dev/raidframe/rf_reconmap.c

/*	$NetBSD: rf_reconmap.c,v 1.3 1999/01/26 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 (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.
 */

/*************************************************************************
 * rf_reconmap.c
 *
 * code to maintain a map of what sectors have/have not been reconstructed
 *
 *************************************************************************/

#include "rf_raid.h"
#include <sys/time.h>
#include "rf_general.h"
#include "rf_utils.h"
#include "rf_sys.h"

/* special pointer values indicating that a reconstruction unit
 * has been either totally reconstructed or not at all.  Both
 * are illegal pointer values, so you have to be careful not to
 * dereference through them.  RU_NOTHING must be zero, since
 * MakeReconMap uses bzero to initialize the structure.  These are used
 * only at the head of the list.
 */
#define RU_ALL      ((RF_ReconMapListElem_t *) -1)
#define RU_NOTHING  ((RF_ReconMapListElem_t *) 0)

/* used to mark the end of the list */
#define RU_NIL      ((RF_ReconMapListElem_t *) 0)


static void compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr,
	int i);
static void crunch_list(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *listPtr);
static RF_ReconMapListElem_t *MakeReconMapListElem(RF_SectorNum_t startSector,
	RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next);
static void FreeReconMapListElem(RF_ReconMap_t *mapPtr,
	RF_ReconMapListElem_t *p);
static void update_size(RF_ReconMap_t *mapPtr, int size);
static void PrintList(RF_ReconMapListElem_t *listPtr);

/*-----------------------------------------------------------------------------
 *
 * Creates and initializes new Reconstruction map
 *
 *-----------------------------------------------------------------------------*/

RF_ReconMap_t *rf_MakeReconMap(raidPtr, ru_sectors, disk_sectors, spareUnitsPerDisk)
  RF_Raid_t            *raidPtr;
  RF_SectorCount_t      ru_sectors;        /* size of reconstruction unit in sectors */
  RF_SectorCount_t      disk_sectors;      /* size of disk in sectors */
  RF_ReconUnitCount_t   spareUnitsPerDisk; /* zero unless distributed sparing */
{
  RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
  RF_ReconUnitCount_t num_rus = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerRU;
  RF_ReconMap_t *p;
  int rc;

  RF_Malloc(p, sizeof(RF_ReconMap_t), (RF_ReconMap_t *));
  p->sectorsPerReconUnit = ru_sectors;
  p->sectorsInDisk = disk_sectors;

  p->totalRUs = num_rus;
  p->spareRUs = spareUnitsPerDisk;
  p->unitsLeft = num_rus - spareUnitsPerDisk;

  RF_Malloc(p->status, num_rus * sizeof(RF_ReconMapListElem_t *), (RF_ReconMapListElem_t **));
  RF_ASSERT(p->status != (RF_ReconMapListElem_t **) NULL);

  (void) bzero((char *) p->status, num_rus * sizeof(RF_ReconMapListElem_t *));

  p->size = sizeof(RF_ReconMap_t) + num_rus * sizeof(RF_ReconMapListElem_t *);
  p->maxSize = p->size;

  rc = rf_mutex_init(&p->mutex);
  if (rc) {
    RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
      __LINE__, rc);
    RF_Free(p->status, num_rus * sizeof(RF_ReconMapListElem_t *));
    RF_Free(p, sizeof(RF_ReconMap_t));
    return(NULL);
  }
  return(p);
}


/*-----------------------------------------------------------------------------
 *
 * marks a new set of sectors as reconstructed.  All the possible mergings get
 * complicated.  To simplify matters, the approach I take is to just dump
 * something into the list, and then clean it up (i.e. merge elements and
 * eliminate redundant ones) in a second pass over the list (compact_stat_entry()).
 * Not 100% efficient, since a structure can be allocated and then immediately
 * freed, but it keeps this code from becoming (more of) a nightmare of
 * special cases.  The only thing that compact_stat_entry() assumes is that the
 * list is sorted by startSector, and so this is the only condition I maintain
 * here.  (MCH)
 *
 *-----------------------------------------------------------------------------*/

void rf_ReconMapUpdate(raidPtr, mapPtr, startSector, stopSector)
  RF_Raid_t       *raidPtr;
  RF_ReconMap_t   *mapPtr;
  RF_SectorNum_t   startSector;
  RF_SectorNum_t   stopSector;
{
  RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit;
  RF_SectorNum_t i, first_in_RU, last_in_RU;
  RF_ReconMapListElem_t *p, *pt;

