From 6e4f83da700fbfac5450dc9ef667585ddc870bc9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Gardou?= <jerome.gardou@reactos.org>
Date: Tue, 16 Feb 2021 17:17:57 +0100
Subject: [PATCH] [NTOS:CC] Wake up lazy scan after inserting elements in the
 list.

---
 ntoskrnl/cc/copy.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/ntoskrnl/cc/copy.c b/ntoskrnl/cc/copy.c
index 30864bc319e..09af125540c 100644
--- a/ntoskrnl/cc/copy.c
+++ b/ntoskrnl/cc/copy.c
@@ -381,16 +381,6 @@ CcCanIWrite (
         return FALSE;
     }
 
-    /* Otherwise, if there are no deferred writes yet, start the lazy writer */
-    if (IsListEmpty(&CcDeferredWrites))
-    {
-        KIRQL OldIrql;
-
-        OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
-        CcScheduleLazyWriteScan(TRUE);
-        KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
-    }
-
     /* Initialize our wait event */
     KeInitializeEvent(&WaitEvent, NotificationEvent, FALSE);
 
@@ -418,6 +408,12 @@ CcCanIWrite (
                                     &CcDeferredWriteSpinLock);
     }
 
+    /* Now make sure that the lazy scan writer will be active */
+    OldIrql = KeAcquireQueuedSpinLock(LockQueueMasterLock);
+    if (!LazyWriter.ScanActive)
+        CcScheduleLazyWriteScan(TRUE);
+    KeReleaseQueuedSpinLock(LockQueueMasterLock, OldIrql);
+
 #if DBG
     DPRINT1("Actively deferring write for: %p\n", FileObject);
     DPRINT1("Because:\n");