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freebsd-nq/sys/dev/raidframe/rf_reconbuffer.c
David E. O'Brien aad970f1fe Use __FBSDID(). 
Also some minor style cleanups.
2003-08-24 17:55:58 +00:00

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/* $NetBSD: rf_reconbuffer.c,v 1.5 2001/01/27 20:10:49 oster Exp $ */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* 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_reconbuffer.c -- reconstruction buffer manager
*
***************************************************/
#include <dev/raidframe/rf_raid.h>
#include <dev/raidframe/rf_reconbuffer.h>
#include <dev/raidframe/rf_acctrace.h>
#include <dev/raidframe/rf_etimer.h>
#include <dev/raidframe/rf_general.h>
#include <dev/raidframe/rf_debugprint.h>
#include <dev/raidframe/rf_revent.h>
#include <dev/raidframe/rf_reconutil.h>
#include <dev/raidframe/rf_nwayxor.h>
#define Dprintf1(s,a) if (rf_reconbufferDebug) printf(s,a)
#define Dprintf2(s,a,b) if (rf_reconbufferDebug) printf(s,a,b)
#define Dprintf3(s,a,b,c) if (rf_reconbufferDebug) printf(s,a,b,c)
#define Dprintf4(s,a,b,c,d) if (rf_reconbufferDebug) printf(s,a,b,c,d)
#define Dprintf5(s,a,b,c,d,e) if (rf_reconbufferDebug) printf(s,a,b,c,d,e)
/*****************************************************************************
*
* Submit a reconstruction buffer to the manager for XOR. We can only
* submit a buffer if (1) we can xor into an existing buffer, which
* means we don't have to acquire a new one, (2) we can acquire a
* floating recon buffer, or (3) the caller has indicated that we are
* allowed to keep the submitted buffer.
*
* Returns non-zero if and only if we were not able to submit.
* In this case, we append the current disk ID to the wait list on the
* indicated RU, so that it will be re-enabled when we acquire a buffer
* for this RU.
*
****************************************************************************/
/*
* nWayXorFuncs[i] is a pointer to a function that will xor "i"
* bufs into the accumulating sum.
*/
static RF_VoidFuncPtr nWayXorFuncs[] = {
NULL,
(RF_VoidFuncPtr) rf_nWayXor1,
(RF_VoidFuncPtr) rf_nWayXor2,
(RF_VoidFuncPtr) rf_nWayXor3,
(RF_VoidFuncPtr) rf_nWayXor4,
(RF_VoidFuncPtr) rf_nWayXor5,
(RF_VoidFuncPtr) rf_nWayXor6,
(RF_VoidFuncPtr) rf_nWayXor7,
(RF_VoidFuncPtr) rf_nWayXor8,
(RF_VoidFuncPtr) rf_nWayXor9
};
int
rf_SubmitReconBuffer(rbuf, keep_it, use_committed)
RF_ReconBuffer_t *rbuf; /* the recon buffer to submit */
int keep_it; /* whether we can keep this buffer or we have
* to return it */
int use_committed; /* whether to use a committed or an available
* recon buffer */
{
RF_LayoutSW_t *lp;
int rc;
lp = rbuf->raidPtr->Layout.map;
rc = lp->SubmitReconBuffer(rbuf, keep_it, use_committed);
return (rc);
}
int
rf_SubmitReconBufferBasic(rbuf, keep_it, use_committed)
RF_ReconBuffer_t *rbuf; /* the recon buffer to submit */
int keep_it; /* whether we can keep this buffer or we have
* to return it */
int use_committed; /* whether to use a committed or an available
* recon buffer */
{
RF_Raid_t *raidPtr = rbuf->raidPtr;
RF_RaidLayout_t *layoutPtr = &raidPtr->Layout;
RF_ReconCtrl_t *reconCtrlPtr = raidPtr->reconControl[rbuf->row];
