/*
 * Copyright (C) 1998-2005 ReactOS Team (and the authors from the programmers section)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 *
 * PROJECT:         ReactOS kernel
 * FILE:            ntoskrnl/cache/section/io.c
 * PURPOSE:         Implements section objects
 *
 * PROGRAMMERS:     Rex Jolliff
 *                  David Welch
 *                  Eric Kohl
 *                  Emanuele Aliberti
 *                  Eugene Ingerman
 *                  Casper Hornstrup
 *                  KJK::Hyperion
 *                  Guido de Jong
 *                  Ge van Geldorp
 *                  Royce Mitchell III
 *                  Filip Navara
 *                  Aleksey Bragin
 *                  Jason Filby
 *                  Thomas Weidenmueller
 *                  Gunnar Andre' Dalsnes
 *                  Mike Nordell
 *                  Alex Ionescu
 *                  Gregor Anich
 *                  Steven Edwards
 *                  Herve Poussineau
 */

/* INCLUDES *****************************************************************/

#include <ntoskrnl.h>
#include "newmm.h"
#define NDEBUG
#include <debug.h>
#include <reactos/exeformat.h>

KEVENT CcpLazyWriteEvent;

PDEVICE_OBJECT
NTAPI
MmGetDeviceObjectForFile(IN PFILE_OBJECT FileObject)
{
    return IoGetRelatedDeviceObject(FileObject);
}

/*

Note:
This completion function is really required. Paging io completion does almost
nothing, including freeing the mdls.

*/
_Function_class_(IO_COMPLETION_ROUTINE)
NTSTATUS
NTAPI
MiSimpleReadComplete(PDEVICE_OBJECT DeviceObject,
                     PIRP Irp,
                     PVOID Context)
{
    PMDL Mdl = Irp->MdlAddress;

    /* Unlock MDL Pages, page 167. */
    DPRINT("MiSimpleReadComplete %p\n", Irp);
    while (Mdl)
    {
        DPRINT("MDL Unlock %p\n", Mdl);
        MmUnlockPages(Mdl);
        Mdl = Mdl->Next;
    }

    /* Check if there's an MDL */
    while ((Mdl = Irp->MdlAddress))
    {
        /* Clear all of them */
        Irp->MdlAddress = Mdl->Next;
        IoFreeMdl(Mdl);
    }

    return STATUS_SUCCESS;
}

/*

MiSimpleRead is a convenience function that provides either paging or non
paging reads.  The caching and mm systems use this in paging mode, where
a completion function is required as above.  The Paging BOOLEAN determines
whether the read is issued as a paging read or as an ordinary buffered read.

*/

NTSTATUS
NTAPI
MiSimpleRead(PFILE_OBJECT FileObject,
             PLARGE_INTEGER FileOffset,
             PVOID Buffer,
             ULONG Length,
             BOOLEAN Paging,
             PIO_STATUS_BLOCK ReadStatus)
{
    NTSTATUS Status;
    PIRP Irp = NULL;
    KEVENT ReadWait;
    PDEVICE_OBJECT DeviceObject;
    PIO_STACK_LOCATION IrpSp;

    ASSERT(FileObject);
    ASSERT(FileOffset);
    ASSERT(Buffer);
    ASSERT(ReadStatus);

    DeviceObject = MmGetDeviceObjectForFile(FileObject);
    ReadStatus->Status = STATUS_INTERNAL_ERROR;
    ReadStatus->Information = 0;

    ASSERT(DeviceObject);

    DPRINT("PAGING READ: FileObject %p <%wZ> Offset %08x%08x Length %ul\n",
           FileObject,
           &FileObject->FileName,
           FileOffset->HighPart,
           FileOffset->LowPart,
           Length);

    KeInitializeEvent(&ReadWait, NotificationEvent, FALSE);

    Irp = IoBuildAsynchronousFsdRequest(IRP_MJ_READ,
                                        DeviceObject,
                                        Buffer,
                                        Length,
                                        FileOffset,
                                        ReadStatus);

    if (!Irp)
    {
        return STATUS_NO_MEMORY;
    }

    Irp->Flags |= (Paging ? IRP_PAGING_IO | IRP_SYNCHRONOUS_PAGING_IO | IRP_NOCACHE : 0) | IRP_SYNCHRONOUS_API;

    Irp->UserEvent = &ReadWait;
    Irp->Tail.Overlay.OriginalFileObject = FileObject;
    Irp->Tail.Overlay.Thread = PsGetCurrentThread();
    IrpSp = IoGetNextIrpStackLocation(Irp);
    IrpSp->Control |= SL_INVOKE_ON_SUCCESS | SL_INVOKE_ON_ERROR;
    IrpSp->FileObject = FileObject;
    IrpSp->CompletionRoutine = MiSimpleReadComplete;

    /* Non paging case, the FileObject will be dereferenced at completion */
    if (!Paging)
        ObReferenceObject(FileObject);

    Status = IoCallDriver(DeviceObject, Irp);
    if (Status == STATUS_PENDING)
    {
        DPRINT("KeWaitForSingleObject(&ReadWait)\n");
        if (!NT_SUCCESS(KeWaitForSingleObject(&ReadWait,
                                              Suspended,
                                              KernelMode,
                                              FALSE,
                                              NULL)))
        {
            DPRINT1("Warning: Failed to wait for synchronous IRP\n");
            ASSERT(FALSE);
            return Status;
        }
    }

    DPRINT("Paging IO Done: %08x\n", ReadStatus->Status);
    /* When "ReadStatus->Information > 0" is false and "ReadStatus->Status == STATUS_END_OF_FILE" is true
     * it means that read pointer is out of file, so we must fail */
    Status = ReadStatus->Status == STATUS_END_OF_FILE && ReadStatus->Information > 0 ? STATUS_SUCCESS : ReadStatus->Status;
    return Status;
}

#ifdef NEWCC
/*

Convenience function for writing from kernel space.  This issues a paging
write in all cases.

