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notification.c
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/*
Dokan : user-mode file system library for Windows
Copyright (C) 2015 - 2019 Adrien J. <liryna.stark@gmail.com> and Maxime C. <maxime@islog.com>
Copyright (C) 2017 - 2018 Google, Inc.
Copyright (C) 2007 - 2011 Hiroki Asakawa <info@dokan-dev.net>
http://dokan-dev.github.io
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your option) any
later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU Lesser General Public License along
with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
IOCTL_EVENT_START:
DokanStartEventNotificationThread
NotificationThread
# PendingEvent has pending IPRs (IOCTL_EVENT_WAIT)
# NotifyEvent has IO events (ex.IRP_MJ_READ)
# notify NotifyEvent using PendingEvent in this loop
NotificationLoop(&Dcb->PendingEvent,
&Dcb->NotifyEvent);
# PendingService has service events (ex. Unmount notification)
# NotifyService has pending IRPs (IOCTL_SERVICE_WAIT)
NotificationLoop(Dcb->Global->PendingService,
&Dcb->Global->NotifyService);
IOCTL_EVENT_RELEASE:
DokanStopEventNotificationThread
IRP_MJ_READ:
DokanDispatchRead
DokanRegisterPendingIrp
# add IRP_MJ_READ to PendingIrp list
DokanRegisterPendingIrpMain(PendingIrp)
# put MJ_READ event into NotifyEvent
DokanEventNotification(NotifyEvent, EventContext)
IOCTL_EVENT_WAIT:
DokanRegisterPendingIrpForEvent
# add this irp to PendingEvent list
DokanRegisterPendingIrpMain(PendingEvent)
IOCTL_EVENT_INFO:
DokanCompleteIrp
DokanCompleteRead
*/
#include "dokan.h"
#include "util/irp_buffer_helper.h"
VOID SetCommonEventContext(__in PDokanDCB Dcb, __in PEVENT_CONTEXT EventContext,
__in PIRP Irp, __in_opt PDokanCCB Ccb) {
PIO_STACK_LOCATION irpSp;
irpSp = IoGetCurrentIrpStackLocation(Irp);
EventContext->MountId = Dcb->MountId;
EventContext->MajorFunction = irpSp->MajorFunction;
EventContext->MinorFunction = irpSp->MinorFunction;
EventContext->Flags = irpSp->Flags;
if (Ccb) {
EventContext->FileFlags = DokanCCBFlagsGet(Ccb);
}
EventContext->ProcessId = IoGetRequestorProcessId(Irp);
}
PEVENT_CONTEXT
AllocateEventContextRaw(__in ULONG EventContextLength) {
ULONG driverContextLength;
PDRIVER_EVENT_CONTEXT driverEventContext;
PEVENT_CONTEXT eventContext;
if (EventContextLength < sizeof(EVENT_CONTEXT) ||
EventContextLength > MAXULONG - sizeof(DRIVER_EVENT_CONTEXT)) {
DDbgPrint(
" AllocateEventContextRaw invalid EventContextLength requested.\n");
return NULL;
}
driverContextLength =
EventContextLength - sizeof(EVENT_CONTEXT) + sizeof(DRIVER_EVENT_CONTEXT);
driverEventContext = DokanAllocZero(driverContextLength);
if (driverEventContext == NULL) {
return NULL;
}
InitializeListHead(&driverEventContext->ListEntry);
eventContext = &driverEventContext->EventContext;
eventContext->Length = EventContextLength;
return eventContext;
}
PEVENT_CONTEXT
AllocateEventContext(__in PDokanDCB Dcb, __in PIRP Irp,
__in ULONG EventContextLength, __in_opt PDokanCCB Ccb) {
PEVENT_CONTEXT eventContext;
