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