/* $OpenBSD: rf_states.c,v 1.9 2002/12/16 07:01:05 tdeval Exp $ */
/* $NetBSD: rf_states.c,v 1.15 2000/10/20 02:24:45 oster Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland, William V. Courtright II, Robby Findler
*
* 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.
*/
#include <sys/errno.h>
#include "rf_archs.h"
#include "rf_threadstuff.h"
#include "rf_raid.h"
#include "rf_dag.h"
#include "rf_desc.h"
#include "rf_aselect.h"
#include "rf_general.h"
#include "rf_states.h"
#include "rf_dagutils.h"
#include "rf_driver.h"
#include "rf_engine.h"
#include "rf_map.h"
#include "rf_etimer.h"
#include "rf_kintf.h"
/*
* Prototypes for some of the available states.
*
* States must:
*
* - not block.
*
* - either schedule rf_ContinueRaidAccess as a callback and return
* RF_TRUE, or complete all of their work and return RF_FALSE.
*
* - increment desc->state when they have finished their work.
*/
char *StateName(RF_AccessState_t);
char *
StateName(RF_AccessState_t state)
{
switch (state) {
case rf_QuiesceState:return "QuiesceState";
case rf_MapState:
return "MapState";
case rf_LockState:
return "LockState";
case rf_CreateDAGState:
return "CreateDAGState";
case rf_ExecuteDAGState:
return "ExecuteDAGState";
case rf_ProcessDAGState:
return "ProcessDAGState";
case rf_CleanupState:
return "CleanupState";
case rf_LastState:
return "LastState";
case rf_IncrAccessesCountState:
return "IncrAccessesCountState";
case rf_DecrAccessesCountState:
return "DecrAccessesCountState";
default:
return "!!! UnnamedState !!!";
}
}
void
rf_ContinueRaidAccess(RF_RaidAccessDesc_t *desc)
{
int suspended = RF_FALSE;
int current_state_index = desc->state;
RF_AccessState_t current_state = desc->states[current_state_index];
int unit = desc->raidPtr->raidid;
do {
current_state_index = desc->state;
current_state = desc->states[current_state_index];
switch (current_state) {
case rf_QuiesceState:
suspended = rf_State_Quiesce(desc);
break;
case rf_IncrAccessesCountState:
suspended = rf_State_IncrAccessCount(desc);
break;
case rf_MapState:
suspended = rf_State_Map(desc);
break;
case rf_LockState:
suspended = rf_State_Lock(desc);
break;
case rf_CreateDAGState:
suspended = rf_State_CreateDAG(desc);
break;
case rf_ExecuteDAGState:
suspended = rf_State_ExecuteDAG(desc);
break;
case rf_ProcessDAGState:
suspended = rf_State_ProcessDAG(desc);
break;
case rf_CleanupState:
suspended = rf_State_Cleanup(desc);
break;
case rf_DecrAccessesCountState:
suspended = rf_State_DecrAccessCount(desc);
break;
case rf_LastState:
suspended = rf_State_LastState(desc);
break;
}
/*
* After this point, we cannot dereference desc since desc may
* have been freed. desc is only freed in LastState, so if we
* reenter this function or loop back up, desc should be valid.
*/
if (rf_printStatesDebug) {
printf("raid%d: State: %-24s StateIndex: %3i desc:"
" 0x%ld %s.\n", unit, StateName(current_state),
current_state_index, (long) desc, suspended ?
"callback scheduled" : "looping");
}
} while (!suspended && current_state != rf_LastState);
return;
}
void
rf_ContinueDagAccess(RF_DagList_t *dagList)
{
RF_AccTraceEntry_t *tracerec = &(dagList->desc->tracerec);
RF_RaidAccessDesc_t *desc;
RF_DagHeader_t *dag_h;
RF_Etimer_t timer;
int i;
desc = dagList->desc;
timer = tracerec->timer;
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.exec_us = RF_ETIMER_VAL_US(timer);
RF_ETIMER_START(tracerec->timer);
/* Skip to dag which just finished. */
dag_h = dagList->dags;
for (i = 0; i < dagList->numDagsDone; i++) {
dag_h = dag_h->next;
}
/* Check to see if retry is required. */
if (dag_h->status == rf_rollBackward) {
/*
* When a dag fails, mark desc status as bad and allow all
* other dags in the desc to execute to completion. Then,
* free all dags and start over.