*/

NTSTATUS
NTAPI
_MiSimpleWrite(PFILE_OBJECT FileObject,
               PLARGE_INTEGER FileOffset,
               PVOID Buffer,
               ULONG Length,
               PIO_STATUS_BLOCK ReadStatus,
               const char *File,
               int Line)
{
    NTSTATUS Status;
    PIRP Irp = NULL;
    KEVENT ReadWait;
    PDEVICE_OBJECT DeviceObject;
    PIO_STACK_LOCATION IrpSp;

    ASSERT(FileObject);
    ASSERT(FileOffset);
    ASSERT(Buffer);
    ASSERT(ReadStatus);

    DeviceObject = MmGetDeviceObjectForFile(FileObject);
    ASSERT(DeviceObject);

    DPRINT("PAGING WRITE: FileObject %p <%wZ> Offset 0x%I64x Length %lu (%s:%d)\n",
           FileObject,
           &FileObject->FileName,
           FileOffset->QuadPart,
           Length,
           File,
           Line);

    KeInitializeEvent(&ReadWait, NotificationEvent, FALSE);

    Irp = IoBuildAsynchronousFsdRequest(IRP_MJ_WRITE,
                                        DeviceObject,
                                        Buffer,
                                        Length,
                                        FileOffset,
                                        ReadStatus);

    if (!Irp)
    {
        return STATUS_NO_MEMORY;
    }

    Irp->Flags = IRP_PAGING_IO | IRP_SYNCHRONOUS_PAGING_IO | IRP_NOCACHE | IRP_SYNCHRONOUS_API;

    Irp->UserEvent = &ReadWait;
    Irp->Tail.Overlay.OriginalFileObject = FileObject;
    Irp->Tail.Overlay.Thread = PsGetCurrentThread();
    IrpSp = IoGetNextIrpStackLocation(Irp);
    IrpSp->Control |= SL_INVOKE_ON_SUCCESS | SL_INVOKE_ON_ERROR;
    IrpSp->FileObject = FileObject;
    IrpSp->CompletionRoutine = MiSimpleReadComplete;

    DPRINT("Call Driver\n");
    Status = IoCallDriver(DeviceObject, Irp);
    DPRINT("Status %x\n", Status);

    if (Status == STATUS_PENDING)
    {
        DPRINT("KeWaitForSingleObject(&ReadWait)\n");
        if (!NT_SUCCESS(KeWaitForSingleObject(&ReadWait,
                                              Suspended,
                                              KernelMode,
                                              FALSE,
                                              NULL)))
        {
            DPRINT1("Warning: Failed to wait for synchronous IRP\n");
            ASSERT(FALSE);
            return Status;
        }
    }

    DPRINT("Paging IO Done: %08x\n", ReadStatus->Status);
    return ReadStatus->Status;
}

extern KEVENT MpwThreadEvent;
FAST_MUTEX MiWriteMutex;

/*

Function which uses MiSimpleWrite to write back a single page to a file.
The page in question does not need to be mapped.  This function could be
made a bit more efficient by avoiding the copy and making a system space
mdl.

*/

NTSTATUS
NTAPI
_MiWriteBackPage(PFILE_OBJECT FileObject,
                 PLARGE_INTEGER FileOffset,
                 ULONG Length,
                 PFN_NUMBER Page,
                 const char *File,
                 int Line)
{
    NTSTATUS Status;
    PVOID Hyperspace;
    IO_STATUS_BLOCK Iosb;
    KIRQL OldIrql;
    PVOID PageBuffer = ExAllocatePool(NonPagedPool, PAGE_SIZE);

    if (!PageBuffer) return STATUS_NO_MEMORY;

    Hyperspace = MiMapPageInHyperSpace(PsGetCurrentProcess(), Page, &OldIrql);
    if (!Hyperspace)
    {
        ExFreePool(PageBuffer);
        return STATUS_NO_MEMORY;
    }
    RtlCopyMemory(PageBuffer, Hyperspace, PAGE_SIZE);
    MiUnmapPageInHyperSpace(PsGetCurrentProcess(), Hyperspace, OldIrql);

    DPRINT("MiWriteBackPage(%wZ,%08x%08x,%s:%d)\n",
           &FileObject->FileName,
           FileOffset->u.HighPart,
           FileOffset->u.LowPart,
           File,
           Line);

    Status = MiSimpleWrite(FileObject,
                           FileOffset,
                           PageBuffer,
                           Length,
                           &Iosb);

    ExFreePool(PageBuffer);

    if (!NT_SUCCESS(Status))
    {
        DPRINT1("MiSimpleWrite failed (%x)\n", Status);
    }

    return Status;
}
#endif