Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
NetBSD/sys/dev/raidframe/rf_reconstruct.c

1633 lines
56 KiB
C
Raw Blame History

/* $NetBSD: rf_reconstruct.c,v 1.74 2004/03/07 22:15:19 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_reconstruct.c -- code to perform on-line reconstruction
*
************************************************************/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rf_reconstruct.c,v 1.74 2004/03/07 22:15:19 oster Exp $");
#include <sys/time.h>
#include <sys/buf.h>
#include <sys/errno.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/ioctl.h>
#include <sys/fcntl.h>
#include <sys/vnode.h>
#include <dev/raidframe/raidframevar.h>
#include "rf_raid.h"
#include "rf_reconutil.h"
#include "rf_revent.h"
#include "rf_reconbuffer.h"
#include "rf_acctrace.h"
#include "rf_etimer.h"
#include "rf_dag.h"
#include "rf_desc.h"
#include "rf_debugprint.h"
#include "rf_general.h"
#include "rf_driver.h"
#include "rf_utils.h"
#include "rf_shutdown.h"
#include "rf_kintf.h"
/* setting these to -1 causes them to be set to their default values if not set by debug options */
#if RF_DEBUG_RECON
#define Dprintf(s) if (rf_reconDebug) rf_debug_printf(s,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf1(s,a) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf2(s,a,b) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
#define Dprintf3(s,a,b,c) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),NULL,NULL,NULL,NULL,NULL)
#define Dprintf4(s,a,b,c,d) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),NULL,NULL,NULL,NULL)
#define Dprintf5(s,a,b,c,d,e) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),NULL,NULL,NULL)
#define Dprintf6(s,a,b,c,d,e,f) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),NULL,NULL)
#define Dprintf7(s,a,b,c,d,e,f,g) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),NULL)
#define DDprintf1(s,a) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
#define DDprintf2(s,a,b) if (rf_reconDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
#else /* RF_DEBUG_RECON */
#define Dprintf(s) {}
#define Dprintf1(s,a) {}
#define Dprintf2(s,a,b) {}
#define Dprintf3(s,a,b,c) {}
#define Dprintf4(s,a,b,c,d) {}
#define Dprintf5(s,a,b,c,d,e) {}
#define Dprintf6(s,a,b,c,d,e,f) {}
#define Dprintf7(s,a,b,c,d,e,f,g) {}
#define DDprintf1(s,a) {}
#define DDprintf2(s,a,b) {}
#endif /* RF_DEBUG_RECON */
#define RF_MAX_FREE_RECOND 10
#define RF_MIN_FREE_RECOND 4
#define RF_MAX_FREE_RECONBUFFER 32
#define RF_MIN_FREE_RECONBUFFER 16
static RF_RaidReconDesc_t *AllocRaidReconDesc(RF_Raid_t *, RF_RowCol_t,
RF_RaidDisk_t *, int, RF_RowCol_t);
static void FreeReconDesc(RF_RaidReconDesc_t *);
static int ProcessReconEvent(RF_Raid_t *, RF_ReconEvent_t *);
static int IssueNextReadRequest(RF_Raid_t *, RF_RowCol_t);
static int TryToRead(RF_Raid_t *, RF_RowCol_t);
static int ComputePSDiskOffsets(RF_Raid_t *, RF_StripeNum_t, RF_RowCol_t,
RF_SectorNum_t *, RF_SectorNum_t *, RF_RowCol_t *,
RF_SectorNum_t *);
static int IssueNextWriteRequest(RF_Raid_t *);
static int ReconReadDoneProc(void *, int);
static int ReconWriteDoneProc(void *, int);
static void CheckForNewMinHeadSep(RF_Raid_t *, RF_HeadSepLimit_t);
static int CheckHeadSeparation(RF_Raid_t *, RF_PerDiskReconCtrl_t *,
RF_RowCol_t, RF_HeadSepLimit_t,
RF_ReconUnitNum_t);
static int CheckForcedOrBlockedReconstruction(RF_Raid_t *,
RF_ReconParityStripeStatus_t *,
RF_PerDiskReconCtrl_t *,
RF_RowCol_t, RF_StripeNum_t,
RF_ReconUnitNum_t);
static void ForceReconReadDoneProc(void *, int);
static void rf_ShutdownReconstruction(void *);
struct RF_ReconDoneProc_s {
void (*proc) (RF_Raid_t *, void *);
void *arg;
RF_ReconDoneProc_t *next;
};
/**************************************************************************
*
* sets up the parameters that will be used by the reconstruction process
* currently there are none, except for those that the layout-specific
* configuration (e.g. rf_ConfigureDeclustered) routine sets up.
*
* in the kernel, we fire off the recon thread.
*
**************************************************************************/
static void
rf_ShutdownReconstruction(void *ignored)
{
pool_destroy(&rf_pools.recond);
pool_destroy(&rf_pools.reconbuffer);
}
int
rf_ConfigureReconstruction(RF_ShutdownList_t **listp)
{
rf_pool_init(&rf_pools.recond, sizeof(RF_RaidReconDesc_t),
"rf_recond_pl", RF_MIN_FREE_RECOND, RF_MAX_FREE_RECOND);
rf_pool_init(&rf_pools.reconbuffer, sizeof(RF_ReconBuffer_t),
"rf_reconbuffer_pl", RF_MIN_FREE_RECONBUFFER, RF_MAX_FREE_RECONBUFFER);
rf_ShutdownCreate(listp, rf_ShutdownReconstruction, NULL);
return (0);
}
static RF_RaidReconDesc_t *
AllocRaidReconDesc(RF_Raid_t *raidPtr, RF_RowCol_t col,
RF_RaidDisk_t *spareDiskPtr, int numDisksDone,
RF_RowCol_t scol)
{
RF_RaidReconDesc_t *reconDesc;
reconDesc = pool_get(&rf_pools.recond, PR_WAITOK);
reconDesc->raidPtr = raidPtr;
reconDesc->col = col;
reconDesc->spareDiskPtr = spareDiskPtr;
reconDesc->numDisksDone = numDisksDone;
reconDesc->scol = scol;
reconDesc->state = 0;
reconDesc->next = NULL;
return (reconDesc);
}
static void
FreeReconDesc(RF_RaidReconDesc_t *reconDesc)
{
#if RF_RECON_STATS > 0
printf("raid%d: %lu recon event waits, %lu recon delays\n",
reconDesc->raidPtr->raidid,
(long) reconDesc->numReconEventWaits,
(long) reconDesc->numReconExecDelays);
#endif /* RF_RECON_STATS > 0 */
printf("raid%d: %lu max exec ticks\n",
reconDesc->raidPtr->raidid,
(long) reconDesc->maxReconExecTicks);
#if (RF_RECON_STATS > 0) || defined(KERNEL)
printf("\n");
#endif /* (RF_RECON_STATS > 0) || KERNEL */
pool_put(&rf_pools.recond, reconDesc);
}
/*****************************************************************************
*
* primary routine to reconstruct a failed disk. This should be called from
* within its own thread. It won't return until reconstruction completes,
* fails, or is aborted.
*****************************************************************************/
int
rf_ReconstructFailedDisk(RF_Raid_t *raidPtr, RF_RowCol_t col)
{
const RF_LayoutSW_t *lp;
int rc;
lp = raidPtr->Layout.map;
if (lp->SubmitReconBuffer) {
/*
* The current infrastructure only supports reconstructing one
* disk at a time for each array.
