f1a1ad338d
Drastically reduces the amount of time spent rewriting parity after an unclean shutdown by keeping better track of which regions might have had outstanding writes. Enabled by default; can be disabled on a per-set basis, or tuned, with the new raidctl(8) commands. Discussed on tech-kern@ to a general air of approval; exhortations to commit from mrg@, christos@, and others. Thanks to Google for their sponsorship, oster@ for mentoring the project, assorted developers for trying very hard to break it, and probably more I'm forgetting.
891 lines
25 KiB
C
891 lines
25 KiB
C
/* $NetBSD: rf_engine.c,v 1.40 2009/11/17 18:54:26 jld Exp $ */
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/*
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* Copyright (c) 1995 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Author: William V. Courtright II, Mark Holland, Rachad Youssef
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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/****************************************************************************
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* *
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* engine.c -- code for DAG execution engine *
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* *
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* Modified to work as follows (holland): *
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* A user-thread calls into DispatchDAG, which fires off the nodes that *
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* are direct successors to the header node. DispatchDAG then returns, *
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* and the rest of the I/O continues asynchronously. As each node *
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* completes, the node execution function calls FinishNode(). FinishNode *
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* scans the list of successors to the node and increments the antecedent *
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* counts. Each node that becomes enabled is placed on a central node *
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* queue. A dedicated dag-execution thread grabs nodes off of this *
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* queue and fires them. *
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* *
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* NULL nodes are never fired. *
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* *
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* Terminator nodes are never fired, but rather cause the callback *
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* associated with the DAG to be invoked. *
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* *
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* If a node fails, the dag either rolls forward to the completion or *
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* rolls back, undoing previously-completed nodes and fails atomically. *
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* The direction of recovery is determined by the location of the failed *
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* node in the graph. If the failure occurred before the commit node in *
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* the graph, backward recovery is used. Otherwise, forward recovery is *
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* used. *
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* *
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****************************************************************************/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: rf_engine.c,v 1.40 2009/11/17 18:54:26 jld Exp $");
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#include <sys/errno.h>
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#include "rf_threadstuff.h"
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#include "rf_dag.h"
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#include "rf_engine.h"
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#include "rf_etimer.h"
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#include "rf_general.h"
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#include "rf_dagutils.h"
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#include "rf_shutdown.h"
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#include "rf_raid.h"
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#include "rf_kintf.h"
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#include "rf_paritymap.h"
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static void rf_ShutdownEngine(void *);
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static void DAGExecutionThread(RF_ThreadArg_t arg);
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static void rf_RaidIOThread(RF_ThreadArg_t arg);
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/* synchronization primitives for this file. DO_WAIT should be enclosed in a while loop. */
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#define DO_LOCK(_r_) \
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do { \
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ks = splbio(); \
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RF_LOCK_MUTEX((_r_)->node_queue_mutex); \
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} while (0)
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#define DO_UNLOCK(_r_) \
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do { \
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RF_UNLOCK_MUTEX((_r_)->node_queue_mutex); \
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splx(ks); \
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} while (0)
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#define DO_WAIT(_r_) \
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RF_WAIT_COND((_r_)->node_queue, (_r_)->node_queue_mutex)
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#define DO_SIGNAL(_r_) \
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RF_BROADCAST_COND((_r_)->node_queue) /* XXX RF_SIGNAL_COND? */
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static void
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rf_ShutdownEngine(void *arg)
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{
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RF_Raid_t *raidPtr;
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int ks;
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raidPtr = (RF_Raid_t *) arg;
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/* Tell the rf_RaidIOThread to shutdown */
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simple_lock(&(raidPtr->iodone_lock));
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raidPtr->shutdown_raidio = 1;
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wakeup(&(raidPtr->iodone));
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/* ...and wait for it to tell us it has finished */
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while (raidPtr->shutdown_raidio)
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ltsleep(&(raidPtr->shutdown_raidio), PRIBIO, "raidshutdown", 0,
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&(raidPtr->iodone_lock));
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simple_unlock(&(raidPtr->iodone_lock));
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/* Now shut down the DAG execution engine. */
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DO_LOCK(raidPtr);
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raidPtr->shutdown_engine = 1;
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DO_SIGNAL(raidPtr);
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DO_UNLOCK(raidPtr);
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}
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int
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rf_ConfigureEngine(RF_ShutdownList_t **listp, RF_Raid_t *raidPtr,
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RF_Config_t *cfgPtr)
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{
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rf_mutex_init(&raidPtr->node_queue_mutex);
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raidPtr->node_queue = NULL;
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raidPtr->dags_in_flight = 0;
