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rf_states.c revision 1.49.14.1
      1  1.49.14.1  jdolecek /*	$NetBSD: rf_states.c,v 1.49.14.1 2017/12/03 11:37:31 jdolecek Exp $	*/
      2        1.1     oster /*
      3        1.1     oster  * Copyright (c) 1995 Carnegie-Mellon University.
      4        1.1     oster  * All rights reserved.
      5        1.1     oster  *
      6        1.1     oster  * Author: Mark Holland, William V. Courtright II, Robby Findler
      7        1.1     oster  *
      8        1.1     oster  * Permission to use, copy, modify and distribute this software and
      9        1.1     oster  * its documentation is hereby granted, provided that both the copyright
     10        1.1     oster  * notice and this permission notice appear in all copies of the
     11        1.1     oster  * software, derivative works or modified versions, and any portions
     12        1.1     oster  * thereof, and that both notices appear in supporting documentation.
     13        1.1     oster  *
     14        1.1     oster  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15        1.1     oster  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     16        1.1     oster  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17        1.1     oster  *
     18        1.1     oster  * Carnegie Mellon requests users of this software to return to
     19        1.1     oster  *
     20        1.1     oster  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21        1.1     oster  *  School of Computer Science
     22        1.1     oster  *  Carnegie Mellon University
     23        1.1     oster  *  Pittsburgh PA 15213-3890
     24        1.1     oster  *
     25        1.1     oster  * any improvements or extensions that they make and grant Carnegie the
     26        1.1     oster  * rights to redistribute these changes.
     27        1.1     oster  */
     28       1.16     lukem 
     29       1.16     lukem #include <sys/cdefs.h>
     30  1.49.14.1  jdolecek __KERNEL_RCSID(0, "$NetBSD: rf_states.c,v 1.49.14.1 2017/12/03 11:37:31 jdolecek Exp $");
     31        1.1     oster 
     32        1.1     oster #include <sys/errno.h>
     33        1.1     oster 
     34        1.1     oster #include "rf_archs.h"
     35        1.1     oster #include "rf_threadstuff.h"
     36        1.1     oster #include "rf_raid.h"
     37        1.1     oster #include "rf_dag.h"
     38        1.1     oster #include "rf_desc.h"
     39        1.1     oster #include "rf_aselect.h"
     40        1.1     oster #include "rf_general.h"
     41        1.1     oster #include "rf_states.h"
     42        1.1     oster #include "rf_dagutils.h"
     43        1.1     oster #include "rf_driver.h"
     44        1.1     oster #include "rf_engine.h"
     45        1.1     oster #include "rf_map.h"
     46        1.1     oster #include "rf_etimer.h"
     47       1.10     oster #include "rf_kintf.h"
     48       1.44       jld #include "rf_paritymap.h"
     49        1.1     oster 
     50       1.19     oster #ifndef RF_DEBUG_STATES
     51       1.19     oster #define RF_DEBUG_STATES 0
     52       1.19     oster #endif
     53       1.19     oster 
     54        1.1     oster /* prototypes for some of the available states.
     55        1.1     oster 
     56        1.1     oster    States must:
     57        1.1     oster 
     58        1.1     oster      - not block.
     59        1.1     oster 
     60        1.1     oster      - either schedule rf_ContinueRaidAccess as a callback and return
     61        1.1     oster        RF_TRUE, or complete all of their work and return RF_FALSE.
     62        1.1     oster 
     63        1.1     oster      - increment desc->state when they have finished their work.
     64        1.1     oster */
     65        1.1     oster 
     66       1.19     oster #if RF_DEBUG_STATES
     67        1.6     oster static char *
     68        1.6     oster StateName(RF_AccessState_t state)
     69        1.1     oster {
     70        1.6     oster 	switch (state) {
     71        1.6     oster 		case rf_QuiesceState:return "QuiesceState";
     72        1.6     oster 	case rf_MapState:
     73        1.6     oster 		return "MapState";
     74        1.6     oster 	case rf_LockState:
     75        1.6     oster 		return "LockState";
     76        1.6     oster 	case rf_CreateDAGState:
     77        1.6     oster 		return "CreateDAGState";
     78        1.6     oster 	case rf_ExecuteDAGState:
     79        1.6     oster 		return "ExecuteDAGState";
     80        1.6     oster 	case rf_ProcessDAGState:
     81        1.6     oster 		return "ProcessDAGState";
     82        1.6     oster 	case rf_CleanupState:
     83        1.6     oster 		return "CleanupState";
     84        1.6     oster 	case rf_LastState:
     85        1.6     oster 		return "LastState";
     86        1.6     oster 	case rf_IncrAccessesCountState:
     87        1.6     oster 		return "IncrAccessesCountState";
     88        1.6     oster 	case rf_DecrAccessesCountState:
     89        1.6     oster 		return "DecrAccessesCountState";
     90        1.6     oster 	default:
     91        1.6     oster 		return "!!! UnnamedState !!!";
     92        1.6     oster 	}
     93        1.6     oster }
     94       1.19     oster #endif
     95        1.6     oster 
     96       1.38     perry void
     97       1.22     oster rf_ContinueRaidAccess(RF_RaidAccessDesc_t *desc)
     98        1.6     oster {
     99        1.6     oster 	int     suspended = RF_FALSE;
    100        1.6     oster 	int     current_state_index = desc->state;
    101        1.6     oster 	RF_AccessState_t current_state = desc->states[current_state_index];
    102       1.19     oster #if RF_DEBUG_STATES
    103       1.12     oster 	int     unit = desc->raidPtr->raidid;
    104       1.19     oster #endif
    105        1.6     oster 
    106        1.6     oster 	do {
    107        1.6     oster 
    108        1.6     oster 		current_state_index = desc->state;