*/
RF_LOCK_MUTEX(raidPtr->mutex);
while (raidPtr->reconInProgress) {
RF_WAIT_COND(raidPtr->waitForReconCond, raidPtr->mutex);
}
raidPtr->reconInProgress++;
RF_UNLOCK_MUTEX(raidPtr->mutex);
rc = rf_ReconstructFailedDiskBasic(raidPtr, col);
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
} else {
RF_ERRORMSG1("RECON: no way to reconstruct failed disk for arch %c\n",
lp->parityConfig);
rc = EIO;
}
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return (rc);
}
int
rf_ReconstructFailedDiskBasic(RF_Raid_t *raidPtr, RF_RowCol_t col)
{
RF_ComponentLabel_t c_label;
RF_RaidDisk_t *spareDiskPtr = NULL;
RF_RaidReconDesc_t *reconDesc;
RF_RowCol_t scol;
int numDisksDone = 0, rc;
/* first look for a spare drive onto which to reconstruct the data */
/* spare disk descriptors are stored in row 0. This may have to
* change eventually */
RF_LOCK_MUTEX(raidPtr->mutex);
RF_ASSERT(raidPtr->Disks[col].status == rf_ds_failed);
#if RF_INCLUDE_PARITY_DECLUSTERING_DS > 0
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
if (raidPtr->status != rf_rs_degraded) {
RF_ERRORMSG1("Unable to reconstruct disk at col %d because status not degraded\n", col);
RF_UNLOCK_MUTEX(raidPtr->mutex);
return (EINVAL);
}
scol = (-1);
} else {
#endif
for (scol = raidPtr->numCol; scol < raidPtr->numCol + raidPtr->numSpare; scol++) {
if (raidPtr->Disks[scol].status == rf_ds_spare) {
spareDiskPtr = &raidPtr->Disks[scol];
spareDiskPtr->status = rf_ds_used_spare;
break;
}
}
if (!spareDiskPtr) {
RF_ERRORMSG1("Unable to reconstruct disk at col %d because no spares are available\n", col);
RF_UNLOCK_MUTEX(raidPtr->mutex);
return (ENOSPC);
}
printf("RECON: initiating reconstruction on col %d -> spare at col %d\n", col, scol);
#if RF_INCLUDE_PARITY_DECLUSTERING_DS > 0
}
#endif
RF_UNLOCK_MUTEX(raidPtr->mutex);
reconDesc = AllocRaidReconDesc((void *) raidPtr, col, spareDiskPtr, numDisksDone, scol);
raidPtr->reconDesc = (void *) reconDesc;
#if RF_RECON_STATS > 0
reconDesc->hsStallCount = 0;
reconDesc->numReconExecDelays = 0;
reconDesc->numReconEventWaits = 0;
#endif /* RF_RECON_STATS > 0 */
reconDesc->reconExecTimerRunning = 0;
reconDesc->reconExecTicks = 0;
reconDesc->maxReconExecTicks = 0;
rc = rf_ContinueReconstructFailedDisk(reconDesc);
if (!rc) {
/* fix up the component label */
/* Don't actually need the read here.. */
raidread_component_label(
raidPtr->raid_cinfo[scol].ci_dev,
raidPtr->raid_cinfo[scol].ci_vp,
&c_label);
raid_init_component_label( raidPtr, &c_label);
c_label.row = 0;
c_label.column = col;
c_label.clean = RF_RAID_DIRTY;
c_label.status = rf_ds_optimal;
c_label.partitionSize = raidPtr->Disks[scol].partitionSize;
/* We've just done a rebuild based on all the other
disks, so at this point the parity is known to be
clean, even if it wasn't before. */
/* XXX doesn't hold for RAID 6!!*/
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->parity_good = RF_RAID_CLEAN;
RF_UNLOCK_MUTEX(raidPtr->mutex);
/* XXXX MORE NEEDED HERE */
raidwrite_component_label(
raidPtr->raid_cinfo[scol].ci_dev,
raidPtr->raid_cinfo[scol].ci_vp,
&c_label);
rf_update_component_labels(raidPtr,
RF_NORMAL_COMPONENT_UPDATE);
}
return (rc);
}
/*
Allow reconstructing a disk in-place -- i.e. component /dev/sd2e goes AWOL,
and you don't get a spare until the next Monday. With this function
(and hot-swappable drives) you can now put your new disk containing
/dev/sd2e on the bus, scsictl it alive, and then use raidctl(8) to
rebuild the data "on the spot".
*/
int
rf_ReconstructInPlace(RF_Raid_t *raidPtr, RF_RowCol_t col)
{
RF_RaidDisk_t *spareDiskPtr = NULL;
RF_RaidReconDesc_t *reconDesc;
const RF_LayoutSW_t *lp;
RF_ComponentLabel_t c_label;
int numDisksDone = 0, rc;
struct partinfo dpart;
struct vnode *vp;
struct vattr va;
struct proc *proc;
int retcode;
int ac;
lp = raidPtr->Layout.map;
if (!lp->SubmitReconBuffer) {
RF_ERRORMSG1("RECON: no way to reconstruct failed disk for arch %c\n",
lp->parityConfig);
/* wakeup anyone who might be waiting to do a reconstruct */
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return(EIO);
}
/*
* The current infrastructure only supports reconstructing one
* disk at a time for each array.
*/
RF_LOCK_MUTEX(raidPtr->mutex);
if (raidPtr->Disks[col].status != rf_ds_failed) {
/* "It's gone..." */
raidPtr->numFailures++;
raidPtr->Disks[col].status = rf_ds_failed;
raidPtr->status = rf_rs_degraded;
RF_UNLOCK_MUTEX(raidPtr->mutex);
rf_update_component_labels(raidPtr,
RF_NORMAL_COMPONENT_UPDATE);
RF_LOCK_MUTEX(raidPtr->mutex);
}
while (raidPtr->reconInProgress) {
RF_WAIT_COND(raidPtr->waitForReconCond, raidPtr->mutex);
}
raidPtr->reconInProgress++;
/* first look for a spare drive onto which to reconstruct the
data. spare disk descriptors are stored in row 0. This
may have to change eventually */
/* Actually, we don't care if it's failed or not... On a RAID
set with correct parity, this function should be callable
on any component without ill affects. */
/* RF_ASSERT(raidPtr->Disks[col].status == rf_ds_failed); */
#if RF_INCLUDE_PARITY_DECLUSTERING_DS > 0
if (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE) {
RF_ERRORMSG1("Unable to reconstruct to disk at col %d: operation not supported for RF_DISTRIBUTE_SPARE\n", col);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return (EINVAL);
}
#endif
proc = raidPtr->engine_thread;
/* This device may have been opened successfully the
first time. Close it before trying to open it again.. */
if (raidPtr->raid_cinfo[col].ci_vp != NULL) {
#if 0
printf("Closed the open device: %s\n",
raidPtr->Disks[col].devname);
#endif
vp = raidPtr->raid_cinfo[col].ci_vp;
ac = raidPtr->Disks[col].auto_configured;
RF_UNLOCK_MUTEX(raidPtr->mutex);
rf_close_component(raidPtr, vp, ac);
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->raid_cinfo[col].ci_vp = NULL;
}
/* note that this disk was *not* auto_configured (any longer)*/
raidPtr->Disks[col].auto_configured = 0;
#if 0
printf("About to (re-)open the device for rebuilding: %s\n",
raidPtr->Disks[col].devname);
#endif
RF_UNLOCK_MUTEX(raidPtr->mutex);
retcode = raidlookup(raidPtr->Disks[col].devname, proc, &vp);
if (retcode) {
printf("raid%d: rebuilding: raidlookup on device: %s failed: %d!\n",raidPtr->raidid,
raidPtr->Disks[col].devname, retcode);
/* the component isn't responding properly...
must be still dead :-( */
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return(retcode);
}
/* Ok, so we can at least do a lookup...
