/*++

Copyright (c) Microsoft Corporation. All rights reserved. 

You may only use this code if you agree to the terms of the Windows Research Kernel Source Code License agreement (see License.txt).
If you do not agree to the terms, do not use the code.


Module Name:

    Create.c

Abstract:

    This module implements the File Create routine for Raw called by the
    dispatch driver.

--*/

#include "RawProcs.h"

#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, RawCreate)
#endif


NTSTATUS
RawCreate (
    IN PVCB Vcb,
    IN PIRP Irp,
    IN PIO_STACK_LOCATION IrpSp
    )

/*++

Routine Description:

    Open the volume.

Arguments:

    Vcb - Supplies the volume being queried.

    Irp - Supplies the Irp being processed.

    IrpSp - Supplies parameters describing the read

Return Value:

    NTSTATUS - the return status for the operation

--*/

{
    NTSTATUS Status;
    BOOLEAN DeleteVolume = FALSE;

    PAGED_CODE();

    //
    //  This is an open/create request.  The only valid operation that
    //  is supported by the RAW file system is if the caller:
    //
    //    o  Specifies the device itself (file name == ""),
    //    o  specifies that this is an OPEN operation,
    //    o  and does not ask to create a directory.
    //

    Status = KeWaitForSingleObject( &Vcb->Mutex,
                                   Executive,
                                   KernelMode,
                                   FALSE,
                                   (PLARGE_INTEGER) NULL );
    ASSERT( NT_SUCCESS( Status ) );

    //
    // Don't allow any relative opens as well as opens with a filename. These opens have
    // only been checked for traverse access by the I/O manager.
    //
    if (((IrpSp->FileObject == NULL) || ((IrpSp->FileObject->FileName.Length == 0) &&
                                          IrpSp->FileObject->RelatedFileObject == NULL)) &&
        ((IrpSp->Parameters.Create.Options >> 24) == FILE_OPEN) &&
        ((IrpSp->Parameters.Create.Options & FILE_DIRECTORY_FILE) == 0)) {

        //
        //  If the volume is locked or dismounted we cannot open it again.
        //

        if ( FlagOn(Vcb->VcbState,  VCB_STATE_FLAG_LOCKED) ) {

            Status = STATUS_ACCESS_DENIED;
            Irp->IoStatus.Information = 0;

        } if ( FlagOn(Vcb->VcbState,  VCB_STATE_FLAG_DISMOUNTED) ) {

            Status = STATUS_VOLUME_DISMOUNTED;
            Irp->IoStatus.Information = 0;

        } else {

            //
            //  If the volume is already opened by someone then we need to check
            //  the share access
            //

            USHORT ShareAccess;
            ACCESS_MASK DesiredAccess;

            ShareAccess = IrpSp->Parameters.Create.ShareAccess;
            DesiredAccess = IrpSp->Parameters.Create.SecurityContext->DesiredAccess;

            if ((Vcb->OpenCount > 0) &&
                !NT_SUCCESS(Status = IoCheckShareAccess( DesiredAccess,
                                                         ShareAccess,
                                                         IrpSp->FileObject,
                                                         &Vcb->ShareAccess,
                                                         TRUE ))) {

                Irp->IoStatus.Information = 0;

            } else {

                //
                //  This is a valid create.  Increment the "OpenCount" and
                //  stuff the Vpb into the file object.
                //

                if (Vcb->OpenCount == 0) {

                    IoSetShareAccess( DesiredAccess,
                                      ShareAccess,
                                      IrpSp->FileObject,
                                      &Vcb->ShareAccess );
                }

                Vcb->OpenCount += 1;

                IrpSp->FileObject->Vpb = Vcb->Vpb;

                Status = STATUS_SUCCESS;
                Irp->IoStatus.Information = FILE_OPENED;

                IrpSp->FileObject->Flags |= FO_NO_INTERMEDIATE_BUFFERING;
            }
        }

    } else {

        //
        //  Fail this I/O request since one of the above conditions was
        //  not met.
        //
        Status = STATUS_INVALID_PARAMETER;
        Irp->IoStatus.Information = 0;
    }

    //
    //  If this was not successful and this was the first open on the
    //  volume, we must implicitly dis-mount the volume.
    //

    if (!NT_SUCCESS(Status) && (Vcb->OpenCount == 0)) {

        DeleteVolume = RawCheckForDismount( Vcb, TRUE );
    }

    if (!DeleteVolume) {
        (VOID)KeReleaseMutex( &Vcb->Mutex, FALSE );
    }

    RawCompleteRequest( Irp, Status );

    return Status;
}