityLogDiskQueue.logBlockTail = NULL;
	raidPtr->parityLogDiskQueue.reintBlockHead = NULL;
	raidPtr->parityLogDiskQueue.reintBlockTail = NULL;
	raidPtr->parityLogDiskQueue.freeDataList = NULL;
	raidPtr->parityLogDiskQueue.freeCommonList = NULL;

	rc = rf_ShutdownCreate(listp,
			       rf_ShutdownParityLoggingDiskQueue,
			       raidPtr);
	if (rc) {
		RF_ERRORMSG3("Unable to create shutdown entry file %s line %d rc=%d\n", __FILE__,
		    __LINE__, rc);
		return (rc);
	}
	for (i = 0; i < rf_numParityRegions; i++) {
		rc = rf_mutex_init(&raidPtr->regionInfo[i].mutex);
		if (rc) {
			rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
			for (j = 0; j < i; j++)
				FreeRegionInfo(raidPtr, j);
			RF_Free(raidPtr->regionInfo,
				(rf_numParityRegions *
				 sizeof(RF_RegionInfo_t)));
			return (ENOMEM);
		}
		rc = rf_mutex_init(&raidPtr->regionInfo[i].reintMutex);
		if (rc) {
			rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
			for (j = 0; j < i; j++)
				FreeRegionInfo(raidPtr, j);
			RF_Free(raidPtr->regionInfo,
				(rf_numParityRegions *
				 sizeof(RF_RegionInfo_t)));
			return (ENOMEM);
		}
		raidPtr->regionInfo[i].reintInProgress = RF_FALSE;
		raidPtr->regionInfo[i].regionStartAddr =
			raidPtr->regionLogCapacity * i;
		raidPtr->regionInfo[i].parityStartAddr =
			raidPtr->regionParityRange * i;
		if (i < rf_numParityRegions - 1) {
			raidPtr->regionInfo[i].capacity =
				raidPtr->regionLogCapacity;
			raidPtr->regionInfo[i].numSectorsParity =
				raidPtr->regionParityRange;
		} else {
			raidPtr->regionInfo[i].capacity =
				lastRegionCapacity;
			raidPtr->regionInfo[i].numSectorsParity =
				raidPtr->sectorsPerDisk -
				raidPtr->regionParityRange * i;
			if (raidPtr->regionInfo[i].numSectorsParity >
			    maxRegionParityRange)
				maxRegionParityRange =
					raidPtr->regionInfo[i].numSectorsParity;
		}
		raidPtr->regionInfo[i].diskCount = 0;
		RF_ASSERT(raidPtr->regionInfo[i].capacity +
			  raidPtr->regionInfo[i].regionStartAddr <=
			  totalLogCapacity);
		RF_ASSERT(raidPtr->regionInfo[i].parityStartAddr +
			  raidPtr->regionInfo[i].numSectorsParity <=
			  raidPtr->sectorsPerDisk);
		printf("Allocating %d bytes for region %d\n",
		       (int) (raidPtr->regionInfo[i].capacity *
			   sizeof(RF_DiskMap_t)), i);
		RF_Malloc(raidPtr->regionInfo[i].diskMap,
			  (raidPtr->regionInfo[i].capacity *
			   sizeof(RF_DiskMap_t)),
			  (RF_DiskMap_t *));
		if (raidPtr->regionInfo[i].diskMap == NULL) {
			for (j = 0; j < i; j++)
				FreeRegionInfo(raidPtr, j);
			RF_Free(raidPtr->regionInfo,
				(rf_numParityRegions *
				 sizeof(RF_RegionInfo_t)));
			return (ENOMEM);
		}
		raidPtr->regionInfo[i].loggingEnabled = RF_FALSE;
		raidPtr->regionInfo[i].coreLog = NULL;
	}
	rc = rf_ShutdownCreate(listp,
			       rf_ShutdownParityLoggingRegionInfo,
			       raidPtr);
	if (rc) {
		RF_ERRORMSG3("Unable to create shutdown entry file %s line %d rc=%d\n", __FILE__,
		    __LINE__, rc);
		rf_ShutdownParityLoggingRegionInfo(raidPtr);
		return (rc);
	}
	RF_ASSERT(raidPtr->parityLogDiskQueue.threadState == 0);
	raidPtr->parityLogDiskQueue.threadState = RF_PLOG_CREATED;
	rc = RF_CREATE_THREAD(raidPtr->pLogDiskThreadHandle,
			      rf_ParityLoggingDiskManager, raidPtr,"rf_log");
	if (rc) {
		raidPtr->parityLogDiskQueue.threadState = 0;
		RF_ERRORMSG3("Unable to create parity logging disk thread file %s line %d rc=%d\n",
		    __FILE__, __LINE__, rc);
		return (ENOMEM);
	}
	/* wait for thread to start */
	RF_LOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);
	while (!(raidPtr->parityLogDiskQueue.threadState & RF_PLOG_RUNNING)) {
		RF_WAIT_COND(raidPtr->parityLogDiskQueue.cond,
			     raidPtr->parityLogDiskQueue.mutex);
	}
	RF_UNLOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);

