misc.c File Reference

#include "vfat.h"
#include <debug.h>

Include dependency graph for misc.c:

Go to the source code of this file.

Macros
#define	NDEBUG

Functions
static VOID	VfatFreeIrpContext (PVFAT_IRP_CONTEXT)
static PVFAT_IRP_CONTEXT	VfatAllocateIrpContext (PDEVICE_OBJECT, PIRP)
static NTSTATUS	VfatQueueRequest (PVFAT_IRP_CONTEXT)
static NTSTATUS	VfatLockControl (IN PVFAT_IRP_CONTEXT IrpContext)
static NTSTATUS	VfatDeviceControl (IN PVFAT_IRP_CONTEXT IrpContext)
static NTSTATUS	VfatDispatchRequest (IN PVFAT_IRP_CONTEXT IrpContext)
VOID NTAPI	VfatHandleDeferredWrite (IN PVOID IrpContext, IN PVOID Unused)
NTSTATUS NTAPI	VfatBuildRequest (IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
static VOID NTAPI	VfatDoRequest (PVOID IrpContext)
PVOID	VfatGetUserBuffer (IN PIRP Irp, IN BOOLEAN Paging)
NTSTATUS	VfatLockUserBuffer (IN PIRP Irp, IN ULONG Length, IN LOCK_OPERATION Operation)
BOOLEAN	VfatCheckForDismount (IN PDEVICE_EXTENSION DeviceExt, IN BOOLEAN Force)

Variables
const char *	MajorFunctionNames []
static LONG	QueueCount = 0
static WORKER_THREAD_ROUTINE	VfatDoRequest

Macro Definition Documentation

NDEBUG

#define NDEBUG

Definition at line 14 of file misc.c.

Function Documentation

VfatAllocateIrpContext()

static PVFAT_IRP_CONTEXT VfatAllocateIrpContext ( PDEVICE_OBJECT  DeviceObject, PIRP  Irp  )

static

Definition at line 264 of file misc.c.

{
    PVFAT_IRP_CONTEXT IrpContext;
    /*PIO_STACK_LOCATION Stack;*/
    UCHAR MajorFunction;

    DPRINT("VfatAllocateIrpContext(DeviceObject %p, Irp %p)\n", DeviceObject, Irp);

    ASSERT(DeviceObject);
    ASSERT(Irp);

    IrpContext = ExAllocateFromNPagedLookasideList(&VfatGlobalData->IrpContextLookasideList);
    if (IrpContext)
    {
        RtlZeroMemory(IrpContext, sizeof(VFAT_IRP_CONTEXT));
        IrpContext->Irp = Irp;
        IrpContext->DeviceObject = DeviceObject;
        IrpContext->DeviceExt = DeviceObject->DeviceExtension;
        IrpContext->Stack = IoGetCurrentIrpStackLocation(Irp);
        ASSERT(IrpContext->Stack);
        MajorFunction = IrpContext->MajorFunction = IrpContext->Stack->MajorFunction;
        IrpContext->MinorFunction = IrpContext->Stack->MinorFunction;
        IrpContext->FileObject = IrpContext->Stack->FileObject;
        IrpContext->Flags = IRPCONTEXT_COMPLETE;