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/* we create the execution thread only once per system boot. no need
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* to check return code b/c the kernel panics if it can't create the
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* thread. */
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#if RF_DEBUG_ENGINE
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if (rf_engineDebug) {
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printf("raid%d: Creating engine thread\n", raidPtr->raidid);
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}
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#endif
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if (RF_CREATE_ENGINE_THREAD(raidPtr->engine_thread,
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DAGExecutionThread, raidPtr,
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"raid%d", raidPtr->raidid)) {
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printf("raid%d: Unable to create engine thread\n",
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raidPtr->raidid);
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return (ENOMEM);
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}
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if (RF_CREATE_ENGINE_THREAD(raidPtr->engine_helper_thread,
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rf_RaidIOThread, raidPtr,
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"raidio%d", raidPtr->raidid)) {
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printf("raid%d: Unable to create raidio thread\n",
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raidPtr->raidid);
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return (ENOMEM);
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}
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#if RF_DEBUG_ENGINE
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if (rf_engineDebug) {
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printf("raid%d: Created engine thread\n", raidPtr->raidid);
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}
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#endif
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/* engine thread is now running and waiting for work */
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#if RF_DEBUG_ENGINE
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if (rf_engineDebug) {
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printf("raid%d: Engine thread running and waiting for events\n", raidPtr->raidid);
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}
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#endif
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rf_ShutdownCreate(listp, rf_ShutdownEngine, raidPtr);
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return (0);
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}
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static int
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BranchDone(RF_DagNode_t *node)
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{
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int i;
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/* return true if forward execution is completed for a node and it's
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* succedents */
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switch (node->status) {
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case rf_wait:
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/* should never be called in this state */
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RF_PANIC();
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break;
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case rf_fired:
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/* node is currently executing, so we're not done */
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return (RF_FALSE);
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case rf_good:
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/* for each succedent recursively check branch */
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for (i = 0; i < node->numSuccedents; i++)
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if (!BranchDone(node->succedents[i]))
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return RF_FALSE;
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return RF_TRUE; /* node and all succedent branches aren't in
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* fired state */
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case rf_bad:
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/* succedents can't fire */
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return (RF_TRUE);
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case rf_recover:
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/* should never be called in this state */
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RF_PANIC();
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break;
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case rf_undone:
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case rf_panic:
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/* XXX need to fix this case */
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/* for now, assume that we're done */
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return (RF_TRUE);
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default:
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/* illegal node status */
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RF_PANIC();
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break;
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}
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}
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static int
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NodeReady(RF_DagNode_t *node)
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{
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int ready;
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switch (node->dagHdr->status) {
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case rf_enable:
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case rf_rollForward:
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if ((node->status == rf_wait) &&
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(node->numAntecedents == node->numAntDone))
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ready = RF_TRUE;
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else
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ready = RF_FALSE;
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break;
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case rf_rollBackward:
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RF_ASSERT(node->numSuccDone <= node->numSuccedents);
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RF_ASSERT(node->numSuccFired <= node->numSuccedents);
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RF_ASSERT(node->numSuccFired <= node->numSuccDone);
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if ((node->status == rf_good) &&
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(node->numSuccDone == node->numSuccedents))
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ready = RF_TRUE;
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else
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ready = RF_FALSE;
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break;
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default:
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printf("Execution engine found illegal DAG status in NodeReady\n");
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RF_PANIC();
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break;
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}
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return (ready);
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}
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/* user context and dag-exec-thread context: Fire a node. The node's
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* status field determines which function, do or undo, to be fired.