RF_ReconParityStripeStatus_t *pssPtr;
RF_ReconBuffer_t *targetRbuf, *t = NULL; /* temporary rbuf
* pointers */
caddr_t ta; /* temporary data buffer pointer */
RF_CallbackDesc_t *cb, *p;
int retcode = 0, created = 0;
RF_Etimer_t timer;
/* makes no sense to have a submission from the failed disk */
RF_ASSERT(rbuf);
RF_ASSERT(rbuf->col != reconCtrlPtr->fcol);
Dprintf5("RECON: submission by row %d col %d for psid %ld ru %d (failed offset %ld)\n",
rbuf->row, rbuf->col, (long) rbuf->parityStripeID, rbuf->which_ru, (long) rbuf->failedDiskSectorOffset);
RF_LOCK_PSS_MUTEX(raidPtr, rbuf->row, rbuf->parityStripeID);
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
pssPtr = rf_LookupRUStatus(raidPtr, reconCtrlPtr->pssTable, rbuf->parityStripeID, rbuf->which_ru, RF_PSS_NONE, &created);
RF_ASSERT(pssPtr); /* if it didn't exist, we wouldn't have gotten
* an rbuf for it */
/* check to see if enough buffers have accumulated to do an XOR. If
* so, there's no need to acquire a floating rbuf. Before we can do
* any XORing, we must have acquired a destination buffer. If we
* have, then we can go ahead and do the XOR if (1) including this
* buffer, enough bufs have accumulated, or (2) this is the last
* submission for this stripe. Otherwise, we have to go acquire a
* floating rbuf. */
targetRbuf = (RF_ReconBuffer_t *) pssPtr->rbuf;
if ((targetRbuf != NULL) &&
((pssPtr->xorBufCount == rf_numBufsToAccumulate - 1) || (targetRbuf->count + pssPtr->xorBufCount + 1 == layoutPtr->numDataCol))) {
pssPtr->rbufsForXor[pssPtr->xorBufCount++] = rbuf; /* install this buffer */
Dprintf3("RECON: row %d col %d invoking a %d-way XOR\n", rbuf->row, rbuf->col, pssPtr->xorBufCount);
RF_ETIMER_START(timer);
rf_MultiWayReconXor(raidPtr, pssPtr);
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
raidPtr->accumXorTimeUs += RF_ETIMER_VAL_US(timer);
if (!keep_it) {
raidPtr->recon_tracerecs[rbuf->col].xor_us = RF_ETIMER_VAL_US(timer);
RF_ETIMER_STOP(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
raidPtr->recon_tracerecs[rbuf->col].specific.recon.recon_return_to_submit_us +=
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
rf_LogTraceRec(raidPtr, &raidPtr->recon_tracerecs[rbuf->col]);
}
rf_CheckForFullRbuf(raidPtr, reconCtrlPtr, pssPtr, layoutPtr->numDataCol);
/* if use_committed is on, we _must_ consume a buffer off the
* committed list. */
if (use_committed) {
t = reconCtrlPtr->committedRbufs;
RF_ASSERT(t);
reconCtrlPtr->committedRbufs = t->next;
rf_ReleaseFloatingReconBuffer(raidPtr, rbuf->row, t);
}
if (keep_it) {
RF_UNLOCK_PSS_MUTEX(raidPtr, rbuf->row, rbuf->parityStripeID);
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
rf_FreeReconBuffer(rbuf);
return (retcode);
}
goto out;
}
/* set the value of "t", which we'll use as the rbuf from here on */
if (keep_it) {
t = rbuf;
} else {
if (use_committed) { /* if a buffer has been committed to
* us, use it */
t = reconCtrlPtr->committedRbufs;
RF_ASSERT(t);
reconCtrlPtr->committedRbufs = t->next;
t->next = NULL;
} else
if (reconCtrlPtr->floatingRbufs) {
t = reconCtrlPtr->floatingRbufs;
reconCtrlPtr->floatingRbufs = t->next;
t->next = NULL;