        /* Easy cases that can wait */
        if (MajorFunction == IRP_MJ_CLEANUP ||
            MajorFunction == IRP_MJ_CREATE ||
            MajorFunction == IRP_MJ_SHUTDOWN ||
            MajorFunction == IRP_MJ_CLOSE /* likely to be fixed */)
        {
            SetFlag(IrpContext->Flags, IRPCONTEXT_CANWAIT);
        }
        /* Cases that can wait if synchronous IRP */
        else if ((MajorFunction == IRP_MJ_DEVICE_CONTROL ||
                  MajorFunction == IRP_MJ_QUERY_INFORMATION ||
                  MajorFunction == IRP_MJ_SET_INFORMATION ||
                  MajorFunction == IRP_MJ_FLUSH_BUFFERS ||
                  MajorFunction == IRP_MJ_LOCK_CONTROL ||
                  MajorFunction == IRP_MJ_QUERY_VOLUME_INFORMATION ||
                  MajorFunction == IRP_MJ_SET_VOLUME_INFORMATION ||
                  MajorFunction == IRP_MJ_DIRECTORY_CONTROL ||
                  MajorFunction == IRP_MJ_WRITE ||
                  MajorFunction == IRP_MJ_READ) &&
                 IoIsOperationSynchronous(Irp))
        {
            SetFlag(IrpContext->Flags, IRPCONTEXT_CANWAIT);
        }
        /* Cases that can wait if synchronous or if no FO */
        else if ((MajorFunction == IRP_MJ_FILE_SYSTEM_CONTROL ||
                  MajorFunction == IRP_MJ_PNP) &&
                 (IoGetCurrentIrpStackLocation(Irp)->FileObject == NULL ||
                  IoIsOperationSynchronous(Irp)))
        {
            SetFlag(IrpContext->Flags, IRPCONTEXT_CANWAIT);
        }

        KeInitializeEvent(&IrpContext->Event, NotificationEvent, FALSE);
        IrpContext->RefCount = 0;
        IrpContext->PriorityBoost = IO_NO_INCREMENT;
    }
    return IrpContext;
}

Referenced by VfatBuildRequest().

VfatBuildRequest()

NTSTATUS NTAPI VfatBuildRequest	(	IN PDEVICE_OBJECT	DeviceObject,
		IN PIRP	Irp
	)

Definition at line 227 of file misc.c.

{
    NTSTATUS Status;
    PVFAT_IRP_CONTEXT IrpContext;

    DPRINT("VfatBuildRequest (DeviceObject %p, Irp %p)\n", DeviceObject, Irp);

    ASSERT(DeviceObject);
    ASSERT(Irp);

    IrpContext = VfatAllocateIrpContext(DeviceObject, Irp);
    if (IrpContext == NULL)
    {
        Status = STATUS_INSUFFICIENT_RESOURCES;
        Irp->IoStatus.Status = Status;
        IoCompleteRequest(Irp, IO_NO_INCREMENT);
    }
    else
    {
        Status = VfatDispatchRequest(IrpContext);
    }
    return Status;
}

VfatCheckForDismount()

BOOLEAN VfatCheckForDismount	(	IN PDEVICE_EXTENSION	DeviceExt,
		IN BOOLEAN	Force
	)

Definition at line 417 of file misc.c.

{
    KIRQL OldIrql;
    ULONG UnCleanCount;
    PVPB Vpb;
    BOOLEAN Delete;

    DPRINT1("VfatCheckForDismount(%p, %u)\n", DeviceExt, Force);

    /* If the VCB is OK (not under uninitialization) and we don't force dismount, do nothing */
    if (BooleanFlagOn(DeviceExt->Flags, VCB_GOOD) && !Force)
    {
        return FALSE;
    }

    /*
     * NOTE: In their *CheckForDismount() function, our 3rd-party FS drivers
     * as well as MS' fastfat, perform a comparison check of the current VCB's
     * VPB ReferenceCount with some sort of "dangling"/"residual" open count,
     * depending on whether or not we are in IRP_MJ_CREATE.
     * It seems to be related to the fact that the volume root directory as
     * well as auxiliary data stream(s) are still opened, and only these are
     * allowed to be opened at that moment. After analysis it appears that for
     * the ReactOS' fastfat, this number is equal to "2".
     */
    UnCleanCount = 2;

    /* Lock VPB */
    IoAcquireVpbSpinLock(&OldIrql);