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* This routine assumes that the node's status field has alread been
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* set to "fired" or "recover" to indicate the direction of execution.
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*/
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static void
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FireNode(RF_DagNode_t *node)
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{
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switch (node->status) {
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case rf_fired:
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/* fire the do function of a node */
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#if RF_DEBUG_ENGINE
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if (rf_engineDebug) {
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printf("raid%d: Firing node 0x%lx (%s)\n",
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node->dagHdr->raidPtr->raidid,
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(unsigned long) node, node->name);
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}
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#endif
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if (node->flags & RF_DAGNODE_FLAG_YIELD) {
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#if defined(__NetBSD__) && defined(_KERNEL)
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/* thread_block(); */
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/* printf("Need to block the thread here...\n"); */
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/* XXX thread_block is actually mentioned in
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* /usr/include/vm/vm_extern.h */
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#else
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thread_block();
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#endif
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}
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(*(node->doFunc)) (node);
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break;
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case rf_recover:
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/* fire the undo function of a node */
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#if RF_DEBUG_ENGINE
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if (rf_engineDebug) {
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printf("raid%d: Firing (undo) node 0x%lx (%s)\n",
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node->dagHdr->raidPtr->raidid,
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(unsigned long) node, node->name);
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}
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#endif
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if (node->flags & RF_DAGNODE_FLAG_YIELD)
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#if defined(__NetBSD__) && defined(_KERNEL)
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/* thread_block(); */
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/* printf("Need to block the thread here...\n"); */
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/* XXX thread_block is actually mentioned in
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* /usr/include/vm/vm_extern.h */
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#else
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thread_block();
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#endif
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(*(node->undoFunc)) (node);
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break;
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default:
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RF_PANIC();
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break;
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}
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}
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/* user context:
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* Attempt to fire each node in a linear array.
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* The entire list is fired atomically.
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*/
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static void
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FireNodeArray(int numNodes, RF_DagNode_t **nodeList)
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{
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RF_DagStatus_t dstat;
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RF_DagNode_t *node;
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int i, j;
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/* first, mark all nodes which are ready to be fired */
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for (i = 0; i < numNodes; i++) {
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node = nodeList[i];
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dstat = node->dagHdr->status;
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RF_ASSERT((node->status == rf_wait) ||
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(node->status == rf_good));
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if (NodeReady(node)) {
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if ((dstat == rf_enable) ||
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(dstat == rf_rollForward)) {
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RF_ASSERT(node->status == rf_wait);
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if (node->commitNode)
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node->dagHdr->numCommits++;
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node->status = rf_fired;
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for (j = 0; j < node->numAntecedents; j++)
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node->antecedents[j]->numSuccFired++;
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} else {
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RF_ASSERT(dstat == rf_rollBackward);
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RF_ASSERT(node->status == rf_good);
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/* only one commit node per graph */
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RF_ASSERT(node->commitNode == RF_FALSE);
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node->status = rf_recover;
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}
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}
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}
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/* now, fire the nodes */
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for (i = 0; i < numNodes; i++) {
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if ((nodeList[i]->status == rf_fired) ||
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(nodeList[i]->status == rf_recover))
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FireNode(nodeList[i]);
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}
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}
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/* user context:
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* Attempt to fire each node in a linked list.
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* The entire list is fired atomically.