    109        1.6     oster 		current_state = desc->states[current_state_index];
    110        1.6     oster 
    111        1.6     oster 		switch (current_state) {
    112        1.6     oster 
    113        1.6     oster 		case rf_QuiesceState:
    114        1.6     oster 			suspended = rf_State_Quiesce(desc);
    115        1.6     oster 			break;
    116        1.6     oster 		case rf_IncrAccessesCountState:
    117        1.6     oster 			suspended = rf_State_IncrAccessCount(desc);
    118        1.6     oster 			break;
    119        1.6     oster 		case rf_MapState:
    120        1.6     oster 			suspended = rf_State_Map(desc);
    121        1.6     oster 			break;
    122        1.6     oster 		case rf_LockState:
    123        1.6     oster 			suspended = rf_State_Lock(desc);
    124        1.6     oster 			break;
    125        1.6     oster 		case rf_CreateDAGState:
    126        1.6     oster 			suspended = rf_State_CreateDAG(desc);
    127        1.6     oster 			break;
    128        1.6     oster 		case rf_ExecuteDAGState:
    129        1.6     oster 			suspended = rf_State_ExecuteDAG(desc);
    130        1.6     oster 			break;
    131        1.6     oster 		case rf_ProcessDAGState:
    132        1.6     oster 			suspended = rf_State_ProcessDAG(desc);
    133        1.6     oster 			break;
    134        1.6     oster 		case rf_CleanupState:
    135        1.6     oster 			suspended = rf_State_Cleanup(desc);
    136        1.6     oster 			break;
    137        1.6     oster 		case rf_DecrAccessesCountState:
    138        1.6     oster 			suspended = rf_State_DecrAccessCount(desc);
    139        1.6     oster 			break;
    140        1.6     oster 		case rf_LastState:
    141        1.6     oster 			suspended = rf_State_LastState(desc);
    142        1.6     oster 			break;
    143        1.6     oster 		}
    144        1.6     oster 
    145       1.23     oster 		/* after this point, we cannot dereference desc since
    146       1.23     oster 		 * desc may have been freed. desc is only freed in
    147       1.23     oster 		 * LastState, so if we renter this function or loop
    148       1.23     oster 		 * back up, desc should be valid. */
    149        1.6     oster 
    150       1.19     oster #if RF_DEBUG_STATES
    151        1.6     oster 		if (rf_printStatesDebug) {
    152       1.12     oster 			printf("raid%d: State: %-24s StateIndex: %3i desc: 0x%ld %s\n",
    153       1.38     perry 			       unit, StateName(current_state),
    154       1.12     oster 			       current_state_index, (long) desc,
    155       1.12     oster 			       suspended ? "callback scheduled" : "looping");
    156        1.6     oster 		}
    157       1.19     oster #endif
    158        1.6     oster 	} while (!suspended && current_state != rf_LastState);
    159        1.6     oster 
    160        1.6     oster 	return;
    161        1.6     oster }
    162        1.6     oster 
    163        1.6     oster 
    164       1.38     perry void
    165       1.22     oster rf_ContinueDagAccess(RF_DagList_t *dagList)
    166        1.6     oster {
    167       1.27     oster #if RF_ACC_TRACE > 0
    168        1.6     oster 	RF_AccTraceEntry_t *tracerec = &(dagList->desc->tracerec);
    169       1.28     oster 	RF_Etimer_t timer;
    170       1.27     oster #endif
    171        1.6     oster 	RF_RaidAccessDesc_t *desc;
    172        1.6     oster 	RF_DagHeader_t *dag_h;
    173        1.6     oster 	int     i;
    174        1.6     oster 
    175        1.6     oster 	desc = dagList->desc;
    176        1.6     oster 
    177       1.27     oster #if RF_ACC_TRACE > 0
    178        1.6     oster 	timer = tracerec->timer;
    179        1.6     oster 	RF_ETIMER_STOP(timer);
    180        1.6     oster 	RF_ETIMER_EVAL(timer);
    181        1.6     oster 	tracerec->specific.user.exec_us = RF_ETIMER_VAL_US(timer);
    182        1.6     oster 	RF_ETIMER_START(tracerec->timer);
    183       1.27     oster #endif
    184        1.6     oster 
    185        1.6     oster 	/* skip to dag which just finished */
    186        1.6     oster 	dag_h = dagList->dags;
    187        1.6     oster 	for (i = 0; i < dagList->numDagsDone; i++) {
    188        1.6     oster 		dag_h = dag_h->next;
    189        1.6     oster 	}
    190        1.6     oster 
    191        1.6     oster 	/* check to see if retry is required */
    192        1.6     oster 	if (dag_h->status == rf_rollBackward) {
    193       1.23     oster 		/* when a dag fails, mark desc status as bad and allow
    194       1.23     oster 		 * all other dags in the desc to execute to
    195       1.23     oster 		 * completion.  then, free all dags and start over */
    196        1.6     oster 		desc->status = 1;	/* bad status */
    197       1.25     oster #if 0
    198       1.25     oster 		printf("raid%d: DAG failure: %c addr 0x%lx "
    199       1.25     oster 		       "(%ld) nblk 0x%x (%d) buf 0x%lx state %d\n",
    200       1.38     perry 		       desc->raidPtr->raidid, desc->type,
    201       1.23     oster 		       (long) desc->raidAddress,
    202       1.23     oster 		       (long) desc->raidAddress, (int) desc->numBlocks,
    203       1.38     perry 		       (int) desc->numBlocks,
    204       1.25     oster 		       (unsigned long) (desc->bufPtr), desc->state);
    205       1.25     oster #endif
    206        1.6     oster 	}
    207        1.6     oster 	dagList->numDagsDone++;
    208        1.6     oster 	rf_ContinueRaidAccess(desc);
    209        1.6     oster }
    210        1.6     oster 
    211       1.38     perry int
    212       1.22     oster rf_State_LastState(RF_RaidAccessDesc_t *desc)
    213        1.1     oster {
    214        1.6     oster 	void    (*callbackFunc) (RF_CBParam_t) = desc->callbackFunc;
    215        1.6     oster 	RF_CBParam_t callbackArg;
    216        1.2  drochner 
    217        1.6     oster 	callbackArg.p = desc->callbackArg;
    218       1.38     perry 
    219        1.8     oster 	/*
    220       1.48       mrg 	 * We don't support non-async IO.