    /* Reference it and check if a create is being done */
    Vpb = DeviceExt->IoVPB;
    DPRINT("Vpb->ReferenceCount = %d\n", Vpb->ReferenceCount);
    if (Vpb->ReferenceCount != UnCleanCount || DeviceExt->OpenHandleCount != 0)
    {
        /* If we force-unmount, copy the VPB to our local own to prepare later dismount */
        if (Force && Vpb->RealDevice->Vpb == Vpb && DeviceExt->SpareVPB != NULL)
        {
            RtlZeroMemory(DeviceExt->SpareVPB, sizeof(VPB));
            DeviceExt->SpareVPB->Type = IO_TYPE_VPB;
            DeviceExt->SpareVPB->Size = sizeof(VPB);
            DeviceExt->SpareVPB->RealDevice = DeviceExt->IoVPB->RealDevice;
            DeviceExt->SpareVPB->DeviceObject = NULL;
            DeviceExt->SpareVPB->Flags = DeviceExt->IoVPB->Flags & VPB_REMOVE_PENDING;
            DeviceExt->IoVPB->RealDevice->Vpb = DeviceExt->SpareVPB;
            DeviceExt->SpareVPB = NULL;
            DeviceExt->IoVPB->Flags |= VPB_PERSISTENT;

            /* We are uninitializing, the VCB cannot be used anymore */
            ClearFlag(DeviceExt->Flags, VCB_GOOD);
        }

        /* Don't do anything for now */
        Delete = FALSE;
    }
    else
    {
        /* Otherwise, delete the volume */
        Delete = TRUE;

        /* Swap the VPB with our local own */
        if (Vpb->RealDevice->Vpb == Vpb && DeviceExt->SpareVPB != NULL)
        {
            RtlZeroMemory(DeviceExt->SpareVPB, sizeof(VPB));
            DeviceExt->SpareVPB->Type = IO_TYPE_VPB;
            DeviceExt->SpareVPB->Size = sizeof(VPB);
            DeviceExt->SpareVPB->RealDevice = DeviceExt->IoVPB->RealDevice;
            DeviceExt->SpareVPB->DeviceObject = NULL;
            DeviceExt->SpareVPB->Flags = DeviceExt->IoVPB->Flags & VPB_REMOVE_PENDING;
            DeviceExt->IoVPB->RealDevice->Vpb = DeviceExt->SpareVPB;
            DeviceExt->SpareVPB = NULL;
            DeviceExt->IoVPB->Flags |= VPB_PERSISTENT;

            /* We are uninitializing, the VCB cannot be used anymore */
            ClearFlag(DeviceExt->Flags, VCB_GOOD);
        }

        /*
         * We defer setting the VPB's DeviceObject to NULL for later because
         * we want to handle the closing of the internal opened meta-files.
         */

        /* Clear the mounted and locked flags in the VPB */
        ClearFlag(Vpb->Flags, VPB_MOUNTED | VPB_LOCKED);
    }

    /* Release lock and return status */
    IoReleaseVpbSpinLock(OldIrql);

    /* If we were to delete, delete volume */
    if (Delete)
    {
        LARGE_INTEGER Zero = {{0,0}};
        PVFATFCB Fcb;

        /* We are uninitializing, the VCB cannot be used anymore */
        ClearFlag(DeviceExt->Flags, VCB_GOOD);

        /* Invalidate and close the internal opened meta-files */
        if (DeviceExt->RootFcb)
        {
            Fcb = DeviceExt->RootFcb;
            CcUninitializeCacheMap(Fcb->FileObject,
                                   &Zero,
                                   NULL);
            ObDereferenceObject(Fcb->FileObject);
            DeviceExt->RootFcb = NULL;
            vfatDestroyFCB(Fcb);
        }
        if (DeviceExt->VolumeFcb)
        {
            Fcb = DeviceExt->VolumeFcb;
#ifndef VOLUME_IS_NOT_CACHED_WORK_AROUND_IT
            CcUninitializeCacheMap(Fcb->FileObject,
                                   &Zero,
                                   NULL);
            ObDereferenceObject(Fcb->FileObject);
#endif
            DeviceExt->VolumeFcb = NULL;
            vfatDestroyFCB(Fcb);
        }
        if (DeviceExt->FATFileObject)
        {
            Fcb = DeviceExt->FATFileObject->FsContext;
            CcUninitializeCacheMap(DeviceExt->FATFileObject,
                                   &Zero,
                                   NULL);
            DeviceExt->FATFileObject->FsContext = NULL;
            ObDereferenceObject(DeviceExt->FATFileObject);
            DeviceExt->FATFileObject = NULL;
            vfatDestroyFCB(Fcb);
        }