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*/
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static void
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FireNodeList(RF_DagNode_t *nodeList)
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{
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RF_DagNode_t *node, *next;
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RF_DagStatus_t dstat;
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int j;
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if (nodeList) {
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/* first, mark all nodes which are ready to be fired */
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for (node = nodeList; node; node = next) {
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next = node->next;
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dstat = node->dagHdr->status;
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RF_ASSERT((node->status == rf_wait) ||
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(node->status == rf_good));
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if (NodeReady(node)) {
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if ((dstat == rf_enable) ||
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(dstat == rf_rollForward)) {
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RF_ASSERT(node->status == rf_wait);
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if (node->commitNode)
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node->dagHdr->numCommits++;
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node->status = rf_fired;
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for (j = 0; j < node->numAntecedents; j++)
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node->antecedents[j]->numSuccFired++;
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} else {
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RF_ASSERT(dstat == rf_rollBackward);
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RF_ASSERT(node->status == rf_good);
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/* only one commit node per graph */
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RF_ASSERT(node->commitNode == RF_FALSE);
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node->status = rf_recover;
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}
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}
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}
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/* now, fire the nodes */
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for (node = nodeList; node; node = next) {
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next = node->next;
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if ((node->status == rf_fired) ||
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(node->status == rf_recover))
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FireNode(node);
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}
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}
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}
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/* interrupt context:
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* for each succedent
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* propagate required results from node to succedent
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* increment succedent's numAntDone
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* place newly-enable nodes on node queue for firing
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*
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* To save context switches, we don't place NIL nodes on the node queue,
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* but rather just process them as if they had fired. Note that NIL nodes
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* that are the direct successors of the header will actually get fired by
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* DispatchDAG, which is fine because no context switches are involved.
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*
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* Important: when running at user level, this can be called by any
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* disk thread, and so the increment and check of the antecedent count
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* must be locked. I used the node queue mutex and locked down the
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* entire function, but this is certainly overkill.
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*/
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static void
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PropagateResults(RF_DagNode_t *node, int context)
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{
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RF_DagNode_t *s, *a;
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RF_Raid_t *raidPtr;
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int i, ks;
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RF_DagNode_t *finishlist = NULL; /* a list of NIL nodes to be
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* finished */
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RF_DagNode_t *skiplist = NULL; /* list of nodes with failed truedata
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* antecedents */
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RF_DagNode_t *firelist = NULL; /* a list of nodes to be fired */