eventContext = AllocateEventContextRaw(EventContextLength);
if (eventContext == NULL) {
return NULL;
}
SetCommonEventContext(Dcb, eventContext, Irp, Ccb);
eventContext->SerialNumber = InterlockedIncrement((LONG *)&Dcb->SerialNumber);
return eventContext;
}
VOID DokanFreeEventContext(__in PEVENT_CONTEXT EventContext) {
PDRIVER_EVENT_CONTEXT driverEventContext =
CONTAINING_RECORD(EventContext, DRIVER_EVENT_CONTEXT, EventContext);
ExFreePool(driverEventContext);
}
VOID DokanEventNotification(__in PIRP_LIST NotifyEvent,
__in PEVENT_CONTEXT EventContext) {
PDRIVER_EVENT_CONTEXT driverEventContext =
CONTAINING_RECORD(EventContext, DRIVER_EVENT_CONTEXT, EventContext);
InitializeListHead(&driverEventContext->ListEntry);
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
// DDbgPrint("DokanEventNotification\n");
ExInterlockedInsertTailList(&NotifyEvent->ListHead,
&driverEventContext->ListEntry,
&NotifyEvent->ListLock);
KeSetEvent(&NotifyEvent->NotEmpty, IO_NO_INCREMENT, FALSE);
}
// Moves the contents of the given Source list to Dest, discarding IRPs that
// have been canceled while waiting in the list. The IRPs that end up in Dest
// should then be acted on in some way that leads to their completion. The
// Source list is still usable and is empty after this function returns.
VOID MoveIrpList(__in PIRP_LIST Source, __out LIST_ENTRY* Dest) {
PLIST_ENTRY listHead;
PIRP_ENTRY irpEntry;
KIRQL oldIrql;
PIRP irp;
InitializeListHead(Dest);
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
KeAcquireSpinLock(&Source->ListLock, &oldIrql);
while (!IsListEmpty(&Source->ListHead)) {
listHead = RemoveHeadList(&Source->ListHead);
irpEntry = CONTAINING_RECORD(listHead, IRP_ENTRY, ListEntry);
irp = irpEntry->Irp;
if (irp == NULL) {
// this IRP has already been canceled
ASSERT(irpEntry->CancelRoutineFreeMemory == FALSE);
DokanFreeIrpEntry(irpEntry);
continue;
}
if (IoSetCancelRoutine(irp, NULL) == NULL) {
// Cancel routine will run as soon as we release the lock
InitializeListHead(&irpEntry->ListEntry);
irpEntry->CancelRoutineFreeMemory = TRUE;
continue;
}
InsertTailList(Dest, &irpEntry->ListEntry);
}
KeClearEvent(&Source->NotEmpty);
KeReleaseSpinLock(&Source->ListLock, oldIrql);
}
VOID ReleasePendingIrp(__in PIRP_LIST PendingIrp) {
PLIST_ENTRY listHead;
LIST_ENTRY completeList;
PIRP_ENTRY irpEntry;
PIRP irp;
MoveIrpList(PendingIrp, &completeList);
while (!IsListEmpty(&completeList)) {
listHead = RemoveHeadList(&completeList);
irpEntry = CONTAINING_RECORD(listHead, IRP_ENTRY, ListEntry);
irp = irpEntry->Irp;
DokanFreeIrpEntry(irpEntry);
DokanCompleteIrpRequest(irp, STATUS_CANCELLED, 0);
}
}
VOID ReleaseNotifyEvent(__in PIRP_LIST NotifyEvent) {
PDRIVER_EVENT_CONTEXT driverEventContext;
PLIST_ENTRY listHead;
KIRQL oldIrql;
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
KeAcquireSpinLock(&NotifyEvent->ListLock, &oldIrql);
while (!IsListEmpty(&NotifyEvent->ListHead)) {
listHead = RemoveHeadList(&NotifyEvent->ListHead);
