From 4f7de22ae47140b5d9adf0bca6d6e374a37408ea Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Mon, 18 May 2015 19:51:14 +0000
Subject: [PATCH] [FASTFAT] Implement support for FastIO for: -
 FastIoQueryBasicInfo - FastIoQueryStandardInfo

Now, with this commit and the two previous, ReactOS won't attempt to issue an IRP for these query, but will directly go with the FastIO path.
The performance improvement is really visible in 1st stage (at least, here with VBox).

svn path=/trunk/; revision=67824
---
 reactos/drivers/filesystems/fastfat/fastio.c | 99 +++++++++++++++++---
 reactos/drivers/filesystems/fastfat/finfo.c  |  2 -
 reactos/drivers/filesystems/fastfat/vfat.h   | 14 +++
 3 files changed, 100 insertions(+), 15 deletions(-)

diff --git a/reactos/drivers/filesystems/fastfat/fastio.c b/reactos/drivers/filesystems/fastfat/fastio.c
index 074defc6bc0..8b4d2b1bf78 100644
--- a/reactos/drivers/filesystems/fastfat/fastio.c
+++ b/reactos/drivers/filesystems/fastfat/fastio.c
@@ -1,9 +1,10 @@
 /*
- * FILE:             drivers/fs/vfat/fastio.c
+ * FILE:             drivers/filesystems/fastfat/fastio.c
  * PURPOSE:          Fast IO routines.
  * COPYRIGHT:        See COPYING in the top level directory
  * PROJECT:          ReactOS kernel
  * PROGRAMMER:       Herve Poussineau (hpoussin@reactos.org)
+ *                   Pierre Schweitzer (pierre@reactos.org)
  */
 
 #include "vfat.h"
@@ -111,15 +112,51 @@ VfatFastIoQueryBasicInfo(
     OUT PIO_STATUS_BLOCK IoStatus,
     IN PDEVICE_OBJECT DeviceObject)
 {
+    NTSTATUS Status;
+    PVFATFCB FCB = NULL;
+    BOOLEAN Success = FALSE;
+    ULONG BufferLength = sizeof(FILE_BASIC_INFORMATION);
+
     DPRINT("VfatFastIoQueryBasicInfo()\n");
 
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(Wait);
-    UNREFERENCED_PARAMETER(Buffer);
-    UNREFERENCED_PARAMETER(IoStatus);
-    UNREFERENCED_PARAMETER(DeviceObject);
+    FCB = (PVFATFCB)FileObject->FsContext;
+    if (FCB == NULL)
+    {
+        return FALSE;
+    }
 
-    return FALSE;
+    FsRtlEnterFileSystem();
+
+    if (!(FCB->Flags & FCB_IS_PAGE_FILE))
+    {
+        if (!ExAcquireResourceSharedLite(&FCB->MainResource, Wait))
+        {
+            FsRtlExitFileSystem();
+            return FALSE;
+        }
+    }
+
+    Status = VfatGetBasicInformation(FileObject,
+                                     FCB,
+                                     DeviceObject,
+                                     Buffer,
+                                     &BufferLength);
+
+    if (!(FCB->Flags & FCB_IS_PAGE_FILE))
+    {
+        ExReleaseResourceLite(&FCB->MainResource);
+    }
+
+    if (NT_SUCCESS(Status))
+    {
+        IoStatus->Status = STATUS_SUCCESS;
+        IoStatus->Information = sizeof(FILE_BASIC_INFORMATION) - BufferLength;
+        Success = TRUE;
+    }
+
+    FsRtlExitFileSystem();
+
+    return Success;
 }
 
 static FAST_IO_QUERY_STANDARD_INFO VfatFastIoQueryStandardInfo;
@@ -134,15 +171,51 @@ VfatFastIoQueryStandardInfo(
     OUT PIO_STATUS_BLOCK IoStatus,
     IN PDEVICE_OBJECT DeviceObject)
 {
-    DPRINT("VfatFastIoQueryStandardInfo\n");
+    NTSTATUS Status;
+    PVFATFCB FCB = NULL;
+    BOOLEAN Success = FALSE;
+    ULONG BufferLength = sizeof(FILE_STANDARD_INFORMATION);
+
+    DPRINT("VfatFastIoQueryStandardInfo()\n");
 
-    UNREFERENCED_PARAMETER(FileObject);
-    UNREFERENCED_PARAMETER(Wait);
-    UNREFERENCED_PARAMETER(Buffer);
-    UNREFERENCED_PARAMETER(IoStatus);
     UNREFERENCED_PARAMETER(DeviceObject);
 
-    return FALSE;
+    FCB = (PVFATFCB)FileObject->FsContext;
+    if (FCB == NULL)
+    {
+        return FALSE;
+    }
+
+    FsRtlEnterFileSystem();
+
+    if (!(FCB->Flags & FCB_IS_PAGE_FILE))
+    {
+        if (!ExAcquireResourceSharedLite(&FCB->MainResource, Wait))
+        {
+            FsRtlExitFileSystem();
+            return FALSE;
+        }
+    }
+
+    Status = VfatGetStandardInformation(FCB,
+                                        Buffer,
+                                        &BufferLength);
+
+    if (!(FCB->Flags & FCB_IS_PAGE_FILE))
+    {
+        ExReleaseResourceLite(&FCB->MainResource);
+    }
+
+    if (NT_SUCCESS(Status))
+    {
+        IoStatus->Status = STATUS_SUCCESS;
+        IoStatus->Information = sizeof(FILE_STANDARD_INFORMATION) - BufferLength;
+        Success = TRUE;
+    }
+
+    FsRtlExitFileSystem();
+
+    return Success;
 }
 
 static FAST_IO_LOCK VfatFastIoLock;
diff --git a/reactos/drivers/filesystems/fastfat/finfo.c b/reactos/drivers/filesystems/fastfat/finfo.c
index 6efe264cf8f..9a359913a30 100644
--- a/reactos/drivers/filesystems/fastfat/finfo.c
+++ b/reactos/drivers/filesystems/fastfat/finfo.c
@@ -71,7 +71,6 @@ const char* FileInformationClassNames[] =
 /*
  * FUNCTION: Retrieve the standard file information
  */
-static
 NTSTATUS
 VfatGetStandardInformation(
     PVFATFCB FCB,
@@ -236,7 +235,6 @@ VfatSetBasicInformation(
     return STATUS_SUCCESS;
 }
 
-static
 NTSTATUS
 VfatGetBasicInformation(
     PFILE_OBJECT FileObject,
diff --git a/reactos/drivers/filesystems/fastfat/vfat.h b/reactos/drivers/filesystems/fastfat/vfat.h
index bc6ac515b6d..2c4a6afb519 100644
--- a/reactos/drivers/filesystems/fastfat/vfat.h
+++ b/reactos/drivers/filesystems/fastfat/vfat.h
@@ -874,6 +874,20 @@ vfatMakeFCBFromDirEntry(
 
 /* finfo.c */
 
+NTSTATUS
+VfatGetStandardInformation(
+    PVFATFCB FCB,
+    PFILE_STANDARD_INFORMATION StandardInfo,
+    PULONG BufferLength);
+
+NTSTATUS
+VfatGetBasicInformation(
+    PFILE_OBJECT FileObject,
+    PVFATFCB FCB,
+    PDEVICE_OBJECT DeviceObject,
+    PFILE_BASIC_INFORMATION BasicInfo,
+    PULONG BufferLength);
+
 NTSTATUS
 VfatQueryInformation(
     PVFAT_IRP_CONTEXT IrpContext);