NTSTATUS
VfatRead(
PVFAT_IRP_CONTEXT IrpContext)
{
NTSTATUS Status;
PVFATFCB Fcb;
ULONG Length = 0;
ULONG ReturnedLength = 0;
PERESOURCE Resource = NULL;
LARGE_INTEGER ByteOffset;
PVOID Buffer;
ULONG BytesPerSector;
ASSERT(IrpContext);
DPRINT("VfatRead(IrpContext %p)\n", IrpContext);
ASSERT(IrpContext->DeviceObject);
// This request is not allowed on the main device object
if (IrpContext->DeviceObject == VfatGlobalData->DeviceObject)
{
DPRINT("VfatRead is called with the main device object.\n");
Status = STATUS_INVALID_DEVICE_REQUEST;
goto ByeBye;
}
ASSERT(IrpContext->DeviceExt);
ASSERT(IrpContext->FileObject);
Fcb = IrpContext->FileObject->FsContext;
ASSERT(Fcb);
if (Fcb->Flags & FCB_IS_PAGE_FILE)
{
PFATINFO FatInfo = &IrpContext->DeviceExt->FatInfo;
IrpContext->Stack->Parameters.Read.ByteOffset.QuadPart += FatInfo->dataStart * FatInfo->BytesPerSector;
IoSkipCurrentIrpStackLocation(IrpContext->Irp);
DPRINT("Read from page file, disk offset %I64x\n", IrpContext->Stack->Parameters.Read.ByteOffset.QuadPart);
Status = IoCallDriver(IrpContext->DeviceExt->StorageDevice, IrpContext->Irp);
VfatFreeIrpContext(IrpContext);
return Status;
}
DPRINT("<%wZ>\n", &Fcb->PathNameU);
ByteOffset = IrpContext->Stack->Parameters.Read.ByteOffset;
Length = IrpContext->Stack->Parameters.Read.Length;
BytesPerSector = IrpContext->DeviceExt->FatInfo.BytesPerSector;
/* fail if file is a directory and no paged read */
if (*Fcb->Attributes & FILE_ATTRIBUTE_DIRECTORY && !(IrpContext->Irp->Flags & IRP_PAGING_IO))
{
Status = STATUS_INVALID_PARAMETER;
goto ByeBye;
}
DPRINT("'%wZ', Offset: %u, Length %u\n", &Fcb->PathNameU, ByteOffset.u.LowPart, Length);
if (ByteOffset.u.HighPart && !(Fcb->Flags & FCB_IS_VOLUME))
{
Status = STATUS_INVALID_PARAMETER;
goto ByeBye;
}
if (ByteOffset.QuadPart >= Fcb->RFCB.FileSize.QuadPart)
{
IrpContext->Irp->IoStatus.Information = 0;
Status = STATUS_END_OF_FILE;
goto ByeBye;
}
if (IrpContext->Irp->Flags & (IRP_PAGING_IO | IRP_NOCACHE) || (Fcb->Flags & FCB_IS_VOLUME))
{
if (ByteOffset.u.LowPart % BytesPerSector != 0 || Length % BytesPerSector != 0)
{
DPRINT("%u %u\n", ByteOffset.u.LowPart, Length);
// non cached read must be sector aligned
Status = STATUS_INVALID_PARAMETER;
goto ByeBye;
}
}
if (Length == 0)
{
IrpContext->Irp->IoStatus.Information = 0;
Status = STATUS_SUCCESS;
goto ByeBye;
}
if (Fcb->Flags & FCB_IS_VOLUME)
{
Resource = &IrpContext->DeviceExt->DirResource;
}
else if (IrpContext->Irp->Flags & IRP_PAGING_IO)
{
Resource = &Fcb->PagingIoResource;
}
else
{
Resource = &Fcb->MainResource;
}
if (!ExAcquireResourceSharedLite(Resource,
IrpContext->Flags & IRPCONTEXT_CANWAIT ? TRUE : FALSE))
{
Resource = NULL;
Status = STATUS_PENDING;
goto ByeBye;
}
if (!(IrpContext->Irp->Flags & IRP_PAGING_IO) &&
