NetBSD/sys/dev/raidframe/rf_reconmap.c

381 lines
12 KiB
C

/* $NetBSD: rf_reconmap.c,v 1.25 2004/03/18 17:46:22 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 <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_reconmap.c,v 1.25 2004/03/18 17:46:22 oster Exp $");
#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 memset 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)
/* For most reconstructs we need at most 3 RF_ReconMapListElem_t's.
* Bounding the number we need is quite difficult, as it depends on how
* badly the sectors to be reconstructed get divided up. In the current
* code, the reconstructed sectors appeared aligned on stripe boundaries,
* and are always presented in stripe width units, so we're probably
* allocating quite a bit more than we'll ever need.
*/
#define RF_NUM_RECON_POOL_ELEM 100
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_ReconMap_t *mapPtr, RF_SectorNum_t startSector,
RF_SectorNum_t stopSector, RF_ReconMapListElem_t * next);
static void
FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t * p);
#if 0
static void PrintList(RF_ReconMapListElem_t * listPtr);
#endif
/*---------------------------------------------------------------------------
*
* Creates and initializes new Reconstruction map
*
* ru_sectors - size of reconstruction unit in sectors
* disk_sectors - size of disk in sectors
* spareUnitsPerDisk - zero unless distributed sparing
*-------------------------------------------------------------------------*/
RF_ReconMap_t *
rf_MakeReconMap(RF_Raid_t *raidPtr, RF_SectorCount_t ru_sectors,
RF_SectorCount_t disk_sectors,
RF_ReconUnitCount_t spareUnitsPerDisk)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_ReconUnitCount_t num_rus = layoutPtr->stripeUnitsPerDisk / layoutPtr->SUsPerRU;
RF_ReconMap_t *p;
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) memset((char *) p->status, 0,
num_rus * sizeof(RF_ReconMapListElem_t *));
pool_init(&p->elem_pool, sizeof(RF_ReconMapListElem_t), 0,
0, 0, "raidreconpl", NULL);
pool_prime(&p->elem_pool, RF_NUM_RECON_POOL_ELEM);
rf_mutex_init(&p->mutex);
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)
*
* This code now uses a pool instead of the previous malloc/free
* stuff.
*-------------------------------------------------------------------------*/
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);
while(mapPtr->lock) {
ltsleep(&mapPtr->lock, PRIBIO, "reconupdate", 0, &mapPtr->mutex);
}
mapPtr->lock = 1;
RF_UNLOCK_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(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), (p == RU_NOTHING) ? NULL : p);
} else {/* general case */
do { /* search for place to insert */
pt = p;
p = p->next;
} while (p && (p->startSector < startSector));
pt->next = MakeReconMapListElem(mapPtr,startSector, RF_MIN(stopSector, last_in_RU), p);
}
compact_stat_entry(raidPtr, mapPtr, i);
}
startSector = RF_MIN(stopSector, last_in_RU) + 1;
}
RF_LOCK_MUTEX(mapPtr->mutex);
mapPtr->lock = 0;
wakeup(&mapPtr->lock);
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(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(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_ReconMap_t *mapPtr, RF_SectorNum_t startSector,
RF_SectorNum_t stopSector, RF_ReconMapListElem_t *next)
{
RF_ReconMapListElem_t *p;
p = pool_get(&mapPtr->elem_pool, PR_WAITOK);
p->startSector = startSector;
p->stopSector = stopSector;
p->next = next;
return (p);
}
/*---------------------------------------------------------------------------
*
* Free a list element
*
*-------------------------------------------------------------------------*/
static void
FreeReconMapListElem(RF_ReconMap_t *mapPtr, RF_ReconMapListElem_t *p)
{
pool_put(&mapPtr->elem_pool, 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));
}
}
pool_destroy(&mapPtr->elem_pool);
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);
}
#if 0
static void
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 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);
}
}
}
#endif
#if RF_DEBUG_RECON
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;
}
}
#endif