How about actually getting a vp for it? */
if ((retcode = VOP_GETATTR(vp, &va, proc->p_ucred, proc)) != 0) {
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return(retcode);
}
retcode = VOP_IOCTL(vp, DIOCGPART, &dpart, FREAD, proc->p_ucred, proc);
if (retcode) {
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return(retcode);
}
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->Disks[col].blockSize = dpart.disklab->d_secsize;
raidPtr->Disks[col].numBlocks = dpart.part->p_size -
rf_protectedSectors;
raidPtr->raid_cinfo[col].ci_vp = vp;
raidPtr->raid_cinfo[col].ci_dev = va.va_rdev;
raidPtr->Disks[col].dev = va.va_rdev;
/* we allow the user to specify that only a fraction
of the disks should be used this is just for debug:
it speeds up * the parity scan */
raidPtr->Disks[col].numBlocks = raidPtr->Disks[col].numBlocks *
rf_sizePercentage / 100;
RF_UNLOCK_MUTEX(raidPtr->mutex);
spareDiskPtr = &raidPtr->Disks[col];
spareDiskPtr->status = rf_ds_used_spare;
printf("raid%d: initiating in-place reconstruction on column %d\n",
raidPtr->raidid, col);
reconDesc = AllocRaidReconDesc((void *) raidPtr, col, spareDiskPtr,
numDisksDone, col);
raidPtr->reconDesc = (void *) reconDesc;
#if RF_RECON_STATS > 0
reconDesc->hsStallCount = 0;
reconDesc->numReconExecDelays = 0;
reconDesc->numReconEventWaits = 0;
#endif /* RF_RECON_STATS > 0 */
reconDesc->reconExecTimerRunning = 0;
reconDesc->reconExecTicks = 0;
reconDesc->maxReconExecTicks = 0;
rc = rf_ContinueReconstructFailedDisk(reconDesc);
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->reconInProgress--;
RF_UNLOCK_MUTEX(raidPtr->mutex);
if (!rc) {
RF_LOCK_MUTEX(raidPtr->mutex);
/* Need to set these here, as at this point it'll be claiming
that the disk is in rf_ds_spared! But we know better :-) */
raidPtr->Disks[col].status = rf_ds_optimal;
raidPtr->status = rf_rs_optimal;
RF_UNLOCK_MUTEX(raidPtr->mutex);
/* fix up the component label */
/* Don't actually need the read here.. */
raidread_component_label(raidPtr->raid_cinfo[col].ci_dev,
raidPtr->raid_cinfo[col].ci_vp,
&c_label);
RF_LOCK_MUTEX(raidPtr->mutex);
raid_init_component_label(raidPtr, &c_label);
c_label.row = 0;
c_label.column = col;
/* We've just done a rebuild based on all the other
disks, so at this point the parity is known to be
clean, even if it wasn't before. */
/* XXX doesn't hold for RAID 6!!*/
raidPtr->parity_good = RF_RAID_CLEAN;
RF_UNLOCK_MUTEX(raidPtr->mutex);
raidwrite_component_label(raidPtr->raid_cinfo[col].ci_dev,
raidPtr->raid_cinfo[col].ci_vp,
&c_label);
rf_update_component_labels(raidPtr,
RF_NORMAL_COMPONENT_UPDATE);
}
RF_SIGNAL_COND(raidPtr->waitForReconCond);
return (rc);
}
int
rf_ContinueReconstructFailedDisk(RF_RaidReconDesc_t *reconDesc)
{
RF_Raid_t *raidPtr = reconDesc->raidPtr;
RF_RowCol_t col = reconDesc->col;
RF_RowCol_t scol = reconDesc->scol;
RF_ReconMap_t *mapPtr;
RF_ReconCtrl_t *tmp_reconctrl;
RF_ReconEvent_t *event;
struct timeval etime, elpsd;
unsigned long xor_s, xor_resid_us;
int i, ds;
switch (reconDesc->state) {
case 0:
raidPtr->accumXorTimeUs = 0;
#if RF_ACC_TRACE > 0
/* create one trace record per physical disk */
RF_Malloc(raidPtr->recon_tracerecs, raidPtr->numCol * sizeof(RF_AccTraceEntry_t), (RF_AccTraceEntry_t *));
#endif
/* quiesce the array prior to starting recon. this is needed
* to assure no nasty interactions with pending user writes.
* We need to do this before we change the disk or row status. */
reconDesc->state = 1;
Dprintf("RECON: begin request suspend\n");
rf_SuspendNewRequestsAndWait(raidPtr);
Dprintf("RECON: end request suspend\n");
rf_StartUserStats(raidPtr); /* zero out the stats kept on
* user accs */
/* fall through to state 1 */
case 1:
/* allocate our RF_ReconCTRL_t before we protect raidPtr->reconControl[row] */
tmp_reconctrl = rf_MakeReconControl(reconDesc, col, scol);
RF_LOCK_MUTEX(raidPtr->mutex);
/* create the reconstruction control pointer and install it in
* the right slot */
raidPtr->reconControl = tmp_reconctrl;
mapPtr = raidPtr->reconControl->reconMap;
raidPtr->status = rf_rs_reconstructing;
raidPtr->Disks[col].status = rf_ds_reconstructing;
raidPtr->Disks[col].spareCol = scol;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_GETTIME(raidPtr->reconControl->starttime);
/* now start up the actual reconstruction: issue a read for
* each surviving disk */
reconDesc->numDisksDone = 0;
for (i = 0; i < raidPtr->numCol; i++) {
if (i != col) {
/* find and issue the next I/O on the
* indicated disk */
if (IssueNextReadRequest(raidPtr, i)) {
Dprintf1("RECON: done issuing for c%d\n", i);
reconDesc->numDisksDone++;
}
}
}
case 2:
Dprintf("RECON: resume requests\n");
rf_ResumeNewRequests(raidPtr);
reconDesc->state = 3;
case 3:
/* process reconstruction events until all disks report that
* they've completed all work */
mapPtr = raidPtr->reconControl->reconMap;
while (reconDesc->numDisksDone < raidPtr->numCol - 1) {
event = rf_GetNextReconEvent(reconDesc, (void (*) (void *)) rf_ContinueReconstructFailedDisk, reconDesc);
RF_ASSERT(event);
if (ProcessReconEvent(raidPtr, event))
reconDesc->numDisksDone++;
raidPtr->reconControl->numRUsTotal =
mapPtr->totalRUs;
raidPtr->reconControl->numRUsComplete =
mapPtr->totalRUs -
rf_UnitsLeftToReconstruct(mapPtr);
#if RF_DEBUG_RECON
raidPtr->reconControl->percentComplete =
(raidPtr->reconControl->numRUsComplete * 100 / raidPtr->reconControl->numRUsTotal);
if (rf_prReconSched) {
rf_PrintReconSchedule(raidPtr->reconControl->reconMap, &(raidPtr->reconControl->starttime));
}
#endif
}
reconDesc->state = 4;
case 4:
mapPtr = raidPtr->reconControl->reconMap;
if (rf_reconDebug) {
printf("RECON: all reads completed\n");
}
/* at this point all the reads have completed. We now wait
* for any pending writes to complete, and then we're done */
while (rf_UnitsLeftToReconstruct(raidPtr->reconControl->reconMap) > 0) {
event = rf_GetNextReconEvent(reconDesc, (void (*) (void *)) rf_ContinueReconstructFailedDisk, reconDesc);
RF_ASSERT(event);
(void) ProcessReconEvent(raidPtr, event); /* ignore return code */
#if RF_DEBUG_RECON
raidPtr->reconControl->percentComplete = 100 - (rf_UnitsLeftToReconstruct(mapPtr) * 100 / mapPtr->totalRUs);
if (rf_prReconSched) {
rf_PrintReconSchedule(raidPtr->reconControl->reconMap, &(raidPtr->reconControl->starttime));
}
#endif
}
reconDesc->state = 5;
case 5:
/* Success: mark the dead disk as reconstructed. We quiesce
* the array here to assure no nasty interactions with pending
* user accesses when we free up the psstatus structure as
* part of FreeReconControl() */
reconDesc->state = 6;
rf_SuspendNewRequestsAndWait(raidPtr);
rf_StopUserStats(raidPtr);
rf_PrintUserStats(raidPtr); /* print out the stats on user
* accs accumulated during
* recon */
/* fall through to state 6 */
case 6:
RF_LOCK_MUTEX(raidPtr->mutex);
raidPtr->numFailures--;
ds = (raidPtr->Layout.map->flags & RF_DISTRIBUTE_SPARE);
raidPtr->Disks[col].status = (ds) ? rf_ds_dist_spared : rf_ds_spared;
raidPtr->status = (ds) ? rf_rs_reconfigured : rf_rs_optimal;
RF_UNLOCK_MUTEX(raidPtr->mutex);
RF_GETTIME(etime);
RF_TIMEVAL_DIFF(&(raidPtr->reconControl->starttime), &etime, &elpsd);
/* XXX -- why is state 7 different from state 6 if there is no
* return() here? -- XXX Note that I set elpsd above & use it
* below, so if you put a return here you'll have to fix this.