        /*
         * Now that the closing of the internal opened meta-files has been
         * handled, we can now set the VPB's DeviceObject to NULL.
         */
        Vpb->DeviceObject = NULL;

        /* If we have a local VPB, we'll have to delete it
         * but we won't dismount us - something went bad before
         */
        if (DeviceExt->SpareVPB)
        {
            ExFreePool(DeviceExt->SpareVPB);
        }
        /* Otherwise, delete any of the available VPB if its reference count is zero */
        else if (DeviceExt->IoVPB->ReferenceCount == 0)
        {
            ExFreePool(DeviceExt->IoVPB);
        }

        /* Remove the volume from the list */
        ExAcquireResourceExclusiveLite(&VfatGlobalData->VolumeListLock, TRUE);
        RemoveEntryList(&DeviceExt->VolumeListEntry);
        ExReleaseResourceLite(&VfatGlobalData->VolumeListLock);

        /* Uninitialize the notify synchronization object */
        FsRtlNotifyUninitializeSync(&DeviceExt->NotifySync);

        /* Release resources */
        ExFreePoolWithTag(DeviceExt->Statistics, TAG_STATS);
        ExDeleteResourceLite(&DeviceExt->DirResource);
        ExDeleteResourceLite(&DeviceExt->FatResource);

        /* Dismount our device if possible */
        ObDereferenceObject(DeviceExt->StorageDevice);
        IoDeleteDevice(DeviceExt->VolumeDevice);
    }

    return Delete;
}

Referenced by VfatCleanupFile(), VfatCloseFile(), and VfatShutdown().

VfatDeviceControl()

static NTSTATUS VfatDeviceControl ( IN PVFAT_IRP_CONTEXT  IrpContext )

static

Definition at line 93 of file misc.c.

{
    IoSkipCurrentIrpStackLocation(IrpContext->Irp);

    IrpContext->Flags &= ~IRPCONTEXT_COMPLETE;

    return IoCallDriver(IrpContext->DeviceExt->StorageDevice, IrpContext->Irp);
}

Referenced by VfatDispatchRequest().

VfatDispatchRequest()

static NTSTATUS VfatDispatchRequest ( IN PVFAT_IRP_CONTEXT  IrpContext )

static

Definition at line 105 of file misc.c.

{
    NTSTATUS Status;
    BOOLEAN QueueIrp, CompleteIrp;

    DPRINT("VfatDispatchRequest (IrpContext %p), is called for %s\n", IrpContext,
           IrpContext->MajorFunction >= IRP_MJ_MAXIMUM_FUNCTION ? "????" : MajorFunctionNames[IrpContext->MajorFunction]);

    ASSERT(IrpContext);

    FsRtlEnterFileSystem();

    switch (IrpContext->MajorFunction)
    {
        case IRP_MJ_CLOSE:
            Status = VfatClose(IrpContext);
            break;

        case IRP_MJ_CREATE:
            Status = VfatCreate(IrpContext);
            break;

        case IRP_MJ_READ:
            Status = VfatRead(IrpContext);
            break;

        case IRP_MJ_WRITE:
            Status = VfatWrite(IrpContext);
            break;

        case IRP_MJ_FILE_SYSTEM_CONTROL:
            Status = VfatFileSystemControl(IrpContext);
            break;

