close.c

/**
 * @file sys/close.c
 *
 * @copyright 2015-2020 Bill Zissimopoulos
 */
/*
 * This file is part of WinFsp.
 *
 * You can redistribute it and/or modify it under the terms of the GNU
 * General Public License version 3 as published by the Free Software
 * Foundation.
 *
 * Licensees holding a valid commercial license may use this software
 * in accordance with the commercial license agreement provided in
 * conjunction with the software.  The terms and conditions of any such
 * commercial license agreement shall govern, supersede, and render
 * ineffective any application of the GPLv3 license to this software,
 * notwithstanding of any reference thereto in the software or
 * associated repository.
 */

#include <sys/driver.h>

static NTSTATUS FspFsctlClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
static NTSTATUS FspFsvrtClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
static NTSTATUS FspFsvolClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
FSP_IOCMPL_DISPATCH FspFsvolCloseComplete;
FSP_DRIVER_DISPATCH FspClose;

#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, FspFsctlClose)
#pragma alloc_text(PAGE, FspFsvrtClose)
#pragma alloc_text(PAGE, FspFsvolClose)
#pragma alloc_text(PAGE, FspFsvolCloseComplete)
#pragma alloc_text(PAGE, FspClose)
#endif

static NTSTATUS FspFsctlClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
{
    PAGED_CODE();

    Irp->IoStatus.Information = 0;
    return STATUS_SUCCESS;
}

static NTSTATUS FspFsvrtClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
{
    PAGED_CODE();

    Irp->IoStatus.Information = 0;
    return STATUS_SUCCESS;
}

static NTSTATUS FspFsvolClose(
    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
{
    PAGED_CODE();

    /* is this a valid FileObject? */
    if (!FspFileNodeIsValid(IrpSp->FileObject->FsContext))
        return STATUS_SUCCESS;

    PFILE_OBJECT FileObject = IrpSp->FileObject;
    FSP_FILE_NODE *FileNode = FileObject->FsContext;
    FSP_FILE_DESC *FileDesc = FileObject->FsContext2;
    FSP_FSCTL_TRANSACT_REQ *Request;

    ASSERT(FileNode == FileDesc->FileNode);

    /* create the user-mode file system request; MustSucceed because IRP_MJ_CLOSE cannot fail */
    FspIopCreateRequestMustSucceed(0, 0, 0, &Request);
    Request->Kind = FspFsctlTransactCloseKind;
    Request->Req.Close.UserContext = FileNode->UserContext;
    Request->Req.Close.UserContext2 = FileDesc->UserContext2;

    FspFileNodeClose(FileNode, 0, FALSE);

    /* delete the FileDesc and deref the FileNode; order is important (FileDesc has FileNode ref) */
    FspFileDescDelete(FileDesc); /* this will also close the MainFileObject if any */
    FspFileNodeDereference(FileNode);

    /* if we are closing files in the context of a rename make it synchronous */
    if (FspFsvolDeviceFileRenameIsAcquiredExclusive(FsvolDeviceObject))
    {
        /* acquire ownership of the Request */
        Request->Hint = (UINT_PTR)Irp;
        FspIrpSetRequest(Irp, Request);

        return FSP_STATUS_IOQ_POST_BEST_EFFORT;
    }

    /*
     * Post as a BestEffort WORK request. This allows us to complete our own IRP
     * and return immediately.
     */
    FspIopPostWorkRequestBestEffort(FsvolDeviceObject, Request);

    /*
     * Note that it is still possible for this request to not be delivered,
     * if the volume device Ioq is stopped. But such failures are benign
     * from our perspective, because they mean that the file system is going
     * away and should correctly tear things down.
     */
    Irp->IoStatus.Information = 0;
    return STATUS_SUCCESS;
}

NTSTATUS FspFsvolCloseComplete(
    PIRP Irp, const FSP_FSCTL_TRANSACT_RSP *Response)
{
    FSP_ENTER_IOC(PAGED_CODE());

    FSP_LEAVE_IOC("FileObject=%p", IrpSp->FileObject);
}

NTSTATUS FspClose(
    PDEVICE_OBJECT DeviceObject, PIRP Irp)
{
    FSP_ENTER_MJ(PAGED_CODE());

    switch (FspDeviceExtension(DeviceObject)->Kind)
    {
    case FspFsvolDeviceExtensionKind:
        FSP_RETURN(Result = FspFsvolClose(DeviceObject, Irp, IrpSp));
    case FspFsvrtDeviceExtensionKind:
        FSP_RETURN(Result = FspFsvrtClose(DeviceObject, Irp, IrpSp));
    case FspFsctlDeviceExtensionKind:
        FSP_RETURN(Result = FspFsctlClose(DeviceObject, Irp, IrpSp));
    default:
        FSP_RETURN(Result = STATUS_INVALID_DEVICE_REQUEST);
    }

    FSP_LEAVE_MJ("FileObject=%p", IrpSp->FileObject);
}