}
}
/* If we weren't able to acquire a buffer, append to the end of the
* buf list in the recon ctrl struct. */
if (!t) {
RF_ASSERT(!keep_it && !use_committed);
Dprintf2("RECON: row %d col %d failed to acquire floating rbuf\n", rbuf->row, rbuf->col);
raidPtr->procsInBufWait++;
if ((raidPtr->procsInBufWait == raidPtr->numCol - 1) && (raidPtr->numFullReconBuffers == 0)) {
printf("Buffer wait deadlock detected. Exiting.\n");
rf_PrintPSStatusTable(raidPtr, rbuf->row);
RF_PANIC();
}
pssPtr->flags |= RF_PSS_BUFFERWAIT;
cb = rf_AllocCallbackDesc(); /* append to buf wait list in
* recon ctrl structure */
cb->row = rbuf->row;
cb->col = rbuf->col;
cb->callbackArg.v = rbuf->parityStripeID;
cb->callbackArg2.v = rbuf->which_ru;
cb->next = NULL;
if (!reconCtrlPtr->bufferWaitList)
reconCtrlPtr->bufferWaitList = cb;
else { /* might want to maintain head/tail pointers
* here rather than search for end of list */
for (p = reconCtrlPtr->bufferWaitList; p->next; p = p->next);
p->next = cb;
}
retcode = 1;
goto out;
}
Dprintf2("RECON: row %d col %d acquired rbuf\n", rbuf->row, rbuf->col);
RF_ETIMER_STOP(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
RF_ETIMER_EVAL(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
raidPtr->recon_tracerecs[rbuf->col].specific.recon.recon_return_to_submit_us +=
RF_ETIMER_VAL_US(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
RF_ETIMER_START(raidPtr->recon_tracerecs[rbuf->col].recon_timer);
rf_LogTraceRec(raidPtr, &raidPtr->recon_tracerecs[rbuf->col]);
/* initialize the buffer */
if (t != rbuf) {
t->row = rbuf->row;
t->col = reconCtrlPtr->fcol;
t->parityStripeID = rbuf->parityStripeID;
t->which_ru = rbuf->which_ru;
t->failedDiskSectorOffset = rbuf->failedDiskSectorOffset;
t->spRow = rbuf->spRow;
t->spCol = rbuf->spCol;
t->spOffset = rbuf->spOffset;
ta = t->buffer;
t->buffer = rbuf->buffer;
rbuf->buffer = ta; /* swap buffers */
}
/* the first installation always gets installed as the destination
* buffer. subsequent installations get stacked up to allow for
* multi-way XOR */
if (!pssPtr->rbuf) {
pssPtr->rbuf = t;
t->count = 1;
} else
pssPtr->rbufsForXor[pssPtr->xorBufCount++] = t; /* install this buffer */
rf_CheckForFullRbuf(raidPtr, reconCtrlPtr, pssPtr, layoutPtr->numDataCol); /* the buffer is full if
* G=2 */
out:
RF_UNLOCK_PSS_MUTEX(raidPtr, rbuf->row, rbuf->parityStripeID);
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
return (retcode);
}
int
rf_MultiWayReconXor(raidPtr, pssPtr)
RF_Raid_t *raidPtr;
RF_ReconParityStripeStatus_t *pssPtr; /* the pss descriptor for this
* parity stripe */
{
int i, numBufs = pssPtr->xorBufCount;
int numBytes = rf_RaidAddressToByte(raidPtr, raidPtr->Layout.sectorsPerStripeUnit * raidPtr->Layout.SUsPerRU);
RF_ReconBuffer_t **rbufs = (RF_ReconBuffer_t **) pssPtr->rbufsForXor;
RF_ReconBuffer_t *targetRbuf = (RF_ReconBuffer_t *) pssPtr->rbuf;
RF_ASSERT(pssPtr->rbuf != NULL);
RF_ASSERT(numBufs > 0 && numBufs < RF_PS_MAX_BUFS);
#ifdef _KERNEL
#ifndef __NetBSD__
#ifndef __FreeBSD__
thread_block(); /* yield the processor before doing a big XOR */
#endif
#endif
#endif /* _KERNEL */
/*
* XXX
*
* What if more than 9 bufs?