  RF_LOCK_MUTEX(mapPtr->mutex);
  RF_ASSERT(startSector >=0 && stopSector < mapPtr->sectorsInDisk && stopSector > startSector);

  while (startSector <= stopSector) {
    i = startSector/mapPtr->sectorsPerReconUnit;
    first_in_RU = i*sectorsPerReconUnit;
    last_in_RU  = first_in_RU + sectorsPerReconUnit -1 ;
    p = mapPtr->status[i];
    if (p!=RU_ALL) {
      if (p==RU_NOTHING || p->startSector > startSector ) {	/* insert at front of list */

	mapPtr->status[i] = MakeReconMapListElem(startSector, RF_MIN(stopSector,last_in_RU), (p==RU_NOTHING) ? NULL : p);
	update_size(mapPtr, sizeof(RF_ReconMapListElem_t));

      } else {						/* general case */
	do {						/* search for place to insert */
	  pt = p; p = p->next;
	} while (p && (p->startSector < startSector));
	pt->next = MakeReconMapListElem(startSector,RF_MIN(stopSector,last_in_RU),p);
	update_size(mapPtr, sizeof(RF_ReconMapListElem_t));
      }
      compact_stat_entry(raidPtr, mapPtr, i);
    }
    startSector = RF_MIN(stopSector, last_in_RU) +1;
  }
  RF_UNLOCK_MUTEX(mapPtr->mutex);
}


/*-----------------------------------------------------------------------------
 *
 * performs whatever list compactions can be done, and frees any space
 * that is no longer necessary.  Assumes only that the list is sorted
 * by startSector.  crunch_list() compacts a single list as much as possible,
 * and the second block of code deletes the entire list if possible.
 * crunch_list() is also called from MakeReconMapAccessList().
 *
 * When a recon unit is detected to be fully reconstructed, we set the
 * corresponding bit in the parity stripe map so that the head follow
 * code will not select this parity stripe again.  This is redundant (but
 * harmless) when compact_stat_entry is called from the reconstruction code,
 * but necessary when called from the user-write code.
 *
 *-----------------------------------------------------------------------------*/

static void compact_stat_entry(raidPtr, mapPtr, i)
  RF_Raid_t      *raidPtr;
  RF_ReconMap_t  *mapPtr;
  int             i;
{
  RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit;
  RF_ReconMapListElem_t *p = mapPtr->status[i];

  crunch_list(mapPtr, p);

  if ((p->startSector == i*sectorsPerReconUnit) &&
      (p->stopSector == i*sectorsPerReconUnit +sectorsPerReconUnit -1)) {
    mapPtr->status[i] = RU_ALL;
    mapPtr->unitsLeft--;
    FreeReconMapListElem(mapPtr,p);
  }
}

static void crunch_list(mapPtr, listPtr)
  RF_ReconMap_t          *mapPtr;
  RF_ReconMapListElem_t  *listPtr;
{
  RF_ReconMapListElem_t *pt, *p = listPtr;

  if (!p) return;
  pt = p;  p = p->next;
  while (p) {
    if (pt->stopSector >= p->startSector-1) {
      pt->stopSector = RF_MAX(pt->stopSector, p->stopSector);
      pt->next = p->next;
      FreeReconMapListElem(mapPtr, p);
      p = pt->next;
    }
    else {
      pt = p;
      p = p->next;
    }
  }
}

/*-----------------------------------------------------------------------------
 *
 * Allocate and fill a new list element
 *
 *-----------------------------------------------------------------------------*/

static RF_ReconMapListElem_t *MakeReconMapListElem(
  RF_SectorNum_t          startSector,
  RF_SectorNum_t          stopSector,
  RF_ReconMapListElem_t  *next)
{
  RF_ReconMapListElem_t *p;

  RF_Malloc(p, sizeof(RF_ReconMapListElem_t), (RF_ReconMapListElem_t *));
  if (p == NULL)
    return(NULL);
  p->startSector = startSector;
  p->stopSector = stopSector;
  p->next = next;
  return(p);
}

