PDMAsyncCompletionFile.cpp@ 26147

Last change on this file since 26147 was 26147, checked in by vboxsync, 15 years ago
AsyncCompletion: Fix incorrect count of outstanding write tasks. Fixes hangs during flush requests. Return VINF_AIO_TASK_PENDING if data needs to be read from the file
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1	/* $Id: PDMAsyncCompletionFile.cpp 26147 2010-02-02 13:55:20Z vboxsync $ */
2	/** @file
3	* PDM Async I/O - Transport data asynchronous in R3 using EMT.
4	*/
5
6	/*
7	* Copyright (C) 2006-2009 Sun Microsystems, Inc.
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*
17	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
18	* Clara, CA 95054 USA or visit http://www.sun.com if you need
19	* additional information or have any questions.
20	*/
21
22
23	/*******************************************************************************
24	* Header Files *
25	*******************************************************************************/
26	#define LOG_GROUP LOG_GROUP_PDM_ASYNC_COMPLETION
27	#define RT_STRICT
28	//#define DEBUG
29	#include "PDMInternal.h"
30	#include <VBox/pdm.h>
31	#include <VBox/mm.h>
32	#include <VBox/vm.h>
33	#include <VBox/err.h>
34	#include <VBox/log.h>
35
36	#include <iprt/asm.h>
37	#include <iprt/assert.h>
38	#include <iprt/critsect.h>
39	#include <iprt/env.h>
40	#include <iprt/file.h>
41	#include <iprt/mem.h>
42	#include <iprt/semaphore.h>
43	#include <iprt/string.h>
44	#include <iprt/thread.h>
45	#include <iprt/path.h>
46
47	#include "PDMAsyncCompletionFileInternal.h"
48
49	/**
50	* Frees a task.
51	*
52	* @returns nothing.
53	* @param pEndpoint Pointer to the endpoint the segment was for.
54	* @param pTask The task to free.
55	*/
56	void pdmacFileTaskFree(PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint,
57	PPDMACTASKFILE pTask)
58	{
59	PPDMASYNCCOMPLETIONEPCLASSFILE pEpClass = (PPDMASYNCCOMPLETIONEPCLASSFILE)pEndpoint->Core.pEpClass;
60
61	LogFlowFunc((": pEndpoint=%p pTask=%p\n", pEndpoint, pTask));
62
63	/* Try the per endpoint cache first. */
64	if (pEndpoint->cTasksCached < pEpClass->cTasksCacheMax)
65	{
66	/* Add it to the list. */
67	pEndpoint->pTasksFreeTail->pNext = pTask;
68	pEndpoint->pTasksFreeTail = pTask;
69	ASMAtomicIncU32(&pEndpoint->cTasksCached);
70	}
71	else if (false)
72	{
73	/* Bigger class cache */
74	}
75	else
76	{
77	Log(("Freeing task %p because all caches are full\n", pTask));
78	MMR3HeapFree(pTask);
79	}
80	}
81
82	/**
83	* Allocates a task segment
84	*
85	* @returns Pointer to the new task segment or NULL
86	* @param pEndpoint Pointer to the endpoint
87	*/
88	PPDMACTASKFILE pdmacFileTaskAlloc(PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint)
89	{
90	PPDMACTASKFILE pTask = NULL;
91
92	/* Try the small per endpoint cache first. */
93	if (pEndpoint->pTasksFreeHead == pEndpoint->pTasksFreeTail)
94	{
95	/* Try the bigger endpoint class cache. */
96	PPDMASYNCCOMPLETIONEPCLASSFILE pEndpointClass = (PPDMASYNCCOMPLETIONEPCLASSFILE)pEndpoint->Core.pEpClass;
97
98	#if 0
99	/* We start with the assigned slot id to distribute the load when allocating new tasks. */
100	unsigned iSlot = pEndpoint->iSlotStart;
101	do
102	{
103	pTask = (PPDMASYNCCOMPLETIONTASK)ASMAtomicXchgPtr((void * volatile *)&pEndpointClass->apTaskCache[iSlot], NULL);
104	if (pTask)
105	break;
106
107	iSlot = (iSlot + 1) % RT_ELEMENTS(pEndpointClass->apTaskCache);
108	} while (iSlot != pEndpoint->iSlotStart);
109	#endif
110	if (!pTask)
111	{
112	/*
113	* Allocate completely new.
114	* If this fails we return NULL.