* (also, FreeReconControl is called below) */
case 7:
rf_ResumeNewRequests(raidPtr);
printf("raid%d: Reconstruction of disk at col %d completed\n",
raidPtr->raidid, col);
xor_s = raidPtr->accumXorTimeUs / 1000000;
xor_resid_us = raidPtr->accumXorTimeUs % 1000000;
printf("raid%d: Recon time was %d.%06d seconds, accumulated XOR time was %ld us (%ld.%06ld)\n",
raidPtr->raidid,
(int) elpsd.tv_sec, (int) elpsd.tv_usec,
raidPtr->accumXorTimeUs, xor_s, xor_resid_us);
printf("raid%d: (start time %d sec %d usec, end time %d sec %d usec)\n",
raidPtr->raidid,
(int) raidPtr->reconControl->starttime.tv_sec,
(int) raidPtr->reconControl->starttime.tv_usec,
(int) etime.tv_sec, (int) etime.tv_usec);
#if RF_RECON_STATS > 0
printf("raid%d: Total head-sep stall count was %d\n",
raidPtr->raidid, (int) reconDesc->hsStallCount);
#endif /* RF_RECON_STATS > 0 */
rf_FreeReconControl(raidPtr);
#if RF_ACC_TRACE > 0
RF_Free(raidPtr->recon_tracerecs, raidPtr->numCol * sizeof(RF_AccTraceEntry_t));
#endif
FreeReconDesc(reconDesc);
}
return (0);
}
/*****************************************************************************
* do the right thing upon each reconstruction event.
* returns nonzero if and only if there is nothing left unread on the
* indicated disk
*****************************************************************************/
static int
ProcessReconEvent(RF_Raid_t *raidPtr, RF_ReconEvent_t *event)
{
int retcode = 0, submitblocked;
RF_ReconBuffer_t *rbuf;
RF_SectorCount_t sectorsPerRU;
Dprintf1("RECON: ProcessReconEvent type %d\n", event->type);
switch (event->type) {
/* a read I/O has completed */
case RF_REVENT_READDONE:
rbuf = raidPtr->reconControl->perDiskInfo[event->col].rbuf;
Dprintf2("RECON: READDONE EVENT: col %d psid %ld\n",
event->col, rbuf->parityStripeID);
Dprintf7("RECON: done read psid %ld buf %lx %02x %02x %02x %02x %02x\n",
rbuf->parityStripeID, rbuf->buffer, rbuf->buffer[0] & 0xff, rbuf->buffer[1] & 0xff,
rbuf->buffer[2] & 0xff, rbuf->buffer[3] & 0xff, rbuf->buffer[4] & 0xff);
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
submitblocked = rf_SubmitReconBuffer(rbuf, 0, 0);
Dprintf1("RECON: submitblocked=%d\n", submitblocked);
if (!submitblocked)
retcode = IssueNextReadRequest(raidPtr, event->col);
break;
/* a write I/O has completed */
case RF_REVENT_WRITEDONE:
#if RF_DEBUG_RECON
if (rf_floatingRbufDebug) {
rf_CheckFloatingRbufCount(raidPtr, 1);
}
#endif
sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU;
rbuf = (RF_ReconBuffer_t *) event->arg;
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
Dprintf3("RECON: WRITEDONE EVENT: psid %d ru %d (%d %% complete)\n",
rbuf->parityStripeID, rbuf->which_ru, raidPtr->reconControl->percentComplete);
rf_ReconMapUpdate(raidPtr, raidPtr->reconControl->reconMap,
rbuf->failedDiskSectorOffset, rbuf->failedDiskSectorOffset + sectorsPerRU - 1);
rf_RemoveFromActiveReconTable(raidPtr, rbuf->parityStripeID, rbuf->which_ru);
if (rbuf->type == RF_RBUF_TYPE_FLOATING) {
RF_LOCK_MUTEX(raidPtr->reconControl->rb_mutex);
raidPtr->numFullReconBuffers--;
rf_ReleaseFloatingReconBuffer(raidPtr, rbuf);
RF_UNLOCK_MUTEX(raidPtr->reconControl->rb_mutex);
} else
if (rbuf->type == RF_RBUF_TYPE_FORCED)
rf_FreeReconBuffer(rbuf);
else
RF_ASSERT(0);
break;
case RF_REVENT_BUFCLEAR: /* A buffer-stall condition has been
* cleared */
Dprintf1("RECON: BUFCLEAR EVENT: col %d\n", event->col);
submitblocked = rf_SubmitReconBuffer(raidPtr->reconControl->perDiskInfo[event->col].rbuf, 0, (int) (long) event->arg);
RF_ASSERT(!submitblocked); /* we wouldn't have gotten the
* BUFCLEAR event if we
* couldn't submit */
retcode = IssueNextReadRequest(raidPtr, event->col);
break;
case RF_REVENT_BLOCKCLEAR: /* A user-write reconstruction
* blockage has been cleared */
DDprintf1("RECON: BLOCKCLEAR EVENT: col %d\n", event->col);
retcode = TryToRead(raidPtr, event->col);
break;
case RF_REVENT_HEADSEPCLEAR: /* A max-head-separation
* reconstruction blockage has been
* cleared */
Dprintf1("RECON: HEADSEPCLEAR EVENT: col %d\n", event->col);
retcode = TryToRead(raidPtr, event->col);
break;
/* a buffer has become ready to write */
case RF_REVENT_BUFREADY:
Dprintf1("RECON: BUFREADY EVENT: col %d\n", event->col);
retcode = IssueNextWriteRequest(raidPtr);
#if RF_DEBUG_RECON
if (rf_floatingRbufDebug) {
rf_CheckFloatingRbufCount(raidPtr, 1);
}
#endif
break;
/* we need to skip the current RU entirely because it got
* recon'd while we were waiting for something else to happen */
case RF_REVENT_SKIP:
DDprintf1("RECON: SKIP EVENT: col %d\n", event->col);
retcode = IssueNextReadRequest(raidPtr, event->col);
break;
/* a forced-reconstruction read access has completed. Just
* submit the buffer */
case RF_REVENT_FORCEDREADDONE:
rbuf = (RF_ReconBuffer_t *) event->arg;
rf_FreeDiskQueueData((RF_DiskQueueData_t *) rbuf->arg);
DDprintf1("RECON: FORCEDREADDONE EVENT: col %d\n", event->col);
submitblocked = rf_SubmitReconBuffer(rbuf, 1, 0);
RF_ASSERT(!submitblocked);
break;
/* A read I/O failed to complete */
case RF_REVENT_READ_FAILED:
/* fallthru to panic... */
/* A write I/O failed to complete */
case RF_REVENT_WRITE_FAILED:
/* fallthru to panic... */
/* a forced read I/O failed to complete */
case RF_REVENT_FORCEDREAD_FAILED:
/* fallthru to panic... */
default:
RF_PANIC();
}
rf_FreeReconEventDesc(event);
return (retcode);
}
/*****************************************************************************
*
* find the next thing that's needed on the indicated disk, and issue
* a read request for it. We assume that the reconstruction buffer
* associated with this process is free to receive the data. If
* reconstruction is blocked on the indicated RU, we issue a
* blockage-release request instead of a physical disk read request.
* If the current disk gets too far ahead of the others, we issue a
* head-separation wait request and return.
