sys: IRP_MJ_READ: implementation

src/sys/read.c

@@ -7,18 +7,160 @@
 #include <sys/driver.h>
 
 static NTSTATUS FspFsvolRead(
-    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
+static NTSTATUS FspFsvolReadCached(
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp,
+    BOOLEAN CanWait);
+static NTSTATUS FspFsvolReadNonCached(
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp);
 FSP_IOCMPL_DISPATCH FspFsvolReadComplete;
+static FSP_IOP_REQUEST_FINI FspFsvolReadNonCachedRequestFini;
 FSP_DRIVER_DISPATCH FspRead;
 
 #ifdef ALLOC_PRAGMA
 #pragma alloc_text(PAGE, FspFsvolRead)
+#pragma alloc_text(PAGE, FspFsvolReadCached)
+#pragma alloc_text(PAGE, FspFsvolReadNonCached)
 #pragma alloc_text(PAGE, FspFsvolReadComplete)
+#pragma alloc_text(PAGE, FspFsvolReadNonCachedRequestFini)
 #pragma alloc_text(PAGE, FspRead)
 #endif
 
 static NTSTATUS FspFsvolRead(
-    PDEVICE_OBJECT DeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
+{
+    PAGED_CODE();
+
+    /* is this a valid FileObject? */
+    if (!FspFileNodeIsValid(IrpSp->FileObject->FsContext))
+        return STATUS_INVALID_DEVICE_REQUEST;
+
+    NTSTATUS Result;
+    PFILE_OBJECT FileObject = IrpSp->FileObject;
+    FSP_FILE_NODE *FileNode = FileObject->FsContext;
+
+    /* is this an MDL complete request? */
+    if (FlagOn(IrpSp->MinorFunction, IRP_MN_COMPLETE))
+    {
+        Result = FspCcMdlReadComplete(FileObject, Irp->MdlAddress);
+        Irp->MdlAddress = 0;
+        return Result;
+    }
+
+    /* only regular files can be read */
+    if (FileNode->IsDirectory)
+        return STATUS_INVALID_PARAMETER;
+
+    /* do we have anything to read? */
+    if (0 == IrpSp->Parameters.Read.Length)
+    {
+        Irp->IoStatus.Information = 0;
+        return STATUS_SUCCESS;
+    }
+
+    /* are we doing cached or non-cached I/O? */
+    if (FlagOn(FileObject->Flags, FO_CACHE_SUPPORTED) &&
+        !FlagOn(Irp->Flags, IRP_PAGING_IO | IRP_NOCACHE))
+        Result = FspFsvolReadCached(FsvolDeviceObject, Irp, IrpSp, IoIsOperationSynchronous(Irp));
+    else
+        Result = FspFsvolReadNonCached(FsvolDeviceObject, Irp, IrpSp);
+
+    return Result;
+}
+
+static NTSTATUS FspFsvolReadCached(
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp,
+    BOOLEAN CanWait)
+{
+    PAGED_CODE();
+
+    NTSTATUS Result;
+    FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension = FspFsvolDeviceExtension(FsvolDeviceObject);
+    PFILE_OBJECT FileObject = IrpSp->FileObject;
+    FSP_FILE_NODE *FileNode = FileObject->FsContext;
+    FSP_FILE_DESC *FileDesc = FileObject->FsContext2;
+    LARGE_INTEGER ReadOffset = IrpSp->Parameters.Read.ByteOffset;
+    ULONG ReadLength = IrpSp->Parameters.Read.Length;
+#if 0
+    /* !!!: lock support! */
+    ULONG ReadKey = IrpSp->Parameters.Read.Key;
+#endif
+    BOOLEAN SynchronousIo = BooleanFlagOn(FileObject->Flags, FO_SYNCHRONOUS_IO);
+    FSP_FSCTL_FILE_INFO FileInfo;
+    CC_FILE_SIZES FileSizes;
+    BOOLEAN Success;
+
+    ASSERT(FileNode == FileDesc->FileNode);
+
+    /* try to acquire the FileNode Main shared */
+    Success = DEBUGTEST(90, TRUE) &&
+        FspFileNodeTryAcquireSharedF(FileNode, FspFileNodeAcquireMain, CanWait);
+    if (!Success)
+        return FspWqRepostIrpWorkItem(Irp, FspFsvolReadCached, 0);
+
+    /* initialize cache if not already initialized! */
+    if (0 == FileObject->PrivateCacheMap)
+    {
+        ASSERT(FspTimeoutInfinity32 == FsvolDeviceExtension->VolumeParams.FileInfoTimeout);
+        FspFileNodeGetFileInfo(FileNode, &FileInfo);
+        FileSizes.AllocationSize.QuadPart = FileInfo.AllocationSize;
+        FileSizes.FileSize.QuadPart = FileInfo.FileSize;
+        FileSizes.ValidDataLength.QuadPart = MAXLONGLONG;
+
+        Result = FspCcInitializeCacheMap(FileObject, &FileSizes, FALSE,
+            &FspCacheManagerCallbacks, FileNode);
+        if (!NT_SUCCESS(Result))
+        {
+            FspFileNodeRelease(FileNode, Main);
+            return Result;
+        }
+    }
+
+    /* are we using the copy or MDL interface? */
+    if (!FlagOn(IrpSp->MinorFunction, IRP_MN_MDL))
+    {
+        PVOID Buffer;
+
+        Buffer = 0 == Irp->MdlAddress ?
+            Irp->UserBuffer : MmGetSystemAddressForMdlSafe(Irp->MdlAddress, NormalPagePriority);
+        if (0 == Buffer)
+        {
+            FspFileNodeRelease(FileNode, Main);
+            return STATUS_INSUFFICIENT_RESOURCES;
+        }
+
+        Result = FspCcCopyRead(FileObject, &ReadOffset, ReadLength, CanWait, Buffer,
+            &Irp->IoStatus);
+        if (STATUS_PENDING == Result)
+        {
+            FspFileNodeRelease(FileNode, Main);
+            return FspWqRepostIrpWorkItem(Irp, FspFsvolReadCached, 0);
+        }
+    }
+    else
+    {
+        ASSERT(0 == Irp->MdlAddress);
+
+        Result = FspCcMdlRead(FileObject, &ReadOffset, ReadLength, &Irp->MdlAddress,
+            &Irp->IoStatus);
+        if (!NT_SUCCESS(Result))
+        {
+            FspFileNodeRelease(FileNode, Main);
+            return Result;
+        }
+    }
+
+    /* update the current file offset if synchronous I/O */
+    if (SynchronousIo)
+        FileObject->CurrentByteOffset.QuadPart = ReadOffset.QuadPart + Irp->IoStatus.Information;
+
+    FspFileNodeRelease(FileNode, Main);
+
+    return STATUS_SUCCESS;
+}
+
+static NTSTATUS FspFsvolReadNonCached(
+    PDEVICE_OBJECT FsvolDeviceObject, PIRP Irp, PIO_STACK_LOCATION IrpSp)
 {
     PAGED_CODE();
 
