From f2c44aa4838de066069a532758965522f482de10 Mon Sep 17 00:00:00 2001
From: Pierre Schweitzer <pierre@reactos.org>
Date: Sun, 29 Apr 2018 20:34:28 +0200
Subject: [PATCH] [NTOSKRNL] Fix lazy writer for in-use VACB.

Adjusting refcount and enabling lazy-write for pinned
VACB makes it actually more efficient, often purging
data to disk, reducing memory stress for the system.

This is required for defering writes.

This commit unfortunately (?) reverts a previous revert.

CORE-12081
CORE-14582
CORE-14313
---
 ntoskrnl/cc/pin.c  | 4 ++++
 ntoskrnl/cc/view.c | 6 +++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/ntoskrnl/cc/pin.c b/ntoskrnl/cc/pin.c
index d81f09d4701..2d48a27a0aa 100644
--- a/ntoskrnl/cc/pin.c
+++ b/ntoskrnl/cc/pin.c
@@ -275,6 +275,10 @@ CcSetDirtyPinnedData (
         Bcb, Lsn);
 
     iBcb->Dirty = TRUE;
+    if (!iBcb->Vacb->Dirty)
+    {
+        CcRosMarkDirtyVacb(iBcb->Vacb);
+    }
 }
 
 
diff --git a/ntoskrnl/cc/view.c b/ntoskrnl/cc/view.c
index c2b89131323..e1d064312ff 100644
--- a/ntoskrnl/cc/view.c
+++ b/ntoskrnl/cc/view.c
@@ -205,6 +205,8 @@ CcRosFlushDirtyPages (
 
     while ((current_entry != &DirtyVacbListHead) && (Target > 0))
     {
+        ULONG Refs;
+
         current = CONTAINING_RECORD(current_entry,
                                     ROS_VACB,
                                     DirtyVacbListEntry);
@@ -231,7 +233,9 @@ CcRosFlushDirtyPages (
         ASSERT(current->Dirty);
 
         /* One reference is added above */
-        if (CcRosVacbGetRefCount(current) > 2)
+        Refs = CcRosVacbGetRefCount(current);
+        if ((Refs > 3 && current->PinCount == 0) ||
+            (Refs > 4 && current->PinCount > 1))
         {
             current->SharedCacheMap->Callbacks->ReleaseFromLazyWrite(
                 current->SharedCacheMap->LazyWriteContext);