115	*/
116	int rc = MMR3HeapAllocZEx(pEndpointClass->Core.pVM, MM_TAG_PDM_ASYNC_COMPLETION,
117	sizeof(PDMACTASKFILE),
118	(void **)&pTask);
119	if (RT_FAILURE(rc))
120	pTask = NULL;
121
122	LogFlow(("Allocated task %p\n", pTask));
123	}
124	#if 0
125	else
126	{
127	/* Remove the first element and put the rest into the slot again. */
128	PPDMASYNCCOMPLETIONTASK pTaskHeadNew = pTask->pNext;
129
130	pTaskHeadNew->pPrev = NULL;
131
132	/* Put back into the list adding any new tasks. */
133	while (true)
134	{
135	bool fChanged = ASMAtomicCmpXchgPtr((void * volatile *)&pEndpointClass->apTaskCache[iSlot], pTaskHeadNew, NULL);
136
137	if (fChanged)
138	break;
139
140	PPDMASYNCCOMPLETIONTASK pTaskHead = (PPDMASYNCCOMPLETIONTASK)ASMAtomicXchgPtr((void * volatile *)&pEndpointClass->apTaskCache[iSlot], NULL);
141
142	/* The new task could be taken inbetween */
143	if (pTaskHead)
144	{
145	/* Go to the end of the probably much shorter new list. */
146	PPDMASYNCCOMPLETIONTASK pTaskTail = pTaskHead;
147	while (pTaskTail->pNext)
148	pTaskTail = pTaskTail->pNext;
149
150	/* Concatenate */
151	pTaskTail->pNext = pTaskHeadNew;
152
153	pTaskHeadNew = pTaskHead;
154	}
155	/* Another round trying to change the list. */
156	}
157	/* We got a task from the global cache so decrement the counter */
158	ASMAtomicDecU32(&pEndpointClass->cTasksCached);
159	}
160	#endif
161	}
162	else
163	{
164	/* Grab a free task from the head. */
165	AssertMsg(pEndpoint->cTasksCached > 0, ("No tasks cached but list contains more than one element\n"));
166
167	pTask = pEndpoint->pTasksFreeHead;
168	pEndpoint->pTasksFreeHead = pTask->pNext;
169	ASMAtomicDecU32(&pEndpoint->cTasksCached);
170	}
171
172	pTask->pNext = NULL;
173
174	return pTask;
175	}
176
177	PPDMACTASKFILE pdmacFileEpGetNewTasks(PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint)
178	{
179	PPDMACTASKFILE pTasks = NULL;
180
181	/*
182	* Get pending tasks.
183	*/
184	pTasks = (PPDMACTASKFILE)ASMAtomicXchgPtr((void * volatile *)&pEndpoint->pTasksNewHead, NULL);
185
186	/* Reverse the list to process in FIFO order. */
187	if (pTasks)
188	{
189	PPDMACTASKFILE pTask = pTasks;
190
191	pTasks = NULL;
192
193	while (pTask)
194	{
195	PPDMACTASKFILE pCur = pTask;
196	pTask = pTask->pNext;
197	pCur->pNext = pTasks;
198	pTasks = pCur;
199	}
200	}
201
202	return pTasks;
203	}
204
205	static void pdmacFileAioMgrWakeup(PPDMACEPFILEMGR pAioMgr)
206	{
207	bool fWokenUp = ASMAtomicXchgBool(&pAioMgr->fWokenUp, true);
208
209	if (!fWokenUp)
210	{
211	int rc = VINF_SUCCESS;
212	bool fWaitingEventSem = ASMAtomicReadBool(&pAioMgr->fWaitingEventSem);
213
214	if (fWaitingEventSem)
215	rc = RTSemEventSignal(pAioMgr->EventSem);
216
217	AssertRC(rc);
218	}
219	}
220
221	static int pdmacFileAioMgrWaitForBlockingEvent(PPDMACEPFILEMGR pAioMgr, PDMACEPFILEAIOMGRBLOCKINGEVENT enmEvent)
222	{
223	int rc = VINF_SUCCESS;
224
225	ASMAtomicWriteU32((volatile uint32_t *)&pAioMgr->enmBlockingEvent, enmEvent);
226	Assert(!pAioMgr->fBlockingEventPending);
227	ASMAtomicXchgBool(&pAioMgr->fBlockingEventPending, true);
228
229	/* Wakeup the async I/O manager */
230	pdmacFileAioMgrWakeup(pAioMgr);
231
232	/* Wait for completion. */
233	rc = RTSemEventWait(pAioMgr->EventSemBlock, RT_INDEFINITE_WAIT);
234	AssertRC(rc);
235
236	ASMAtomicXchgBool(&pAioMgr->fBlockingEventPending, false);
237	ASMAtomicWriteU32((volatile uint32_t *)&pAioMgr->enmBlockingEvent, PDMACEPFILEAIOMGRBLOCKINGEVENT_INVALID);
238
239	return rc;
240	}
241
242	int pdmacFileAioMgrAddEndpoint(PPDMACEPFILEMGR pAioMgr, PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint)
243	{
244	int rc;
245
246	rc = RTCritSectEnter(&pAioMgr->CritSectBlockingEvent);
247	AssertRCReturn(rc, rc);
248
249	ASMAtomicWritePtr((void * volatile *)&pAioMgr->BlockingEventData.AddEndpoint.pEndpoint, pEndpoint);
250	rc = pdmacFileAioMgrWaitForBlockingEvent(pAioMgr, PDMACEPFILEAIOMGRBLOCKINGEVENT_ADD_ENDPOINT);
251
252	RTCritSectLeave(&pAioMgr->CritSectBlockingEvent);
253
254	if (RT_SUCCESS(rc))
255	ASMAtomicWritePtr((void * volatile *)&pEndpoint->pAioMgr, pAioMgr);
256
257	return rc;
258	}
259
