From 66dbfb24ff35a4816c0357c8074e1c8261cd53ad Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Wed, 6 Apr 2016 16:04:42 -0700
Subject: [PATCH] sys: IRP_MJ_READ, IRP_MJ_WRITE: file lock support

---
 src/sys/read.c  | 18 ++++++++++++++----
 src/sys/write.c | 18 ++++++++++++++----
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/sys/read.c b/src/sys/read.c
index 8b05ce0b..0fd5c185 100644
--- a/src/sys/read.c
+++ b/src/sys/read.c
@@ -97,10 +97,6 @@ static NTSTATUS FspFsvolReadCached(
     FSP_FILE_NODE *FileNode = FileObject->FsContext;
     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;
@@ -112,6 +108,13 @@ static NTSTATUS FspFsvolReadCached(
     if (!Success)
         return FspWqRepostIrpWorkItem(Irp, FspFsvolReadCached, 0);
 
+    /* check the file locks */
+    if (!FsRtlCheckLockForReadAccess(&FileNode->FileLock, Irp))
+    {
+        FspFileNodeRelease(FileNode, Main);
+        return STATUS_FILE_LOCK_CONFLICT;
+    }
+
     /* trim ReadLength; the cache manager does not tolerate reads beyond file size */
     ASSERT(FspTimeoutInfinity32 ==
         FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.FileInfoTimeout);
@@ -234,6 +237,13 @@ static NTSTATUS FspFsvolReadNonCached(
     if (!Success)
         return FspWqRepostIrpWorkItem(Irp, FspFsvolReadNonCached, 0);
 
+    /* check the file locks */
+    if (!PagingIo && !FsRtlCheckLockForReadAccess(&FileNode->FileLock, Irp))
+    {
+        FspFileNodeRelease(FileNode, Full);
+        return STATUS_FILE_LOCK_CONFLICT;
+    }
+
     /* if this is a non-cached transfer on a cached file then flush the file */
     if (!PagingIo && 0 != FileObject->SectionObjectPointer->DataSectionObject)
     {
diff --git a/src/sys/write.c b/src/sys/write.c
index ba14b35e..e72b1769 100644
--- a/src/sys/write.c
+++ b/src/sys/write.c
@@ -98,10 +98,6 @@ static NTSTATUS FspFsvolWriteCached(
     FSP_FILE_NODE *FileNode = FileObject->FsContext;
     LARGE_INTEGER WriteOffset = IrpSp->Parameters.Write.ByteOffset;
     ULONG WriteLength = IrpSp->Parameters.Write.Length;
-#if 0
-    /* !!!: lock support! */
-    ULONG WriteKey = IrpSp->Parameters.Write.Key;
-#endif
     BOOLEAN WriteToEndOfFile =
         FILE_WRITE_TO_END_OF_FILE == WriteOffset.LowPart && -1L == WriteOffset.HighPart;
     BOOLEAN SynchronousIo = BooleanFlagOn(FileObject->Flags, FO_SYNCHRONOUS_IO);
@@ -134,6 +130,13 @@ static NTSTATUS FspFsvolWriteCached(
     if (!Success)
         return FspWqRepostIrpWorkItem(Irp, FspFsvolWriteCached, 0);
 
+    /* check the file locks */
+    if (!FsRtlCheckLockForWriteAccess(&FileNode->FileLock, Irp))
+    {
+        FspFileNodeRelease(FileNode, Main);
+        return STATUS_FILE_LOCK_CONFLICT;
+    }
+
     /* compute new file size */
     ASSERT(FspTimeoutInfinity32 ==
         FspFsvolDeviceExtension(FsvolDeviceObject)->VolumeParams.FileInfoTimeout);
@@ -300,6 +303,13 @@ static NTSTATUS FspFsvolWriteNonCached(
     if (!Success)
         return FspWqRepostIrpWorkItem(Irp, FspFsvolWriteNonCached, 0);
 
+    /* check the file locks */
+    if (!PagingIo && !FsRtlCheckLockForWriteAccess(&FileNode->FileLock, Irp))
+    {
+        FspFileNodeRelease(FileNode, Full);
+        return STATUS_FILE_LOCK_CONFLICT;
+    }
+
     /* if this is a non-cached transfer on a cached file then flush and purge the file */
     if (!PagingIo && 0 != FileObject->SectionObjectPointer->DataSectionObject)
     {