    221        1.8     oster 	 */
    222       1.48       mrg 	KASSERT(desc->async_flag);
    223       1.15     oster 
    224       1.15     oster 	/*
    225       1.44       jld 	 * The parity_map hook has to go here, because the iodone
    226       1.44       jld 	 * callback goes straight into the kintf layer.
    227       1.44       jld 	 */
    228       1.44       jld 	if (desc->raidPtr->parity_map != NULL &&
    229       1.44       jld 	    desc->type == RF_IO_TYPE_WRITE)
    230       1.44       jld 		rf_paritymap_end(desc->raidPtr->parity_map,
    231       1.44       jld 		    desc->raidAddress, desc->numBlocks);
    232       1.44       jld 
    233  1.49.14.1  jdolecek 	/* printf("Calling raiddone on 0x%x\n",desc->bp); */
    234  1.49.14.1  jdolecek 	raiddone(desc->raidPtr, desc->bp); /* access came through ioctl */
    235        1.3  explorer 
    236        1.6     oster 	if (callbackFunc)
    237        1.6     oster 		callbackFunc(callbackArg);
    238        1.6     oster 	rf_FreeRaidAccDesc(desc);
    239        1.6     oster 
    240        1.6     oster 	return RF_FALSE;
    241        1.6     oster }
    242        1.6     oster 
    243       1.38     perry int
    244       1.22     oster rf_State_IncrAccessCount(RF_RaidAccessDesc_t *desc)
    245        1.6     oster {
    246        1.6     oster 	RF_Raid_t *raidPtr;
    247        1.6     oster 
    248        1.6     oster 	raidPtr = desc->raidPtr;
    249        1.6     oster 	/* Bummer. We have to do this to be 100% safe w.r.t. the increment
    250        1.6     oster 	 * below */
    251       1.47       mrg 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
    252        1.6     oster 	raidPtr->accs_in_flight++;	/* used to detect quiescence */
    253       1.47       mrg 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
    254        1.6     oster 
    255        1.6     oster 	desc->state++;
    256        1.6     oster 	return RF_FALSE;
    257        1.6     oster }
    258        1.6     oster 
    259       1.38     perry int
    260       1.22     oster rf_State_DecrAccessCount(RF_RaidAccessDesc_t *desc)
    261        1.6     oster {
    262        1.6     oster 	RF_Raid_t *raidPtr;
    263        1.6     oster 
    264        1.6     oster 	raidPtr = desc->raidPtr;
    265        1.6     oster 
    266       1.47       mrg 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
    267        1.6     oster 	raidPtr->accs_in_flight--;
    268        1.6     oster 	if (raidPtr->accesses_suspended && raidPtr->accs_in_flight == 0) {
    269       1.20     oster 		rf_SignalQuiescenceLock(raidPtr);
    270        1.6     oster 	}
    271       1.47       mrg 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
    272        1.6     oster 
    273        1.6     oster 	desc->state++;
    274        1.6     oster 	return RF_FALSE;
    275        1.6     oster }
    276        1.6     oster 
    277       1.38     perry int
    278       1.22     oster rf_State_Quiesce(RF_RaidAccessDesc_t *desc)
    279        1.6     oster {
    280       1.27     oster #if RF_ACC_TRACE > 0
    281        1.6     oster 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
    282        1.6     oster 	RF_Etimer_t timer;
    283       1.27     oster #endif
    284       1.31     oster 	RF_CallbackDesc_t *cb;
    285       1.31     oster 	RF_Raid_t *raidPtr;
    286        1.6     oster 	int     suspended = RF_FALSE;
    287       1.31     oster 	int need_cb, used_cb;
    288        1.6     oster 
    289        1.6     oster 	raidPtr = desc->raidPtr;
    290        1.6     oster 
    291       1.27     oster #if RF_ACC_TRACE > 0
    292        1.6     oster 	RF_ETIMER_START(timer);
    293        1.6     oster 	RF_ETIMER_START(desc->timer);
    294       1.27     oster #endif
    295        1.6     oster 
    296       1.31     oster 	need_cb = 0;
    297       1.31     oster 	used_cb = 0;
    298       1.31     oster 	cb = NULL;
    299       1.31     oster 
    300       1.47       mrg 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
    301       1.31     oster 	/* Do an initial check to see if we might need a callback structure */
    302        1.6     oster 	if (raidPtr->accesses_suspended) {
    303       1.31     oster 		need_cb = 1;
    304       1.31     oster 	}
    305       1.47       mrg 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
    306       1.31     oster 
    307       1.31     oster 	if (need_cb) {
    308       1.31     oster 		/* create a callback if we might need it...