260	static int pdmacFileAioMgrRemoveEndpoint(PPDMACEPFILEMGR pAioMgr, PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint)
261	{
262	int rc;
263
264	rc = RTCritSectEnter(&pAioMgr->CritSectBlockingEvent);
265	AssertRCReturn(rc, rc);
266
267	ASMAtomicWritePtr((void * volatile *)&pAioMgr->BlockingEventData.RemoveEndpoint.pEndpoint, pEndpoint);
268	rc = pdmacFileAioMgrWaitForBlockingEvent(pAioMgr, PDMACEPFILEAIOMGRBLOCKINGEVENT_REMOVE_ENDPOINT);
269
270	RTCritSectLeave(&pAioMgr->CritSectBlockingEvent);
271
272	return rc;
273	}
274
275	static int pdmacFileAioMgrCloseEndpoint(PPDMACEPFILEMGR pAioMgr, PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint)
276	{
277	int rc;
278
279	rc = RTCritSectEnter(&pAioMgr->CritSectBlockingEvent);
280	AssertRCReturn(rc, rc);
281
282	ASMAtomicWritePtr((void * volatile *)&pAioMgr->BlockingEventData.CloseEndpoint.pEndpoint, pEndpoint);
283	rc = pdmacFileAioMgrWaitForBlockingEvent(pAioMgr, PDMACEPFILEAIOMGRBLOCKINGEVENT_CLOSE_ENDPOINT);
284
285	RTCritSectLeave(&pAioMgr->CritSectBlockingEvent);
286
287	return rc;
288	}
289
290	static int pdmacFileAioMgrShutdown(PPDMACEPFILEMGR pAioMgr)
291	{
292	int rc;
293
294	rc = RTCritSectEnter(&pAioMgr->CritSectBlockingEvent);
295	AssertRCReturn(rc, rc);
296
297	rc = pdmacFileAioMgrWaitForBlockingEvent(pAioMgr, PDMACEPFILEAIOMGRBLOCKINGEVENT_SHUTDOWN);
298
299	RTCritSectLeave(&pAioMgr->CritSectBlockingEvent);
300
301	return rc;
302	}
303
304	int pdmacFileEpAddTask(PPDMASYNCCOMPLETIONENDPOINTFILE pEndpoint, PPDMACTASKFILE pTask)
305	{
306	PPDMACTASKFILE pNext;
307	do
308	{
309	pNext = pEndpoint->pTasksNewHead;
310	pTask->pNext = pNext;
311	} while (!ASMAtomicCmpXchgPtr((void * volatile )&pEndpoint->pTasksNewHead, (void )pTask, (void *)pNext));
312
313	pdmacFileAioMgrWakeup((PPDMACEPFILEMGR)ASMAtomicReadPtr((void * volatile *)&pEndpoint->pAioMgr));
314
315	return VINF_SUCCESS;
316	}
317
318	void pdmacFileEpTaskCompleted(PPDMACTASKFILE pTask, void *pvUser)
319	{
320	PPDMASYNCCOMPLETIONTASKFILE pTaskFile = (PPDMASYNCCOMPLETIONTASKFILE)pvUser;
321
322	if (pTask->enmTransferType == PDMACTASKFILETRANSFER_FLUSH)
323	{
324	pdmR3AsyncCompletionCompleteTask(&pTaskFile->Core, true);
325	}
326	else
327	{
328	uint32_t uOld = ASMAtomicSubU32(&pTaskFile->cbTransferLeft, pTask->DataSeg.cbSeg);
329
330	if (!(uOld - pTask->DataSeg.cbSeg)
331	&& !ASMAtomicXchgBool(&pTaskFile->fCompleted, true))
332	pdmR3AsyncCompletionCompleteTask(&pTaskFile->Core, true);
333	}
334	}
335
336	int pdmacFileEpTaskInitiate(PPDMASYNCCOMPLETIONTASK pTask,
337	PPDMASYNCCOMPLETIONENDPOINT pEndpoint, RTFOFF off,
338	PCPDMDATASEG paSegments, size_t cSegments,
339	size_t cbTransfer, PDMACTASKFILETRANSFER enmTransfer)
340	{
341	int rc = VINF_SUCCESS;
342	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
343	PPDMASYNCCOMPLETIONTASKFILE pTaskFile = (PPDMASYNCCOMPLETIONTASKFILE)pTask;
344	PPDMACEPFILEMGR pAioMgr = pEpFile->pAioMgr;
345
346	Assert( (enmTransfer == PDMACTASKFILETRANSFER_READ)
347	\|\| (enmTransfer == PDMACTASKFILETRANSFER_WRITE));
348
349	ASMAtomicWriteS32(&pTaskFile->cbTransferLeft, cbTransfer);
350	ASMAtomicWriteBool(&pTaskFile->fCompleted, false);
351
352	for (unsigned i = 0; i < cSegments; i++)
353	{
354	PPDMACTASKFILE pIoTask = pdmacFileTaskAlloc(pEpFile);
355	AssertPtr(pIoTask);
356
357	pIoTask->pEndpoint = pEpFile;
358	pIoTask->enmTransferType = enmTransfer;
359	pIoTask->Off = off;
360	pIoTask->DataSeg.cbSeg = paSegments[i].cbSeg;
361	pIoTask->DataSeg.pvSeg = paSegments[i].pvSeg;
362	pIoTask->pvUser = pTaskFile;
363	pIoTask->pfnCompleted = pdmacFileEpTaskCompleted;
364
365	/* Send it off to the I/O manager. */
366	pdmacFileEpAddTask(pEpFile, pIoTask);
367	off += paSegments[i].cbSeg;
368	cbTransfer -= paSegments[i].cbSeg;
369	}
370
371	AssertMsg(!cbTransfer, ("Incomplete transfer %u bytes left\n", cbTransfer));
372
373	if (ASMAtomicReadS32(&pTaskFile->cbTransferLeft) == 0
374	&& !ASMAtomicXchgBool(&pTaskFile->fCompleted, true))
375	pdmR3AsyncCompletionCompleteTask(pTask, false);
376	else
377	rc = VINF_AIO_TASK_PENDING;
378
379	return rc;
380	}
381
382	/**
383	* Creates a new async I/O manager.