*/
nWayXorFuncs[numBufs] (pssPtr->rbufsForXor, targetRbuf, numBytes / sizeof(long));
/* release all the reconstruction buffers except the last one, which
* belongs to the disk whose submission caused this XOR to take place */
for (i = 0; i < numBufs - 1; i++) {
if (rbufs[i]->type == RF_RBUF_TYPE_FLOATING)
rf_ReleaseFloatingReconBuffer(raidPtr, rbufs[i]->row, rbufs[i]);
else
if (rbufs[i]->type == RF_RBUF_TYPE_FORCED)
rf_FreeReconBuffer(rbufs[i]);
else
RF_ASSERT(0);
}
targetRbuf->count += pssPtr->xorBufCount;
pssPtr->xorBufCount = 0;
return (0);
}
/* removes one full buffer from one of the full-buffer lists and returns it.
*
* ASSUMES THE RB_MUTEX IS UNLOCKED AT ENTRY.
*/
RF_ReconBuffer_t *
rf_GetFullReconBuffer(reconCtrlPtr)
RF_ReconCtrl_t *reconCtrlPtr;
{
RF_ReconBuffer_t *p;
RF_LOCK_MUTEX(reconCtrlPtr->rb_mutex);
if ((p = reconCtrlPtr->priorityList) != NULL) {
reconCtrlPtr->priorityList = p->next;
p->next = NULL;
goto out;
}
if ((p = reconCtrlPtr->fullBufferList) != NULL) {
reconCtrlPtr->fullBufferList = p->next;
p->next = NULL;
goto out;
}
out:
RF_UNLOCK_MUTEX(reconCtrlPtr->rb_mutex);
return (p);
}
/* if the reconstruction buffer is full, move it to the full list,
* which is maintained sorted by failed disk sector offset
*
* ASSUMES THE RB_MUTEX IS LOCKED AT ENTRY. */
int
rf_CheckForFullRbuf(raidPtr, reconCtrl, pssPtr, numDataCol)
RF_Raid_t *raidPtr;
RF_ReconCtrl_t *reconCtrl;
RF_ReconParityStripeStatus_t *pssPtr;
int numDataCol;
{
RF_ReconBuffer_t *p, *pt, *rbuf = (RF_ReconBuffer_t *) pssPtr->rbuf;
if (rbuf->count == numDataCol) {
raidPtr->numFullReconBuffers++;
Dprintf2("RECON: rbuf for psid %ld ru %d has filled\n",
(long) rbuf->parityStripeID, rbuf->which_ru);
if (!reconCtrl->fullBufferList || (rbuf->failedDiskSectorOffset < reconCtrl->fullBufferList->failedDiskSectorOffset)) {
Dprintf2("RECON: rbuf for psid %ld ru %d is head of list\n",
(long) rbuf->parityStripeID, rbuf->which_ru);
rbuf->next = reconCtrl->fullBufferList;
reconCtrl->fullBufferList = rbuf;
} else {
for (pt = reconCtrl->fullBufferList, p = pt->next; p && p->failedDiskSectorOffset < rbuf->failedDiskSectorOffset; pt = p, p = p->next);
rbuf->next = p;
pt->next = rbuf;
Dprintf2("RECON: rbuf for psid %ld ru %d is in list\n",
(long) rbuf->parityStripeID, rbuf->which_ru);
}
#if 0
pssPtr->writeRbuf = pssPtr->rbuf; /* DEBUG ONLY: we like
* to be able to find
* this rbuf while it's
* awaiting write */
#else
rbuf->pssPtr = pssPtr;
#endif
pssPtr->rbuf = NULL;
rf_CauseReconEvent(raidPtr, rbuf->row, rbuf->col, NULL, RF_REVENT_BUFREADY);
}
return (0);
}
/* release a floating recon buffer for someone else to use.