    309       1.31     oster 		   and we likely do. */
    310        1.6     oster 		cb = rf_AllocCallbackDesc();
    311       1.31     oster 	}
    312       1.23     oster 
    313       1.47       mrg 	rf_lock_mutex2(raidPtr->access_suspend_mutex);
    314       1.31     oster 	if (raidPtr->accesses_suspended) {
    315        1.6     oster 		cb->callbackFunc = (void (*) (RF_CBParam_t)) rf_ContinueRaidAccess;
    316        1.6     oster 		cb->callbackArg.p = (void *) desc;
    317        1.6     oster 		cb->next = raidPtr->quiesce_wait_list;
    318        1.6     oster 		raidPtr->quiesce_wait_list = cb;
    319        1.6     oster 		suspended = RF_TRUE;
    320       1.31     oster 		used_cb = 1;
    321        1.6     oster 	}
    322       1.47       mrg 	rf_unlock_mutex2(raidPtr->access_suspend_mutex);
    323        1.6     oster 
    324       1.31     oster 	if ((need_cb == 1) && (used_cb == 0)) {
    325       1.31     oster 		rf_FreeCallbackDesc(cb);
    326       1.31     oster 	}
    327       1.31     oster 
    328       1.27     oster #if RF_ACC_TRACE > 0
    329        1.6     oster 	RF_ETIMER_STOP(timer);
    330        1.6     oster 	RF_ETIMER_EVAL(timer);
    331        1.6     oster 	tracerec->specific.user.suspend_ovhd_us += RF_ETIMER_VAL_US(timer);
    332       1.27     oster #endif
    333        1.6     oster 
    334       1.18     oster #if RF_DEBUG_QUIESCE
    335        1.6     oster 	if (suspended && rf_quiesceDebug)
    336        1.6     oster 		printf("Stalling access due to quiescence lock\n");
    337       1.18     oster #endif
    338        1.6     oster 	desc->state++;
    339        1.6     oster 	return suspended;
    340        1.6     oster }
    341        1.6     oster 
    342       1.38     perry int
    343       1.22     oster rf_State_Map(RF_RaidAccessDesc_t *desc)
    344        1.6     oster {
    345        1.6     oster 	RF_Raid_t *raidPtr = desc->raidPtr;
    346       1.27     oster #if RF_ACC_TRACE > 0
    347        1.6     oster 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
    348        1.6     oster 	RF_Etimer_t timer;
    349        1.6     oster 
    350        1.6     oster 	RF_ETIMER_START(timer);
    351       1.27     oster #endif
    352        1.6     oster 
    353        1.6     oster 	if (!(desc->asmap = rf_MapAccess(raidPtr, desc->raidAddress, desc->numBlocks,
    354        1.6     oster 		    desc->bufPtr, RF_DONT_REMAP)))
    355        1.6     oster 		RF_PANIC();
    356        1.6     oster 
    357       1.27     oster #if RF_ACC_TRACE > 0
    358        1.6     oster 	RF_ETIMER_STOP(timer);
    359        1.6     oster 	RF_ETIMER_EVAL(timer);
    360        1.6     oster 	tracerec->specific.user.map_us = RF_ETIMER_VAL_US(timer);
    361       1.27     oster #endif
    362        1.6     oster 
    363        1.6     oster 	desc->state++;
    364        1.6     oster 	return RF_FALSE;
    365        1.6     oster }
    366        1.6     oster 
    367       1.38     perry int
    368       1.22     oster rf_State_Lock(RF_RaidAccessDesc_t *desc)
    369        1.6     oster {
    370       1.27     oster #if RF_ACC_TRACE > 0
    371        1.6     oster 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
    372       1.28     oster 	RF_Etimer_t timer;
    373       1.27     oster #endif
    374        1.6     oster 	RF_Raid_t *raidPtr = desc->raidPtr;
    375        1.6     oster 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
    376        1.6     oster 	RF_AccessStripeMap_t *asm_p;
    377       1.32     oster 	RF_StripeNum_t lastStripeID = -1;
    378        1.6     oster 	int     suspended = RF_FALSE;
    379        1.6     oster 
    380       1.27     oster #if RF_ACC_TRACE > 0
    381        1.6     oster 	RF_ETIMER_START(timer);
    382       1.27     oster #endif
    383       1.38     perry 
    384       1.32     oster 	/* acquire each lock that we don't already hold */
    385       1.32     oster 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
    386       1.32     oster 		RF_ASSERT(RF_IO_IS_R_OR_W(desc->type));
    387       1.32     oster 		if (!rf_suppressLocksAndLargeWrites &&
    388       1.32     oster 		    asm_p->parityInfo &&
    389       1.32     oster 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS) &&
    390       1.32     oster 		    !(asm_p->flags & RF_ASM_FLAGS_LOCK_TRIED)) {
    391       1.32     oster 			asm_p->flags |= RF_ASM_FLAGS_LOCK_TRIED;
    392       1.23     oster 				/* locks must be acquired hierarchically */
    393       1.32     oster 			RF_ASSERT(asm_p->stripeID > lastStripeID);
    394       1.32     oster 			lastStripeID = asm_p->stripeID;
    395       1.38     perry 
    396       1.32     oster 			RF_INIT_LOCK_REQ_DESC(asm_p->lockReqDesc, desc->type,
    397       1.32     oster 					      (void (*) (struct buf *)) rf_ContinueRaidAccess, desc, asm_p,
    398       1.32     oster 					      raidPtr->Layout.dataSectorsPerStripe);
    399       1.32     oster 			if (rf_AcquireStripeLock(raidPtr->lockTable, asm_p->stripeID,
    400       1.32     oster 						 &asm_p->lockReqDesc)) {
    401       1.32     oster 				suspended = RF_TRUE;
    402       1.32     oster 				break;
    403       1.32     oster 			}
    404       1.32     oster 		}