384	*
385	* @returns VBox status code.
386	* @param pEpClass Pointer to the endpoint class data.
387	* @param ppAioMgr Where to store the pointer to the new async I/O manager on success.
388	* @param fFailsafe Flag to force a failsafe manager even if the global flag is not set.
389	*/
390	int pdmacFileAioMgrCreate(PPDMASYNCCOMPLETIONEPCLASSFILE pEpClass, PPPDMACEPFILEMGR ppAioMgr, bool fFailsafe)
391	{
392	int rc = VINF_SUCCESS;
393	PPDMACEPFILEMGR pAioMgrNew;
394
395	LogFlowFunc((": Entered\n"));
396
397	rc = MMR3HeapAllocZEx(pEpClass->Core.pVM, MM_TAG_PDM_ASYNC_COMPLETION, sizeof(PDMACEPFILEMGR), (void **)&pAioMgrNew);
398	if (RT_SUCCESS(rc))
399	{
400	pAioMgrNew->fFailsafe = fFailsafe \|\| pEpClass->fFailsafe;
401
402	rc = RTSemEventCreate(&pAioMgrNew->EventSem);
403	if (RT_SUCCESS(rc))
404	{
405	rc = RTSemEventCreate(&pAioMgrNew->EventSemBlock);
406	if (RT_SUCCESS(rc))
407	{
408	rc = RTCritSectInit(&pAioMgrNew->CritSectBlockingEvent);
409	if (RT_SUCCESS(rc))
410	{
411	/* Init the rest of the manager. */
412	if (!pAioMgrNew->fFailsafe)
413	rc = pdmacFileAioMgrNormalInit(pAioMgrNew);
414
415	if (RT_SUCCESS(rc))
416	{
417	pAioMgrNew->enmState = PDMACEPFILEMGRSTATE_RUNNING;
418
419	rc = RTThreadCreateF(&pAioMgrNew->Thread,
420	pAioMgrNew->fFailsafe
421	? pdmacFileAioMgrFailsafe
422	: pdmacFileAioMgrNormal,
423	pAioMgrNew,
424	0,
425	RTTHREADTYPE_IO,
426	0,
427	"AioMgr%d-%s", pEpClass->cAioMgrs,
428	pAioMgrNew->fFailsafe
429	? "F"
430	: "N");
431	if (RT_SUCCESS(rc))
432	{
433	/* Link it into the list. */
434	RTCritSectEnter(&pEpClass->CritSect);
435	pAioMgrNew->pNext = pEpClass->pAioMgrHead;
436	if (pEpClass->pAioMgrHead)
437	pEpClass->pAioMgrHead->pPrev = pAioMgrNew;
438	pEpClass->pAioMgrHead = pAioMgrNew;
439	pEpClass->cAioMgrs++;
440	RTCritSectLeave(&pEpClass->CritSect);
441
442	*ppAioMgr = pAioMgrNew;
443
444	Log(("PDMAC: Successfully created new file AIO Mgr {%s}\n", RTThreadGetName(pAioMgrNew->Thread)));
445	return VINF_SUCCESS;
446	}
447	pdmacFileAioMgrNormalDestroy(pAioMgrNew);
448	}
449	RTCritSectDelete(&pAioMgrNew->CritSectBlockingEvent);
450	}
451	RTSemEventDestroy(pAioMgrNew->EventSem);
452	}
453	RTSemEventDestroy(pAioMgrNew->EventSemBlock);
454	}
455	MMR3HeapFree(pAioMgrNew);
456	}
457
458	LogFlowFunc((": Leave rc=%Rrc\n", rc));
459
460	return rc;
461	}
462
463	/**
464	* Destroys a async I/O manager.
465	*
466	* @returns nothing.
467	* @param pAioMgr The async I/O manager to destroy.