*/
desc->status = 1; /* Bad status. */
{
printf("raid%d: DAG failure: %c addr 0x%lx (%ld)"
" nblk 0x%x (%d) buf 0x%lx.\n",
desc->raidPtr->raidid, desc->type,
(long) desc->raidAddress,
(long) desc->raidAddress,
(int) desc->numBlocks, (int) desc->numBlocks,
(unsigned long) (desc->bufPtr));
}
}
dagList->numDagsDone++;
rf_ContinueRaidAccess(desc);
}
int
rf_State_LastState(RF_RaidAccessDesc_t *desc)
{
void (*callbackFunc) (RF_CBParam_t) = desc->callbackFunc;
RF_CBParam_t callbackArg;
callbackArg.p = desc->callbackArg;
/*
* If this is not an async request, wake up the caller.
*/
if (desc->async_flag == 0)
wakeup(desc->bp);
/*
* That's all the IO for this one... Unbusy the 'disk'.
*/
rf_disk_unbusy(desc);
/*
* Wakeup any requests waiting to go.
*/
RF_LOCK_MUTEX(((RF_Raid_t *) desc->raidPtr)->mutex);
((RF_Raid_t *) desc->raidPtr)->openings++;
RF_UNLOCK_MUTEX(((RF_Raid_t *) desc->raidPtr)->mutex);
/* Wake up any pending I/O. */
raidstart(((RF_Raid_t *) desc->raidPtr));
/* printf("%s: Calling biodone on 0x%x.\n", __func__, desc->bp); */
splassert(IPL_BIO);
biodone(desc->bp); /* Access came through ioctl. */
if (callbackFunc)
callbackFunc(callbackArg);
rf_FreeRaidAccDesc(desc);
return RF_FALSE;
}
int
rf_State_IncrAccessCount(RF_RaidAccessDesc_t *desc)
{
RF_Raid_t *raidPtr;
raidPtr = desc->raidPtr;
/*
* Bummer. We have to do this to be 100% safe w.r.t. the increment
* below.
*/
RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
raidPtr->accs_in_flight++; /* Used to detect quiescence. */
RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
desc->state++;
return RF_FALSE;
}
int
rf_State_DecrAccessCount(RF_RaidAccessDesc_t *desc)
{
RF_Raid_t *raidPtr;
raidPtr = desc->raidPtr;
RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
raidPtr->accs_in_flight--;
if (raidPtr->accesses_suspended && raidPtr->accs_in_flight == 0) {
rf_SignalQuiescenceLock(raidPtr, raidPtr->reconDesc);
}
rf_UpdateUserStats(raidPtr, RF_ETIMER_VAL_US(desc->timer),
desc->numBlocks);
RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
desc->state++;
return RF_FALSE;
}
int
rf_State_Quiesce(RF_RaidAccessDesc_t *desc)
{
RF_AccTraceEntry_t *tracerec = &desc->tracerec;
RF_Etimer_t timer;
int suspended = RF_FALSE;
RF_Raid_t *raidPtr;
raidPtr = desc->raidPtr;
RF_ETIMER_START(timer);
RF_ETIMER_START(desc->timer);
RF_LOCK_MUTEX(raidPtr->access_suspend_mutex);
if (raidPtr->accesses_suspended) {
RF_CallbackDesc_t *cb;
cb = rf_AllocCallbackDesc();
/*
* XXX The following cast is quite bogus...