        case IRP_MJ_QUERY_INFORMATION:
            Status = VfatQueryInformation(IrpContext);
            break;

        case IRP_MJ_SET_INFORMATION:
            Status = VfatSetInformation(IrpContext);
            break;

        case IRP_MJ_DIRECTORY_CONTROL:
            Status = VfatDirectoryControl(IrpContext);
            break;

        case IRP_MJ_QUERY_VOLUME_INFORMATION:
            Status = VfatQueryVolumeInformation(IrpContext);
            break;

        case IRP_MJ_SET_VOLUME_INFORMATION:
            Status = VfatSetVolumeInformation(IrpContext);
            break;

        case IRP_MJ_LOCK_CONTROL:
            Status = VfatLockControl(IrpContext);
            break;

        case IRP_MJ_DEVICE_CONTROL:
            Status = VfatDeviceControl(IrpContext);
            break;

        case IRP_MJ_CLEANUP:
            Status = VfatCleanup(IrpContext);
            break;

        case IRP_MJ_FLUSH_BUFFERS:
            Status = VfatFlush(IrpContext);
            break;

        case IRP_MJ_PNP:
            Status = VfatPnp(IrpContext);
            break;

        default:
            DPRINT1("Unexpected major function %x\n", IrpContext->MajorFunction);
            Status = STATUS_DRIVER_INTERNAL_ERROR;
    }

    QueueIrp = BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_QUEUE);
    CompleteIrp = BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_COMPLETE);

    ASSERT((!CompleteIrp && !QueueIrp) ||
           (CompleteIrp && !QueueIrp) ||
           (!CompleteIrp && QueueIrp));

    if (CompleteIrp)
    {
        IrpContext->Irp->IoStatus.Status = Status;
        IoCompleteRequest(IrpContext->Irp, IrpContext->PriorityBoost);
    }

    if (QueueIrp)
    {
        /* Reset our status flags before queueing the IRP */
        IrpContext->Flags |= IRPCONTEXT_COMPLETE;
        IrpContext->Flags &= ~IRPCONTEXT_QUEUE;
        Status = VfatQueueRequest(IrpContext);
    }
    else
    {
        /* Unless the IRP was queued, always free the IRP context */
        VfatFreeIrpContext(IrpContext);
    }

    FsRtlExitFileSystem();

    return Status;
}

Referenced by VfatBuildRequest(), VfatDoRequest(), and VfatHandleDeferredWrite().

VfatDoRequest()

static VOID NTAPI VfatDoRequest ( PVOID  IrpContext )

static

Definition at line 335 of file misc.c.

{
    InterlockedDecrement(&QueueCount);
    DPRINT("VfatDoRequest(IrpContext %p), MajorFunction %x, %d\n",
           IrpContext, ((PVFAT_IRP_CONTEXT)IrpContext)->MajorFunction, QueueCount);
    VfatDispatchRequest((PVFAT_IRP_CONTEXT)IrpContext);
}

VfatFreeIrpContext()

static VOID VfatFreeIrpContext ( PVFAT_IRP_CONTEXT  IrpContext )

static

Definition at line 255 of file misc.c.

{
    ASSERT(IrpContext);
    ExFreeToNPagedLookasideList(&VfatGlobalData->IrpContextLookasideList, IrpContext);
}

Referenced by VfatDispatchRequest().

VfatGetUserBuffer()

PVOID VfatGetUserBuffer	(	IN PIRP	Irp,
		IN BOOLEAN	Paging
	)

Definition at line 365 of file misc.c.

{
    ASSERT(Irp);

    if (Irp->MdlAddress)
    {
        return MmGetSystemAddressForMdlSafe(Irp->MdlAddress, (Paging ? HighPagePriority : NormalPagePriority));
    }
    else
    {
        return Irp->UserBuffer;
    }
}

Referenced by DoQuery(), VfatCommonRead(), and VfatWrite().