driverEventContext =
CONTAINING_RECORD(listHead, DRIVER_EVENT_CONTEXT, ListEntry);
ExFreePool(driverEventContext);
}
KeClearEvent(&NotifyEvent->NotEmpty);
KeReleaseSpinLock(&NotifyEvent->ListLock, oldIrql);
}
VOID RetryIrps(__in PIRP_LIST PendingRetryIrp) {
PLIST_ENTRY listHead;
LIST_ENTRY retryList;
PIRP_ENTRY irpEntry;
PIRP irp;
PDEVICE_OBJECT deviceObject = NULL;
MoveIrpList(PendingRetryIrp, &retryList);
while (!IsListEmpty(&retryList)) {
listHead = RemoveHeadList(&retryList);
irpEntry = CONTAINING_RECORD(listHead, IRP_ENTRY, ListEntry);
irp = irpEntry->Irp;
deviceObject = irpEntry->IrpSp->DeviceObject;
DokanFreeIrpEntry(irpEntry);
DokanBuildRequest(deviceObject, irp);
}
}
VOID NotificationLoop(__in PIRP_LIST PendingIrp, __in PIRP_LIST NotifyEvent) {
PDRIVER_EVENT_CONTEXT driverEventContext;
PLIST_ENTRY listHead;
PIRP_ENTRY irpEntry;
LIST_ENTRY completeList;
KIRQL irpIrql;
KIRQL notifyIrql;
PIRP irp;
ULONG eventLen;
ULONG bufferLen;
PVOID buffer;
DDbgPrint("=> NotificationLoop\n");
InitializeListHead(&completeList);
ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
DDbgPrint("Try acquire SpinLock...\n");
KeAcquireSpinLock(&PendingIrp->ListLock, &irpIrql);
DDbgPrint("SpinLock irp Acquired\n");
KeAcquireSpinLock(&NotifyEvent->ListLock, ¬ifyIrql);
DDbgPrint("SpinLock notify Acquired\n");
while (!IsListEmpty(&PendingIrp->ListHead) &&
!IsListEmpty(&NotifyEvent->ListHead)) {
listHead = RemoveHeadList(&NotifyEvent->ListHead);
driverEventContext =
CONTAINING_RECORD(listHead, DRIVER_EVENT_CONTEXT, ListEntry);
listHead = RemoveHeadList(&PendingIrp->ListHead);
irpEntry = CONTAINING_RECORD(listHead, IRP_ENTRY, ListEntry);
eventLen = driverEventContext->EventContext.Length;
// ensure this eventIrp is not cancelled
irp = irpEntry->Irp;
if (irp == NULL) {
// this IRP has already been canceled
DDbgPrint("Irp canceled\n");
ASSERT(irpEntry->CancelRoutineFreeMemory == FALSE);
DokanFreeIrpEntry(irpEntry);
// push back
InsertTailList(&NotifyEvent->ListHead, &driverEventContext->ListEntry);
continue;
}
if (IoSetCancelRoutine(irp, NULL) == NULL) {
DDbgPrint("IoSetCancelRoutine return NULL\n");
// Cancel routine will run as soon as we release the lock
InitializeListHead(&irpEntry->ListEntry);
irpEntry->CancelRoutineFreeMemory = TRUE;
// push back
InsertTailList(&NotifyEvent->ListHead, &driverEventContext->ListEntry);
continue;
}
// available size that is used for event notification
bufferLen = irpEntry->IrpSp->Parameters.DeviceIoControl.OutputBufferLength;
// buffer that is used to inform Event
buffer = irp->AssociatedIrp.SystemBuffer;
// buffer is not specified or short of length
if (bufferLen == 0 || buffer == NULL || bufferLen < eventLen) {
DDbgPrint("EventNotice : STATUS_INSUFFICIENT_RESOURCES\n");
DDbgPrint(" bufferLen: %d, eventLen: %d\n", bufferLen, eventLen);
// push back
InsertTailList(&NotifyEvent->ListHead, &driverEventContext->ListEntry);
// marks as STATUS_INSUFFICIENT_RESOURCES
irpEntry->SerialNumber = 0;
