[NTOSKRNL:CC] Implemented CcUnpinFileDataEx

Implemented CcUnpinFileDataEx responsible for unpinning BCB and cleaning if it is dirty 
*Fixed Typo for freeing pool memory of some other function

NTOSKRNL/CC/ccpinsupport.cpp

@@ -77,10 +77,110 @@ VOID
 NTAPI
 CcUnpinFileDataEx(
     _In_ PCC_BCB Bcb,
-    _In_ BOOLEAN WriteStatus,
+    _In_ BOOLEAN& WriteStatus,
-    _In_ ULONG Type)
+    _In_ ULONG& UnPinType)
 {
-    // Unimplementd
+	PSHARED_CACHE_MAP SharedCacheMap = nullptr;
+    KIRQL OldIrql = {0};
+    ULONG NumberOfPages = {0};
+	BOOLEAN ReadOnly = false;
+
+
+    /* If it is not BCB Ptr,it must be VACB Pointer, free it*/
+    if (Bcb->NodeTypeCode != BCB_NODE_TYPE_CODE)
+    {   
+        PVACB Vacb = reinterpret_cast<PVACB>(Bcb);
+       
+        CcFreeVirtualAddress(Vacb);
+
+        return;
+    }
+
+    SharedCacheMap = Bcb->SharedCacheMap;
+    /* Is it only Unpinning if so is their no write performed by Cache Controller */
+    if (!(SharedCacheMap->Flags & SHARED_CACHE_MAP_MODIFIED_NO_WRITE) || UnPinType == UnPin)
+        ReadOnly = TRUE;
+
+    OldIrql = KeAcquireSpinLockRaiseToDpc(&SharedCacheMap->BcbSpinLock);
+    /* Just reduce pin count if BCB is not set to be cleaned else perform cleaning of BCB*/
+    if (UnPinType < CLEAN_BCB_PIN)
+    {
+        ASSERT(Bcb->PinCount > 0);
+        Bcb->PinCount--;
+    }
+    else
+    {
+        if (UnPinType != CLEAN_BCB_PIN)
+            KeBugCheckEx(UNEXPECTED_VALUE, UnPinType, (ULONG_PTR)Bcb, 0, 0);
+
+        if (Bcb->IsBCBDirty)
+        {
+            NumberOfPages = (Bcb->Length / PAGE_SIZE);
+
+            Bcb->IsBCBDirty = FALSE;
+            Bcb->NewestDirtiedPage = 0;
+            Bcb->NewestLsn.QuadPart = 0;
+
+            CcDeductIsBCBDirtyPages(SharedCacheMap, NumberOfPages);
+            /*Adjust page count */
+            if (CcPagesYetToWrite <= NumberOfPages)
+                CcPagesYetToWrite = 0;
+            else
+                CcPagesYetToWrite -= NumberOfPages;
+
+            if (!SharedCacheMap->IsBCBDirtyPages && SharedCacheMap->OpenCount)
+                CcInsertIntoCleanSharedCacheMapList(SharedCacheMap);
+        }
+    }
+
+    if (Bcb->PinCount)
+    {   /* If not read only BCB, release resources,their no point being pinned at that case */
+        if (!ReadOnly)
+            ExReleaseResourceLite(&Bcb->BcbResource);
+
+        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
+    }
+	/*if BCB is dirty, free the virtual adress*/
+    else if (Bcb->IsBCBDirty)
+    {
+        if (Bcb->BaseAddress)
+        {
+            CcFreeVirtualAddress(Bcb->Vacb);
+
+            Bcb->BaseAddress = NULL;
+            Bcb->Vacb = NULL;
+        }
+
+        if (!ReadOnly)
+            ExReleaseResourceLite(&Bcb->BcbResource);
+
+        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
+    }
+    else
+    {
+        KeAcquireSpinLockAtDpcLevel(&SharedCacheMap->VacbSpinLock);
+
+        RemoveEntryList(&Bcb->Link);
+
+        if (SharedCacheMap->SectionSize.QuadPart > CACHE_OVERALL_SIZE &&
+            (SharedCacheMap->Flags & SHARED_CACHE_MAP_MODIFIED_NO_WRITE))
+        {
+            CcAdjustVacbLevelLockCount(SharedCacheMap, &Bcb->FileOffset.QuadPart, -1); 
+        }
+
+        KeReleaseSpinLockFromDpcLevel(&SharedCacheMap->VacbSpinLock);
+
+        if (Bcb->BaseAddress)
+            CcFreeVirtualAddress(Bcb->Vacb); 
+
+        if (!ReadOnly)
+            ExReleaseResourceLite(&Bcb->BcbResource);
+
+        KeReleaseSpinLock(&SharedCacheMap->BcbSpinLock, OldIrql);
+
+        CcDeallocateBcb(Bcb);
+    }
+    
 }
 
 BOOLEAN
@@ -183,7 +283,7 @@ CcUnpinData(
 	PCC_BCB Bcb = reinterpret_cast<PCC_BCB>(BcbPtr);
     BOOLEAN WRITE_FLAG = NULL;
 		
-if (reinterpret_cast<ULONG_PTR>(Bcb) & 1)
+if (reinterpret_cast<ULONG_PTR>((Bcb & 1))
 {
     WRITE_FLAG = TRUE;
     Bcb = reinterpret_cast<PCC_BCB>(reinterpret_cast<ULONG_PTR>(Bcb) & ~(1));
@@ -206,7 +306,7 @@ if (reinterpret_cast<ULONG_PTR>(Bcb) & 1)
 		CcUnpinData(BCB_CURRENT);
 		
 }
-ExFreePoolWithTag(Bcb);
+ExFreePoolWithTag(Bcb,NULL);
 }
 
 VOID
@@ -217,7 +317,7 @@ CcUnpinDataForThread(IN PVOID BcbPtr,
     PCC_BCB Bcb = BcbPtr;
     BOOLEAN WRITE_FLAG = NULL;
 
-if (reinterpret_cast<ULONG_PTR>(Bcb) & 1)
+if (reinterpret_cast<ULONG_PTR>((Bcb & 1))
 {
     WRITE_FLAG = TRUE;
     Bcb = reinterpret_cast<PCC_BCB>(reinterpret_cast<ULONG_PTR>(Bcb) & ~(1));
@@ -241,7 +341,7 @@ if (Bcb->NodeTypeCode != 762)
 		CcUnpinData(BCB_CURRENT);
 		
 }
-ExFreePoolWithTag(Bcb);
+ExFreePoolWithTag(Bcb,NULL);
     
 }