FsRtlAreThereCurrentFileLocks(&Fcb->FileLock))
{
if (!FsRtlCheckLockForReadAccess(&Fcb->FileLock, IrpContext->Irp))
{
Status = STATUS_FILE_LOCK_CONFLICT;
goto ByeBye;
}
}
Buffer = VfatGetUserBuffer(IrpContext->Irp);
if (!Buffer)
{
Status = STATUS_INVALID_USER_BUFFER;
goto ByeBye;
}
if (!(IrpContext->Irp->Flags & (IRP_NOCACHE|IRP_PAGING_IO)) &&
!(Fcb->Flags & (FCB_IS_PAGE_FILE|FCB_IS_VOLUME)))
{
// cached read
Status = STATUS_SUCCESS;
if (ByteOffset.u.LowPart + Length > Fcb->RFCB.FileSize.u.LowPart)
{
Length = Fcb->RFCB.FileSize.u.LowPart - ByteOffset.u.LowPart;
Status = /*STATUS_END_OF_FILE*/STATUS_SUCCESS;
}
_SEH2_TRY
{
if (IrpContext->FileObject->PrivateCacheMap == NULL)
{
CcInitializeCacheMap(IrpContext->FileObject,
(PCC_FILE_SIZES)(&Fcb->RFCB.AllocationSize),
FALSE,
&(VfatGlobalData->CacheMgrCallbacks),
Fcb);
}
if (!CcCopyRead(IrpContext->FileObject,
&ByteOffset,
Length,
(IrpContext->Flags & IRPCONTEXT_CANWAIT) != 0,
Buffer,
&IrpContext->Irp->IoStatus))
{
ASSERT((IrpContext->Flags & IRPCONTEXT_CANWAIT) == 0);
Status = STATUS_PENDING;
goto ByeBye;
}
}
_SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
{
Status = _SEH2_GetExceptionCode();
goto ByeBye;
}
_SEH2_END;
if (!NT_SUCCESS(IrpContext->Irp->IoStatus.Status))
{
Status = IrpContext->Irp->IoStatus.Status;
}
}
NTSTATUS
Ext2ReadFile(IN PEXT2_IRP_CONTEXT IrpContext)
{
NTSTATUS Status = STATUS_UNSUCCESSFUL;
PEXT2_VCB Vcb = NULL;
PEXT2_FCB Fcb = NULL;
PEXT2_CCB Ccb = NULL;
PFILE_OBJECT FileObject = NULL;
PDEVICE_OBJECT DeviceObject = NULL;
PIRP Irp = NULL;
PIO_STACK_LOCATION IoStackLocation = NULL;
ULONG Length;
ULONG ReturnedLength = 0;
LARGE_INTEGER ByteOffset;
BOOLEAN OpPostIrp = FALSE;
BOOLEAN PagingIo;
BOOLEAN Nocache;
BOOLEAN SynchronousIo;
BOOLEAN MainResourceAcquired = FALSE;
BOOLEAN PagingIoResourceAcquired = FALSE;
PUCHAR Buffer;
__try {
ASSERT(IrpContext);
ASSERT((IrpContext->Identifier.Type == EXT2ICX) &&
(IrpContext->Identifier.Size == sizeof(EXT2_IRP_CONTEXT)));
DeviceObject = IrpContext->DeviceObject;
Vcb = (PEXT2_VCB) DeviceObject->DeviceExtension;
ASSERT(Vcb != NULL);
ASSERT((Vcb->Identifier.Type == EXT2VCB) &&
(Vcb->Identifier.Size == sizeof(EXT2_VCB)));
FileObject = IrpContext->FileObject;
Fcb = (PEXT2_FCB) FileObject->FsContext;
ASSERT(Fcb);
ASSERT((Fcb->Identifier.Type == EXT2FCB) &&
(Fcb->Identifier.Size == sizeof(EXT2_FCB)));
Ccb = (PEXT2_CCB) FileObject->FsContext2;
Irp = IrpContext->Irp;
IoStackLocation = IoGetCurrentIrpStackLocation(Irp);
Length = IoStackLocation->Parameters.Read.Length;
ByteOffset = IoStackLocation->Parameters.Read.ByteOffset;
PagingIo = IsFlagOn(Irp->Flags, IRP_PAGING_IO);
Nocache = IsFlagOn(Irp->Flags, IRP_NOCACHE);
SynchronousIo = IsFlagOn(FileObject->Flags, FO_SYNCHRONOUS_IO);
if (PagingIo) {