*
* ctrl->{ru_count, curPSID, diskOffset} and
* rbuf->failedDiskSectorOffset are maintained to point to the unit
* we're currently accessing. Note that this deviates from the
* standard C idiom of having counters point to the next thing to be
* accessed. This allows us to easily retry when we're blocked by
* head separation or reconstruction-blockage events.
*
* returns nonzero if and only if there is nothing left unread on the
* indicated disk
*
*****************************************************************************/
static int
IssueNextReadRequest(RF_Raid_t *raidPtr, RF_RowCol_t col)
{
RF_PerDiskReconCtrl_t *ctrl = &raidPtr->reconControl->perDiskInfo[col];
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_ReconBuffer_t *rbuf = ctrl->rbuf;
RF_ReconUnitCount_t RUsPerPU = layoutPtr->SUsPerPU / layoutPtr->SUsPerRU;
RF_SectorCount_t sectorsPerRU = layoutPtr->sectorsPerStripeUnit * layoutPtr->SUsPerRU;
int do_new_check = 0, retcode = 0, status;
/* if we are currently the slowest disk, mark that we have to do a new
* check */
if (ctrl->headSepCounter <= raidPtr->reconControl->minHeadSepCounter)
do_new_check = 1;
while (1) {
ctrl->ru_count++;
if (ctrl->ru_count < RUsPerPU) {
ctrl->diskOffset += sectorsPerRU;
rbuf->failedDiskSectorOffset += sectorsPerRU;
} else {
ctrl->curPSID++;
ctrl->ru_count = 0;
/* code left over from when head-sep was based on
* parity stripe id */
if (ctrl->curPSID >= raidPtr->reconControl->lastPSID) {
CheckForNewMinHeadSep(raidPtr, ++(ctrl->headSepCounter));
return (1); /* finito! */
}
/* find the disk offsets of the start of the parity
* stripe on both the current disk and the failed
* disk. skip this entire parity stripe if either disk
* does not appear in the indicated PS */
status = ComputePSDiskOffsets(raidPtr, ctrl->curPSID, col, &ctrl->diskOffset, &rbuf->failedDiskSectorOffset,
&rbuf->spCol, &rbuf->spOffset);
if (status) {
ctrl->ru_count = RUsPerPU - 1;
continue;
}
}
rbuf->which_ru = ctrl->ru_count;
/* skip this RU if it's already been reconstructed */
if (rf_CheckRUReconstructed(raidPtr->reconControl->reconMap, rbuf->failedDiskSectorOffset)) {
Dprintf2("Skipping psid %ld ru %d: already reconstructed\n", ctrl->curPSID, ctrl->ru_count);
continue;
}
break;
}
ctrl->headSepCounter++;
if (do_new_check)
CheckForNewMinHeadSep(raidPtr, ctrl->headSepCounter); /* update min if needed */
/* at this point, we have definitely decided what to do, and we have
* only to see if we can actually do it now */
rbuf->parityStripeID = ctrl->curPSID;
rbuf->which_ru = ctrl->ru_count;
#if RF_ACC_TRACE > 0
memset((char *) &raidPtr->recon_tracerecs[col], 0,
sizeof(raidPtr->recon_tracerecs[col]));
raidPtr->recon_tracerecs[col].reconacc = 1;
RF_ETIMER_START(raidPtr->recon_tracerecs[col].recon_timer);
#endif
retcode = TryToRead(raidPtr, col);
return (retcode);
}
/*
* tries to issue the next read on the indicated disk. We may be
* blocked by (a) the heads being too far apart, or (b) recon on the
* indicated RU being blocked due to a write by a user thread. In
* this case, we issue a head-sep or blockage wait request, which will
* cause this same routine to be invoked again later when the blockage
* has cleared.
*/
static int
TryToRead(RF_Raid_t *raidPtr, RF_RowCol_t col)
{
RF_PerDiskReconCtrl_t *ctrl = &raidPtr->reconControl->perDiskInfo[col];
RF_SectorCount_t sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU;
RF_StripeNum_t psid = ctrl->curPSID;
RF_ReconUnitNum_t which_ru = ctrl->ru_count;
RF_DiskQueueData_t *req;
int status;
RF_ReconParityStripeStatus_t *pssPtr, *newpssPtr;
/* if the current disk is too far ahead of the others, issue a
* head-separation wait and return */
if (CheckHeadSeparation(raidPtr, ctrl, col, ctrl->headSepCounter, which_ru))
return (0);
/* allocate a new PSS in case we need it */
newpssPtr = rf_AllocPSStatus(raidPtr);
RF_LOCK_PSS_MUTEX(raidPtr, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl->pssTable, psid, which_ru, RF_PSS_CREATE, newpssPtr);
if (pssPtr != newpssPtr) {
rf_FreePSStatus(raidPtr, newpssPtr);
}
/* if recon is blocked on the indicated parity stripe, issue a
* block-wait request and return. this also must mark the indicated RU
* in the stripe as under reconstruction if not blocked. */
status = CheckForcedOrBlockedReconstruction(raidPtr, pssPtr, ctrl, col, psid, which_ru);
if (status == RF_PSS_RECON_BLOCKED) {
Dprintf2("RECON: Stalling psid %ld ru %d: recon blocked\n", psid, which_ru);
goto out;
} else
if (status == RF_PSS_FORCED_ON_WRITE) {
rf_CauseReconEvent(raidPtr, col, NULL, RF_REVENT_SKIP);
goto out;
}
/* make one last check to be sure that the indicated RU didn't get
* reconstructed while we were waiting for something else to happen.
* This is unfortunate in that it causes us to make this check twice
* in the normal case. Might want to make some attempt to re-work
* this so that we only do this check if we've definitely blocked on
* one of the above checks. When this condition is detected, we may
* have just created a bogus status entry, which we need to delete. */
if (rf_CheckRUReconstructed(raidPtr->reconControl->reconMap, ctrl->rbuf->failedDiskSectorOffset)) {
Dprintf2("RECON: Skipping psid %ld ru %d: prior recon after stall\n", psid, which_ru);
if (pssPtr == newpssPtr)
rf_PSStatusDelete(raidPtr, raidPtr->reconControl->pssTable, pssPtr);
rf_CauseReconEvent(raidPtr, col, NULL, RF_REVENT_SKIP);
goto out;
}
/* found something to read. issue the I/O */
Dprintf4("RECON: Read for psid %ld on col %d offset %ld buf %lx\n",
psid, col, ctrl->diskOffset, ctrl->rbuf->buffer);
#if RF_ACC_TRACE > 0
RF_ETIMER_STOP(raidPtr->recon_tracerecs[col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[col].recon_timer);
raidPtr->recon_tracerecs[col].specific.recon.recon_start_to_fetch_us =
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[col].recon_timer);
#endif
/* should be ok to use a NULL proc pointer here, all the bufs we use
* should be in kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_READ, ctrl->diskOffset, sectorsPerRU, ctrl->rbuf->buffer, psid, which_ru,
ReconReadDoneProc, (void *) ctrl, NULL,
#if RF_ACC_TRACE > 0
&raidPtr->recon_tracerecs[col],
#else
NULL,
#endif
(void *) raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this -- XXX */
ctrl->rbuf->arg = (void *) req;
rf_DiskIOEnqueue(&raidPtr->Queues[col], req, RF_IO_RECON_PRIORITY);
pssPtr->issued[col] = 1;
out:
RF_UNLOCK_PSS_MUTEX(raidPtr, psid);
return (0);
}
/*
* given a parity stripe ID, we want to find out whether both the
* current disk and the failed disk exist in that parity stripe. If
* not, we want to skip this whole PS. If so, we want to find the
* disk offset of the start of the PS on both the current disk and the
* failed disk.
*
* this works by getting a list of disks comprising the indicated
* parity stripe, and searching the list for the current and failed
* disks. Once we've decided they both exist in the parity stripe, we
* need to decide whether each is data or parity, so that we'll know
* which mapping function to call to get the corresponding disk
* offsets.