@@ -30,7 +172,13 @@ NTSTATUS FspFsvolReadComplete(
 {
     FSP_ENTER_IOC(PAGED_CODE());
 
-    FSP_LEAVE_IOC("%s", "");
+    FSP_LEAVE_IOC(
+        "FileObject=%p, UserBuffer=%p, MdlAddress=%p, "
+        "Key=%#lx, ByteOffset=%#lx:%#lx, Length=%ld",
+        IrpSp->FileObject, Irp->UserBuffer, Irp->MdlAddress,
+        IrpSp->Parameters.Read.Key,
+        IrpSp->Parameters.Read.ByteOffset.HighPart, IrpSp->Parameters.Read.ByteOffset.LowPart,
+        IrpSp->Parameters.Read.Length);
 }
 
 NTSTATUS FspRead(
@@ -46,5 +194,11 @@ NTSTATUS FspRead(
         FSP_RETURN(Result = STATUS_INVALID_DEVICE_REQUEST);
     }
 
-    FSP_LEAVE_MJ("%s", "");
+    FSP_LEAVE_MJ(
+        "FileObject=%p, UserBuffer=%p, MdlAddress=%p, "
+        "Key=%#lx, ByteOffset=%#lx:%#lx, Length=%ld",
+        IrpSp->FileObject, Irp->UserBuffer, Irp->MdlAddress,
+        IrpSp->Parameters.Read.Key,
+        IrpSp->Parameters.Read.ByteOffset.HighPart, IrpSp->Parameters.Read.ByteOffset.LowPart,
+        IrpSp->Parameters.Read.Length);
 }