	rc = rf_ShutdownCreate(listp, rf_ShutdownParityLogging, raidPtr);
	if (rc) {
		RF_ERRORMSG1("Got rc=%d adding parity logging shutdown event\n", rc);
		rf_ShutdownParityLogging(raidPtr);
		return (rc);
	}
	if (rf_parityLogDebug) {
		printf("                            size of disk log in sectors: %d\n",
		    (int) totalLogCapacity);
		printf("                            total number of parity regions is %d\n", (int) rf_numParityRegions);
		printf("                            nominal sectors of log per parity region is %d\n", (int) raidPtr->regionLogCapacity);
		printf("                            nominal region fragmentation is %d sectors\n", (int) fragmentation);
		printf("                            total number of parity logs is %d\n", raidPtr->numParityLogs);
		printf("                            parity log size is %d sectors\n", raidPtr->numSectorsPerLog);
		printf("                            total in-core log space is %d bytes\n", (int) rf_totalInCoreLogCapacity);
	}
	rf_EnableParityLogging(raidPtr);

	return (0);
}

static void
FreeRegionInfo(
    RF_Raid_t * raidPtr,
    RF_RegionId_t regionID)
{
	RF_LOCK_MUTEX(raidPtr->regionInfo[regionID].mutex);
	RF_Free(raidPtr->regionInfo[regionID].diskMap,
		(raidPtr->regionInfo[regionID].capacity *
		 sizeof(RF_DiskMap_t)));
	if (!rf_forceParityLogReint && raidPtr->regionInfo[regionID].coreLog) {
		rf_ReleaseParityLogs(raidPtr,
				     raidPtr->regionInfo[regionID].coreLog);
		raidPtr->regionInfo[regionID].coreLog = NULL;
	} else {
		RF_ASSERT(raidPtr->regionInfo[regionID].coreLog == NULL);
		RF_ASSERT(raidPtr->regionInfo[regionID].diskCount == 0);
	}
	RF_UNLOCK_MUTEX(raidPtr->regionInfo[regionID].mutex);
}


static void
FreeParityLogQueue(
    RF_Raid_t * raidPtr,
    RF_ParityLogQueue_t * queue)
{
	RF_ParityLog_t *l1, *l2;

	RF_LOCK_MUTEX(queue->mutex);
	l1 = queue->parityLogs;
	while (l1) {
		l2 = l1;
		l1 = l2->next;
		RF_Free(l2->records, (raidPtr->numSectorsPerLog *
				      sizeof(RF_ParityLogRecord_t)));
		RF_Free(l2, sizeof(RF_ParityLog_t));
	}
	RF_UNLOCK_MUTEX(queue->mutex);
}


static void
FreeRegionBufferQueue(RF_RegionBufferQueue_t * queue)
{
	int     i;

