From e4b4e6a1f99e35f41006f6a3d1f05e0b4a1c884b Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Thu, 29 Dec 2016 13:16:11 -0800
Subject: [PATCH] sys: FSP_FILE_NODE::MainFileNode: reference/dereference on
 create/delete

---
 src/sys/create.c | 2 ++
 src/sys/driver.h | 2 +-
 src/sys/file.c   | 3 +++
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/sys/create.c b/src/sys/create.c
index b45ae50e..a4d3372e 100644
--- a/src/sys/create.c
+++ b/src/sys/create.c
@@ -444,7 +444,9 @@ static NTSTATUS FspFsvolCreateNoLock(
         FileAttributes = 0;
 
         /* remember the main file node */
+        ASSERT(0 == FileNode->MainFileNode);
         FileNode->MainFileNode = FileDesc->MainFileObject->FsContext;
+        FspFileNodeReference(FileNode->MainFileNode);
 
         Result = STATUS_SUCCESS;
 
diff --git a/src/sys/driver.h b/src/sys/driver.h
index 4819f3a4..c3226757 100644
--- a/src/sys/driver.h
+++ b/src/sys/driver.h
@@ -1208,7 +1208,7 @@ typedef struct FSP_FILE_NODE
     UINT64 IndexNumber;
     BOOLEAN IsDirectory;
     BOOLEAN IsRootDirectory;
-    struct FSP_FILE_NODE *MainFileNode; /* this becomes invalid after our last desc close */
+    struct FSP_FILE_NODE *MainFileNode;
     WCHAR FileNameBuf[];
 } FSP_FILE_NODE;
 typedef struct
diff --git a/src/sys/file.c b/src/sys/file.c
index f75f9d57..8c745594 100644
--- a/src/sys/file.c
+++ b/src/sys/file.c
@@ -252,6 +252,9 @@ VOID FspFileNodeDelete(FSP_FILE_NODE *FileNode)
     FSP_FSVOL_DEVICE_EXTENSION *FsvolDeviceExtension =
         FspFsvolDeviceExtension(FileNode->FsvolDeviceObject);
 
+    if (0 != FileNode->MainFileNode)
+        FspFileNodeDereference(FileNode->MainFileNode);
+
     FsRtlUninitializeOplock(FspFileNodeAddrOfOplock(FileNode));
     FsRtlUninitializeFileLock(&FileNode->FileLock);