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/*++
Copyright (c) 1989 Microsoft Corporation
Module Name:
FlushBuf.c
Abstract:
This module implements the File Flush Buffers routine for NPFS called by
the dispatch driver.
Author:
Gary Kimura [GaryKi] 21-Aug-1990
Revision History:
--*/
#include "NpProcs.h"
//
// The debug trace level
//
#define Dbg (DEBUG_TRACE_FLUSH_BUFFERS)
//
// local procedure prototypes
//
NTSTATUS
NpCommonFlushBuffers (
IN PNPFS_DEVICE_OBJECT NpfsDeviceObject,
IN PIRP Irp
);
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, NpCommonFlushBuffers)
#pragma alloc_text(PAGE, NpFsdFlushBuffers)
#endif
NTSTATUS
NpFsdFlushBuffers (
IN PNPFS_DEVICE_OBJECT NpfsDeviceObject,
IN PIRP Irp
)
/*++
Routine Description:
This routine implements the FSD part of the NtFlushBuffersFile API calls.
Arguments:
NpfsDeviceObject - Supplies the device object to use.
Irp - Supplies the Irp being processed
Return Value:
NTSTATUS - The Fsd status for the Irp
--*/
{
NTSTATUS Status;
PAGED_CODE();
DebugTrace(+1, Dbg, "NpFsdFlushBuffers\n", 0);
//
// Call the common Flush routine.
//
FsRtlEnterFileSystem();
NpAcquireSharedVcb();
try {
Status = NpCommonFlushBuffers( NpfsDeviceObject, Irp );
} except(NpExceptionFilter( GetExceptionCode() )) {
//
// We had some trouble trying to perform the requested
// operation, so we'll abort the I/O request with
// the error status that we get back from the
// execption code
//
Status = NpProcessException( NpfsDeviceObject, Irp, GetExceptionCode() );
}
NpReleaseVcb();
FsRtlExitFileSystem();
//
// And return to our caller
//
DebugTrace(-1, Dbg, "NpFsdFlushBuffers -> %08lx\n", Status );
return Status;
}
//
// Internal support routine
//
NTSTATUS
NpCommonFlushBuffers (
IN PNPFS_DEVICE_OBJECT NpfsDeviceObject,
IN PIRP Irp
)
/*++
Routine Description:
This is the common routine for Flushing buffers for a file.
Arguments:
Irp - Supplies the Irp to process
Return Value:
NTSTATUS - the return status for the operation
--*/
{
NTSTATUS Status;
PIO_STACK_LOCATION IrpSp;
PCCB Ccb;
NAMED_PIPE_END NamedPipeEnd;
PDATA_QUEUE WriteQueue;
//
// Get the current stack location
//
PAGED_CODE();
IrpSp = IoGetCurrentIrpStackLocation( Irp );
DebugTrace(+1, Dbg, "NpCommonFlushBuffers\n", 0);
DebugTrace( 0, Dbg, "Irp = %08lx\n", Irp);
DebugTrace( 0, Dbg, "FileObject = %08lx\n", IrpSp->FileObject);
//
// Decode the file object to figure out who we are. If the result
// is not a ccb then the pipe has been disconnected. We don't need the
// Fcb back from the call
//
if (NpDecodeFileObject( IrpSp->FileObject,
NULL,
&Ccb,
&NamedPipeEnd ) != NPFS_NTC_CCB) {
DebugTrace(0, Dbg, "Pipe is disconnected from us\n", 0);
NpCompleteRequest( Irp, STATUS_PIPE_DISCONNECTED );
Status = STATUS_PIPE_DISCONNECTED;
DebugTrace(-1, Dbg, "NpCommonFlushBuffers -> %08lx\n", Status );
return Status;
}
NpAcquireExclusiveCcb(Ccb);
try {
//
// Figure out the data queue that the flush buffer is
// targetted at. It is the queue that we do writes into
//
if (NamedPipeEnd == FILE_PIPE_SERVER_END) {
WriteQueue = &Ccb->DataQueue[ FILE_PIPE_OUTBOUND ];
} else {
WriteQueue = &Ccb->DataQueue[ FILE_PIPE_INBOUND ];
}
//
// Now from the write queue check if contains write entries. If
// it does not contain write entries then we immediately complete
// this irp with success because there isn't anything to flush
//
if (!NpIsDataQueueWriters( WriteQueue )) {
DebugTrace(0, Dbg, "Pipe does not contain write entries\n", 0);
NpCompleteRequest( Irp, STATUS_SUCCESS );
try_return(Status = STATUS_SUCCESS);
}
//
// Otherwise the queue is full of writes so we simply
// enqueue this irp to the back to the queue and set our
// return status to pending, also mark the irp pending
//
IoMarkIrpPending( Irp );
(VOID)NpAddDataQueueEntry( WriteQueue,
WriteEntries,
Flush,
0,
Irp,
NULL );
Status = STATUS_PENDING;
try_exit: NOTHING;
} finally {
NpReleaseCcb(Ccb);
}
DebugTrace(-1, Dbg, "NpCommonFlushBuffers -> %08lx\n", Status);
return Status;
}
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