ASSERT(Nocache);
}
DEBUG(DL_INF, ("Ext2ReadFile: reading %wZ Off=%I64xh Len=%xh Paging=%xh Nocache=%xh\n",
&Fcb->Mcb->ShortName, ByteOffset.QuadPart, Length, PagingIo, Nocache));
if ((IsSymLink(Fcb) && IsFileDeleted(Fcb->Mcb->Target)) ||
IsFileDeleted(Fcb->Mcb)) {
Status = STATUS_FILE_DELETED;
__leave;
}
if (Length == 0) {
Irp->IoStatus.Information = 0;
Status = STATUS_SUCCESS;
__leave;
}
if (Nocache &&
(ByteOffset.LowPart & (SECTOR_SIZE - 1) ||
Length & (SECTOR_SIZE - 1))) {
Status = STATUS_INVALID_PARAMETER;
DbgBreak();
__leave;
}
if (FlagOn(IrpContext->MinorFunction, IRP_MN_DPC)) {
ClearFlag(IrpContext->MinorFunction, IRP_MN_DPC);
Status = STATUS_PENDING;
DbgBreak();
__leave;
}
if (!PagingIo && Nocache && (FileObject->SectionObjectPointer->DataSectionObject != NULL)) {
CcFlushCache( FileObject->SectionObjectPointer,
&ByteOffset,
Length,
&Irp->IoStatus );
if (!NT_SUCCESS(Irp->IoStatus.Status)) {
__leave;
}
}
ReturnedLength = Length;
if (PagingIo) {
if (!ExAcquireResourceSharedLite(
&Fcb->PagingIoResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
PagingIoResourceAcquired = TRUE;
} else {
if (Nocache) {
if (!ExAcquireResourceExclusiveLite(
&Fcb->MainResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
MainResourceAcquired = TRUE;
} else {
if (!ExAcquireResourceSharedLite(
&Fcb->MainResource,
IsFlagOn(IrpContext->Flags, IRP_CONTEXT_FLAG_WAIT) )) {
Status = STATUS_PENDING;
__leave;
}
MainResourceAcquired = TRUE;
}
if (!FsRtlCheckLockForReadAccess(
&Fcb->FileLockAnchor,
Irp )) {
Status = STATUS_FILE_LOCK_CONFLICT;
__leave;
}
}
if ((ByteOffset.QuadPart + (LONGLONG)Length) > Fcb->Header.FileSize.QuadPart) {
if (ByteOffset.QuadPart >= Fcb->Header.FileSize.QuadPart) {
Irp->IoStatus.Information = 0;
Status = STATUS_END_OF_FILE;
__leave;
}
ReturnedLength = (ULONG)(Fcb->Header.FileSize.QuadPart - ByteOffset.QuadPart);
}
if (!IsDirectory(Fcb) && Ccb != NULL) {
Status = FsRtlCheckOplock( &Fcb->Oplock,
Irp,
IrpContext,
Ext2OplockComplete,
Ext2LockIrp );
if (Status != STATUS_SUCCESS) {
OpPostIrp = TRUE;
__leave;
}
//
// Set the flag indicating if Fast I/O is possible
//
Fcb->Header.IsFastIoPossible = Ext2IsFastIoPossible(Fcb);
}
if (!Nocache) {
if (IsDirectory(Fcb)) {
__leave;
}
if (FileObject->PrivateCacheMap == NULL) {
CcInitializeCacheMap(
FileObject,
(PCC_FILE_SIZES)(&Fcb->Header.AllocationSize),
FALSE,
&Ext2Global->CacheManagerCallbacks,
Fcb );
CcSetReadAheadGranularity(
FileObject,
READ_AHEAD_GRANULARITY );
}
if (FlagOn(IrpContext->MinorFunction, IRP_MN_MDL)) {
CcMdlRead(
FileObject,
(&ByteOffset),
ReturnedLength,
&Irp->MdlAddress,
&Irp->IoStatus );
Status = Irp->IoStatus.Status;
} else {
Buffer = Ext2GetUserBuffer(Irp);
if (Buffer == NULL) {
Status = STATUS_INVALID_USER_BUFFER;
DbgBreak();
__leave;
}
