From 78c5fdb6f2996e8a03c692b7ec2e0fcb039d5936 Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Thu, 24 Dec 2015 11:52:37 -0800
Subject: [PATCH] Major refactoring: IRP_MJ_CREATE

---
 build/VStudio/winfsp_sys.vcxproj         |  1 +
 build/VStudio/winfsp_sys.vcxproj.filters |  3 +
 src/sys/driver.h                         |  2 +-
 src/sys/filectx.c                        | 72 ++++++++++++++++++++++++
 4 files changed, 77 insertions(+), 1 deletion(-)
 create mode 100644 src/sys/filectx.c

diff --git a/build/VStudio/winfsp_sys.vcxproj b/build/VStudio/winfsp_sys.vcxproj
index 2177afe5..4d50bb29 100644
--- a/build/VStudio/winfsp_sys.vcxproj
+++ b/build/VStudio/winfsp_sys.vcxproj
@@ -156,6 +156,7 @@
     <ClCompile Include="..\..\src\sys\driver.c" />
     <ClCompile Include="..\..\src\sys\ea.c" />
     <ClCompile Include="..\..\src\sys\fastio.c" />
+    <ClCompile Include="..\..\src\sys\filectx.c" />
     <ClCompile Include="..\..\src\sys\fileinfo.c" />
     <ClCompile Include="..\..\src\sys\flush.c" />
     <ClCompile Include="..\..\src\sys\fsctl.c" />
diff --git a/build/VStudio/winfsp_sys.vcxproj.filters b/build/VStudio/winfsp_sys.vcxproj.filters
index fea8d778..29d159a0 100644
--- a/build/VStudio/winfsp_sys.vcxproj.filters
+++ b/build/VStudio/winfsp_sys.vcxproj.filters
@@ -83,6 +83,9 @@
     <ClCompile Include="..\..\src\sys\volume.c">
       <Filter>Source</Filter>
     </ClCompile>
+    <ClCompile Include="..\..\src\sys\filectx.c">
+      <Filter>Source</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="..\..\src\sys\driver.h">
diff --git a/src/sys/driver.h b/src/sys/driver.h
index 94353413..bb7b15d7 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -476,10 +476,10 @@ typedef struct
     BOOLEAN DeletePending;              /* FileDispositionInformation */
     BOOLEAN DeleteOnClose;              /* FILE_DELETE_ON_CLOSE */
     FSP_DEVICE_GENERIC_TABLE_ELEMENT ElementStorage;
-    PDEVICE_OBJECT FsvolDeviceObject;
     UINT64 UserContext;
 #endif
     /* read-only after creation */
+    PDEVICE_OBJECT FsvolDeviceObject;
     UNICODE_STRING FileName;
     WCHAR FileNameBuf[];
 } FSP_FILE_CONTEXT;
diff --git a/src/sys/filectx.c b/src/sys/filectx.c
new file mode 100644
index 00000000..7444c0f4
--- /dev/null
+++ b/src/sys/filectx.c
@@ -0,0 +1,72 @@
+/**
+ * @file sys/filectx.c
+ *
+ * @copyright 2015 Bill Zissimopoulos
+ */
+
+#include <sys/driver.h>
+
+NTSTATUS FspFileContextCreate(PDEVICE_OBJECT DeviceObject,
+    ULONG ExtraSize, FSP_FILE_CONTEXT **PFsContext);
+VOID FspFileContextDelete(FSP_FILE_CONTEXT *Context);
+
+#ifdef ALLOC_PRAGMA
+#pragma alloc_text(PAGE, FspFileContextCreate)
+#pragma alloc_text(PAGE, FspFileContextDelete)
+#endif
+
+NTSTATUS FspFileContextCreate(PDEVICE_OBJECT DeviceObject,
+    ULONG ExtraSize, FSP_FILE_CONTEXT **PFsContext)
+{
+    PAGED_CODE();
+
+    *PFsContext = 0;
+
+    FSP_FILE_CONTEXT_NONPAGED *NonPaged = FspAllocNonPaged(sizeof *NonPaged);
+    if (0 == NonPaged)
+        return STATUS_INSUFFICIENT_RESOURCES;
+
+    FSP_FILE_CONTEXT *FsContext = FspAlloc(sizeof *FsContext + ExtraSize);
+    if (0 == FsContext)
+    {
+        FspFree(NonPaged);
+        return STATUS_INSUFFICIENT_RESOURCES;
+    }
+
+    RtlZeroMemory(NonPaged, sizeof *NonPaged);
+    ExInitializeResourceLite(&NonPaged->Resource);
+    ExInitializeResourceLite(&NonPaged->PagingIoResource);
+    ExInitializeFastMutex(&NonPaged->HeaderFastMutex);
+
+    RtlZeroMemory(FsContext, sizeof *FsContext + ExtraSize);
+    FsContext->Header.NodeTypeCode = FspFileContextFileKind;
+    FsContext->Header.NodeByteSize = sizeof *FsContext;
+    FsContext->Header.IsFastIoPossible = FastIoIsQuestionable;
+    FsContext->Header.Resource = &NonPaged->Resource;
+    FsContext->Header.PagingIoResource = &NonPaged->PagingIoResource;
+    FsRtlSetupAdvancedHeader(&FsContext->Header, &NonPaged->HeaderFastMutex);
+    FsContext->NonPaged = NonPaged;
+    FsContext->RefCount = 1;
+    FsContext->FsvolDeviceObject = DeviceObject;
+    FspDeviceRetain(FsContext->FsvolDeviceObject);
+    RtlInitEmptyUnicodeString(&FsContext->FileName, FsContext->FileNameBuf, (USHORT)ExtraSize);
+
+    *PFsContext = FsContext;
+
+    return STATUS_SUCCESS;
+}
+
+VOID FspFileContextDelete(FSP_FILE_CONTEXT *FsContext)
+{
+    PAGED_CODE();
+
+    FsRtlTeardownPerStreamContexts(&FsContext->Header);
+
+    FspDeviceRelease(FsContext->FsvolDeviceObject);
+
+    ExDeleteResourceLite(&FsContext->NonPaged->PagingIoResource);
+    ExDeleteResourceLite(&FsContext->NonPaged->Resource);
+    FspFree(FsContext->NonPaged);
+
+    FspFree(FsContext);
+}