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RF_DagNode_t *q = NULL, *qh = NULL, *next;
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int j, skipNode;
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raidPtr = node->dagHdr->raidPtr;
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DO_LOCK(raidPtr);
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/* debug - validate fire counts */
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for (i = 0; i < node->numAntecedents; i++) {
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a = *(node->antecedents + i);
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RF_ASSERT(a->numSuccFired >= a->numSuccDone);
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RF_ASSERT(a->numSuccFired <= a->numSuccedents);
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a->numSuccDone++;
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}
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switch (node->dagHdr->status) {
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case rf_enable:
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case rf_rollForward:
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for (i = 0; i < node->numSuccedents; i++) {
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s = *(node->succedents + i);
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RF_ASSERT(s->status == rf_wait);
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(s->numAntDone)++;
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if (s->numAntDone == s->numAntecedents) {
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/* look for NIL nodes */
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if (s->doFunc == rf_NullNodeFunc) {
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/* don't fire NIL nodes, just process
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* them */
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s->next = finishlist;
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finishlist = s;
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} else {
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/* look to see if the node is to be
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* skipped */
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skipNode = RF_FALSE;
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for (j = 0; j < s->numAntecedents; j++)
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if ((s->antType[j] == rf_trueData) && (s->antecedents[j]->status == rf_bad))
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skipNode = RF_TRUE;
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if (skipNode) {
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/* this node has one or more
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* failed true data
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* dependencies, so skip it */
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s->next = skiplist;
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skiplist = s;
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} else
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/* add s to list of nodes (q)
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* to execute */
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if (context != RF_INTR_CONTEXT) {
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/* we only have to
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* enqueue if we're at
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* intr context */
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/* put node on
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a list to
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be fired
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after we
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unlock */
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s->next = firelist;
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firelist = s;
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} else {
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/* enqueue the
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node for
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the dag
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exec thread
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to fire */
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RF_ASSERT(NodeReady(s));
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if (q) {
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q->next = s;
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q = s;
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} else {
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qh = q = s;
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qh->next = NULL;
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}
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}
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}
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}
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}
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if (q) {
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/* xfer our local list of nodes to the node queue */
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q->next = raidPtr->node_queue;
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raidPtr->node_queue = qh;
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DO_SIGNAL(raidPtr);
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}
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DO_UNLOCK(raidPtr);