468	*/
469	static void pdmacFileAioMgrDestroy(PPDMASYNCCOMPLETIONEPCLASSFILE pEpClassFile, PPDMACEPFILEMGR pAioMgr)
470	{
471	int rc = pdmacFileAioMgrShutdown(pAioMgr);
472	AssertRC(rc);
473
474	/* Unlink from the list. */
475	rc = RTCritSectEnter(&pEpClassFile->CritSect);
476	AssertRC(rc);
477
478	PPDMACEPFILEMGR pPrev = pAioMgr->pPrev;
479	PPDMACEPFILEMGR pNext = pAioMgr->pNext;
480
481	if (pPrev)
482	pPrev->pNext = pNext;
483	else
484	pEpClassFile->pAioMgrHead = pNext;
485
486	if (pNext)
487	pNext->pPrev = pPrev;
488
489	pEpClassFile->cAioMgrs--;
490
491	rc = RTCritSectLeave(&pEpClassFile->CritSect);
492	AssertRC(rc);
493
494	/* Free the ressources. */
495	RTCritSectDelete(&pAioMgr->CritSectBlockingEvent);
496	RTSemEventDestroy(pAioMgr->EventSem);
497	if (!pAioMgr->fFailsafe)
498	pdmacFileAioMgrNormalDestroy(pAioMgr);
499
500	MMR3HeapFree(pAioMgr);
501	}
502
503	static int pdmacFileInitialize(PPDMASYNCCOMPLETIONEPCLASS pClassGlobals, PCFGMNODE pCfgNode)
504	{
505	int rc = VINF_SUCCESS;
506	RTFILEAIOLIMITS AioLimits; /** < Async I/O limitations. */
507
508	PPDMASYNCCOMPLETIONEPCLASSFILE pEpClassFile = (PPDMASYNCCOMPLETIONEPCLASSFILE)pClassGlobals;
509
510	rc = RTFileAioGetLimits(&AioLimits);
511	#ifdef DEBUG
512	if (RT_SUCCESS(rc) && RTEnvExist("VBOX_ASYNC_IO_FAILBACK"))
513	rc = VERR_ENV_VAR_NOT_FOUND;
514	#endif
515	if (RT_FAILURE(rc))
516	{
517	LogRel(("AIO: Async I/O manager not supported (rc=%Rrc). Falling back to failsafe manager\n",
518	rc));
519	pEpClassFile->fFailsafe = true;
520	}
521	else
522	{
523	pEpClassFile->uBitmaskAlignment = AioLimits.cbBufferAlignment ? ~((RTR3UINTPTR)AioLimits.cbBufferAlignment - 1) : RTR3UINTPTR_MAX;
524	pEpClassFile->cReqsOutstandingMax = AioLimits.cReqsOutstandingMax;
525
526	/* The user can force the failsafe manager. */
527	rc = CFGMR3QueryBoolDef(pCfgNode, "UseFailsafeIo", &pEpClassFile->fFailsafe, false);
528	AssertLogRelRCReturn(rc, rc);
529
530	if (pEpClassFile->fFailsafe)
531	LogRel(("AIOMgr: Failsafe I/O was requested by user\n"));
532	}
533
534	/* Init critical section. */
535	rc = RTCritSectInit(&pEpClassFile->CritSect);
536	if (RT_SUCCESS(rc))
537	{
538	/* Check if the host cache should be used too. */
539	#ifndef RT_OS_LINUX
540	rc = CFGMR3QueryBoolDef(pCfgNode, "HostCacheEnabled", &pEpClassFile->fHostCacheEnabled, false);
541	AssertLogRelRCReturn(rc, rc);
542	#else
543	/*
544	* Host cache + async I/O is not supported on Linux. Check if the user enabled the cache,
545	* leave a warning and disable it always.
546	*/
547	bool fDummy;
548	rc = CFGMR3QueryBool(pCfgNode, "HostCacheEnabled", &fDummy);
549	if (RT_SUCCESS(rc))
550	LogRel(("AIOMgr: The host cache is not supported with async I/O on Linux\n"));
551
552	pEpClassFile->fHostCacheEnabled = false;
553	#endif
554
555	/* Check if the cache was disabled by the user. */
556	rc = CFGMR3QueryBoolDef(pCfgNode, "CacheEnabled", &pEpClassFile->fCacheEnabled, true);
557	AssertLogRelRCReturn(rc, rc);
558
559	if (pEpClassFile->fCacheEnabled)
560	{
561	/* Init cache structure */
562	rc = pdmacFileCacheInit(pEpClassFile, pCfgNode);
563	if (RT_FAILURE(rc))
564	{
565	RTCritSectDelete(&pEpClassFile->CritSect);
566	pEpClassFile->fCacheEnabled = false;
567	LogRel(("AIOMgr: Failed to initialise the cache (rc=%Rrc), disabled caching\n"));
568	}
569	}
570	else
571	LogRel(("AIOMgr: Cache was globally disabled\n"));
572	}
573