* rf_ContinueRaidAccess takes a (RF_RaidAccessDesc_t *)
* as an argument... GO
*/
cb->callbackFunc = (void (*) (RF_CBParam_t))
rf_ContinueRaidAccess;
cb->callbackArg.p = (void *) desc;
cb->next = raidPtr->quiesce_wait_list;
raidPtr->quiesce_wait_list = cb;
suspended = RF_TRUE;
}
RF_UNLOCK_MUTEX(raidPtr->access_suspend_mutex);
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.suspend_ovhd_us += RF_ETIMER_VAL_US(timer);
if (suspended && rf_quiesceDebug)
printf("Stalling access due to quiescence lock.\n");
desc->state++;
return suspended;
}
int
rf_State_Map(RF_RaidAccessDesc_t *desc)
{
RF_Raid_t *raidPtr = desc->raidPtr;
RF_AccTraceEntry_t *tracerec = &desc->tracerec;
RF_Etimer_t timer;
RF_ETIMER_START(timer);
if (!(desc->asmap = rf_MapAccess(raidPtr, desc->raidAddress,
desc->numBlocks, desc->bufPtr, RF_DONT_REMAP)))
RF_PANIC();
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.map_us = RF_ETIMER_VAL_US(timer);
desc->state++;
return RF_FALSE;
}
int
rf_State_Lock(RF_RaidAccessDesc_t *desc)
{
RF_AccTraceEntry_t *tracerec = &desc->tracerec;
RF_Raid_t *raidPtr = desc->raidPtr;
RF_AccessStripeMapHeader_t *asmh = desc->asmap;
RF_AccessStripeMap_t *asm_p;
RF_Etimer_t timer;
int suspended = RF_FALSE;
RF_ETIMER_START(timer);
if (!(raidPtr->Layout.map->flags & RF_NO_STRIPE_LOCKS)) {
RF_StripeNum_t lastStripeID = -1;
/* Acquire each lock that we don't already hold. */
for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
RF_ASSERT(RF_IO_IS_R_OR_W(desc->type));
if (!rf_suppressLocksAndLargeWrites &&
asm_p->parityInfo &&
!(desc->flags & RF_DAG_SUPPRESS_LOCKS) &&
!(asm_p->flags & RF_ASM_FLAGS_LOCK_TRIED)) {
asm_p->flags |= RF_ASM_FLAGS_LOCK_TRIED;
/* Locks must be acquired hierarchically. */
RF_ASSERT(asm_p->stripeID > lastStripeID);
lastStripeID = asm_p->stripeID;
/*
* XXX The cast to (void (*)(RF_CBParam_t))
* below is bogus ! GO
*/
RF_INIT_LOCK_REQ_DESC(asm_p->lockReqDesc,
desc->type, (void (*) (struct buf *))
rf_ContinueRaidAccess, desc, asm_p,
raidPtr->Layout.dataSectorsPerStripe);
if (rf_AcquireStripeLock(raidPtr->lockTable,
asm_p->stripeID, &asm_p->lockReqDesc)) {
suspended = RF_TRUE;
break;
}
}
if (desc->type == RF_IO_TYPE_WRITE &&
raidPtr->status[asm_p->physInfo->row] ==
rf_rs_reconstructing) {
if (!(asm_p->flags & RF_ASM_FLAGS_FORCE_TRIED))
{
int val;
asm_p->flags |=
RF_ASM_FLAGS_FORCE_TRIED;
/*
* XXX The cast below is quite
* bogus !!! XXX GO
*/
val = rf_ForceOrBlockRecon(raidPtr,
asm_p,
(void (*) (RF_Raid_t *, void *))
rf_ContinueRaidAccess, desc);
if (val == 0) {
asm_p->flags |=
RF_ASM_FLAGS_RECON_BLOCKED;
} else {
suspended = RF_TRUE;
break;
}
} else {
if (rf_pssDebug) {
printf("raid%d: skipping"
" force/block because"
" already done, psid"
" %ld.\n",
desc->raidPtr->raidid,
(long) asm_p->stripeID);
}
}
} else {
if (rf_pssDebug) {
printf("raid%d: skipping force/block"
" because not write or not"
" under recon, psid %ld.\n",
desc->raidPtr->raidid,
(long) asm_p->stripeID);
}
}
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
if (suspended)
return (RF_TRUE);
}
desc->state++;
return (RF_FALSE);
}
/*
* The following three states create, execute, and post-process DAGs.
* The error recovery unit is a single DAG.
* By default, SelectAlgorithm creates an array of DAGs, one per parity stripe.
* In some tricky cases, multiple dags per stripe are created.
* - DAGs within a parity stripe are executed sequentially (arbitrary order).
* - DAGs for distinct parity stripes are executed concurrently.
*
* Repeat until all DAGs complete successfully -or- DAG selection fails.
