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sys: FastIo: read/write implementation

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This commit is contained in:
Bill Zissimopoulos
2022-03-20 20:31:54 +00:00
parent 00d4aba946
commit 20680fa5b5
7 changed files with 311 additions and 5 deletions
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103
src/sys/read.c
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@@ -21,6 +21,7 @@
#include <sys/driver.h>
FAST_IO_READ FspFastIoRead;
static NTSTATUS FspFsvolRead(
PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
static NTSTATUS FspFsvolReadCached(
@@ -35,6 +36,7 @@ static FSP_IOP_REQUEST_FINI FspFsvolReadNonCachedRequestFini;
FSP_DRIVER_DISPATCH FspRead;
#ifdef ALLOC_PRAGMA
#pragma alloc_text(PAGE, FspFastIoRead)
#pragma alloc_text(PAGE, FspFsvolRead)
#pragma alloc_text(PAGE, FspFsvolReadCached)
#pragma alloc_text(PAGE, FspFsvolReadNonCached)
@@ -55,6 +57,107 @@ enum
};
FSP_FSCTL_STATIC_ASSERT(RequestCookie == RequestSafeMdl, "");
BOOLEAN FspFastIoRead(
PFILE_OBJECT FileObject,
PLARGE_INTEGER ByteOffset,
ULONG Length,
BOOLEAN CanWait,
ULONG Key,
PVOID UserBuffer,
PIO_STATUS_BLOCK IoStatus,
PDEVICE_OBJECT DeviceObject)
{
FSP_ENTER_FIO(PAGED_CODE());
IoStatus->Status = STATUS_SUCCESS;
IoStatus->Information = 0;
if (!FspFileNodeIsValid(FileObject->FsContext))
{
IoStatus->Status = STATUS_INVALID_DEVICE_REQUEST;
FSP_RETURN(Result = TRUE);
}
FSP_FILE_NODE* FileNode = FileObject->FsContext;
LARGE_INTEGER ReadOffset = *ByteOffset;
ULONG ReadLength = Length;
FSP_FSCTL_FILE_INFO FileInfo;
/* only regular files can be read */
if (FileNode->IsDirectory)
{
IoStatus->Status = STATUS_INVALID_PARAMETER;
FSP_RETURN(Result = TRUE);
}
/* do we have anything to read? */
if (0 == ReadLength)
FSP_RETURN(Result = TRUE);
/* does the file support caching? */
if (!FlagOn(FileObject->Flags, FO_CACHE_SUPPORTED))
FSP_RETURN(Result = FALSE);
/* try to acquire the FileNode Main shared */
Result = DEBUGTEST(90) &&
FspFileNodeTryAcquireSharedF(FileNode, FspFileNodeAcquireMain, CanWait);
if (!Result)
FSP_RETURN(Result = FALSE);
/* is the file actually cached? */
if (0 == FileObject->PrivateCacheMap)
{
FspFileNodeRelease(FileNode, Main);
FSP_RETURN(Result = FALSE);
}
/* does the file have oplocks or file locks? */
Result =
FsRtlOplockIsFastIoPossible(FspFileNodeAddrOfOplock(FileNode)) &&
!FsRtlAreThereCurrentFileLocks(&FileNode->FileLock);
if (!Result)
{
FspFileNodeRelease(FileNode, Main);
FSP_RETURN(Result = FALSE);
}
/* trim ReadLength; the cache manager does not tolerate reads beyond file size */
ASSERT(FspTimeoutInfinity32 ==
FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.FileInfoTimeout);
FspFileNodeGetFileInfo(FileNode, &FileInfo);
if ((UINT64)ReadOffset.QuadPart >= FileInfo.FileSize)
{
FspFileNodeRelease(FileNode, Main);
IoStatus->Status = STATUS_END_OF_FILE;
FSP_RETURN(Result = TRUE);
}
if ((UINT64)ReadLength > FileInfo.FileSize - ReadOffset.QuadPart)
ReadLength = (ULONG)(FileInfo.FileSize - ReadOffset.QuadPart);
NTSTATUS Result0 =
FspCcCopyRead(FileObject, &ReadOffset, ReadLength, CanWait, UserBuffer, IoStatus);
if (!NT_SUCCESS(Result0))
{
IoStatus->Status = Result0;
IoStatus->Information = 0;
FspFileNodeRelease(FileNode, Main);
FSP_RETURN(Result = TRUE);
}
Result = STATUS_SUCCESS == Result0;
SetFlag(FileObject->Flags, FO_FILE_FAST_IO_READ);
if (Result)
FileObject->CurrentByteOffset.QuadPart = ReadOffset.QuadPart + ReadLength;
FspFileNodeRelease(FileNode, Main);
FSP_LEAVE_FIO(
"FileObject=%p, UserBuffer=%p, CanWait=%d, "
"Key=%#lx, ByteOffset=%#lx:%#lx, Length=%ld",
FileObject, UserBuffer, CanWait,
Key, ByteOffset->HighPart, ByteOffset->LowPart, Length);
}
static NTSTATUS FspFsvolRead(
PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
{