574	return rc;
575	}
576
577	static void pdmacFileTerminate(PPDMASYNCCOMPLETIONEPCLASS pClassGlobals)
578	{
579	PPDMASYNCCOMPLETIONEPCLASSFILE pEpClassFile = (PPDMASYNCCOMPLETIONEPCLASSFILE)pClassGlobals;
580
581	/* All endpoints should be closed at this point. */
582	AssertMsg(!pEpClassFile->Core.pEndpointsHead, ("There are still endpoints left\n"));
583
584	/* Destroy all left async I/O managers. */
585	while (pEpClassFile->pAioMgrHead)
586	pdmacFileAioMgrDestroy(pEpClassFile, pEpClassFile->pAioMgrHead);
587
588	/* Destroy the cache. */
589	if (pEpClassFile->fCacheEnabled)
590	pdmacFileCacheDestroy(pEpClassFile);
591
592	RTCritSectDelete(&pEpClassFile->CritSect);
593	}
594
595	static int pdmacFileEpInitialize(PPDMASYNCCOMPLETIONENDPOINT pEndpoint,
596	const char *pszUri, uint32_t fFlags)
597	{
598	int rc = VINF_SUCCESS;
599	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
600	PPDMASYNCCOMPLETIONEPCLASSFILE pEpClassFile = (PPDMASYNCCOMPLETIONEPCLASSFILE)pEndpoint->pEpClass;
601	bool fUseFailsafeManager = pEpClassFile->fFailsafe;
602
603	AssertMsgReturn((fFlags & ~(PDMACEP_FILE_FLAGS_READ_ONLY \| PDMACEP_FILE_FLAGS_CACHING)) == 0,
604	("PDMAsyncCompletion: Invalid flag specified\n"), VERR_INVALID_PARAMETER);
605
606	unsigned fFileFlags = fFlags & PDMACEP_FILE_FLAGS_READ_ONLY
607	? RTFILE_O_READ \| RTFILE_O_OPEN \| RTFILE_O_DENY_NONE
608	: RTFILE_O_READWRITE \| RTFILE_O_OPEN \| RTFILE_O_DENY_WRITE;
609
610	if (!pEpClassFile->fFailsafe)
611	{
612	fFileFlags \|= (RTFILE_O_ASYNC_IO \| RTFILE_O_WRITE_THROUGH);
613
614	/*
615	* We only disable the cache if the size of the file is a multiple of 512.
616	* Certain hosts like Windows, Linux and Solaris require that transfer sizes
617	* are aligned to the volume sector size.
618	* If not we just make sure that the data is written to disk with RTFILE_O_WRITE_THROUGH
619	* which will trash the host cache but ensures that the host cache will not
620	* contain dirty buffers.
621	*/
622	RTFILE File = NIL_RTFILE;
623
624	rc = RTFileOpen(&File, pszUri, RTFILE_O_READ \| RTFILE_O_OPEN \| RTFILE_O_DENY_NONE);
625	if (RT_SUCCESS(rc))
626	{
627	uint64_t cbSize;
628
629	rc = RTFileGetSize(File, &cbSize);
630	if (RT_SUCCESS(rc) && ((cbSize % 512) == 0))
631	{
632	fFileFlags &= ~RTFILE_O_WRITE_THROUGH;
633
634	#if defined(RT_OS_LINUX)
635	AssertMsg(!pEpClassFile->fHostCacheEnabled, ("Host cache + async I/O is not supported on Linux\n"));
636	fFileFlags \|= RTFILE_O_NO_CACHE;
637	#else
638	if (!pEpClassFile->fHostCacheEnabled)
639	fFileFlags \|= RTFILE_O_NO_CACHE;
640	#endif
641	}
642
643	pEpFile->cbFile = cbSize;
644
645	RTFileClose(File);
646	}
647	}
648
649	/* Open with final flags. */
650	rc = RTFileOpen(&pEpFile->File, pszUri, fFileFlags);
651	if ((rc == VERR_INVALID_FUNCTION) \|\| (rc == VERR_INVALID_PARAMETER))
652	{
653	LogRel(("pdmacFileEpInitialize: RTFileOpen %s / %08x failed with %Rrc\n",
654	pszUri, fFileFlags, rc));
655	/*
656	* Solaris doesn't support directio on ZFS so far. :-\
657	* Trying to enable it returns VERR_INVALID_FUNCTION
658	* (ENOTTY). Remove it and hope for the best.
659	* ZFS supports write throttling in case applications
660	* write more data than can be synced to the disk
661	* without blocking the whole application.
662	*
663	* On Linux we have the same problem with cifs.
664	* Have to disable async I/O here too because it requires O_DIRECT.