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for (; skiplist; skiplist = next) {
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|
next = skiplist->next;
|
|
skiplist->status = rf_skipped;
|
|
for (i = 0; i < skiplist->numAntecedents; i++) {
|
|
skiplist->antecedents[i]->numSuccFired++;
|
|
}
|
|
if (skiplist->commitNode) {
|
|
skiplist->dagHdr->numCommits++;
|
|
}
|
|
rf_FinishNode(skiplist, context);
|
|
}
|
|
for (; finishlist; finishlist = next) {
|
|
/* NIL nodes: no need to fire them */
|
|
next = finishlist->next;
|
|
finishlist->status = rf_good;
|
|
for (i = 0; i < finishlist->numAntecedents; i++) {
|
|
finishlist->antecedents[i]->numSuccFired++;
|
|
}
|
|
if (finishlist->commitNode)
|
|
finishlist->dagHdr->numCommits++;
|
|
/*
|
|
* Okay, here we're calling rf_FinishNode() on
|
|
* nodes that have the null function as their
|
|
* work proc. Such a node could be the
|
|
* terminal node in a DAG. If so, it will
|
|
* cause the DAG to complete, which will in
|
|
* turn free memory used by the DAG, which
|
|
* includes the node in question. Thus, we
|
|
* must avoid referencing the node at all
|
|
* after calling rf_FinishNode() on it. */
|
|
rf_FinishNode(finishlist, context); /* recursive call */
|
|
}
|
|
/* fire all nodes in firelist */
|
|
FireNodeList(firelist);
|
|
break;
|
|
|
|
case rf_rollBackward:
|
|
for (i = 0; i < node->numAntecedents; i++) {
|
|
a = *(node->antecedents + i);
|
|
RF_ASSERT(a->status == rf_good);
|
|
RF_ASSERT(a->numSuccDone <= a->numSuccedents);
|
|
RF_ASSERT(a->numSuccDone <= a->numSuccFired);
|
|
|
|
if (a->numSuccDone == a->numSuccFired) {
|
|
if (a->undoFunc == rf_NullNodeFunc) {
|
|
/* don't fire NIL nodes, just process
|
|
* them */
|
|
a->next = finishlist;
|
|
finishlist = a;
|
|
} else {
|
|
if (context != RF_INTR_CONTEXT) {
|
|
/* we only have to enqueue if
|
|
* we're at intr context */
|
|
/* put node on a list to be
|
|
fired after we unlock */
|
|
a->next = firelist;
|
|
|
|
firelist = a;
|
|
} else {
|
|
/* enqueue the node for the
|
|
dag exec thread to fire */
|
|
RF_ASSERT(NodeReady(a));
|
|
if (q) {
|
|
q->next = a;
|
|
q = a;
|
|
} else {
|
|
qh = q = a;
|
|
qh->next = NULL;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (q) {
|
|
/* xfer our local list of nodes to the node queue */
|
|
q->next = raidPtr->node_queue;
|
|
raidPtr->node_queue = qh;
|
|
DO_SIGNAL(raidPtr);
|
|
}
|
|
DO_UNLOCK(raidPtr);
|
|
for (; finishlist; finishlist = next) {
|
|
/* NIL nodes: no need to fire them */
|
|
next = finishlist->next;
|
|
finishlist->status = rf_good;
|
|
/*
|
|
* Okay, here we're calling rf_FinishNode() on
|
|
* nodes that have the null function as their
|
|
* work proc. Such a node could be the first
|
|
* node in a DAG. If so, it will cause the DAG
|
|
* to complete, which will in turn free memory
|
|
* used by the DAG, which includes the node in
|
|
* question. Thus, we must avoid referencing
|
|
* the node at all after calling
|
|
* rf_FinishNode() on it. */
|
|
rf_FinishNode(finishlist, context); /* recursive call */
|
|
}
|
|
/* fire all nodes in firelist */
|
|
FireNodeList(firelist);
|
|
|
|
break;
|
|
default:
|
|
printf("Engine found illegal DAG status in PropagateResults()\n");
|
|
RF_PANIC();
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Process a fired node which has completed
|
|
*/
|
|
static void
|
|
ProcessNode(RF_DagNode_t *node, int context)
|
|
{
|
|
RF_Raid_t *raidPtr;
|
|
|
|
raidPtr = node->dagHdr->raidPtr;
|
|
|
|
switch (node->status) {
|
|
case rf_good:
|
|
/* normal case, don't need to do anything */
|
|
break;
|
|
case rf_bad:
|
|
if ((node->dagHdr->numCommits > 0) ||
|
|
(node->dagHdr->numCommitNodes == 0)) {
|
|
/* crossed commit barrier */
|
|
node->dagHdr->status = rf_rollForward;
|
|
#if RF_DEBUG_ENGINE
|
|
if (rf_engineDebug) {
|
|
printf("raid%d: node (%s) returned fail, rolling forward\n", raidPtr->raidid, node->name);
|
|
}
|
|
#endif
|
|
} else {
|
|
/* never reached commit barrier */
|
|
node->dagHdr->status = rf_rollBackward;
|
|
#if RF_DEBUG_ENGINE
|
|
if (rf_engineDebug) {
|
|
printf("raid%d: node (%s) returned fail, rolling backward\n", raidPtr->raidid, node->name);
|
|
}
|
|
#endif
|
|
}
|
|
break;
|
|
case rf_undone:
|
|
/* normal rollBackward case, don't need to do anything */
|
|
break;
|
|
case rf_panic:
|
|
/* an undo node failed!!! */
|
|
printf("UNDO of a node failed!!!/n");
|
|
break;
|
|
default:
|
|
printf("node finished execution with an illegal status!!!\n");
|
|
RF_PANIC();
|
|
break;
|
|
}
|
|
|
|
/* enqueue node's succedents (antecedents if rollBackward) for
|
|
* execution */
|
|
PropagateResults(node, context);
|
|
}
|
|
|
|
|
|
|
|
/* user context or dag-exec-thread context:
|
|
* This is the first step in post-processing a newly-completed node.
|
|
* This routine is called by each node execution function to mark the node
|
|
* as complete and fire off any successors that have been enabled.
|
|
*/
|
|
int
|
|
rf_FinishNode(RF_DagNode_t *node, int context)
|
|
{
|
|
int retcode = RF_FALSE;
|
|
node->dagHdr->numNodesCompleted++;
|
|
ProcessNode(node, context);
|
|
|
|
return (retcode);
|
|
}
|
|
|
|
|
|
/* user context: submit dag for execution, return non-zero if we have
|
|
* to wait for completion. if and only if we return non-zero, we'll
|
|
* cause cbFunc to get invoked with cbArg when the DAG has completed.
|
|
*
|
|
* for now we always return 1. If the DAG does not cause any I/O,
|
|
* then the callback may get invoked before DispatchDAG returns.
|
|
* There's code in state 5 of ContinueRaidAccess to handle this.
|
|
*
|
|
* All we do here is fire the direct successors of the header node.
