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https://github.com/reactos/reactos.git
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0daa5547d9
This implies that a sample for W10. It has been backported to NT5.2; not sure how it would work on a W2K3 (feel free to test!)
373 lines
7.9 KiB
C
373 lines
7.9 KiB
C
/*++
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Copyright (c) 1989-2000 Microsoft Corporation
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Module Name:
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WorkQue.c
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Abstract:
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This module implements the Work queue routines for the Fat File
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system.
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--*/
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#include "fatprocs.h"
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//
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// The following constant is the maximum number of ExWorkerThreads that we
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// will allow to be servicing a particular target device at any one time.
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//
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#define FSP_PER_DEVICE_THRESHOLD (2)
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#ifdef ALLOC_PRAGMA
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#pragma alloc_text(PAGE, FatOplockComplete)
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#pragma alloc_text(PAGE, FatPrePostIrp)
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#pragma alloc_text(PAGE, FatFsdPostRequest)
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#endif
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VOID
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NTAPI
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FatOplockComplete (
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IN PVOID Context,
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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 is called by the oplock package when an oplock break has
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completed, allowing an Irp to resume execution. If the status in
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the Irp is STATUS_SUCCESS, then we queue the Irp to the Fsp queue.
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Otherwise we complete the Irp with the status in the Irp.
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Arguments:
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Context - Pointer to the IrpContext to be queued to the Fsp
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Irp - I/O Request Packet.
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Return Value:
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None.
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--*/
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{
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PAGED_CODE();
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//
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// Check on the return value in the Irp.
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//
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if (Irp->IoStatus.Status == STATUS_SUCCESS) {
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//
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// Insert the Irp context in the workqueue.
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//
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FatAddToWorkque( (PIRP_CONTEXT) Context, Irp );
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//
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// Otherwise complete the request.
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//
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} else {
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FatCompleteRequest( (PIRP_CONTEXT) Context, Irp, Irp->IoStatus.Status );
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}
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return;
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}
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VOID
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NTAPI
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FatPrePostIrp (
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IN PVOID Context,
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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 performs any neccessary work before STATUS_PENDING is
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returned with the Fsd thread. This routine is called within the
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filesystem and by the oplock package.
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Arguments:
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Context - Pointer to the IrpContext to be queued to the Fsp
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Irp - I/O Request Packet.
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Return Value:
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None.
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--*/
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{
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PIO_STACK_LOCATION IrpSp;
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PIRP_CONTEXT IrpContext;
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PAGED_CODE();
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//
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// If there is no Irp, we are done.
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//
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if (Irp == NULL) {
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return;
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}
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IrpSp = IoGetCurrentIrpStackLocation( Irp );
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IrpContext = (PIRP_CONTEXT) Context;
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//
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// If there is a STACK FatIoContext pointer, clean and NULL it.
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//
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if ((IrpContext->FatIoContext != NULL) &&
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FlagOn(IrpContext->Flags, IRP_CONTEXT_STACK_IO_CONTEXT)) {
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ClearFlag(IrpContext->Flags, IRP_CONTEXT_STACK_IO_CONTEXT);
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IrpContext->FatIoContext = NULL;
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}
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//
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// We need to lock the user's buffer, unless this is an MDL-read,
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// in which case there is no user buffer.
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//
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// **** we need a better test than non-MDL (read or write)!
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if (IrpContext->MajorFunction == IRP_MJ_READ ||
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IrpContext->MajorFunction == IRP_MJ_WRITE) {
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//
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// If not an Mdl request, lock the user's buffer.
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//
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if (!FlagOn( IrpContext->MinorFunction, IRP_MN_MDL )) {
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FatLockUserBuffer( IrpContext,
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Irp,
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(IrpContext->MajorFunction == IRP_MJ_READ) ?
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IoWriteAccess : IoReadAccess,
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(IrpContext->MajorFunction == IRP_MJ_READ) ?
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IrpSp->Parameters.Read.Length : IrpSp->Parameters.Write.Length );
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}
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//
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// We also need to check whether this is a query file operation.
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//
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} else if (IrpContext->MajorFunction == IRP_MJ_DIRECTORY_CONTROL
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&& IrpContext->MinorFunction == IRP_MN_QUERY_DIRECTORY) {
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FatLockUserBuffer( IrpContext,
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Irp,
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IoWriteAccess,
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IrpSp->Parameters.QueryDirectory.Length );
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//
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// We also need to check whether this is a query ea operation.
