/*
 * Copyright (c) 2008, 2009, 2010, 2011 Kernel Drivers, LLC.
 * Copyright (c) 2009, 2010, 2011 Your File System, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice,
 *   this list of conditions and the following disclaimer in the
 *   documentation
 *   and/or other materials provided with the distribution.
 * - Neither the names of Kernel Drivers, LLC and Your File System, Inc.
 *   nor the names of their contributors may be used to endorse or promote
 *   products derived from this software without specific prior written
 *   permission from Kernel Drivers, LLC and Your File System, Inc.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

//
// File: AFSFlushBuffers.cpp
//

#include "AFSCommon.h"

NTSTATUS
AFSFlushBuffers( IN PDEVICE_OBJECT LibDeviceObject,
                 IN PIRP Irp)
{

    UNREFERENCED_PARAMETER(LibDeviceObject);
    NTSTATUS           ntStatus = STATUS_SUCCESS;
    IO_STACK_LOCATION *pIrpSp = IoGetCurrentIrpStackLocation( Irp);
    PFILE_OBJECT       pFileObject = pIrpSp->FileObject;
    AFSFcb            *pFcb = (AFSFcb *)pFileObject->FsContext;
    AFSCcb            *pCcb = (AFSCcb *)pFileObject->FsContext2;
    IO_STATUS_BLOCK    iosb = {0};
    BOOLEAN            bReleaseSectionObject = FALSE;

    pIrpSp = IoGetCurrentIrpStackLocation( Irp);

    __Enter
    {

        if( pFcb == NULL)
        {

            AFSDbgLogMsg( AFS_SUBSYSTEM_FILE_PROCESSING,
                          AFS_TRACE_LEVEL_ERROR,
                          "AFSFlushBuffers Attempted access (%08lX) when pFcb == NULL\n",
                          Irp);

            try_return( ntStatus = STATUS_INVALID_DEVICE_REQUEST);
        }

        if( pFcb->Header.NodeTypeCode == AFS_ROOT_FCB ||
            pFcb->Header.NodeTypeCode == AFS_ROOT_ALL )
        {

            //
            // Once we support ADS's on directories we need to perform a flush ehre
            //

            try_return( ntStatus = STATUS_SUCCESS);

        }
        else if (pFcb->Header.NodeTypeCode != AFS_FILE_FCB)
        {
            //
            // Nothing to flush Everything but files are write through
            //
            try_return( ntStatus = STATUS_INVALID_PARAMETER);
        }

        AFSDbgLogMsg( AFS_SUBSYSTEM_LOCK_PROCESSING,
                      AFS_TRACE_LEVEL_VERBOSE,
                      "AFSFlushBuffers Acquiring Fcb SectionObject lock %08lX SHARED %08lX\n",
                      &pFcb->NPFcb->SectionObjectResource,
                      PsGetCurrentThread());

        AFSAcquireShared( &pFcb->NPFcb->SectionObjectResource,
                          TRUE);

        bReleaseSectionObject = TRUE;

        //
        // The flush consists of two parts.  We firstly flush our
        // cache (if we have one), then we tell the service to write
        // to the remote server
        //
        __try
        {

            CcFlushCache( &pFcb->NPFcb->SectionObjectPointers, NULL, 0, &iosb);

            if (!NT_SUCCESS( iosb.Status ))
            {

                AFSDbgLogMsg( AFS_SUBSYSTEM_IO_PROCESSING,
                              AFS_TRACE_LEVEL_ERROR,
                              "AFSFlushBuffers CcFlushCache [1] failure FID %08lX-%08lX-%08lX-%08lX Status 0x%08lX Bytes 0x%08lX\n",
                              pFcb->ObjectInformation->FileId.Cell,
                              pFcb->ObjectInformation->FileId.Volume,
                              pFcb->ObjectInformation->FileId.Vnode,
                              pFcb->ObjectInformation->FileId.Unique,
                              iosb.Status,
                              iosb.Information);

                try_return( ntStatus = iosb.Status );
            }
        }
        __except( EXCEPTION_EXECUTE_HANDLER)
        {

            try_return( ntStatus = GetExceptionCode());
        }

        AFSDbgLogMsg( AFS_SUBSYSTEM_LOCK_PROCESSING,
                      AFS_TRACE_LEVEL_VERBOSE,
                      "AFSFlushBuffers Releasing Fcb SectionObject lock %08lX SHARED %08lX\n",
                      &pFcb->NPFcb->SectionObjectResource,
                      PsGetCurrentThread());

        AFSReleaseResource( &pFcb->NPFcb->SectionObjectResource);

        bReleaseSectionObject = FALSE;

        //
        // Now, flush to the server - if there is stuff to do
        //

        ntStatus = AFSFlushExtents( pFcb,
                                    &pCcb->AuthGroup);

        if( !NT_SUCCESS( ntStatus))
        {

            AFSReleaseExtentsWithFlush( pFcb,
                                        &pCcb->AuthGroup,
                                        TRUE);

            ntStatus = STATUS_SUCCESS;
        }

try_exit:

        if ( bReleaseSectionObject)
        {

            AFSDbgLogMsg( AFS_SUBSYSTEM_LOCK_PROCESSING,
                          AFS_TRACE_LEVEL_VERBOSE,
                          "AFSFlushBuffers Releasing Fcb SectionObject lock %08lX SHARED %08lX\n",
                          &pFcb->NPFcb->SectionObjectResource,
                          PsGetCurrentThread());

            AFSReleaseResource( &pFcb->NPFcb->SectionObjectResource);
        }

        AFSCompleteRequest( Irp, ntStatus);
    }

    return ntStatus;
}