*
* while !done
* create dag(s) (SelectAlgorithm)
* if dag
* execute dag (DispatchDAG)
* if dag successful
* done (SUCCESS)
* else
* !done (RETRY - start over with new dags)
* else
* done (FAIL)
*/
int
rf_State_CreateDAG(RF_RaidAccessDesc_t *desc)
{
RF_AccTraceEntry_t *tracerec = &desc->tracerec;
RF_Etimer_t timer;
RF_DagHeader_t *dag_h;
int i, selectStatus;
/*
* Generate a dag for the access, and fire it off. When the dag
* completes, we'll get re-invoked in the next state.
*/
RF_ETIMER_START(timer);
/* SelectAlgorithm returns one or more dags. */
selectStatus = rf_SelectAlgorithm(desc,
desc->flags | RF_DAG_SUPPRESS_LOCKS);
if (rf_printDAGsDebug)
for (i = 0; i < desc->numStripes; i++)
rf_PrintDAGList(desc->dagArray[i].dags);
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
/* Update time to create all dags. */
tracerec->specific.user.dag_create_us = RF_ETIMER_VAL_US(timer);
desc->status = 0; /* Good status. */
if (selectStatus) {
/* Failed to create a dag. */
/*
* This happens when there are too many faults or incomplete
* dag libraries.
*/
printf("[Failed to create a DAG]\n");
RF_PANIC();
} else {
/* Bind dags to desc. */
for (i = 0; i < desc->numStripes; i++) {
dag_h = desc->dagArray[i].dags;
while (dag_h) {
dag_h->bp = (struct buf *) desc->bp;
dag_h->tracerec = tracerec;
dag_h = dag_h->next;
}
}
desc->flags |= RF_DAG_DISPATCH_RETURNED;
desc->state++; /* Next state should be rf_State_ExecuteDAG. */
}
return RF_FALSE;
}
/*
* The access has an array of dagLists, one dagList per parity stripe.
* Fire the first DAG in each parity stripe (dagList).
* DAGs within a stripe (dagList) must be executed sequentially.
* - This preserves atomic parity update.
* DAGs for independents parity groups (stripes) are fired concurrently.
*/
int
rf_State_ExecuteDAG(RF_RaidAccessDesc_t *desc)
{
int i;
RF_DagHeader_t *dag_h;
RF_DagList_t *dagArray = desc->dagArray;
/*
* Next state is always rf_State_ProcessDAG. Important to do this
* before firing the first dag (it may finish before we leave this
* routine).
*/
desc->state++;
/*
* Sweep dag array, a stripe at a time, firing the first dag in each
* stripe.
*/
for (i = 0; i < desc->numStripes; i++) {
RF_ASSERT(dagArray[i].numDags > 0);
RF_ASSERT(dagArray[i].numDagsDone == 0);
RF_ASSERT(dagArray[i].numDagsFired == 0);
RF_ETIMER_START(dagArray[i].tracerec.timer);
/* Fire first dag in this stripe. */
dag_h = dagArray[i].dags;
RF_ASSERT(dag_h);
dagArray[i].numDagsFired++;
/*
* XXX Yet another case where we pass in a conflicting
* function pointer :-( XXX GO
*/
rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess,
&dagArray[i]);
}
/*
* The DAG will always call the callback, even if there was no
* blocking, so we are always suspended in this state.
*/
return RF_TRUE;
}
/*
* rf_State_ProcessDAG is entered when a dag completes.
* First, check that all DAGs in the access have completed.
* If not, fire as many DAGs as possible.
*/
int
rf_State_ProcessDAG(RF_RaidAccessDesc_t *desc)
{
RF_AccessStripeMapHeader_t *asmh = desc->asmap;
RF_Raid_t *raidPtr = desc->raidPtr;
RF_DagHeader_t *dag_h;
int i, j, done = RF_TRUE;
RF_DagList_t *dagArray = desc->dagArray;
RF_Etimer_t timer;
/* Check to see if this is the last dag. */
for (i = 0; i < desc->numStripes; i++)
if (dagArray[i].numDags != dagArray[i].numDagsDone)
done = RF_FALSE;
if (done) {
if (desc->status) {
/* A dag failed, retry. */
RF_ETIMER_START(timer);
/* Free all dags. */
for (i = 0; i < desc->numStripes; i++) {
rf_FreeDAG(desc->dagArray[i].dags);
}
rf_MarkFailuresInASMList(raidPtr, asmh);
/* Back up to rf_State_CreateDAG. */
desc->state = desc->state - 2;
return RF_FALSE;
} else {
/* Move on to rf_State_Cleanup. */
desc->state++;
}
return RF_FALSE;
} else {
/* More dags to execute. */
/* See if any are ready to be fired. If so, fire them. */
/*
* Don't fire the initial dag in a list, it's fired in
* rf_State_ExecuteDAG.