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//
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} else if (IrpContext->MajorFunction == IRP_MJ_QUERY_EA) {
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FatLockUserBuffer( IrpContext,
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Irp,
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IoWriteAccess,
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IrpSp->Parameters.QueryEa.Length );
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//
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// We also need to check whether this is a set ea operation.
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//
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} else if (IrpContext->MajorFunction == IRP_MJ_SET_EA) {
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FatLockUserBuffer( IrpContext,
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Irp,
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IoReadAccess,
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IrpSp->Parameters.SetEa.Length );
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//
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// These two FSCTLs use neither I/O, so check for them.
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//
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} else if ((IrpContext->MajorFunction == IRP_MJ_FILE_SYSTEM_CONTROL) &&
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(IrpContext->MinorFunction == IRP_MN_USER_FS_REQUEST) &&
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((IrpSp->Parameters.FileSystemControl.FsControlCode == FSCTL_GET_VOLUME_BITMAP) ||
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(IrpSp->Parameters.FileSystemControl.FsControlCode == FSCTL_GET_RETRIEVAL_POINTERS))) {
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FatLockUserBuffer( IrpContext,
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Irp,
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IoWriteAccess,
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IrpSp->Parameters.FileSystemControl.OutputBufferLength );
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}
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//
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// Mark that we've already returned pending to the user
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//
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IoMarkIrpPending( Irp );
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return;
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}
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NTSTATUS
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FatFsdPostRequest(
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IN PIRP_CONTEXT IrpContext,
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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 enqueues the request packet specified by IrpContext to the
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Ex Worker threads. This is a FSD routine.
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Arguments:
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IrpContext - Pointer to the IrpContext to be queued to the Fsp
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Irp - I/O Request Packet, or NULL if it has already been completed.
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Return Value:
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STATUS_PENDING
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--*/
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{
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PAGED_CODE();
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NT_ASSERT( ARGUMENT_PRESENT(Irp) );
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NT_ASSERT( IrpContext->OriginatingIrp == Irp );
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FatPrePostIrp( IrpContext, Irp );
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FatAddToWorkque( IrpContext, Irp );
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//
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// And return to our caller
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//
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return STATUS_PENDING;
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}
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//
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// Local support routine.
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//
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VOID
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FatAddToWorkque (
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IN PIRP_CONTEXT IrpContext,
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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 is called to acually store the posted Irp to the Fsp
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workque.
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Arguments:
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IrpContext - Pointer to the IrpContext to be queued to the Fsp
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Irp - I/O Request Packet.
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Return Value:
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None.
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--*/
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{
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KIRQL SavedIrql;
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PIO_STACK_LOCATION IrpSp;
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IrpSp = IoGetCurrentIrpStackLocation( Irp );
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//
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// Check if this request has an associated file object, and thus volume
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// device object.
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//
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if ( IrpSp->FileObject != NULL ) {
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PVOLUME_DEVICE_OBJECT Vdo;
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Vdo = CONTAINING_RECORD( IrpSp->DeviceObject,
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VOLUME_DEVICE_OBJECT,
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DeviceObject );
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//
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// Check to see if this request should be sent to the overflow
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// queue. If not, then send it off to an exworker thread.
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//
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KeAcquireSpinLock( &Vdo->OverflowQueueSpinLock, &SavedIrql );
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if ( Vdo->PostedRequestCount > FSP_PER_DEVICE_THRESHOLD) {
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//
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// We cannot currently respond to this IRP so we'll just enqueue it
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// to the overflow queue on the volume.
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//
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InsertTailList( &Vdo->OverflowQueue,
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&IrpContext->WorkQueueItem.List );
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Vdo->OverflowQueueCount += 1;
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KeReleaseSpinLock( &Vdo->OverflowQueueSpinLock, SavedIrql );
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return;
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} else {
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//
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// We are going to send this Irp to an ex worker thread so up
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// the count.
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//
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Vdo->PostedRequestCount += 1;
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KeReleaseSpinLock( &Vdo->OverflowQueueSpinLock, SavedIrql );
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}
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}
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//
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// Send it off.....
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//
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ExInitializeWorkItem( &IrpContext->WorkQueueItem,
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FatFspDispatch,
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IrpContext );
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#ifdef _MSC_VER
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#pragma prefast( suppress:28159, "prefast indicates this is an obsolete API but it is ok for fastfat to keep using it." )
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#endif
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ExQueueWorkItem( &IrpContext->WorkQueueItem, CriticalWorkQueue );
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return;
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}
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