	RF_LOCK_MUTEX(queue->mutex);
	if (queue->availableBuffers != queue->totalBuffers) {
		printf("Attempt to free region queue which is still in use!\n");
		RF_ASSERT(0);
	}
	for (i = 0; i < queue->totalBuffers; i++)
		RF_Free(queue->buffers[i], queue->bufferSize);
	RF_Free(queue->buffers, queue->totalBuffers * sizeof(caddr_t));
	RF_UNLOCK_MUTEX(queue->mutex);
}

static void
rf_ShutdownParityLoggingRegionInfo(RF_ThreadArg_t arg)
{
	RF_Raid_t *raidPtr;
	RF_RegionId_t i;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLoggingRegionInfo\n",
		       raidPtr->raidid);
	}
	/* free region information structs */
	for (i = 0; i < rf_numParityRegions; i++)
		FreeRegionInfo(raidPtr, i);
	RF_Free(raidPtr->regionInfo, (rf_numParityRegions *
				      sizeof(raidPtr->regionInfo)));
	raidPtr->regionInfo = NULL;
}

static void
rf_ShutdownParityLoggingPool(RF_ThreadArg_t arg)
{
	RF_Raid_t *raidPtr;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLoggingPool\n", raidPtr->raidid);
	}
	/* free contents of parityLogPool */
	FreeParityLogQueue(raidPtr, &raidPtr->parityLogPool);
	RF_Free(raidPtr->parityLogBufferHeap, raidPtr->numParityLogs *
		raidPtr->numSectorsPerLog * raidPtr->bytesPerSector);
}

static void
rf_ShutdownParityLoggingRegionBufferPool(RF_ThreadArg_t arg)
{
	RF_Raid_t *raidPtr;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLoggingRegionBufferPool\n",
		       raidPtr->raidid);
	}
	FreeRegionBufferQueue(&raidPtr->regionBufferPool);
}

static void
rf_ShutdownParityLoggingParityBufferPool(RF_ThreadArg_t arg)
{
	RF_Raid_t *raidPtr;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLoggingParityBufferPool\n",
		       raidPtr->raidid);
	}
	FreeRegionBufferQueue(&raidPtr->parityBufferPool);
}

static void
rf_ShutdownParityLoggingDiskQueue(RF_ThreadArg_t arg)
{
	RF_ParityLogData_t *d;
	RF_CommonLogData_t *c;
	RF_Raid_t *raidPtr;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLoggingDiskQueue\n",
		       raidPtr->raidid);
	}
	/* free disk manager stuff */
	RF_ASSERT(raidPtr->parityLogDiskQueue.bufHead == NULL);
	RF_ASSERT(raidPtr->parityLogDiskQueue.bufTail == NULL);
	RF_ASSERT(raidPtr->parityLogDiskQueue.reintHead == NULL);
	RF_ASSERT(raidPtr->parityLogDiskQueue.reintTail == NULL);
	while (raidPtr->parityLogDiskQueue.freeDataList) {
		d = raidPtr->parityLogDiskQueue.freeDataList;
		raidPtr->parityLogDiskQueue.freeDataList =
			raidPtr->parityLogDiskQueue.freeDataList->next;
		RF_Free(d, sizeof(RF_ParityLogData_t));
	}
	while (raidPtr->parityLogDiskQueue.freeCommonList) {
		c = raidPtr->parityLogDiskQueue.freeCommonList;
		raidPtr->parityLogDiskQueue.freeCommonList =
			raidPtr->parityLogDiskQueue.freeCommonList->next;
		RF_Free(c, sizeof(RF_CommonLogData_t));
	}
}

static void
rf_ShutdownParityLogging(RF_ThreadArg_t arg)
{
	RF_Raid_t *raidPtr;

	raidPtr = (RF_Raid_t *) arg;
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLogging\n", raidPtr->raidid);
	}
	/* shutdown disk thread */
	/* This has the desirable side-effect of forcing all regions to be
	 * reintegrated.  This is necessary since all parity log maps are
	 * currently held in volatile memory. */

