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/* $OpenBSD: rf_reconmap.c,v 1.4 2002/12/16 07:01:05 tdeval Exp $ */
/* $NetBSD: rf_reconmap.c,v 1.6 1999/08/14 21:44:24 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_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"
/*
* 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)
void rf_compact_stat_entry(RF_Raid_t *, RF_ReconMap_t *, int);
void rf_crunch_list(RF_ReconMap_t *, RF_ReconMapListElem_t *);
RF_ReconMapListElem_t * rf_MakeReconMapListElem(RF_SectorNum_t, RF_SectorNum_t,
RF_ReconMapListElem_t *);
void rf_FreeReconMapListElem(RF_ReconMap_t *, RF_ReconMapListElem_t *);
void rf_update_size(RF_ReconMap_t *, int);
void rf_PrintList(RF_ReconMapListElem_t *);
/*****************************************************************************
*
* Creates and initializes new Reconstruction map.
*
*****************************************************************************/
RF_ReconMap_t *
rf_MakeReconMap(
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
* (rf_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 rf_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(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] =
rf_MakeReconMapListElem(startSector,
RF_MIN(stopSector, last_in_RU),
(p == RU_NOTHING) ? NULL : p);
rf_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 = rf_MakeReconMapListElem(startSector,
RF_MIN(stopSector, last_in_RU), p);
rf_update_size(mapPtr,
sizeof(RF_ReconMapListElem_t));
}
rf_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. rf_crunch_list() compacts a single list as much as possible,
* and the second block of code deletes the entire list if possible.
* rf_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 rf_compact_stat_entry is called from the reconstruction
* code, but necessary when called from the user-write code.
*
*****************************************************************************/
void
rf_compact_stat_entry(RF_Raid_t *raidPtr, RF_ReconMap_t *mapPtr, int i)
{
RF_SectorCount_t sectorsPerReconUnit = mapPtr->sectorsPerReconUnit;
RF_ReconMapListElem_t *p = mapPtr->status[i];
rf_crunch_list(mapPtr, p);
if ((p->startSector == i * sectorsPerReconUnit) &&
(p->stopSector == i * sectorsPerReconUnit +
sectorsPerReconUnit - 1)) {
mapPtr->status[i] = RU_ALL;
mapPtr->unitsLeft--;
rf_FreeReconMapListElem(mapPtr, p);
}
}
void
rf_crunch_list(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;
rf_FreeReconMapListElem(mapPtr, p);
p = pt->next;
} else {
pt = p;
p = p->next;
}
}
}
/*****************************************************************************
*
* Allocate and fill a new list element.
*
*****************************************************************************/
RF_ReconMapListElem_t *
rf_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.
*
*****************************************************************************/
void
rf_FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p)
{
int delta;
if (mapPtr) {
delta = 0 - (int) sizeof(RF_ReconMapListElem_t);
rf_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(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(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(RF_ReconMap_t *mapPtr)
{
RF_ASSERT(mapPtr != NULL);
return (mapPtr->unitsLeft);
}
/* Updates the size fields of a status descriptor. */
void
rf_update_size(RF_ReconMap_t *mapPtr, int size)
{
mapPtr->size += size;
mapPtr->maxSize = RF_MAX(mapPtr->size, mapPtr->maxSize);
}
void
rf_PrintList(RF_ReconMapListElem_t *listPtr)
{
while (listPtr) {
printf("%d,%d -> ", (int) listPtr->startSector,
(int) listPtr->stopSector);
listPtr = listPtr->next;
}
printf("\n");
}
void
rf_PrintReconMap(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);
rf_PrintList(p);
}
}
}
void
rf_PrintReconSchedule(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;
}
}
|