665	*/
666	fFileFlags &= ~RTFILE_O_NO_CACHE;
667
668	#ifdef RT_OS_LINUX
669	fFileFlags &= ~RTFILE_O_ASYNC_IO;
670	fUseFailsafeManager = true;
671	#endif
672
673	/* Open again. */
674	rc = RTFileOpen(&pEpFile->File, pszUri, fFileFlags);
675
676	if (RT_FAILURE(rc))
677	{
678	LogRel(("pdmacFileEpInitialize: RTFileOpen %s / %08x failed AGAIN(!) with %Rrc\n",
679	pszUri, fFileFlags, rc));
680	}
681	}
682
683	if (RT_SUCCESS(rc))
684	{
685	pEpFile->fFlags = fFileFlags;
686
687	rc = RTFileGetSize(pEpFile->File, (uint64_t *)&pEpFile->cbFile);
688	if (RT_SUCCESS(rc) && (pEpFile->cbFile == 0))
689	{
690	/* Could be a block device */
691	rc = RTFileSeek(pEpFile->File, 0, RTFILE_SEEK_END, (uint64_t *)&pEpFile->cbFile);
692	}
693
694	if (RT_SUCCESS(rc))
695	{
696	/* Initialize the segment cache */
697	rc = MMR3HeapAllocZEx(pEpClassFile->Core.pVM, MM_TAG_PDM_ASYNC_COMPLETION,
698	sizeof(PDMACTASKFILE),
699	(void **)&pEpFile->pTasksFreeHead);
700	if (RT_SUCCESS(rc))
701	{
702	PPDMACEPFILEMGR pAioMgr = NULL;
703
704	pEpFile->pTasksFreeTail = pEpFile->pTasksFreeHead;
705	pEpFile->cTasksCached = 0;
706
707	if (fUseFailsafeManager)
708	{
709	/* Safe mode. Every file has its own async I/O manager. */
710	rc = pdmacFileAioMgrCreate(pEpClassFile, &pAioMgr, true);
711	AssertRC(rc);
712	}
713	else
714	{
715	if ( (fFlags & PDMACEP_FILE_FLAGS_CACHING)
716	&& (pEpClassFile->fCacheEnabled))
717	{
718	pEpFile->fCaching = true;
719	rc = pdmacFileEpCacheInit(pEpFile, pEpClassFile);
720	if (RT_FAILURE(rc))
721	{
722	LogRel(("AIOMgr: Endpoint for \"%s\" was opened with caching but initializing cache failed. Disabled caching\n", pszUri));
723	pEpFile->fCaching = false;
724	}
725	}
726
727	pAioMgr = pEpClassFile->pAioMgrHead;
728
729	/* Check for an idling not failsafe one or create new if not found */
730	while (pAioMgr && pAioMgr->fFailsafe)
731	pAioMgr = pAioMgr->pNext;
732
733	if (!pAioMgr)
734	{
735	rc = pdmacFileAioMgrCreate(pEpClassFile, &pAioMgr, false);
736	AssertRC(rc);
737	}
738	}
739
740	pEpFile->enmState = PDMASYNCCOMPLETIONENDPOINTFILESTATE_ACTIVE;
741
742	/* Assign the endpoint to the thread. */
743	rc = pdmacFileAioMgrAddEndpoint(pAioMgr, pEpFile);
744	if (RT_FAILURE(rc))
745	MMR3HeapFree(pEpFile->pTasksFreeHead);
746	}
747	}
748
749	if (RT_FAILURE(rc))
750	RTFileClose(pEpFile->File);
751	}
752
753	#ifdef VBOX_WITH_STATISTICS
754	if (RT_SUCCESS(rc))
755	{
756	STAMR3RegisterF(pEpClassFile->Core.pVM, &pEpFile->StatRead,
757	STAMTYPE_PROFILE_ADV, STAMVISIBILITY_ALWAYS,
758	STAMUNIT_TICKS_PER_CALL, "Time taken to read from the endpoint",
759	"/PDM/AsyncCompletion/File/%s/Read", RTPathFilename(pEpFile->Core.pszUri));
760
761	STAMR3RegisterF(pEpClassFile->Core.pVM, &pEpFile->StatWrite,
762	STAMTYPE_PROFILE_ADV, STAMVISIBILITY_ALWAYS,
763	STAMUNIT_TICKS_PER_CALL, "Time taken to write to the endpoint",
764	"/PDM/AsyncCompletion/File/%s/Write", RTPathFilename(pEpFile->Core.pszUri));
765	}
766	#endif
767
768	return rc;
769	}
770
771	static int pdmacFileEpClose(PPDMASYNCCOMPLETIONENDPOINT pEndpoint)
772	{
773	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
774	PPDMASYNCCOMPLETIONEPCLASSFILE pEpClassFile = (PPDMASYNCCOMPLETIONEPCLASSFILE)pEndpoint->pEpClass;
775
776	/* Make sure that all tasks finished for this endpoint. */
777	int rc = pdmacFileAioMgrCloseEndpoint(pEpFile->pAioMgr, pEpFile);
778	AssertRC(rc);
779
780	/*
781	* If the async I/O manager is in failsafe mode this is the only endpoint
782	* he processes and thus can be destroyed now.