	RF_LOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);
	raidPtr->parityLogDiskQueue.threadState |= RF_PLOG_TERMINATE;
	RF_UNLOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);
	RF_SIGNAL_COND(raidPtr->parityLogDiskQueue.cond);
	/*
         * pLogDiskThread will now terminate when queues are cleared
         * now wait for it to be done
         */
	RF_LOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);
	while (!(raidPtr->parityLogDiskQueue.threadState & RF_PLOG_SHUTDOWN)) {
		RF_WAIT_COND(raidPtr->parityLogDiskQueue.cond,
			     raidPtr->parityLogDiskQueue.mutex);
	}
	RF_UNLOCK_MUTEX(raidPtr->parityLogDiskQueue.mutex);
	if (rf_parityLogDebug) {
		printf("raid%d: ShutdownParityLogging done (thread completed)\n", raidPtr->raidid);
	}
}

int
rf_GetDefaultNumFloatingReconBuffersParityLogging(RF_Raid_t * raidPtr)
{
	return (20);
}

RF_HeadSepLimit_t
rf_GetDefaultHeadSepLimitParityLogging(RF_Raid_t * raidPtr)
{
	return (10);
}
/* return the region ID for a given RAID address */
RF_RegionId_t
rf_MapRegionIDParityLogging(
    RF_Raid_t * raidPtr,
    RF_SectorNum_t address)
{
	RF_RegionId_t regionID;

/*  regionID = address / (raidPtr->regionParityRange * raidPtr->Layout.numDataCol); */
	regionID = address / raidPtr->regionParityRange;
	if (regionID == rf_numParityRegions) {
		/* last region may be larger than other regions */
		regionID--;
	}
	RF_ASSERT(address >= raidPtr->regionInfo[regionID].parityStartAddr);
	RF_ASSERT(address < raidPtr->regionInfo[regionID].parityStartAddr +
		  raidPtr->regionInfo[regionID].numSectorsParity);
	RF_ASSERT(regionID < rf_numParityRegions);
	return (regionID);
}


/* given a logical RAID sector, determine physical disk address of data */
void
rf_MapSectorParityLogging(
    RF_Raid_t * raidPtr,
    RF_RaidAddr_t raidSector,
    RF_RowCol_t * col,
    RF_SectorNum_t * diskSector,
    int remap)
{
	RF_StripeNum_t SUID = raidSector /
		raidPtr->Layout.sectorsPerStripeUnit;
	/* *col = (SUID % (raidPtr->numCol -
	 * raidPtr->Layout.numParityLogCol)); */
	*col = SUID % raidPtr->Layout.numDataCol;
	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) *
		raidPtr->Layout.sectorsPerStripeUnit +
		(raidSector % raidPtr->Layout.sectorsPerStripeUnit);
}


/* given a logical RAID sector, determine physical disk address of parity  */
void
rf_MapParityParityLogging(
    RF_Raid_t * raidPtr,
    RF_RaidAddr_t raidSector,
    RF_RowCol_t * col,
    RF_SectorNum_t * diskSector,
    int remap)
{
	RF_StripeNum_t SUID = raidSector /
		raidPtr->Layout.sectorsPerStripeUnit;

	/* *col =
	 * raidPtr->Layout.numDataCol-(SUID/raidPtr->Layout.numDataCol)%(raidPt
	 * r->numCol - raidPtr->Layout.numParityLogCol); */
	*col = raidPtr->Layout.numDataCol;
	*diskSector = (SUID / (raidPtr->Layout.numDataCol)) *
		raidPtr->Layout.sectorsPerStripeUnit +
		(raidSector % raidPtr->Layout.sectorsPerStripeUnit);
}


