read.c File Reference

#include "npfs.h"

Include dependency graph for read.c:

Go to the source code of this file.

Macros
#define	NPFS_BUGCHECK_FILE_ID   (NPFS_BUGCHECK_READ)

Functions
BOOLEAN NTAPI	NpCommonRead (IN PFILE_OBJECT FileObject, IN PVOID Buffer, IN ULONG BufferSize, OUT PIO_STATUS_BLOCK IoStatus, IN PIRP Irp, IN PLIST_ENTRY List)
NTSTATUS NTAPI	NpFsdRead (IN PDEVICE_OBJECT DeviceObject, IN PIRP Irp)
	_Function_class_ (FAST_IO_READ)

Variables
LONG	NpSlowReadCalls
ULONG	NpFastReadTrue
ULONG	NpFastReadFalse

Macro Definition Documentation

NPFS_BUGCHECK_FILE_ID

#define NPFS_BUGCHECK_FILE_ID   (NPFS_BUGCHECK_READ)

Definition at line 14 of file read.c.

Function Documentation

_Function_class_()

_Function_class_

(

FAST_IO_READ

)

Definition at line 196 of file read.c.

{
    LIST_ENTRY DeferredList;
    BOOLEAN Result;
    PAGED_CODE();
 
    InitializeListHead(&DeferredList);
 
    FsRtlEnterFileSystem();
    NpAcquireSharedVcb();
 
    Result = NpCommonRead(FileObject,
                          Buffer,
                          Length,
                          IoStatus,
                          NULL,
                          &DeferredList);
    if (Result)
        ++NpFastReadTrue;
    else
        ++NpFastReadFalse;
 
    NpReleaseVcb();
    NpCompleteDeferredIrps(&DeferredList);
    FsRtlExitFileSystem();
 
    return Result;
}

NpCommonRead()

BOOLEAN NTAPI NpCommonRead	(	IN PFILE_OBJECT	FileObject,
		IN PVOID	Buffer,
		IN ULONG	BufferSize,
		OUT PIO_STATUS_BLOCK	IoStatus,
		IN PIRP	Irp,
		IN PLIST_ENTRY	List
	)

Definition at line 26 of file read.c.

{
    NODE_TYPE_CODE NodeType;
    PNP_DATA_QUEUE ReadQueue;
    PNP_EVENT_BUFFER EventBuffer;
    NTSTATUS Status;
    ULONG NamedPipeEnd;
    PNP_CCB Ccb;
    PNP_NONPAGED_CCB NonPagedCcb;
    BOOLEAN ReadOk;
    PAGED_CODE();
 
    IoStatus->Information = 0;
    NodeType = NpDecodeFileObject(FileObject, NULL, &Ccb, &NamedPipeEnd);
 
    if (!NodeType)
    {
        IoStatus->Status = STATUS_PIPE_DISCONNECTED;
        return TRUE;
    }
 
    if (NodeType != NPFS_NTC_CCB)
    {
        IoStatus->Status = STATUS_INVALID_PARAMETER;
        return TRUE;
    }
 
    NonPagedCcb = Ccb->NonPagedCcb;
    ExAcquireResourceExclusiveLite(&NonPagedCcb->Lock, TRUE);
 
    if (Ccb->NamedPipeState == FILE_PIPE_DISCONNECTED_STATE || Ccb->NamedPipeState == FILE_PIPE_LISTENING_STATE)
    {
        IoStatus->Status = Ccb->NamedPipeState != FILE_PIPE_DISCONNECTED_STATE ? STATUS_PIPE_LISTENING : STATUS_PIPE_DISCONNECTED;
        ReadOk = TRUE;
        goto Quickie;
    }
 