/*-----------------------------------------------------------------------------
 *
 * Free a list element
 *
 *-----------------------------------------------------------------------------*/

static void FreeReconMapListElem(mapPtr,p)
  RF_ReconMap_t          *mapPtr;
  RF_ReconMapListElem_t  *p;
{
  int delta;

  if (mapPtr) {
    delta = 0 - (int)sizeof(RF_ReconMapListElem_t);
    update_size(mapPtr, delta);
  }
  RF_Free(p, sizeof(*p));
}

/*-----------------------------------------------------------------------------
 *
 * Free an entire status structure.  Inefficient, but can be called at any time.
 *
 *-----------------------------------------------------------------------------*/
void rf_FreeReconMap(mapPtr)
  RF_ReconMap_t  *mapPtr;
{
  RF_ReconMapListElem_t *p, *q;
  RF_ReconUnitCount_t numRUs;
  RF_ReconUnitNum_t i;

  numRUs = mapPtr->sectorsInDisk / mapPtr->sectorsPerReconUnit;
  if (mapPtr->sectorsInDisk % mapPtr->sectorsPerReconUnit)
    numRUs++;

  for (i=0; i<numRUs; i++) {
    p = mapPtr->status[i];
    while (p != RU_NOTHING && p != RU_ALL) {
      q = p; p = p->next;
      RF_Free(q, sizeof(*q));
    }
  }
  rf_mutex_destroy(&mapPtr->mutex);
  RF_Free(mapPtr->status, mapPtr->totalRUs * sizeof(RF_ReconMapListElem_t *));
  RF_Free(mapPtr, sizeof(RF_ReconMap_t));
}

/*-----------------------------------------------------------------------------
 *
 * returns nonzero if the indicated RU has been reconstructed already
 *
 *---------------------------------------------------------------------------*/

int rf_CheckRUReconstructed(mapPtr, startSector)
  RF_ReconMap_t   *mapPtr;
  RF_SectorNum_t   startSector;
{
  RF_ReconMapListElem_t *l;		/* used for searching */
  RF_ReconUnitNum_t i;

  i = startSector / mapPtr->sectorsPerReconUnit;
  l = mapPtr->status[i];
  return( (l == RU_ALL) ? 1 : 0 );
}

RF_ReconUnitCount_t rf_UnitsLeftToReconstruct(mapPtr)
  RF_ReconMap_t  *mapPtr;
{
  RF_ASSERT(mapPtr != NULL);
  return( mapPtr->unitsLeft );
}

/* updates the size fields of a status descriptor */
static void update_size(mapPtr, size)
  RF_ReconMap_t  *mapPtr;
  int             size;
{
  mapPtr->size += size;
  mapPtr->maxSize = RF_MAX(mapPtr->size, mapPtr->maxSize);
}

static void PrintList(listPtr)
  RF_ReconMapListElem_t  *listPtr;
{
  while (listPtr) {
    printf("%d,%d -> ",(int)listPtr->startSector,(int)listPtr->stopSector);
    listPtr = listPtr->next;
  }
  printf("\n");
}

void rf_PrintReconMap(raidPtr, mapPtr, frow, fcol)
  RF_Raid_t      *raidPtr;
  RF_ReconMap_t  *mapPtr;
  RF_RowCol_t     frow;
  RF_RowCol_t     fcol;
{
  RF_ReconUnitCount_t numRUs;
  RF_ReconMapListElem_t *p;
  RF_ReconUnitNum_t i;

  numRUs = mapPtr->totalRUs;
  if (mapPtr->sectorsInDisk % mapPtr->sectorsPerReconUnit)
    numRUs++;

  for (i=0; i<numRUs; i++) {
    p = mapPtr->status[i];
    if (p==RU_ALL) /*printf("[%d] ALL\n",i)*/;
    else if (p == RU_NOTHING) {
      printf("%d: Unreconstructed\n",i);
    } else {
      printf("%d: ", i);
      PrintList(p);
    }
  }
}

void rf_PrintReconSchedule(mapPtr, starttime)
  RF_ReconMap_t   *mapPtr;
  struct timeval  *starttime;
{
  static int old_pctg = -1;
  struct timeval tv, diff;
  int new_pctg;

  new_pctg = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 100 / mapPtr->totalRUs);
  if (new_pctg != old_pctg) {
    RF_GETTIME(tv);
    RF_TIMEVAL_DIFF(starttime, &tv, &diff);
    printf("%d %d.%06d\n",(int)new_pctg, (int)diff.tv_sec, (int)diff.tv_usec);
    old_pctg = new_pctg;
  }
}