} else {
// let's copy EVENT_CONTEXT
RtlCopyMemory(buffer, &driverEventContext->EventContext, eventLen);
// save event length
irpEntry->SerialNumber = eventLen;
if (driverEventContext->Completed) {
KeSetEvent(driverEventContext->Completed, IO_NO_INCREMENT, FALSE);
}
ExFreePool(driverEventContext);
}
InsertTailList(&completeList, &irpEntry->ListEntry);
}
DDbgPrint("Clear Events...\n");
KeClearEvent(&NotifyEvent->NotEmpty);
DDbgPrint("Notify event cleared\n");
KeClearEvent(&PendingIrp->NotEmpty);
DDbgPrint("Pending event cleared\n");
DDbgPrint("Release SpinLock...\n");
KeReleaseSpinLock(&NotifyEvent->ListLock, notifyIrql);
DDbgPrint("SpinLock notify Released\n");
KeReleaseSpinLock(&PendingIrp->ListLock, irpIrql);
DDbgPrint("SpinLock irp Released\n");
while (!IsListEmpty(&completeList)) {
listHead = RemoveHeadList(&completeList);
irpEntry = CONTAINING_RECORD(listHead, IRP_ENTRY, ListEntry);
irp = irpEntry->Irp;
if (irpEntry->SerialNumber == 0) {
irp->IoStatus.Information = 0;
irp->IoStatus.Status = STATUS_INSUFFICIENT_RESOURCES;
} else {
irp->IoStatus.Information = irpEntry->SerialNumber;
irp->IoStatus.Status = STATUS_SUCCESS;
}
DokanFreeIrpEntry(irpEntry);
DokanCompleteIrpRequest(irp, irp->IoStatus.Status,
irp->IoStatus.Information);
}
DDbgPrint("<= NotificationLoop\n");
}
KSTART_ROUTINE NotificationThread;
VOID NotificationThread(__in PVOID pDcb) {
PKEVENT events[6];
PKWAIT_BLOCK waitBlock;
NTSTATUS status;
PDokanDCB Dcb = pDcb;
DDbgPrint("==> NotificationThread\n");
waitBlock = DokanAlloc(sizeof(KWAIT_BLOCK) * 6);
if (waitBlock == NULL) {
DDbgPrint(" Can't allocate WAIT_BLOCK\n");
return;
}
events[0] = &Dcb->ReleaseEvent;
events[1] = &Dcb->NotifyEvent.NotEmpty;
events[2] = &Dcb->PendingEvent.NotEmpty;
events[3] = &Dcb->Global->PendingService.NotEmpty;
events[4] = &Dcb->Global->NotifyService.NotEmpty;
events[5] = &Dcb->PendingRetryIrp.NotEmpty;
do {
status = KeWaitForMultipleObjects(6, events, WaitAny, Executive, KernelMode,
FALSE, NULL, waitBlock);
if (status != STATUS_WAIT_0) {
if (status == STATUS_WAIT_1 || status == STATUS_WAIT_2) {
NotificationLoop(&Dcb->PendingEvent, &Dcb->NotifyEvent);
} else if (status == STATUS_WAIT_0 + 3 || status == STATUS_WAIT_0 + 4) {
NotificationLoop(&Dcb->Global->PendingService,
&Dcb->Global->NotifyService);
} else {
RetryIrps(&Dcb->PendingRetryIrp);
}
}
} while (status != STATUS_WAIT_0);
ExFreePool(waitBlock);
DDbgPrint("<== NotificationThread\n");
}
NTSTATUS
DokanStartEventNotificationThread(__in PDokanDCB Dcb) {
NTSTATUS status;
HANDLE thread;
DDbgPrint("==> DokanStartEventNotificationThread\n");
KeResetEvent(&Dcb->ReleaseEvent);
status = PsCreateSystemThread(&thread, THREAD_ALL_ACCESS, NULL, NULL, NULL,
(PKSTART_ROUTINE)NotificationThread, Dcb);
if (!NT_SUCCESS(status)) {
return status;
}
ObReferenceObjectByHandle(thread, THREAD_ALL_ACCESS, NULL, KernelMode,
(PVOID *)&Dcb->EventNotificationThread, NULL);
ZwClose(thread);
DDbgPrint("<== DokanStartEventNotificationThread\n");