    405       1.32     oster 		if (desc->type == RF_IO_TYPE_WRITE &&
    406       1.32     oster 		    raidPtr->status == rf_rs_reconstructing) {
    407       1.32     oster 			if (!(asm_p->flags & RF_ASM_FLAGS_FORCE_TRIED)) {
    408       1.32     oster 				int     val;
    409       1.38     perry 
    410       1.32     oster 				asm_p->flags |= RF_ASM_FLAGS_FORCE_TRIED;
    411       1.32     oster 				val = rf_ForceOrBlockRecon(raidPtr, asm_p,
    412       1.32     oster 							   (void (*) (RF_Raid_t *, void *)) rf_ContinueRaidAccess, desc);
    413       1.32     oster 				if (val == 0) {
    414       1.32     oster 					asm_p->flags |= RF_ASM_FLAGS_RECON_BLOCKED;
    415       1.32     oster 				} else {
    416        1.6     oster 					suspended = RF_TRUE;
    417        1.6     oster 					break;
    418        1.6     oster 				}
    419        1.6     oster 			} else {
    420       1.29     oster #if RF_DEBUG_PSS > 0
    421        1.6     oster 				if (rf_pssDebug) {
    422       1.32     oster 					printf("raid%d: skipping force/block because already done, psid %ld\n",
    423       1.38     perry 					       desc->raidPtr->raidid,
    424       1.13     oster 					       (long) asm_p->stripeID);
    425        1.6     oster 				}
    426       1.29     oster #endif
    427        1.6     oster 			}
    428       1.32     oster 		} else {
    429       1.32     oster #if RF_DEBUG_PSS > 0
    430       1.32     oster 			if (rf_pssDebug) {
    431       1.32     oster 				printf("raid%d: skipping force/block because not write or not under recon, psid %ld\n",
    432       1.38     perry 				       desc->raidPtr->raidid,
    433       1.32     oster 				       (long) asm_p->stripeID);
    434       1.32     oster 			}
    435       1.32     oster #endif
    436        1.6     oster 		}
    437       1.32     oster 	}
    438       1.27     oster #if RF_ACC_TRACE > 0
    439       1.32     oster 	RF_ETIMER_STOP(timer);
    440       1.32     oster 	RF_ETIMER_EVAL(timer);
    441       1.32     oster 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
    442       1.27     oster #endif
    443       1.32     oster 	if (suspended)
    444       1.32     oster 		return (RF_TRUE);
    445       1.32     oster 
    446        1.6     oster 	desc->state++;
    447        1.6     oster 	return (RF_FALSE);
    448        1.1     oster }
    449        1.1     oster /*
    450        1.1     oster  * the following three states create, execute, and post-process dags
    451        1.1     oster  * the error recovery unit is a single dag.
    452        1.1     oster  * by default, SelectAlgorithm creates an array of dags, one per parity stripe
    453        1.1     oster  * in some tricky cases, multiple dags per stripe are created
    454        1.1     oster  *   - dags within a parity stripe are executed sequentially (arbitrary order)
    455        1.1     oster  *   - dags for distinct parity stripes are executed concurrently
    456        1.1     oster  *
    457        1.1     oster  * repeat until all dags complete successfully -or- dag selection fails
    458        1.1     oster  *
    459        1.1     oster  * while !done
    460        1.1     oster  *   create dag(s) (SelectAlgorithm)
    461        1.1     oster  *   if dag
    462        1.1     oster  *     execute dag (DispatchDAG)
    463        1.1     oster  *     if dag successful
    464        1.1     oster  *       done (SUCCESS)
    465        1.1     oster  *     else
    466        1.1     oster  *       !done (RETRY - start over with new dags)
    467        1.1     oster  *   else
    468        1.1     oster  *     done (FAIL)
    469        1.1     oster  */
    470       1.38     perry int
    471       1.22     oster rf_State_CreateDAG(RF_RaidAccessDesc_t *desc)
    472        1.1     oster {
    473       1.27     oster #if RF_ACC_TRACE > 0
    474        1.6     oster 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
    475        1.6     oster 	RF_Etimer_t timer;
    476       1.27     oster #endif
    477        1.6     oster 	RF_DagHeader_t *dag_h;
    478       1.26     oster 	RF_DagList_t *dagList;
    479       1.25     oster 	struct buf *bp;
    480        1.6     oster 	int     i, selectStatus;
    481        1.6     oster 
    482        1.6     oster 	/* generate a dag for the access, and fire it off.  When the dag
    483        1.6     oster 	 * completes, we'll get re-invoked in the next state. */
    484       1.27     oster #if RF_ACC_TRACE > 0
    485        1.6     oster 	RF_ETIMER_START(timer);
    486       1.27     oster #endif
    487        1.6     oster 	/* SelectAlgorithm returns one or more dags */
    488        1.6     oster 	selectStatus = rf_SelectAlgorithm(desc, desc->flags | RF_DAG_SUPPRESS_LOCKS);
    489       1.17     oster #if RF_DEBUG_VALIDATE_DAG
    490       1.26     oster 	if (rf_printDAGsDebug) {
    491       1.26     oster 		dagList = desc->dagList;
    492       1.26     oster 		for (i = 0; i < desc->numStripes; i++) {
    493       1.42     oster 			rf_PrintDAGList(dagList->dags);
    494       1.26     oster 			dagList = dagList->next;
    495       1.26     oster 		}
    496       1.26     oster 	}
    497       1.17     oster #endif /* RF_DEBUG_VALIDATE_DAG */
    498       1.27     oster #if RF_ACC_TRACE > 0