|
|
* The DAG execution thread does the rest of the dag processing. */
|
|
int
|
|
rf_DispatchDAG(RF_DagHeader_t *dag, void (*cbFunc) (void *),
|
|
void *cbArg)
|
|
{
|
|
RF_Raid_t *raidPtr;
|
|
|
|
raidPtr = dag->raidPtr;
|
|
#if RF_ACC_TRACE > 0
|
|
if (dag->tracerec) {
|
|
RF_ETIMER_START(dag->tracerec->timer);
|
|
}
|
|
#endif
|
|
#if DEBUG
|
|
#if RF_DEBUG_VALIDATE_DAG
|
|
if (rf_engineDebug || rf_validateDAGDebug) {
|
|
if (rf_ValidateDAG(dag))
|
|
RF_PANIC();
|
|
}
|
|
#endif
|
|
#endif
|
|
#if RF_DEBUG_ENGINE
|
|
if (rf_engineDebug) {
|
|
printf("raid%d: Entering DispatchDAG\n", raidPtr->raidid);
|
|
}
|
|
#endif
|
|
raidPtr->dags_in_flight++; /* debug only: blow off proper
|
|
* locking */
|
|
dag->cbFunc = cbFunc;
|
|
dag->cbArg = cbArg;
|
|
dag->numNodesCompleted = 0;
|
|
dag->status = rf_enable;
|
|
FireNodeArray(dag->numSuccedents, dag->succedents);
|
|
return (1);
|
|
}
|
|
/* dedicated kernel thread: the thread that handles all DAG node
|
|
* firing. To minimize locking and unlocking, we grab a copy of the
|
|
* entire node queue and then set the node queue to NULL before doing
|
|
* any firing of nodes. This way we only have to release the lock
|
|
* once. Of course, it's probably rare that there's more than one
|
|
* node in the queue at any one time, but it sometimes happens.
|
|
*/
|
|
|
|
static void
|
|
DAGExecutionThread(RF_ThreadArg_t arg)
|
|
{
|
|
RF_DagNode_t *nd, *local_nq, *term_nq, *fire_nq;
|
|
RF_Raid_t *raidPtr;
|
|
int ks;
|
|
int s;
|
|
|
|
raidPtr = (RF_Raid_t *) arg;
|
|
|
|
#if RF_DEBUG_ENGINE
|
|
if (rf_engineDebug) {
|
|
printf("raid%d: Engine thread is running\n", raidPtr->raidid);
|
|
}
|
|
#endif
|
|
s = splbio();
|
|
|
|
DO_LOCK(raidPtr);
|
|
while (!raidPtr->shutdown_engine) {
|
|
|
|
while (raidPtr->node_queue != NULL) {
|
|
local_nq = raidPtr->node_queue;
|
|
fire_nq = NULL;
|
|
term_nq = NULL;
|
|
raidPtr->node_queue = NULL;
|
|
DO_UNLOCK(raidPtr);
|
|
|
|
/* first, strip out the terminal nodes */
|
|
while (local_nq) {
|
|
nd = local_nq;
|
|
local_nq = local_nq->next;
|
|
switch (nd->dagHdr->status) {
|
|
case rf_enable:
|
|
case rf_rollForward:
|
|
if (nd->numSuccedents == 0) {
|
|
/* end of the dag, add to
|
|
* callback list */
|
|
nd->next = term_nq;
|
|
term_nq = nd;
|
|
} else {
|
|
/* not the end, add to the
|
|
* fire queue */
|
|
nd->next = fire_nq;
|
|
fire_nq = nd;
|
|
}
|
|
break;
|
|
case rf_rollBackward:
|
|
if (nd->numAntecedents == 0) {
|
|
/* end of the dag, add to the
|
|
* callback list */
|
|
nd->next = term_nq;
|
|
term_nq = nd;
|
|
} else {
|
|
/* not the end, add to the
|
|
* fire queue */
|
|
nd->next = fire_nq;
|
|
fire_nq = nd;
|
|