VfatHandleDeferredWrite()

VOID NTAPI VfatHandleDeferredWrite	(	IN PVOID	IrpContext,
		IN PVOID	Unused
	)

Definition at line 218 of file misc.c.

{
    VfatDispatchRequest((PVFAT_IRP_CONTEXT)IrpContext);
}

Referenced by VfatWrite().

VfatLockControl()

static NTSTATUS VfatLockControl ( IN PVFAT_IRP_CONTEXT  IrpContext )

static

Definition at line 62 of file misc.c.

{
    PVFATFCB Fcb;
    NTSTATUS Status;

    DPRINT("VfatLockControl(IrpContext %p)\n", IrpContext);

    ASSERT(IrpContext);

    Fcb = (PVFATFCB)IrpContext->FileObject->FsContext;

    if (IrpContext->DeviceObject == VfatGlobalData->DeviceObject)
    {
        return STATUS_INVALID_DEVICE_REQUEST;
    }

    if (vfatFCBIsDirectory(Fcb))
    {
        return STATUS_INVALID_PARAMETER;
    }

    IrpContext->Flags &= ~IRPCONTEXT_COMPLETE;
    Status = FsRtlProcessFileLock(&Fcb->FileLock,
                                  IrpContext->Irp,
                                  NULL);
    return Status;
}

Referenced by VfatDispatchRequest().

VfatLockUserBuffer()

NTSTATUS VfatLockUserBuffer	(	IN PIRP	Irp,
		IN ULONG	Length,
		IN LOCK_OPERATION	Operation
	)

Definition at line 382 of file misc.c.

{
    ASSERT(Irp);

    if (Irp->MdlAddress)
    {
        return STATUS_SUCCESS;
    }

    IoAllocateMdl(Irp->UserBuffer, Length, FALSE, FALSE, Irp);

    if (!Irp->MdlAddress)
    {
        return STATUS_INSUFFICIENT_RESOURCES;
    }

    _SEH2_TRY
    {
        MmProbeAndLockPages(Irp->MdlAddress, Irp->RequestorMode, Operation);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        IoFreeMdl(Irp->MdlAddress);
        Irp->MdlAddress = NULL;
        _SEH2_YIELD(return _SEH2_GetExceptionCode());
    }
    _SEH2_END;

    return STATUS_SUCCESS;
}

Referenced by DoQuery(), VfatCommonRead(), VfatRead(), and VfatWrite().

VfatQueueRequest()

static NTSTATUS VfatQueueRequest ( PVFAT_IRP_CONTEXT  IrpContext )

static

Definition at line 346 of file misc.c.

{
    InterlockedIncrement(&QueueCount);
    DPRINT("VfatQueueRequest(IrpContext %p), %d\n", IrpContext, QueueCount);

    ASSERT(IrpContext != NULL);
    ASSERT(IrpContext->Irp != NULL);
    ASSERT(!(IrpContext->Flags & IRPCONTEXT_QUEUE) &&
           (IrpContext->Flags & IRPCONTEXT_COMPLETE));

    IrpContext->Flags |= IRPCONTEXT_CANWAIT;
    IoMarkIrpPending(IrpContext->Irp);
    ExInitializeWorkItem(&IrpContext->WorkQueueItem, VfatDoRequest, IrpContext);
    ExQueueWorkItem(&IrpContext->WorkQueueItem, CriticalWorkQueue);
    return STATUS_PENDING;
}

Referenced by VfatDispatchRequest().

Variable Documentation

MajorFunctionNames

const char* MajorFunctionNames[]

Definition at line 19 of file misc.c.

Referenced by VfatDispatchRequest().

QueueCount

LONG QueueCount = 0

static

Definition at line 52 of file misc.c.

Referenced by VfatDoRequest(), and VfatQueueRequest().

VfatDoRequest

WORKER_THREAD_ROUTINE VfatDoRequest

static

Definition at line 330 of file misc.c.

Referenced by VfatQueueRequest().