if (!CcCopyRead(FileObject, &ByteOffset, ReturnedLength,
Ext2CanIWait(), Buffer, &Irp->IoStatus)) {
if (Ext2CanIWait() || !CcCopyRead(FileObject, &ByteOffset,
ReturnedLength, TRUE,
Buffer, &Irp->IoStatus)) {
Status = STATUS_PENDING;
DbgBreak();
__leave;
}
}
Status = Irp->IoStatus.Status;
}
} else {
ULONG BytesRead = ReturnedLength;
PUCHAR SystemVA = Ext2GetUserBuffer(IrpContext->Irp);
if (ByteOffset.QuadPart + BytesRead > Fcb->Header.ValidDataLength.QuadPart) {
if (ByteOffset.QuadPart >= Fcb->Header.ValidDataLength.QuadPart) {
if (SystemVA) {
SafeZeroMemory(SystemVA, Length);
}
Irp->IoStatus.Information = ReturnedLength;
Status = STATUS_SUCCESS;
__leave;
} else {
BytesRead = (ULONG)(Fcb->Header.ValidDataLength.QuadPart - ByteOffset.QuadPart);
if (SystemVA) {
SafeZeroMemory(SystemVA + BytesRead, Length - BytesRead);
}
}
}
Status = Ext2LockUserBuffer(
IrpContext->Irp,
BytesRead,
IoReadAccess );
if (!NT_SUCCESS(Status)) {
__leave;
}
Status = Ext2ReadInode(
IrpContext,
Vcb,
Fcb->Mcb,
ByteOffset.QuadPart,
NULL,
BytesRead,
TRUE,
NULL );
/* we need re-queue this request in case STATUS_CANT_WAIT
and fail it in other failure cases */
if (!NT_SUCCESS(Status)) {
__leave;
}
/* pended by low level device */
if (Status == STATUS_PENDING) {
IrpContext->Irp = Irp = NULL;
__leave;
}
Irp = IrpContext->Irp;
ASSERT(Irp);
Status = Irp->IoStatus.Status;
if (!NT_SUCCESS(Status)) {
Ext2NormalizeAndRaiseStatus(IrpContext, Status);
}
}
Irp->IoStatus.Information = ReturnedLength;
} __finally {
if (Irp) {
if (PagingIoResourceAcquired) {
ExReleaseResourceLite(&Fcb->PagingIoResource);
}
if (MainResourceAcquired) {
ExReleaseResourceLite(&Fcb->MainResource);
}
}
if (!OpPostIrp && !IrpContext->ExceptionInProgress) {
if (Irp) {
if ( Status == STATUS_PENDING ||
Status == STATUS_CANT_WAIT) {
Status = Ext2LockUserBuffer(
IrpContext->Irp,
Length,
IoWriteAccess );
if (NT_SUCCESS(Status)) {
Status = Ext2QueueRequest(IrpContext);
} else {
Ext2CompleteIrpContext(IrpContext, Status);
}
} else {
if (NT_SUCCESS(Status)) {
if (!PagingIo) {
if (SynchronousIo) {
FileObject->CurrentByteOffset.QuadPart =
ByteOffset.QuadPart + Irp->IoStatus.Information;
}
FileObject->Flags |= FO_FILE_FAST_IO_READ;
}
}
Ext2CompleteIrpContext(IrpContext, Status);
}
} else {
Ext2FreeIrpContext(IrpContext);
}
}
}
DEBUG(DL_IO, ("Ext2ReadFile: %wZ fetch at Off=%I64xh Len=%xh Paging=%xh Nocache=%xh Returned=%xh Status=%xh\n",
&Fcb->Mcb->ShortName, ByteOffset.QuadPart, Length, PagingIo, Nocache, ReturnedLength, Status));
return Status;
}
NTSTATUS
DokanDispatchRead(__in PDEVICE_OBJECT DeviceObject, __in PIRP Irp)
/*++
Routine Description:
This device control dispatcher handles read IRPs.
Arguments:
DeviceObject - Context for the activity.
Irp - The device control argument block.