/* given a regionID and sector offset, determine the physical disk address of the parity log */
void
rf_MapLogParityLogging(
    RF_Raid_t * raidPtr,
    RF_RegionId_t regionID,
    RF_SectorNum_t regionOffset,
    RF_RowCol_t * col,
    RF_SectorNum_t * startSector)
{
	*col = raidPtr->numCol - 1;
	*startSector = raidPtr->regionInfo[regionID].regionStartAddr + regionOffset;
}


/* given a regionID, determine the physical disk address of the logged
   parity for that region */
void
rf_MapRegionParity(
    RF_Raid_t * raidPtr,
    RF_RegionId_t regionID,
    RF_RowCol_t * col,
    RF_SectorNum_t * startSector,
    RF_SectorCount_t * numSector)
{
	*col = raidPtr->numCol - 2;
	*startSector = raidPtr->regionInfo[regionID].parityStartAddr;
	*numSector = raidPtr->regionInfo[regionID].numSectorsParity;
}


/* given a logical RAID address, determine the participating disks in
   the stripe */
void
rf_IdentifyStripeParityLogging(
    RF_Raid_t * raidPtr,
    RF_RaidAddr_t addr,
    RF_RowCol_t ** diskids)
{
	RF_StripeNum_t stripeID = rf_RaidAddressToStripeID(&raidPtr->Layout,
							   addr);
	RF_ParityLoggingConfigInfo_t *info = (RF_ParityLoggingConfigInfo_t *)
		raidPtr->Layout.layoutSpecificInfo;
	*diskids = info->stripeIdentifier[stripeID % raidPtr->numCol];
}


void
rf_MapSIDToPSIDParityLogging(
    RF_RaidLayout_t * layoutPtr,
    RF_StripeNum_t stripeID,
    RF_StripeNum_t * psID,
    RF_ReconUnitNum_t * which_ru)
{
	*which_ru = 0;
	*psID = stripeID;
}


/* select an algorithm for performing an access.  Returns two pointers,
 * one to a function that will return information about the DAG, and
 * another to a function that will create the dag.
 */
void
rf_ParityLoggingDagSelect(
    RF_Raid_t * raidPtr,
    RF_IoType_t type,
    RF_AccessStripeMap_t * asmp,
    RF_VoidFuncPtr * createFunc)
{
	RF_RaidLayout_t *layoutPtr = &(raidPtr->Layout);
	RF_PhysDiskAddr_t *failedPDA = NULL;
	RF_RowCol_t fcol;
	RF_RowStatus_t rstat;
	int     prior_recon;

	RF_ASSERT(RF_IO_IS_R_OR_W(type));

	if (asmp->numDataFailed + asmp->numParityFailed > 1) {
		RF_ERRORMSG("Multiple disks failed in a single group!  Aborting I/O operation.\n");
		*createFunc = NULL;
		return;
	} else
		if (asmp->numDataFailed + asmp->numParityFailed == 1) {

			/* if under recon & already reconstructed, redirect
			 * the access to the spare drive and eliminate the
			 * failure indication */
			failedPDA = asmp->failedPDAs[0];
			fcol = failedPDA->col;
			rstat = raidPtr->status;
			prior_recon = (rstat == rf_rs_reconfigured) || (
			    (rstat == rf_rs_reconstructing) ?
			    rf_CheckRUReconstructed(raidPtr->reconControl->reconMap, failedPDA->startSector) : 0
			    );
			if (prior_recon) {
				RF_RowCol_t oc = failedPDA->col;
				RF_SectorNum_t oo = failedPDA->startSector;
				if (layoutPtr->map->flags &
				    RF_DISTRIBUTE_SPARE) {
					/* redirect to dist spare space */

					if (failedPDA == asmp->parityInfo) {

						/* parity has failed */
						(layoutPtr->map->MapParity) (raidPtr, failedPDA->raidAddress,
						    &failedPDA->col, &failedPDA->startSector, RF_REMAP);