*
* this is kind of unpleasant, but doing it this way allows the
* reconstruction code to use parity stripe IDs rather than physical
* disks address to march through the failed disk, which greatly
* simplifies a lot of code, as well as eliminating the need for a
* reverse-mapping function. I also think it will execute faster,
* since the calls to the mapping module are kept to a minimum.
*
* ASSUMES THAT THE STRIPE IDENTIFIER IDENTIFIES THE DISKS COMPRISING
* THE STRIPE IN THE CORRECT ORDER
*
* raidPtr - raid descriptor
* psid - parity stripe identifier
* col - column of disk to find the offsets for
* spCol - out: col of spare unit for failed unit
* spOffset - out: offset into disk containing spare unit
*
*/
static int
ComputePSDiskOffsets(RF_Raid_t *raidPtr, RF_StripeNum_t psid,
RF_RowCol_t col, RF_SectorNum_t *outDiskOffset,
RF_SectorNum_t *outFailedDiskSectorOffset,
RF_RowCol_t *spCol, RF_SectorNum_t *spOffset)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_RowCol_t fcol = raidPtr->reconControl->fcol;
RF_RaidAddr_t sosRaidAddress; /* start-of-stripe */
RF_RowCol_t *diskids;
u_int i, j, k, i_offset, j_offset;
RF_RowCol_t pcol;
int testcol;
RF_SectorNum_t poffset;
char i_is_parity = 0, j_is_parity = 0;
RF_RowCol_t stripeWidth = layoutPtr->numDataCol + layoutPtr->numParityCol;
/* get a listing of the disks comprising that stripe */
sosRaidAddress = rf_ParityStripeIDToRaidAddress(layoutPtr, psid);
(layoutPtr->map->IdentifyStripe) (raidPtr, sosRaidAddress, &diskids);
RF_ASSERT(diskids);
/* reject this entire parity stripe if it does not contain the
* indicated disk or it does not contain the failed disk */
for (i = 0; i < stripeWidth; i++) {
if (col == diskids[i])
break;
}
if (i == stripeWidth)
goto skipit;
for (j = 0; j < stripeWidth; j++) {
if (fcol == diskids[j])
break;
}
if (j == stripeWidth) {
goto skipit;
}
/* find out which disk the parity is on */
(layoutPtr->map->MapParity) (raidPtr, sosRaidAddress, &pcol, &poffset, RF_DONT_REMAP);
/* find out if either the current RU or the failed RU is parity */
/* also, if the parity occurs in this stripe prior to the data and/or
* failed col, we need to decrement i and/or j */
for (k = 0; k < stripeWidth; k++)
if (diskids[k] == pcol)
break;
RF_ASSERT(k < stripeWidth);
i_offset = i;
j_offset = j;
if (k < i)
i_offset--;
else
if (k == i) {
i_is_parity = 1;
i_offset = 0;
} /* set offsets to zero to disable multiply
* below */
if (k < j)
j_offset--;
else
if (k == j) {
j_is_parity = 1;
j_offset = 0;
}
/* at this point, [ij]_is_parity tells us whether the [current,failed]
* disk is parity at the start of this RU, and, if data, "[ij]_offset"
* tells us how far into the stripe the [current,failed] disk is. */
/* call the mapping routine to get the offset into the current disk,
* repeat for failed disk. */
if (i_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + i_offset * layoutPtr->sectorsPerStripeUnit, &testcol, outDiskOffset, RF_DONT_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + i_offset * layoutPtr->sectorsPerStripeUnit, &testcol, outDiskOffset, RF_DONT_REMAP);
RF_ASSERT(col == testcol);
if (j_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, &testcol, outFailedDiskSectorOffset, RF_DONT_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, &testcol, outFailedDiskSectorOffset, RF_DONT_REMAP);
RF_ASSERT(fcol == testcol);
/* now locate the spare unit for the failed unit */
#if RF_INCLUDE_PARITY_DECLUSTERING_DS > 0
if (layoutPtr->map->flags & RF_DISTRIBUTE_SPARE) {
if (j_is_parity)
layoutPtr->map->MapParity(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, spCol, spOffset, RF_REMAP);
else
layoutPtr->map->MapSector(raidPtr, sosRaidAddress + j_offset * layoutPtr->sectorsPerStripeUnit, spCol, spOffset, RF_REMAP);
} else {
#endif
*spCol = raidPtr->reconControl->spareCol;
*spOffset = *outFailedDiskSectorOffset;
#if RF_INCLUDE_PARITY_DECLUSTERING_DS > 0
}
#endif
return (0);
skipit:
Dprintf2("RECON: Skipping psid %ld: nothing needed from r%d c%d\n",
psid, col);
return (1);
}
/* this is called when a buffer has become ready to write to the replacement disk */
static int
IssueNextWriteRequest(RF_Raid_t *raidPtr)
{
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_SectorCount_t sectorsPerRU = layoutPtr->sectorsPerStripeUnit * layoutPtr->SUsPerRU;
#if RF_ACC_TRACE > 0
RF_RowCol_t fcol = raidPtr->reconControl->fcol;
#endif
RF_ReconBuffer_t *rbuf;
RF_DiskQueueData_t *req;
rbuf = rf_GetFullReconBuffer(raidPtr->reconControl);
RF_ASSERT(rbuf); /* there must be one available, or we wouldn't
* have gotten the event that sent us here */
RF_ASSERT(rbuf->pssPtr);
rbuf->pssPtr->writeRbuf = rbuf;
rbuf->pssPtr = NULL;
Dprintf6("RECON: New write (c %d offs %d) for psid %ld ru %d (failed disk offset %ld) buf %lx\n",
rbuf->spCol, rbuf->spOffset, rbuf->parityStripeID,
rbuf->which_ru, rbuf->failedDiskSectorOffset, rbuf->buffer);
Dprintf6("RECON: new write psid %ld %02x %02x %02x %02x %02x\n",
rbuf->parityStripeID, rbuf->buffer[0] & 0xff, rbuf->buffer[1] & 0xff,
rbuf->buffer[2] & 0xff, rbuf->buffer[3] & 0xff, rbuf->buffer[4] & 0xff);
/* should be ok to use a NULL b_proc here b/c all addrs should be in
* kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_WRITE, rbuf->spOffset,
sectorsPerRU, rbuf->buffer,
rbuf->parityStripeID, rbuf->which_ru,
ReconWriteDoneProc, (void *) rbuf, NULL,
#if RF_ACC_TRACE > 0
&raidPtr->recon_tracerecs[fcol],
#else
NULL,
#endif
(void *) raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this -- XXX */
rbuf->arg = (void *) req;
rf_DiskIOEnqueue(&raidPtr->Queues[rbuf->spCol], req, RF_IO_RECON_PRIORITY);
return (0);
}
/*
* this gets called upon the completion of a reconstruction read
* operation the arg is a pointer to the per-disk reconstruction
* control structure for the process that just finished a read.
*
* called at interrupt context in the kernel, so don't do anything
* illegal here.
*/
static int
ReconReadDoneProc(void *arg, int status)
{
RF_PerDiskReconCtrl_t *ctrl = (RF_PerDiskReconCtrl_t *) arg;
RF_Raid_t *raidPtr = ctrl->reconCtrl->reconDesc->raidPtr;
if (status) {
printf("raid%d: Recon read failed!\n", raidPtr->raidid);
rf_CauseReconEvent(raidPtr, ctrl->col, NULL, RF_REVENT_READ_FAILED);
return(0);
}
#if RF_ACC_TRACE > 0
RF_ETIMER_STOP(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
raidPtr->recon_tracerecs[ctrl->col].specific.recon.recon_fetch_to_return_us =
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[ctrl->col].recon_timer);
#endif
rf_CauseReconEvent(raidPtr, ctrl->col, NULL, RF_REVENT_READDONE);
return (0);
}
/* this gets called upon the completion of a reconstruction write operation.