    499        1.6     oster 	RF_ETIMER_STOP(timer);
    500        1.6     oster 	RF_ETIMER_EVAL(timer);
    501        1.6     oster 	/* update time to create all dags */
    502        1.6     oster 	tracerec->specific.user.dag_create_us = RF_ETIMER_VAL_US(timer);
    503       1.27     oster #endif
    504        1.6     oster 
    505        1.6     oster 	desc->status = 0;	/* good status */
    506        1.6     oster 
    507       1.36     oster 	if (selectStatus || (desc->numRetries > RF_RETRY_THRESHOLD)) {
    508        1.6     oster 		/* failed to create a dag */
    509        1.6     oster 		/* this happens when there are too many faults or incomplete
    510        1.6     oster 		 * dag libraries */
    511       1.36     oster 		if (selectStatus) {
    512       1.36     oster 			printf("raid%d: failed to create a dag. "
    513       1.38     perry 			       "Too many component failures.\n",
    514       1.36     oster 			       desc->raidPtr->raidid);
    515       1.36     oster 		} else {
    516       1.36     oster 			printf("raid%d: IO failed after %d retries.\n",
    517       1.36     oster 			       desc->raidPtr->raidid, RF_RETRY_THRESHOLD);
    518       1.36     oster 		}
    519       1.25     oster 
    520       1.38     perry 		desc->status = 1; /* bad status */
    521       1.25     oster 		/* skip straight to rf_State_Cleanup() */
    522       1.25     oster 		desc->state = rf_CleanupState;
    523       1.25     oster 		bp = (struct buf *)desc->bp;
    524       1.25     oster 		bp->b_error = EIO;
    525       1.43     oster 		bp->b_resid = bp->b_bcount;
    526        1.6     oster 	} else {
    527        1.6     oster 		/* bind dags to desc */
    528       1.26     oster 		dagList = desc->dagList;
    529        1.6     oster 		for (i = 0; i < desc->numStripes; i++) {
    530       1.26     oster 			dag_h = dagList->dags;
    531        1.6     oster 			while (dag_h) {
    532        1.6     oster 				dag_h->bp = (struct buf *) desc->bp;
    533       1.27     oster #if RF_ACC_TRACE > 0
    534        1.6     oster 				dag_h->tracerec = tracerec;
    535       1.27     oster #endif
    536        1.6     oster 				dag_h = dag_h->next;
    537        1.6     oster 			}
    538       1.26     oster 			dagList = dagList->next;
    539        1.6     oster 		}
    540        1.6     oster 		desc->flags |= RF_DAG_DISPATCH_RETURNED;
    541        1.6     oster 		desc->state++;	/* next state should be rf_State_ExecuteDAG */
    542        1.6     oster 	}
    543        1.6     oster 	return RF_FALSE;
    544        1.1     oster }
    545        1.1     oster 
    546        1.1     oster 
    547        1.1     oster 
    548       1.26     oster /* the access has an list of dagLists, one dagList per parity stripe.
    549        1.1     oster  * fire the first dag in each parity stripe (dagList).
    550        1.1     oster  * dags within a stripe (dagList) must be executed sequentially
    551        1.1     oster  *  - this preserves atomic parity update
    552        1.1     oster  * dags for independents parity groups (stripes) are fired concurrently */
    553        1.1     oster 
    554       1.38     perry int
    555       1.22     oster rf_State_ExecuteDAG(RF_RaidAccessDesc_t *desc)
    556        1.1     oster {
    557        1.6     oster 	int     i;
    558        1.6     oster 	RF_DagHeader_t *dag_h;
    559       1.26     oster 	RF_DagList_t *dagList;
    560        1.6     oster 
    561       1.23     oster 	/* next state is always rf_State_ProcessDAG important to do
    562       1.23     oster 	 * this before firing the first dag (it may finish before we
    563       1.23     oster 	 * leave this routine) */
    564        1.6     oster 	desc->state++;
    565        1.6     oster 
    566       1.23     oster 	/* sweep dag array, a stripe at a time, firing the first dag
    567       1.23     oster 	 * in each stripe */
    568       1.26     oster 	dagList = desc->dagList;
    569        1.6     oster 	for (i = 0; i < desc->numStripes; i++) {
    570       1.26     oster 		RF_ASSERT(dagList->numDags > 0);
    571       1.26     oster 		RF_ASSERT(dagList->numDagsDone == 0);
    572       1.26     oster 		RF_ASSERT(dagList->numDagsFired == 0);
    573       1.27     oster #if RF_ACC_TRACE > 0
    574       1.26     oster 		RF_ETIMER_START(dagList->tracerec.timer);
    575       1.27     oster #endif
    576        1.6     oster 		/* fire first dag in this stripe */
    577       1.26     oster 		dag_h = dagList->dags;
    578        1.6     oster 		RF_ASSERT(dag_h);
    579       1.26     oster 		dagList->numDagsFired++;
    580       1.26     oster 		rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess, dagList);
    581       1.26     oster 		dagList = dagList->next;
    582        1.6     oster 	}
    583        1.6     oster 
    584        1.6     oster 	/* the DAG will always call the callback, even if there was no
    585        1.6     oster 	 * blocking, so we are always suspended in this state */
    586        1.6     oster 	return RF_TRUE;
    587        1.1     oster }
    588        1.1     oster 
    589        1.1     oster 
    590        1.1     oster 
    591        1.1     oster /* rf_State_ProcessDAG is entered when a dag completes.