return STATUS_SUCCESS;
}
VOID DokanStopEventNotificationThread(__in PDokanDCB Dcb) {
DDbgPrint("==> DokanStopEventNotificationThread\n");
if (KeSetEvent(&Dcb->ReleaseEvent, 0, FALSE) > 0 &&
Dcb->EventNotificationThread) {
DDbgPrint("Waiting for Notify thread to terminate.\n");
ASSERT(KeGetCurrentIrql() <= APC_LEVEL);
if (Dcb->EventNotificationThread) {
KeWaitForSingleObject(Dcb->EventNotificationThread, Executive, KernelMode,
FALSE, NULL);
DDbgPrint("Notify thread successfully terminated.\n");
ObDereferenceObject(Dcb->EventNotificationThread);
Dcb->EventNotificationThread = NULL;
}
}
DDbgPrint("<== DokanStopEventNotificationThread\n");
}
VOID DokanCleanupAllChangeNotificationWaiters(__in PDokanVCB Vcb) {
DokanVCBLockRW(Vcb);
DOKAN_INIT_LOGGER(logger, Vcb->Dcb->DeviceObject->DriverObject, 0);
DokanLogInfo(&logger, L"Cleaning up all change notification waiters.");
FsRtlNotifyCleanupAll(Vcb->NotifySync, &Vcb->DirNotifyList);
DokanVCBUnlock(Vcb);
}
VOID DokanStopFcbGarbageCollectorThread(__in PDokanVCB Vcb) {
if (Vcb->FcbGarbageCollectorThread != NULL) {
KeWaitForSingleObject(Vcb->FcbGarbageCollectorThread, Executive, KernelMode,
FALSE, NULL);
ObDereferenceObject(Vcb->FcbGarbageCollectorThread);
Vcb->FcbGarbageCollectorThread = NULL;
}
}
NTSTATUS DokanEventRelease(__in PDEVICE_OBJECT DeviceObject, __in PIRP Irp) {
PDokanDCB dcb;
PDokanVCB vcb;
NTSTATUS status = STATUS_SUCCESS;
DOKAN_INIT_LOGGER(logger,
DeviceObject == NULL ? NULL
: DeviceObject->DriverObject,
0);
if (DeviceObject == NULL) {
return STATUS_INVALID_PARAMETER;
}
DokanLogInfo(&logger, L"Entered event release.");
vcb = DeviceObject->DeviceExtension;
if (GetIdentifierType(vcb) != VCB) {
return DokanLogError(&logger, STATUS_INVALID_PARAMETER,
L"VCB being released has wrong identifier type.");
}
dcb = vcb->Dcb;
if (IsDeletePending(dcb->DeviceObject)) {
DokanLogInfo(&logger, L"Event release is already running for this device.");
return STATUS_SUCCESS;
}
if (IsUnmountPendingVcb(vcb)) {
DokanLogInfo(&logger, L"Event release is already running for this volume.");
return STATUS_SUCCESS;
}
status = IoAcquireRemoveLock(&dcb->RemoveLock, Irp);
if (!NT_SUCCESS(status)) {
DokanLogError(&logger, status, L"IoAcquireRemoveLock failed in release.");
return STATUS_DEVICE_REMOVED;
}
// as first delete the mountpoint
// in case of MountManager some request because of delete
// must be handled properly
DokanDeleteMountPoint(dcb);
// then mark the device for unmount pending
SetLongFlag(vcb->Flags, VCB_DISMOUNT_PENDING);
SetLongFlag(dcb->Flags, DCB_DELETE_PENDING);
DokanLogInfo(&logger, L"Starting unmount for device %wZ",
dcb->DiskDeviceName);
ReleasePendingIrp(&dcb->PendingIrp);
ReleasePendingIrp(&dcb->PendingEvent);
ReleasePendingIrp(&dcb->PendingRetryIrp);
DokanStopCheckThread(dcb);
DokanStopEventNotificationThread(dcb);
// Note that the garbage collector thread also gets signalled to stop by
// DokanStopEventNotificationThread. TODO(drivefs-team): maybe seperate out
// the signal to stop.