* the arg is a pointer to the rbuf that was just written
*
* called at interrupt context in the kernel, so don't do anything illegal here.
*/
static int
ReconWriteDoneProc(void *arg, int status)
{
RF_ReconBuffer_t *rbuf = (RF_ReconBuffer_t *) arg;
Dprintf2("Reconstruction completed on psid %ld ru %d\n", rbuf->parityStripeID, rbuf->which_ru);
if (status) {
printf("raid%d: Recon write failed!\n", rbuf->raidPtr->raidid);
rf_CauseReconEvent(rbuf->raidPtr, rbuf->col, arg, RF_REVENT_WRITE_FAILED);
return(0);
}
rf_CauseReconEvent(rbuf->raidPtr, rbuf->col, arg, RF_REVENT_WRITEDONE);
return (0);
}
/*
* computes a new minimum head sep, and wakes up anyone who needs to
* be woken as a result
*/
static void
CheckForNewMinHeadSep(RF_Raid_t *raidPtr, RF_HeadSepLimit_t hsCtr)
{
RF_ReconCtrl_t *reconCtrlPtr = raidPtr->reconControl;
RF_HeadSepLimit_t new_min;
RF_RowCol_t i;
RF_CallbackDesc_t *p;
RF_ASSERT(hsCtr >= reconCtrlPtr->minHeadSepCounter); /* from the definition
* of a minimum */
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
new_min = ~(1L << (8 * sizeof(long) - 1)); /* 0x7FFF....FFF */
for (i = 0; i < raidPtr->numCol; i++)
if (i != reconCtrlPtr->fcol) {
if (reconCtrlPtr->perDiskInfo[i].headSepCounter < new_min)
new_min = reconCtrlPtr->perDiskInfo[i].headSepCounter;
}
/* set the new minimum and wake up anyone who can now run again */
if (new_min != reconCtrlPtr->minHeadSepCounter) {
reconCtrlPtr->minHeadSepCounter = new_min;
Dprintf1("RECON: new min head pos counter val is %ld\n", new_min);
while (reconCtrlPtr->headSepCBList) {
if (reconCtrlPtr->headSepCBList->callbackArg.v > new_min)
break;
p = reconCtrlPtr->headSepCBList;
reconCtrlPtr->headSepCBList = p->next;
p->next = NULL;
rf_CauseReconEvent(raidPtr, p->col, NULL, RF_REVENT_HEADSEPCLEAR);
rf_FreeCallbackDesc(p);
}
}
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
}
/*
* checks to see that the maximum head separation will not be violated
* if we initiate a reconstruction I/O on the indicated disk.
* Limiting the maximum head separation between two disks eliminates
* the nasty buffer-stall conditions that occur when one disk races
* ahead of the others and consumes all of the floating recon buffers.
* This code is complex and unpleasant but it's necessary to avoid
* some very nasty, albeit fairly rare, reconstruction behavior.
*
* returns non-zero if and only if we have to stop working on the
* indicated disk due to a head-separation delay.
*/
static int
CheckHeadSeparation(RF_Raid_t *raidPtr, RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t col, RF_HeadSepLimit_t hsCtr,
RF_ReconUnitNum_t which_ru)
{
RF_ReconCtrl_t *reconCtrlPtr = raidPtr->reconControl;
RF_CallbackDesc_t *cb, *p, *pt;
int retval = 0;
/* if we're too far ahead of the slowest disk, stop working on this
* disk until the slower ones catch up. We do this by scheduling a
* wakeup callback for the time when the slowest disk has caught up.
* We define "caught up" with 20% hysteresis, i.e. the head separation
* must have fallen to at most 80% of the max allowable head
* separation before we'll wake up.
*
*/
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
if ((raidPtr->headSepLimit >= 0) &&
((ctrl->headSepCounter - reconCtrlPtr->minHeadSepCounter) > raidPtr->headSepLimit)) {
Dprintf5("raid%d: RECON: head sep stall: col %d hsCtr %ld minHSCtr %ld limit %ld\n",
raidPtr->raidid, col, ctrl->headSepCounter,
reconCtrlPtr->minHeadSepCounter,
raidPtr->headSepLimit);
cb = rf_AllocCallbackDesc();
/* the minHeadSepCounter value we have to get to before we'll
* wake up. build in 20% hysteresis. */
cb->callbackArg.v = (ctrl->headSepCounter - raidPtr->headSepLimit + raidPtr->headSepLimit / 5);
cb->col = col;
cb->next = NULL;
/* insert this callback descriptor into the sorted list of
* pending head-sep callbacks */
p = reconCtrlPtr->headSepCBList;
if (!p)
reconCtrlPtr->headSepCBList = cb;
else
if (cb->callbackArg.v < p->callbackArg.v) {
cb->next = reconCtrlPtr->headSepCBList;
reconCtrlPtr->headSepCBList = cb;
} else {
for (pt = p, p = p->next; p && (p->callbackArg.v < cb->callbackArg.v); pt = p, p = p->next);
cb->next = p;
pt->next = cb;
}
retval = 1;
#if RF_RECON_STATS > 0
ctrl->reconCtrl->reconDesc->hsStallCount++;
#endif /* RF_RECON_STATS > 0 */
}
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
return (retval);
}
/*
* checks to see if reconstruction has been either forced or blocked
* by a user operation. if forced, we skip this RU entirely. else if
* blocked, put ourselves on the wait list. else return 0.
*
* ASSUMES THE PSS MUTEX IS LOCKED UPON ENTRY
*/
static int
CheckForcedOrBlockedReconstruction(RF_Raid_t *raidPtr,
RF_ReconParityStripeStatus_t *pssPtr,
RF_PerDiskReconCtrl_t *ctrl,
RF_RowCol_t col, RF_StripeNum_t psid,
RF_ReconUnitNum_t which_ru)
{
RF_CallbackDesc_t *cb;
int retcode = 0;
if ((pssPtr->flags & RF_PSS_FORCED_ON_READ) || (pssPtr->flags & RF_PSS_FORCED_ON_WRITE))
retcode = RF_PSS_FORCED_ON_WRITE;
else
if (pssPtr->flags & RF_PSS_RECON_BLOCKED) {
Dprintf3("RECON: col %d blocked at psid %ld ru %d\n", col, psid, which_ru);
cb = rf_AllocCallbackDesc(); /* append ourselves to
* the blockage-wait
* list */
cb->col = col;
cb->next = pssPtr->blockWaitList;
pssPtr->blockWaitList = cb;
retcode = RF_PSS_RECON_BLOCKED;
}
if (!retcode)
pssPtr->flags |= RF_PSS_UNDER_RECON; /* mark this RU as under
* reconstruction */
return (retcode);
}
/*
* if reconstruction is currently ongoing for the indicated stripeID,
* reconstruction is forced to completion and we return non-zero to
* indicate that the caller must wait. If not, then reconstruction is
* blocked on the indicated stripe and the routine returns zero. If
* and only if we return non-zero, we'll cause the cbFunc to get
* invoked with the cbArg when the reconstruction has completed.
*/
int
rf_ForceOrBlockRecon(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap,
void (*cbFunc)(RF_Raid_t *, void *), void *cbArg)
{
RF_StripeNum_t stripeID = asmap->stripeID; /* the stripe ID we're
* forcing recon on */
RF_SectorCount_t sectorsPerRU = raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU; /* num sects in one RU */
RF_ReconParityStripeStatus_t *pssPtr, *newpssPtr; /* a pointer to the parity
* stripe status structure */
RF_StripeNum_t psid; /* parity stripe id */
RF_SectorNum_t offset, fd_offset; /* disk offset, failed-disk
* offset */
RF_RowCol_t *diskids;
RF_ReconUnitNum_t which_ru; /* RU within parity stripe */
RF_RowCol_t fcol, diskno, i;
RF_ReconBuffer_t *new_rbuf; /* ptr to newly allocated rbufs */
RF_DiskQueueData_t *req;/* disk I/O req to be enqueued */
RF_CallbackDesc_t *cb;
int nPromoted;
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);
/* allocate a new PSS in case we need it */
newpssPtr = rf_AllocPSStatus(raidPtr);
RF_LOCK_PSS_MUTEX(raidPtr, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl->pssTable, psid, which_ru, RF_PSS_CREATE | RF_PSS_RECON_BLOCKED, newpssPtr);
if (pssPtr != newpssPtr) {
rf_FreePSStatus(raidPtr, newpssPtr);
}
/* if recon is not ongoing on this PS, just return */
if (!(pssPtr->flags & RF_PSS_UNDER_RECON)) {
RF_UNLOCK_PSS_MUTEX(raidPtr, psid);
return (0);
}
/* otherwise, we have to wait for reconstruction to complete on this
* RU. */
/* In order to avoid waiting for a potentially large number of
* low-priority accesses to complete, we force a normal-priority (i.e.