*/
for (i = 0; i < desc->numStripes; i++) {
if ((dagArray[i].numDagsDone < dagArray[i].numDags) &&
(dagArray[i].numDagsDone ==
dagArray[i].numDagsFired) &&
(dagArray[i].numDagsFired > 0)) {
RF_ETIMER_START(dagArray[i].tracerec.timer);
/* Fire next dag in this stripe. */
/*
* First, skip to next dag awaiting execution.
*/
dag_h = dagArray[i].dags;
for (j = 0; j < dagArray[i].numDagsDone; j++)
dag_h = dag_h->next;
dagArray[i].numDagsFired++;
/*
* XXX And again we pass a different function
* pointer... GO
*/
rf_DispatchDAG(dag_h, (void (*) (void *))
rf_ContinueDagAccess, &dagArray[i]);
}
}
return RF_TRUE;
}
}
/* Only make it this far if all dags complete successfully. */
int
rf_State_Cleanup(RF_RaidAccessDesc_t *desc)
{
RF_AccTraceEntry_t *tracerec = &desc->tracerec;
RF_AccessStripeMapHeader_t *asmh = desc->asmap;
RF_Raid_t *raidPtr = desc->raidPtr;
RF_AccessStripeMap_t *asm_p;
RF_DagHeader_t *dag_h;
RF_Etimer_t timer;
int i;
desc->state++;
timer = tracerec->timer;
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.dag_retry_us = RF_ETIMER_VAL_US(timer);
/* The RAID I/O is complete. Clean up. */
tracerec->specific.user.dag_retry_us = 0;
RF_ETIMER_START(timer);
if (desc->flags & RF_DAG_RETURN_DAG) {
/* Copy dags into paramDAG. */
*(desc->paramDAG) = desc->dagArray[0].dags;
dag_h = *(desc->paramDAG);
for (i = 1; i < desc->numStripes; i++) {
/* Concatenate dags from remaining stripes. */
RF_ASSERT(dag_h);
while (dag_h->next)
dag_h = dag_h->next;
dag_h->next = desc->dagArray[i].dags;
}
} else {
/* Free all dags. */
for (i = 0; i < desc->numStripes; i++) {
rf_FreeDAG(desc->dagArray[i].dags);
}
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.cleanup_us = RF_ETIMER_VAL_US(timer);
RF_ETIMER_START(timer);
if (!(raidPtr->Layout.map->flags & RF_NO_STRIPE_LOCKS)) {
for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
if (!rf_suppressLocksAndLargeWrites &&
asm_p->parityInfo &&
!(desc->flags & RF_DAG_SUPPRESS_LOCKS)) {
RF_ASSERT_VALID_LOCKREQ(&asm_p->lockReqDesc);
rf_ReleaseStripeLock(raidPtr->lockTable,
asm_p->stripeID, &asm_p->lockReqDesc);
}
if (asm_p->flags & RF_ASM_FLAGS_RECON_BLOCKED) {
rf_UnblockRecon(raidPtr, asm_p);
}
}
}
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
RF_ETIMER_START(timer);
if (desc->flags & RF_DAG_RETURN_ASM)
*(desc->paramASM) = asmh;
else
rf_FreeAccessStripeMap(asmh);
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
tracerec->specific.user.cleanup_us += RF_ETIMER_VAL_US(timer);
RF_ETIMER_STOP(desc->timer);
RF_ETIMER_EVAL(desc->timer);
timer = desc->tracerec.tot_timer;
RF_ETIMER_STOP(timer);
RF_ETIMER_EVAL(timer);
desc->tracerec.total_us = RF_ETIMER_VAL_US(timer);
rf_LogTraceRec(raidPtr, tracerec);
desc->flags |= RF_DAG_ACCESS_COMPLETE;
return RF_FALSE;
}
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