Return Value:
NTSTATUS
--*/
{
PIO_STACK_LOCATION irpSp;
PFILE_OBJECT fileObject;
ULONG bufferLength;
LARGE_INTEGER byteOffset;
NTSTATUS status = STATUS_INVALID_PARAMETER;
ULONG readLength = 0;
PDokanCCB ccb;
PDokanFCB fcb = NULL;
PDokanVCB vcb;
PVOID currentAddress = NULL;
PEVENT_CONTEXT eventContext;
ULONG eventLength;
BOOLEAN fcbLocked = FALSE;
BOOLEAN isPagingIo = FALSE;
BOOLEAN isSynchronousIo = FALSE;
BOOLEAN noCache = FALSE;
__try {
DDbgPrint("==> DokanRead\n");
irpSp = IoGetCurrentIrpStackLocation(Irp);
fileObject = irpSp->FileObject;
//
// If this is a zero length read then return SUCCESS immediately.
//
if (irpSp->Parameters.Read.Length == 0) {
DDbgPrint(" Parameters.Read.Length == 0 \n");
Irp->IoStatus.Information = 0;
status = STATUS_SUCCESS;
__leave;
}
if (irpSp->MinorFunction == IRP_MN_COMPLETE) {
Irp->MdlAddress = NULL;
status = STATUS_SUCCESS;
__leave;
}
if (fileObject == NULL && Irp->MdlAddress != NULL) {
DDbgPrint(" Reads by File System Recognizers\n");
currentAddress = MmGetSystemAddressForMdlNormalSafe(Irp->MdlAddress);
if (currentAddress == NULL) {
status = STATUS_INSUFFICIENT_RESOURCES;
__leave;
}
// here we could return the bootsector. If we don't have one
// the requested read lenght must be returned as requested
readLength = irpSp->Parameters.Read.Length;
status = STATUS_SUCCESS;
__leave;
}
if (fileObject == NULL) {
DDbgPrint(" fileObject == NULL\n");
status = STATUS_INVALID_DEVICE_REQUEST;
__leave;
}
vcb = DeviceObject->DeviceExtension;
if (GetIdentifierType(vcb) != VCB ||
!DokanCheckCCB(vcb->Dcb, fileObject->FsContext2)) {
status = STATUS_INVALID_DEVICE_REQUEST;
__leave;
}
bufferLength = irpSp->Parameters.Read.Length;
if (irpSp->Parameters.Read.ByteOffset.LowPart ==
FILE_USE_FILE_POINTER_POSITION &&
irpSp->Parameters.Read.ByteOffset.HighPart == -1) {
// irpSp->Parameters.Read.ByteOffset == NULL don't need check?
DDbgPrint("use FileObject ByteOffset\n");
byteOffset = fileObject->CurrentByteOffset;
} else {
byteOffset = irpSp->Parameters.Read.ByteOffset;
}
DDbgPrint(" ProcessId %lu\n", IoGetRequestorProcessId(Irp));
DokanPrintFileName(fileObject);
DDbgPrint(" ByteCount:%lu ByteOffset:%I64d\n", bufferLength,
byteOffset.QuadPart);
if (bufferLength == 0) {
status = STATUS_SUCCESS;
readLength = 0;
__leave;
}
// make a MDL for UserBuffer that can be used later on another thread
// context
if (Irp->MdlAddress == NULL) {
status = DokanAllocateMdl(Irp, irpSp->Parameters.Read.Length);
if (!NT_SUCCESS(status)) {
__leave;
}
}
ccb = fileObject->FsContext2;
ASSERT(ccb != NULL);
fcb = ccb->Fcb;
ASSERT(fcb != NULL);
if (DokanFCBFlagsIsSet(fcb, DOKAN_FILE_DIRECTORY)) {
DDbgPrint(" DOKAN_FILE_DIRECTORY %p\n", fcb);
status = STATUS_INVALID_PARAMETER;
__leave;
}
if (Irp->Flags & IRP_PAGING_IO) {
isPagingIo = TRUE;
}
if (fileObject->Flags & FO_SYNCHRONOUS_IO) {
isSynchronousIo = TRUE;
}
if (Irp->Flags & IRP_NOCACHE) {
noCache = TRUE;
}
if (!isPagingIo && (fileObject->SectionObjectPointer != NULL) &&
(fileObject->SectionObjectPointer->DataSectionObject != NULL)) {
ExAcquireResourceExclusiveLite(&fcb->PagingIoResource, TRUE);
CcFlushCache(&fcb->SectionObjectPointers,
&irpSp->Parameters.Read.ByteOffset,