DokanStopFcbGarbageCollectorThread(vcb);
ClearLongFlag(vcb->Flags, VCB_MOUNTED);
DokanCleanupAllChangeNotificationWaiters(vcb);
IoReleaseRemoveLockAndWait(&dcb->RemoveLock, Irp);
DokanDeleteDeviceObject(dcb);
DokanLogInfo(&logger, L"Finished event release.");
return status;
}
ULONG GetCurrentSessionId(__in PIRP Irp) {
ULONG sessionNumber;
NTSTATUS status;
status = IoGetRequestorSessionId(Irp, &sessionNumber);
if (!NT_SUCCESS(status)) {
DDbgPrint(" IoGetRequestorSessionId failed\n");
return (ULONG)-1;
}
DDbgPrint(" GetCurrentSessionId %lu\n", sessionNumber);
return sessionNumber;
}
NTSTATUS DokanGlobalEventRelease(__in PDEVICE_OBJECT DeviceObject,
__in PIRP Irp) {
PDOKAN_GLOBAL dokanGlobal;
PDOKAN_UNICODE_STRING_INTERMEDIATE szMountPoint;
DOKAN_CONTROL dokanControl;
PMOUNT_ENTRY mountEntry;
dokanGlobal = DeviceObject->DeviceExtension;
if (GetIdentifierType(dokanGlobal) != DGL) {
return STATUS_INVALID_PARAMETER;
}
GET_IRP_UNICODE_STRING_INTERMEDIATE_OR_RETURN(Irp, szMountPoint)
RtlZeroMemory(&dokanControl, sizeof(DOKAN_CONTROL));
RtlStringCchCopyW(dokanControl.MountPoint, MAXIMUM_FILENAME_LENGTH,
L"\\DosDevices\\");
if ((szMountPoint->Length / sizeof(WCHAR)) < 4) {
dokanControl.MountPoint[12] = towupper(szMountPoint->Buffer[0]);
dokanControl.MountPoint[13] = L':';
dokanControl.MountPoint[14] = L'\0';
} else {
if (szMountPoint->Length >
sizeof(dokanControl.MountPoint) - 12 * sizeof(WCHAR)) {
DDbgPrint("Mount point buffer has invalid size\n");
return STATUS_BUFFER_OVERFLOW;
}
RtlCopyMemory(&dokanControl.MountPoint[12], szMountPoint->Buffer,
szMountPoint->Length);
}
dokanControl.SessionId = GetCurrentSessionId(Irp);
mountEntry = FindMountEntry(dokanGlobal, &dokanControl, TRUE);
if (mountEntry == NULL) {
dokanControl.SessionId = (ULONG)-1;
DDbgPrint("Cannot found device associated to mount point %ws\n",
dokanControl.MountPoint);
return STATUS_BUFFER_TOO_SMALL;
}
if (IsDeletePending(mountEntry->MountControl.VolumeDeviceObject)) {
DDbgPrint("Device is deleted\n") return STATUS_DEVICE_REMOVED;
}
if (!IsMounted(mountEntry->MountControl.VolumeDeviceObject)) {
DDbgPrint("Device is still not mounted, so an unmount not possible at this "
"point\n") return STATUS_DEVICE_BUSY;
}
return DokanEventRelease(mountEntry->MountControl.VolumeDeviceObject, Irp);
}