783	*/
784	if (pEpFile->pAioMgr->fFailsafe)
785	pdmacFileAioMgrDestroy(pEpClassFile, pEpFile->pAioMgr);
786
787	/* Free cached tasks. */
788	PPDMACTASKFILE pTask = pEpFile->pTasksFreeHead;
789
790	while (pTask)
791	{
792	PPDMACTASKFILE pTaskFree = pTask;
793	pTask = pTask->pNext;
794	MMR3HeapFree(pTaskFree);
795	}
796
797	/* Free the cached data. */
798	if (pEpFile->fCaching)
799	pdmacFileEpCacheDestroy(pEpFile);
800
801	RTFileClose(pEpFile->File);
802
803	#ifdef VBOX_WITH_STATISTICS
804	STAMR3Deregister(pEpClassFile->Core.pVM, &pEpFile->StatRead);
805	STAMR3Deregister(pEpClassFile->Core.pVM, &pEpFile->StatWrite);
806	#endif
807
808	return VINF_SUCCESS;
809	}
810
811	static int pdmacFileEpRead(PPDMASYNCCOMPLETIONTASK pTask,
812	PPDMASYNCCOMPLETIONENDPOINT pEndpoint, RTFOFF off,
813	PCPDMDATASEG paSegments, size_t cSegments,
814	size_t cbRead)
815	{
816	int rc = VINF_SUCCESS;
817	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
818
819	STAM_PROFILE_ADV_START(&pEpFile->StatRead, Read);
820
821	if (pEpFile->fCaching)
822	rc = pdmacFileEpCacheRead(pEpFile, (PPDMASYNCCOMPLETIONTASKFILE)pTask,
823	off, paSegments, cSegments, cbRead);
824	else
825	rc = pdmacFileEpTaskInitiate(pTask, pEndpoint, off, paSegments, cSegments, cbRead,
826	PDMACTASKFILETRANSFER_READ);
827
828	STAM_PROFILE_ADV_STOP(&pEpFile->StatRead, Read);
829
830	return rc;
831	}
832
833	static int pdmacFileEpWrite(PPDMASYNCCOMPLETIONTASK pTask,
834	PPDMASYNCCOMPLETIONENDPOINT pEndpoint, RTFOFF off,
835	PCPDMDATASEG paSegments, size_t cSegments,
836	size_t cbWrite)
837	{
838	int rc = VINF_SUCCESS;
839	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
840
841	if (RT_UNLIKELY(pEpFile->fReadonly))
842	return VERR_NOT_SUPPORTED;
843
844	STAM_PROFILE_ADV_START(&pEpFile->StatWrite, Write);
845
846	if (pEpFile->fCaching)
847	rc = pdmacFileEpCacheWrite(pEpFile, (PPDMASYNCCOMPLETIONTASKFILE)pTask,
848	off, paSegments, cSegments, cbWrite);
849	else
850	rc = pdmacFileEpTaskInitiate(pTask, pEndpoint, off, paSegments, cSegments, cbWrite,
851	PDMACTASKFILETRANSFER_WRITE);
852
853	STAM_PROFILE_ADV_STOP(&pEpFile->StatWrite, Write);
854
855	return rc;
856	}
857
858	static int pdmacFileEpFlush(PPDMASYNCCOMPLETIONTASK pTask,
859	PPDMASYNCCOMPLETIONENDPOINT pEndpoint)
860	{
861	int rc = VINF_SUCCESS;
862	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
863	PPDMASYNCCOMPLETIONTASKFILE pTaskFile = (PPDMASYNCCOMPLETIONTASKFILE)pTask;
864
865	if (RT_UNLIKELY(pEpFile->fReadonly))
866	return VERR_NOT_SUPPORTED;
867
868	pTaskFile->cbTransferLeft = 0;
869
870	if (pEpFile->fCaching)
871	rc = pdmacFileEpCacheFlush(pEpFile, pTaskFile);
872	else
873	{
874	PPDMACTASKFILE pIoTask = pdmacFileTaskAlloc(pEpFile);
875	AssertPtr(pIoTask);
876
877	pIoTask->pEndpoint = pEpFile;
878	pIoTask->enmTransferType = PDMACTASKFILETRANSFER_FLUSH;
879	pIoTask->pvUser = pTaskFile;
880	pIoTask->pfnCompleted = pdmacFileEpTaskCompleted;
881	pdmacFileEpAddTask(pEpFile, pIoTask);
882	rc = VINF_AIO_TASK_PENDING;
883	}
884
885	return rc;
886	}
887
888	static int pdmacFileEpGetSize(PPDMASYNCCOMPLETIONENDPOINT pEndpoint, uint64_t *pcbSize)
889	{
890	PPDMASYNCCOMPLETIONENDPOINTFILE pEpFile = (PPDMASYNCCOMPLETIONENDPOINTFILE)pEndpoint;
891
892	*pcbSize = ASMAtomicReadU64(&pEpFile->cbFile);
893
894	return VINF_SUCCESS;
895	}
896
897	const PDMASYNCCOMPLETIONEPCLASSOPS g_PDMAsyncCompletionEndpointClassFile =
898	{
899	/* u32Version */
900	PDMAC_EPCLASS_OPS_VERSION,
901	/* pcszName */
902	"File",
903	/* enmClassType */
904	PDMASYNCCOMPLETIONEPCLASSTYPE_FILE,
905	/* cbEndpointClassGlobal */
906	sizeof(PDMASYNCCOMPLETIONEPCLASSFILE),
907	/* cbEndpoint */
908	sizeof(PDMASYNCCOMPLETIONENDPOINTFILE),
909	/* cbTask */
910	sizeof(PDMASYNCCOMPLETIONTASKFILE),
911	/* pfnInitialize */
912	pdmacFileInitialize,
913	/* pfnTerminate */
914	pdmacFileTerminate,
915	/* pfnEpInitialize. */
916	pdmacFileEpInitialize,
917	/* pfnEpClose */
918	pdmacFileEpClose,
919	/* pfnEpRead */
920	pdmacFileEpRead,
921	/* pfnEpWrite */
922	pdmacFileEpWrite,
923	/* pfnEpFlush */
924	pdmacFileEpFlush,
925	/* pfnEpGetSize */
926	pdmacFileEpGetSize,
927	/* u32VersionEnd */
928	PDMAC_EPCLASS_OPS_VERSION
929	};
930

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source: vbox/trunk/src/VBox/VMM/PDMAsyncCompletionFile.cpp@ 26147

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