irpSp->Parameters.Read.Length, NULL);
ExReleaseResourceLite(&fcb->PagingIoResource);
}
DokanFCBLockRO(fcb);
fcbLocked = TRUE;
// length of EventContext is sum of file name length and itself
eventLength = sizeof(EVENT_CONTEXT) + fcb->FileName.Length;
eventContext = AllocateEventContext(vcb->Dcb, Irp, eventLength, ccb);
if (eventContext == NULL) {
status = STATUS_INSUFFICIENT_RESOURCES;
__leave;
}
eventContext->Context = ccb->UserContext;
// DDbgPrint(" get Context %X\n", (ULONG)ccb->UserContext);
if (isPagingIo) {
DDbgPrint(" Paging IO\n");
eventContext->FileFlags |= DOKAN_PAGING_IO;
}
if (isSynchronousIo) {
DDbgPrint(" Synchronous IO\n");
eventContext->FileFlags |= DOKAN_SYNCHRONOUS_IO;
}
if (noCache) {
DDbgPrint(" Nocache\n");
eventContext->FileFlags |= DOKAN_NOCACHE;
}
// offset of file to read
eventContext->Operation.Read.ByteOffset = byteOffset;
// buffer size for read
// user-mode file system application can return this size
eventContext->Operation.Read.BufferLength = irpSp->Parameters.Read.Length;
// copy the accessed file name
eventContext->Operation.Read.FileNameLength = fcb->FileName.Length;
RtlCopyMemory(eventContext->Operation.Read.FileName, fcb->FileName.Buffer,
fcb->FileName.Length);
//
// We now check whether we can proceed based on the state of
// the file oplocks.
//
if (!FlagOn(Irp->Flags, IRP_PAGING_IO)) {
// FsRtlCheckOpLock is called with non-NULL completion routine - not blocking.
status = FsRtlCheckOplock(DokanGetFcbOplock(fcb), Irp, eventContext,
DokanOplockComplete, DokanPrePostIrp);
//
// if FsRtlCheckOplock returns STATUS_PENDING the IRP has been posted
// to service an oplock break and we need to leave now.
//
if (status != STATUS_SUCCESS) {
if (status == STATUS_PENDING) {
DDbgPrint(" FsRtlCheckOplock returned STATUS_PENDING\n");
} else {
DokanFreeEventContext(eventContext);
}
__leave;
}
//
// We have to check for read access according to the current
// state of the file locks, and set FileSize from the Fcb.
//
// FsRtlCheckLockForReadAccess does not block.
if (!FsRtlCheckLockForReadAccess(&fcb->FileLock, Irp)) {
status = STATUS_FILE_LOCK_CONFLICT;
__leave;
}
}
// register this IRP to pending IPR list and make it pending status
status = DokanRegisterPendingIrp(DeviceObject, Irp, eventContext, 0);
} __finally {
if(fcbLocked)
DokanFCBUnlock(fcb);
DokanCompleteIrpRequest(Irp, status, readLength);
DDbgPrint("<== DokanRead\n");
}
return status;
}
NTSTATUS STDCALL drv_read(PDEVICE_OBJECT DeviceObject, PIRP Irp) {
PIO_STACK_LOCATION IrpSp = IoGetCurrentIrpStackLocation(Irp);
UINT8* data;
PFILE_OBJECT FileObject = IrpSp->FileObject;
fcb* fcb = FileObject->FsContext;
UINT64 start;
ULONG length, bytes_read;
NTSTATUS Status;
BOOL top_level;
FsRtlEnterFileSystem();
top_level = is_top_level(Irp);
TRACE("read\n");
Irp->IoStatus.Information = 0;
if (IrpSp->MinorFunction & IRP_MN_COMPLETE) {
CcMdlReadComplete(IrpSp->FileObject, Irp->MdlAddress);
Irp->MdlAddress = NULL;
Status = STATUS_SUCCESS;
bytes_read = 0;
goto exit;
}
start = IrpSp->Parameters.Read.ByteOffset.QuadPart;
length = IrpSp->Parameters.Read.Length;
bytes_read = 0;
if (!fcb || !fcb->Vcb || !fcb->subvol) {
Status = STATUS_INTERNAL_ERROR; // FIXME - invalid param error?