    ASSERT((Ccb->NamedPipeState == FILE_PIPE_CONNECTED_STATE) || (Ccb->NamedPipeState == FILE_PIPE_CLOSING_STATE));
 
    if ((NamedPipeEnd == FILE_PIPE_SERVER_END && Ccb->Fcb->NamedPipeConfiguration == FILE_PIPE_OUTBOUND) ||
        (NamedPipeEnd == FILE_PIPE_CLIENT_END && Ccb->Fcb->NamedPipeConfiguration == FILE_PIPE_INBOUND))
    {
        IoStatus->Status = STATUS_INVALID_PARAMETER;
        ReadOk = TRUE;
        goto Quickie;
    }
 
    if (NamedPipeEnd == FILE_PIPE_SERVER_END)
    {
        ReadQueue = &Ccb->DataQueue[FILE_PIPE_INBOUND];
    }
    else
    {
        ReadQueue = &Ccb->DataQueue[FILE_PIPE_OUTBOUND];
    }
 
    EventBuffer = NonPagedCcb->EventBuffer[NamedPipeEnd];
 
    if (ReadQueue->QueueState == WriteEntries)
    {
        *IoStatus = NpReadDataQueue(ReadQueue,
                                    FALSE,
                                    FALSE,
                                    Buffer,
                                    BufferSize,
                                    Ccb->ReadMode[NamedPipeEnd],
                                    Ccb,
                                    List);
        if (!NT_SUCCESS(IoStatus->Status))
        {
            ReadOk = TRUE;
            goto Quickie;
        }
 
        ReadOk = TRUE;
        if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
        goto Quickie;
    }
 
    if (Ccb->NamedPipeState == FILE_PIPE_CLOSING_STATE)
    {
        IoStatus->Status = STATUS_PIPE_BROKEN;
        ReadOk = TRUE;
        if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
        goto Quickie;
    }
 
    if (Ccb->CompletionMode[NamedPipeEnd] == FILE_PIPE_COMPLETE_OPERATION)
    {
        IoStatus->Status = STATUS_PIPE_EMPTY;
        ReadOk = TRUE;
        if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
        goto Quickie;
    }
 
    if (!Irp)
    {
        ReadOk = FALSE;
        goto Quickie;
    }
 
    Status = NpAddDataQueueEntry(NamedPipeEnd,
                                 Ccb,
                                 ReadQueue,
                                 ReadEntries,
                                 Buffered,
                                 BufferSize,
                                 Irp,
                                 NULL,
                                 0);
    IoStatus->Status = Status;
    if (!NT_SUCCESS(Status))
    {
        ReadOk = FALSE;
    }
    else
    {
        ReadOk = TRUE;
        if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
    }
 
Quickie:
    ExReleaseResourceLite(&Ccb->NonPagedCcb->Lock);
    return ReadOk;
}

Referenced by _Function_class_(), and NpFsdRead().

NpFsdRead()

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

Definition at line 159 of file read.c.

{
    PIO_STACK_LOCATION IoStack;
    IO_STATUS_BLOCK IoStatus;
    LIST_ENTRY DeferredList;
    PAGED_CODE();
    NpSlowReadCalls++;
 
    InitializeListHead(&DeferredList);
    IoStack = IoGetCurrentIrpStackLocation(Irp);
 
    FsRtlEnterFileSystem();
    NpAcquireSharedVcb();
 
    NpCommonRead(IoStack->FileObject,
                 Irp->UserBuffer,
                 IoStack->Parameters.Read.Length,
                 &IoStatus,
                 Irp,
                 &DeferredList);
 
    NpReleaseVcb();
    NpCompleteDeferredIrps(&DeferredList);
    FsRtlExitFileSystem();
 
    if (IoStatus.Status != STATUS_PENDING)
    {
        Irp->IoStatus.Information = IoStatus.Information;
        Irp->IoStatus.Status = IoStatus.Status;
        IoCompleteRequest(Irp, IO_NAMED_PIPE_INCREMENT);
    }
 
    return IoStatus.Status;
}

Referenced by DriverEntry().

Variable Documentation

NpFastReadFalse

ULONG NpFastReadFalse

Definition at line 20 of file read.c.

Referenced by _Function_class_().

NpFastReadTrue

ULONG NpFastReadTrue

Definition at line 19 of file read.c.

Referenced by _Function_class_().

NpSlowReadCalls

LONG NpSlowReadCalls

Definition at line 18 of file read.c.

Referenced by NpFsdRead().