    592        1.1     oster  * first, check to all dags in the access have completed
    593        1.1     oster  * if not, fire as many dags as possible */
    594        1.1     oster 
    595       1.38     perry int
    596       1.22     oster rf_State_ProcessDAG(RF_RaidAccessDesc_t *desc)
    597        1.1     oster {
    598        1.6     oster 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
    599        1.6     oster 	RF_Raid_t *raidPtr = desc->raidPtr;
    600        1.6     oster 	RF_DagHeader_t *dag_h;
    601        1.6     oster 	int     i, j, done = RF_TRUE;
    602       1.26     oster 	RF_DagList_t *dagList, *temp;
    603        1.6     oster 
    604        1.6     oster 	/* check to see if this is the last dag */
    605       1.26     oster 	dagList = desc->dagList;
    606       1.26     oster 	for (i = 0; i < desc->numStripes; i++) {
    607       1.26     oster 		if (dagList->numDags != dagList->numDagsDone)
    608        1.6     oster 			done = RF_FALSE;
    609       1.26     oster 		dagList = dagList->next;
    610       1.26     oster 	}
    611        1.6     oster 
    612        1.6     oster 	if (done) {
    613        1.6     oster 		if (desc->status) {
    614        1.6     oster 			/* a dag failed, retry */
    615        1.6     oster 			/* free all dags */
    616       1.26     oster 			dagList = desc->dagList;
    617        1.6     oster 			for (i = 0; i < desc->numStripes; i++) {
    618       1.26     oster 				rf_FreeDAG(dagList->dags);
    619       1.26     oster 				temp = dagList;
    620       1.35     oster 				dagList = dagList->next;
    621       1.34     oster 				rf_FreeDAGList(temp);
    622        1.6     oster 			}
    623       1.37     oster 			desc->dagList = NULL;
    624       1.37     oster 
    625        1.6     oster 			rf_MarkFailuresInASMList(raidPtr, asmh);
    626       1.36     oster 
    627       1.36     oster 			/* note the retry so that we'll bail in
    628       1.36     oster 			   rf_State_CreateDAG() once we've retired
    629       1.36     oster 			   the IO RF_RETRY_THRESHOLD times */
    630       1.36     oster 
    631       1.36     oster 			desc->numRetries++;
    632       1.36     oster 
    633        1.6     oster 			/* back up to rf_State_CreateDAG */
    634        1.6     oster 			desc->state = desc->state - 2;
    635        1.6     oster 			return RF_FALSE;
    636        1.6     oster 		} else {
    637        1.6     oster 			/* move on to rf_State_Cleanup */
    638        1.6     oster 			desc->state++;
    639        1.6     oster 		}
    640        1.6     oster 		return RF_FALSE;
    641        1.6     oster 	} else {
    642        1.6     oster 		/* more dags to execute */
    643        1.6     oster 		/* see if any are ready to be fired.  if so, fire them */
    644        1.6     oster 		/* don't fire the initial dag in a list, it's fired in
    645        1.6     oster 		 * rf_State_ExecuteDAG */
    646       1.26     oster 		dagList = desc->dagList;
    647        1.6     oster 		for (i = 0; i < desc->numStripes; i++) {
    648       1.26     oster 			if ((dagList->numDagsDone < dagList->numDags)
    649       1.26     oster 			    && (dagList->numDagsDone == dagList->numDagsFired)
    650       1.26     oster 			    && (dagList->numDagsFired > 0)) {
    651       1.27     oster #if RF_ACC_TRACE > 0
    652       1.26     oster 				RF_ETIMER_START(dagList->tracerec.timer);
    653       1.27     oster #endif
    654        1.6     oster 				/* fire next dag in this stripe */
    655        1.6     oster 				/* first, skip to next dag awaiting execution */
    656       1.26     oster 				dag_h = dagList->dags;
    657       1.26     oster 				for (j = 0; j < dagList->numDagsDone; j++)
    658        1.6     oster 					dag_h = dag_h->next;
    659       1.26     oster 				dagList->numDagsFired++;
    660        1.6     oster 				rf_DispatchDAG(dag_h, (void (*) (void *)) rf_ContinueDagAccess,
    661       1.26     oster 				    dagList);
    662        1.6     oster 			}
    663       1.26     oster 			dagList = dagList->next;
    664        1.6     oster 		}
    665        1.6     oster 		return RF_TRUE;
    666        1.6     oster 	}
    667        1.1     oster }