goto exit;
}
TRACE("file = %S (fcb = %p)\n", file_desc(FileObject), fcb);
TRACE("offset = %llx, length = %x\n", start, length);
TRACE("paging_io = %s, no cache = %s\n", Irp->Flags & IRP_PAGING_IO ? "TRUE" : "FALSE", Irp->Flags & IRP_NOCACHE ? "TRUE" : "FALSE");
if (fcb->type == BTRFS_TYPE_DIRECTORY) {
Status = STATUS_INVALID_DEVICE_REQUEST;
goto exit;
}
if (!(Irp->Flags & IRP_PAGING_IO) && !FsRtlCheckLockForReadAccess(&fcb->lock, Irp)) {
WARN("tried to read locked region\n");
Status = STATUS_FILE_LOCK_CONFLICT;
goto exit;
}
if (length == 0) {
WARN("tried to read zero bytes\n");
Status = STATUS_SUCCESS;
goto exit;
}
if (start >= fcb->Header.FileSize.QuadPart) {
TRACE("tried to read with offset after file end (%llx >= %llx)\n", start, fcb->Header.FileSize.QuadPart);
Status = STATUS_END_OF_FILE;
goto exit;
}
TRACE("FileObject %p fcb %p FileSize = %llx st_size = %llx (%p)\n", FileObject, fcb, fcb->Header.FileSize.QuadPart, fcb->inode_item.st_size, &fcb->inode_item.st_size);
// int3;
if (Irp->Flags & IRP_NOCACHE || !(IrpSp->MinorFunction & IRP_MN_MDL)) {
data = map_user_buffer(Irp);
if (Irp->MdlAddress && !data) {
ERR("MmGetSystemAddressForMdlSafe returned NULL\n");
Status = STATUS_INSUFFICIENT_RESOURCES;
goto exit;
}
if (length + start > fcb->Header.ValidDataLength.QuadPart) {
RtlZeroMemory(data + (fcb->Header.ValidDataLength.QuadPart - start), length - (fcb->Header.ValidDataLength.QuadPart - start));
length = fcb->Header.ValidDataLength.QuadPart - start;
}
}
if (!(Irp->Flags & IRP_NOCACHE)) {
BOOL wait;
Status = STATUS_SUCCESS;
_SEH2_TRY {
if (!FileObject->PrivateCacheMap) {
CC_FILE_SIZES ccfs;
ccfs.AllocationSize = fcb->Header.AllocationSize;
ccfs.FileSize = fcb->Header.FileSize;
ccfs.ValidDataLength = fcb->Header.ValidDataLength;
TRACE("calling CcInitializeCacheMap (%llx, %llx, %llx)\n",
ccfs.AllocationSize.QuadPart, ccfs.FileSize.QuadPart, ccfs.ValidDataLength.QuadPart);
CcInitializeCacheMap(FileObject, &ccfs, FALSE, cache_callbacks, FileObject);
CcSetReadAheadGranularity(FileObject, READ_AHEAD_GRANULARITY);
}
// FIXME - uncomment this when async is working
// wait = IoIsOperationSynchronous(Irp) ? TRUE : FALSE;
wait = TRUE;
if (IrpSp->MinorFunction & IRP_MN_MDL) {
CcMdlRead(FileObject,&IrpSp->Parameters.Read.ByteOffset, length, &Irp->MdlAddress, &Irp->IoStatus);
} else {
TRACE("CcCopyRead(%p, %llx, %x, %u, %p, %p)\n", FileObject, IrpSp->Parameters.Read.ByteOffset.QuadPart, length, wait, data, &Irp->IoStatus);
TRACE("sizes = %llx, %llx, %llx\n", fcb->Header.AllocationSize, fcb->Header.FileSize, fcb->Header.ValidDataLength);
if (!CcCopyRead(FileObject, &IrpSp->Parameters.Read.ByteOffset, length, wait, data, &Irp->IoStatus)) {
TRACE("CcCopyRead failed\n");
IoMarkIrpPending(Irp);
Status = STATUS_PENDING;
goto exit;
}
TRACE("CcCopyRead finished\n");
}
} _SEH2_EXCEPT (EXCEPTION_EXECUTE_HANDLER) {
Status = _SEH2_GetExceptionCode();
} _SEH2_END;
if (NT_SUCCESS(Status)) {
Status = Irp->IoStatus.Status;
bytes_read = Irp->IoStatus.Information;
} else
ERR("EXCEPTION - %08x\n", Status);
} else {
