From c779dbd4c5779cfddfd4054601d996c15ae22ff4 Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Mon, 15 Jan 2018 23:20:53 +0100
Subject: [PATCH] [NTOSKRNL] Implement CcIsThereDirtyData()

---
 ntoskrnl/cc/fs.c               | 40 +++++++++++++++++++++++++++++++---
 ntoskrnl/cc/view.c             |  2 +-
 ntoskrnl/include/internal/cc.h |  1 +
 3 files changed, 39 insertions(+), 4 deletions(-)

diff --git a/ntoskrnl/cc/fs.c b/ntoskrnl/cc/fs.c
index fb5f99aab26..d62e18dee0a 100644
--- a/ntoskrnl/cc/fs.c
+++ b/ntoskrnl/cc/fs.c
@@ -111,17 +111,51 @@ CcInitializeCacheMap (
 }
 
 /*
- * @unimplemented
+ * @implemented
  */
 BOOLEAN
 NTAPI
 CcIsThereDirtyData (
     IN PVPB Vpb)
 {
+    PROS_VACB Vacb;
+    PLIST_ENTRY Entry;
+    /* Assume no dirty data */
+    BOOLEAN Dirty = FALSE;
+
     CCTRACE(CC_API_DEBUG, "Vpb=%p\n", Vpb);
 
-    UNIMPLEMENTED;
-    return FALSE;
+    KeAcquireGuardedMutex(&ViewLock);
+
+    /* Browse dirty VACBs */
+    for (Entry = DirtyVacbListHead.Flink; Entry != &DirtyVacbListHead; Entry = Entry->Flink)
+    {
+        Vacb = CONTAINING_RECORD(Entry, ROS_VACB, DirtyVacbListEntry);
+        /* Look for these associated with our volume */
+        if (Vacb->SharedCacheMap->FileObject->Vpb != Vpb)
+        {
+            continue;
+        }
+
+        /* From now on, we are associated with our VPB */
+
+        /* Temporary files are not counted as dirty */
+        if (BooleanFlagOn(Vacb->SharedCacheMap->FileObject->Flags, FO_TEMPORARY_FILE))
+        {
+            continue;
+        }
+
+        /* A single dirty VACB is enough to have dirty data */
+        if (Vacb->Dirty)
+        {
+            Dirty = TRUE;
+            break;
+        }
+    }
+
+    KeReleaseGuardedMutex(&ViewLock);
+
+    return Dirty;
 }
 
 /*
diff --git a/ntoskrnl/cc/view.c b/ntoskrnl/cc/view.c
index f38a028d9ba..0e37b77efca 100644
--- a/ntoskrnl/cc/view.c
+++ b/ntoskrnl/cc/view.c
@@ -41,7 +41,7 @@
 
 /* GLOBALS *******************************************************************/
 
-static LIST_ENTRY DirtyVacbListHead;
+LIST_ENTRY DirtyVacbListHead;
 static LIST_ENTRY VacbLruListHead;
 ULONG DirtyPageCount = 0;
 
diff --git a/ntoskrnl/include/internal/cc.h b/ntoskrnl/include/internal/cc.h
index 4f7c4823af3..58d2b15a507 100644
--- a/ntoskrnl/include/internal/cc.h
+++ b/ntoskrnl/include/internal/cc.h
@@ -40,6 +40,7 @@
 // Global Cc Data
 //
 extern ULONG CcRosTraceLevel;
+extern LIST_ENTRY DirtyVacbListHead;
 
 typedef struct _PF_SCENARIO_ID
 {