    668        1.1     oster /* only make it this far if all dags complete successfully */
    669       1.38     perry int
    670       1.22     oster rf_State_Cleanup(RF_RaidAccessDesc_t *desc)
    671        1.1     oster {
    672       1.27     oster #if RF_ACC_TRACE > 0
    673        1.6     oster 	RF_AccTraceEntry_t *tracerec = &desc->tracerec;
    674       1.28     oster 	RF_Etimer_t timer;
    675       1.27     oster #endif
    676        1.6     oster 	RF_AccessStripeMapHeader_t *asmh = desc->asmap;
    677        1.6     oster 	RF_Raid_t *raidPtr = desc->raidPtr;
    678        1.6     oster 	RF_AccessStripeMap_t *asm_p;
    679       1.26     oster 	RF_DagList_t *dagList;
    680       1.11     oster 	int i;
    681        1.6     oster 
    682        1.6     oster 	desc->state++;
    683        1.6     oster 
    684       1.27     oster #if RF_ACC_TRACE > 0
    685        1.6     oster 	timer = tracerec->timer;
    686        1.6     oster 	RF_ETIMER_STOP(timer);
    687        1.6     oster 	RF_ETIMER_EVAL(timer);
    688        1.6     oster 	tracerec->specific.user.dag_retry_us = RF_ETIMER_VAL_US(timer);
    689        1.6     oster 
    690        1.6     oster 	/* the RAID I/O is complete.  Clean up. */
    691        1.6     oster 	tracerec->specific.user.dag_retry_us = 0;
    692        1.6     oster 
    693        1.6     oster 	RF_ETIMER_START(timer);
    694       1.27     oster #endif
    695       1.24     oster 	/* free all dags */
    696       1.26     oster 	dagList = desc->dagList;
    697       1.24     oster 	for (i = 0; i < desc->numStripes; i++) {
    698       1.26     oster 		rf_FreeDAG(dagList->dags);
    699       1.26     oster 		dagList = dagList->next;
    700        1.6     oster 	}
    701       1.27     oster #if RF_ACC_TRACE > 0
    702        1.6     oster 	RF_ETIMER_STOP(timer);
    703        1.6     oster 	RF_ETIMER_EVAL(timer);
    704        1.6     oster 	tracerec->specific.user.cleanup_us = RF_ETIMER_VAL_US(timer);
    705        1.6     oster 
    706        1.6     oster 	RF_ETIMER_START(timer);
    707       1.27     oster #endif
    708       1.32     oster 	for (asm_p = asmh->stripeMap; asm_p; asm_p = asm_p->next) {
    709       1.32     oster 		if (!rf_suppressLocksAndLargeWrites &&
    710       1.32     oster 		    asm_p->parityInfo &&
    711       1.32     oster 		    !(desc->flags & RF_DAG_SUPPRESS_LOCKS)) {
    712       1.32     oster 			RF_ASSERT_VALID_LOCKREQ(&asm_p->lockReqDesc);
    713       1.38     perry 			rf_ReleaseStripeLock(raidPtr->lockTable,
    714       1.32     oster 					     asm_p->stripeID,
    715       1.32     oster 					     &asm_p->lockReqDesc);
    716       1.32     oster 		}
    717       1.32     oster 		if (asm_p->flags & RF_ASM_FLAGS_RECON_BLOCKED) {
    718       1.32     oster 			rf_UnblockRecon(raidPtr, asm_p);
    719        1.6     oster 		}
    720        1.6     oster 	}
    721       1.27     oster #if RF_ACC_TRACE > 0
    722        1.6     oster 	RF_ETIMER_STOP(timer);
    723        1.6     oster 	RF_ETIMER_EVAL(timer);
    724        1.6     oster 	tracerec->specific.user.lock_us += RF_ETIMER_VAL_US(timer);
    725        1.6     oster 
    726        1.6     oster 	RF_ETIMER_START(timer);
    727       1.27     oster #endif
    728       1.24     oster 	rf_FreeAccessStripeMap(asmh);
    729       1.27     oster #if RF_ACC_TRACE > 0
    730        1.6     oster 	RF_ETIMER_STOP(timer);
    731        1.6     oster 	RF_ETIMER_EVAL(timer);
    732        1.6     oster 	tracerec->specific.user.cleanup_us += RF_ETIMER_VAL_US(timer);
    733        1.6     oster 
    734        1.6     oster 	RF_ETIMER_STOP(desc->timer);
    735        1.6     oster 	RF_ETIMER_EVAL(desc->timer);
    736        1.6     oster 
    737        1.6     oster 	timer = desc->tracerec.tot_timer;
    738        1.6     oster 	RF_ETIMER_STOP(timer);
    739        1.6     oster 	RF_ETIMER_EVAL(timer);
    740        1.6     oster 	desc->tracerec.total_us = RF_ETIMER_VAL_US(timer);
    741        1.1     oster 
    742        1.6     oster 	rf_LogTraceRec(raidPtr, tracerec);
    743       1.27     oster #endif
    744        1.6     oster 	desc->flags |= RF_DAG_ACCESS_COMPLETE;
    745        1.1     oster 
    746        1.6     oster 	return RF_FALSE;
    747        1.1     oster }
    748