* assumes the rb_mutex is LOCKED at entry
*/
void
rf_ReleaseFloatingReconBuffer(raidPtr, row, rbuf)
RF_Raid_t *raidPtr;
RF_RowCol_t row;
RF_ReconBuffer_t *rbuf;
{
RF_ReconCtrl_t *rcPtr = raidPtr->reconControl[row];
RF_CallbackDesc_t *cb;
Dprintf2("RECON: releasing rbuf for psid %ld ru %d\n",
(long) rbuf->parityStripeID, rbuf->which_ru);
/* if anyone is waiting on buffers, wake one of them up. They will
* subsequently wake up anyone else waiting on their RU */
if (rcPtr->bufferWaitList) {
rbuf->next = rcPtr->committedRbufs;
rcPtr->committedRbufs = rbuf;
cb = rcPtr->bufferWaitList;
rcPtr->bufferWaitList = cb->next;
rf_CauseReconEvent(raidPtr, cb->row, cb->col, (void *) 1, RF_REVENT_BUFCLEAR); /* arg==1 => we've
* committed a buffer */
rf_FreeCallbackDesc(cb);
raidPtr->procsInBufWait--;
} else {
rbuf->next = rcPtr->floatingRbufs;
rcPtr->floatingRbufs = rbuf;
}
}
/* release any disk that is waiting on a buffer for the indicated RU.
* assumes the rb_mutex is LOCKED at entry
*/
void
rf_ReleaseBufferWaiters(raidPtr, pssPtr)
RF_Raid_t *raidPtr;
RF_ReconParityStripeStatus_t *pssPtr;
{
RF_CallbackDesc_t *cb1, *cb = pssPtr->bufWaitList;
Dprintf2("RECON: releasing buf waiters for psid %ld ru %d\n",
(long) pssPtr->parityStripeID, pssPtr->which_ru);
pssPtr->flags &= ~RF_PSS_BUFFERWAIT;
while (cb) {
cb1 = cb->next;
cb->next = NULL;
rf_CauseReconEvent(raidPtr, cb->row, cb->col, (void *) 0, RF_REVENT_BUFCLEAR); /* arg==0 => we haven't
* committed a buffer */
rf_FreeCallbackDesc(cb);
cb = cb1;
}
pssPtr->bufWaitList = NULL;
}
/* when reconstruction is forced on an RU, there may be some disks waiting to
* acquire a buffer for that RU. Since we allocate a new buffer as part of
* the forced-reconstruction process, we no longer have to wait for any
* buffers, so we wakeup any waiter that we find in the bufferWaitList
*
* assumes the rb_mutex is LOCKED at entry
*/
void
rf_ReleaseBufferWaiter(rcPtr, rbuf)
RF_ReconCtrl_t *rcPtr;
RF_ReconBuffer_t *rbuf;
{
RF_CallbackDesc_t *cb, *cbt;
for (cbt = NULL, cb = rcPtr->bufferWaitList; cb; cbt = cb, cb = cb->next) {
if ((cb->callbackArg.v == rbuf->parityStripeID) && (cb->callbackArg2.v == rbuf->which_ru)) {
Dprintf2("RECON: Dropping row %d col %d from buffer wait list\n", cb->row, cb->col);
if (cbt)
cbt->next = cb->next;
else
rcPtr->bufferWaitList = cb->next;
rf_CauseReconEvent((RF_Raid_t *) rbuf->raidPtr, cb->row, cb->col, (void *) 0, RF_REVENT_BUFREADY); /* arg==0 => no
* committed buffer */
rf_FreeCallbackDesc(cb);
return;
}
}
}
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