* not low-priority) reconstruction on this RU. */
if (!(pssPtr->flags & RF_PSS_FORCED_ON_WRITE) && !(pssPtr->flags & RF_PSS_FORCED_ON_READ)) {
DDprintf1("Forcing recon on psid %ld\n", psid);
pssPtr->flags |= RF_PSS_FORCED_ON_WRITE; /* mark this RU as under
* forced recon */
pssPtr->flags &= ~RF_PSS_RECON_BLOCKED; /* clear the blockage
* that we just set */
fcol = raidPtr->reconControl->fcol;
/* get a listing of the disks comprising the indicated stripe */
(raidPtr->Layout.map->IdentifyStripe) (raidPtr, asmap->raidAddress, &diskids);
/* For previously issued reads, elevate them to normal
* priority. If the I/O has already completed, it won't be
* found in the queue, and hence this will be a no-op. For
* unissued reads, allocate buffers and issue new reads. The
* fact that we've set the FORCED bit means that the regular
* recon procs will not re-issue these reqs */
for (i = 0; i < raidPtr->Layout.numDataCol + raidPtr->Layout.numParityCol; i++)
if ((diskno = diskids[i]) != fcol) {
if (pssPtr->issued[diskno]) {
nPromoted = rf_DiskIOPromote(&raidPtr->Queues[diskno], psid, which_ru);
if (rf_reconDebug && nPromoted)
printf("raid%d: promoted read from col %d\n", raidPtr->raidid, diskno);
} else {
new_rbuf = rf_MakeReconBuffer(raidPtr, diskno, RF_RBUF_TYPE_FORCED); /* create new buf */
ComputePSDiskOffsets(raidPtr, psid, diskno, &offset, &fd_offset,
&new_rbuf->spCol, &new_rbuf->spOffset); /* find offsets & spare
* location */
new_rbuf->parityStripeID = psid; /* fill in the buffer */
new_rbuf->which_ru = which_ru;
new_rbuf->failedDiskSectorOffset = fd_offset;
new_rbuf->priority = RF_IO_NORMAL_PRIORITY;
/* use NULL b_proc b/c all addrs
* should be in kernel space */
req = rf_CreateDiskQueueData(RF_IO_TYPE_READ, offset + which_ru * sectorsPerRU, sectorsPerRU, new_rbuf->buffer,
psid, which_ru, (int (*) (void *, int)) ForceReconReadDoneProc, (void *) new_rbuf, NULL,
NULL, (void *) raidPtr, 0, NULL);
RF_ASSERT(req); /* XXX -- fix this --
* XXX */
new_rbuf->arg = req;
rf_DiskIOEnqueue(&raidPtr->Queues[diskno], req, RF_IO_NORMAL_PRIORITY); /* enqueue the I/O */
Dprintf2("raid%d: Issued new read req on col %d\n", raidPtr->raidid, diskno);
}
}
/* if the write is sitting in the disk queue, elevate its
* priority */
if (rf_DiskIOPromote(&raidPtr->Queues[fcol], psid, which_ru))
printf("raid%d: promoted write to col %d\n",
raidPtr->raidid, fcol);
}
/* install a callback descriptor to be invoked when recon completes on
* this parity stripe. */
cb = rf_AllocCallbackDesc();
/* XXX the following is bogus.. These functions don't really match!!
* GO */
cb->callbackFunc = (void (*) (RF_CBParam_t)) cbFunc;
cb->callbackArg.p = (void *) cbArg;
cb->next = pssPtr->procWaitList;
pssPtr->procWaitList = cb;
DDprintf2("raid%d: Waiting for forced recon on psid %ld\n",
raidPtr->raidid, psid);
RF_UNLOCK_PSS_MUTEX(raidPtr, psid);
return (1);
}
/* called upon the completion of a forced reconstruction read.
* all we do is schedule the FORCEDREADONE event.
* called at interrupt context in the kernel, so don't do anything illegal here.
*/
static void
ForceReconReadDoneProc(void *arg, int status)
{
RF_ReconBuffer_t *rbuf = arg;
if (status) {
printf("raid%d: Forced recon read failed!\n", rbuf->raidPtr->raidid);
rf_CauseReconEvent(rbuf->raidPtr, rbuf->col, (void *) rbuf, RF_REVENT_FORCEDREAD_FAILED);
}
rf_CauseReconEvent(rbuf->raidPtr, rbuf->col, (void *) rbuf, RF_REVENT_FORCEDREADDONE);
}
/* releases a block on the reconstruction of the indicated stripe */
int
rf_UnblockRecon(RF_Raid_t *raidPtr, RF_AccessStripeMap_t *asmap)
{
RF_StripeNum_t stripeID = asmap->stripeID;
RF_ReconParityStripeStatus_t *pssPtr;
RF_ReconUnitNum_t which_ru;
RF_StripeNum_t psid;
RF_CallbackDesc_t *cb;
psid = rf_MapStripeIDToParityStripeID(&raidPtr->Layout, stripeID, &which_ru);
RF_LOCK_PSS_MUTEX(raidPtr, psid);
pssPtr = rf_LookupRUStatus(raidPtr, raidPtr->reconControl->pssTable, psid, which_ru, RF_PSS_NONE, NULL);
/* When recon is forced, the pss desc can get deleted before we get
* back to unblock recon. But, this can _only_ happen when recon is
* forced. It would be good to put some kind of sanity check here, but
* how to decide if recon was just forced or not? */
if (!pssPtr) {
/* printf("Warning: no pss descriptor upon unblock on psid %ld
* RU %d\n",psid,which_ru); */
#if (RF_DEBUG_RECON > 0) || (RF_DEBUG_PSS > 0)
if (rf_reconDebug || rf_pssDebug)
printf("Warning: no pss descriptor upon unblock on psid %ld RU %d\n", (long) psid, which_ru);
#endif
goto out;
}
pssPtr->blockCount--;
Dprintf3("raid%d: unblocking recon on psid %ld: blockcount is %d\n",
raidPtr->raidid, psid, pssPtr->blockCount);
if (pssPtr->blockCount == 0) { /* if recon blockage has been released */
/* unblock recon before calling CauseReconEvent in case
* CauseReconEvent causes us to try to issue a new read before
* returning here. */
pssPtr->flags &= ~RF_PSS_RECON_BLOCKED;
while (pssPtr->blockWaitList) {
/* spin through the block-wait list and
release all the waiters */
cb = pssPtr->blockWaitList;
pssPtr->blockWaitList = cb->next;
cb->next = NULL;
rf_CauseReconEvent(raidPtr, cb->col, NULL, RF_REVENT_BLOCKCLEAR);
rf_FreeCallbackDesc(cb);
}
if (!(pssPtr->flags & RF_PSS_UNDER_RECON)) {
/* if no recon was requested while recon was blocked */
rf_PSStatusDelete(raidPtr, raidPtr->reconControl->pssTable, pssPtr);
}
}
out:
RF_UNLOCK_PSS_MUTEX(raidPtr, psid);
return (0);
}
Reference in New Issue View Git Blame Copy Permalink