						if (asmp->parityInfo->next) {	/* redir 2nd component,
										 * if any */
							RF_PhysDiskAddr_t *p = asmp->parityInfo->next;
							RF_SectorNum_t SUoffs = p->startSector % layoutPtr->sectorsPerStripeUnit;
							p->col = failedPDA->col;
							p->startSector = rf_RaidAddressOfPrevStripeUnitBoundary(layoutPtr, failedPDA->startSector) +
							    SUoffs;	/* cheating:
									 * startSector is not
									 * really a RAID address */
						}
					} else
						if (asmp->parityInfo->next && failedPDA == asmp->parityInfo->next) {
							RF_ASSERT(0);	/* should not ever
									 * happen */
						} else {

							/* data has failed */
							(layoutPtr->map->MapSector) (raidPtr, failedPDA->raidAddress,
							    &failedPDA->col, &failedPDA->startSector, RF_REMAP);

						}

				} else {
					/* redirect to dedicated spare space */

					failedPDA->col = raidPtr->Disks[fcol].spareCol;

					/* the parity may have two distinct
					 * components, both of which may need
					 * to be redirected */
					if (asmp->parityInfo->next) {
						if (failedPDA == asmp->parityInfo) {
							failedPDA->next->col = failedPDA->col;
						} else
							if (failedPDA == asmp->parityInfo->next) {	/* paranoid:  should never occur */
								asmp->parityInfo->col = failedPDA->col;
							}
					}
				}

				RF_ASSERT(failedPDA->col != -1);

				if (rf_dagDebug || rf_mapDebug) {
					printf("raid%d: Redirected type '%c' c %d o %ld -> c %d o %ld\n",
					    raidPtr->raidid, type, oc, (long) oo, failedPDA->col, (long) failedPDA->startSector);
				}
				asmp->numDataFailed = asmp->numParityFailed = 0;
			}
		}
	if (type == RF_IO_TYPE_READ) {

		if (asmp->numDataFailed == 0)
			*createFunc = (RF_VoidFuncPtr) rf_CreateFaultFreeReadDAG;
		else
			*createFunc = (RF_VoidFuncPtr) rf_CreateRaidFiveDegradedReadDAG;

	} else {


		/* if mirroring, always use large writes.  If the access
		 * requires two distinct parity updates, always do a small
		 * write.  If the stripe contains a failure but the access
		 * does not, do a small write. The first conditional
		 * (numStripeUnitsAccessed <= numDataCol/2) uses a
		 * less-than-or-equal rather than just a less-than because
		 * when G is 3 or 4, numDataCol/2 is 1, and I want
		 * single-stripe-unit updates to use just one disk. */
		if ((asmp->numDataFailed + asmp->numParityFailed) == 0) {
			if (((asmp->numStripeUnitsAccessed <=
			      (layoutPtr->numDataCol / 2)) &&
			     (layoutPtr->numDataCol != 1)) ||
			    (asmp->parityInfo->next != NULL) ||
			    rf_CheckStripeForFailures(raidPtr, asmp)) {
				*createFunc = (RF_VoidFuncPtr) rf_CreateParityLoggingSmallWriteDAG;
			} else
				*createFunc = (RF_VoidFuncPtr) rf_CreateParityLoggingLargeWriteDAG;
		} else
			if (asmp->numParityFailed == 1)
				*createFunc = (RF_VoidFuncPtr) rf_CreateNonRedundantWriteDAG;
			else
				if (asmp->numStripeUnitsAccessed != 1 && failedPDA->numSector != layoutPtr->sectorsPerStripeUnit)
					*createFunc = NULL;
				else
					*createFunc = (RF_VoidFuncPtr) rf_CreateDegradedWriteDAG;
	}
}
#endif				/* RF_INCLUDE_PARITYLOGGING > 0 */