}
|
|
break;
|
|
default:
|
|
RF_PANIC();
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* execute callback of dags which have reached the
|
|
* terminal node */
|
|
while (term_nq) {
|
|
nd = term_nq;
|
|
term_nq = term_nq->next;
|
|
nd->next = NULL;
|
|
(nd->dagHdr->cbFunc) (nd->dagHdr->cbArg);
|
|
raidPtr->dags_in_flight--; /* debug only */
|
|
}
|
|
|
|
/* fire remaining nodes */
|
|
FireNodeList(fire_nq);
|
|
|
|
DO_LOCK(raidPtr);
|
|
}
|
|
while (!raidPtr->shutdown_engine &&
|
|
raidPtr->node_queue == NULL) {
|
|
DO_WAIT(raidPtr);
|
|
}
|
|
}
|
|
DO_UNLOCK(raidPtr);
|
|
|
|
splx(s);
|
|
kthread_exit(0);
|
|
}
|
|
|
|
/*
|
|
* rf_RaidIOThread() -- When I/O to a component begins, raidstrategy()
|
|
* puts the I/O on a buf_queue, and then signals raidPtr->iodone. If
|
|
* necessary, this function calls raidstart() to initiate the I/O.
|
|
* When I/O to a component completes, KernelWakeupFunc() puts the
|
|
* completed request onto raidPtr->iodone TAILQ. This function looks
|
|
* after requests on that queue by calling rf_DiskIOComplete() for the
|
|
* request, and by calling any required CompleteFunc for the request.
|
|
*/
|
|
|
|
static void
|
|
rf_RaidIOThread(RF_ThreadArg_t arg)
|
|
{
|
|
RF_Raid_t *raidPtr;
|
|
RF_DiskQueueData_t *req;
|
|
int s;
|
|
|
|
raidPtr = (RF_Raid_t *) arg;
|
|
|
|
s = splbio();
|
|
simple_lock(&(raidPtr->iodone_lock));
|
|
|
|
while (!raidPtr->shutdown_raidio) {
|
|
/* if there is nothing to do, then snooze. */
|
|
if (TAILQ_EMPTY(&(raidPtr->iodone)) &&
|
|
rf_buf_queue_check(raidPtr->raidid)) {
|
|
ltsleep(&(raidPtr->iodone), PRIBIO, "raidiow", 0,
|
|
&(raidPtr->iodone_lock));
|
|
}
|
|
|
|
/* Check for deferred parity-map-related work. */
|
|
if (raidPtr->parity_map != NULL) {
|
|
simple_unlock(&(raidPtr->iodone_lock));
|
|
rf_paritymap_checkwork(raidPtr->parity_map);
|
|
simple_lock(&(raidPtr->iodone_lock));
|
|
}
|
|
|
|
/* See what I/Os, if any, have arrived */
|
|
while ((req = TAILQ_FIRST(&(raidPtr->iodone))) != NULL) {
|
|
TAILQ_REMOVE(&(raidPtr->iodone), req, iodone_entries);
|
|
simple_unlock(&(raidPtr->iodone_lock));
|
|
rf_DiskIOComplete(req->queue, req, req->error);
|
|
(req->CompleteFunc) (req->argument, req->error);
|
|
simple_lock(&(raidPtr->iodone_lock));
|
|
}
|
|
|
|
/* process any pending outgoing IO */
|
|
simple_unlock(&(raidPtr->iodone_lock));
|
|
raidstart(raidPtr);
|
|
simple_lock(&(raidPtr->iodone_lock));
|
|
|
|
}
|
|
|
|
/* Let rf_ShutdownEngine know that we're done... */
|
|
raidPtr->shutdown_raidio = 0;
|
|
wakeup(&(raidPtr->shutdown_raidio));
|
|
|
|
simple_unlock(&(raidPtr->iodone_lock));
|
|
splx(s);
|
|
|
|
kthread_exit(0);
|
|
}
|