[ros-diffs] [cgutman] 54746: [NTOSKRNL] - Fix inconsistent locking

Author: cgutman
Date: Sat Dec 24 03:57:10 2011
New Revision: 54746

URL: http://svn.reactos.org/svn/reactos?rev=54746&view=rev
Log:
[NTOSKRNL]
- Fix inconsistent locking

Modified:
    trunk/reactos/ntoskrnl/cc/view.c

Modified: trunk/reactos/ntoskrnl/cc/view.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/cc/view.c?rev=5474...
==============================================================================
--- trunk/reactos/ntoskrnl/cc/view.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/cc/view.c [iso-8859-1] Sat Dec 24 03:57:10 2011
@@ -398,7 +398,7 @@
    		 BOOLEAN Dirty,
    		 BOOLEAN Mapped)
 {
-  BOOLEAN WasDirty = CacheSeg->Dirty;
+  BOOLEAN WasDirty;
   KIRQL oldIrql;

ASSERT(Bcb);
@@ -406,10 +406,14 @@
   DPRINT("CcReleaseCacheSegment(Bcb 0x%p, CacheSeg 0x%p, Valid %d)\n",
     Bcb, CacheSeg, Valid);

+  KeAcquireGuardedMutex(&ViewLock);
+  KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
+
   CacheSeg->Valid = Valid;
+
+  WasDirty = CacheSeg->Dirty;
   CacheSeg->Dirty = CacheSeg->Dirty || Dirty;

-  KeAcquireGuardedMutex(&ViewLock);
   if (!WasDirty && CacheSeg->Dirty)
     {
       InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
@@ -420,7 +424,6 @@
   {
      CacheSeg->MappedCount++;
   }
-  KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
   CcRosCacheSegmentDecRefCount(CacheSeg);
   if (Mapped && CacheSeg->MappedCount == 1)
   {
@@ -430,6 +433,7 @@
   {
       CcRosCacheSegmentIncRefCount(CacheSeg);
   }
+
   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
   KeReleaseGuardedMutex(&ViewLock);
   KeReleaseMutex(&CacheSeg->Mutex, 0);
@@ -449,8 +453,10 @@
     ASSERT(Bcb);

DPRINT("CcRosLookupCacheSegment(Bcb -x%p, FileOffset %d)\n", Bcb, FileOffset);
-    
+
+    KeAcquireGuardedMutex(&ViewLock);
     KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
+
     current_entry = Bcb->BcbSegmentListHead.Flink;
     while (current_entry != &Bcb->BcbSegmentListHead)
     {
@@ -461,6 +467,7 @@
         {
             CcRosCacheSegmentIncRefCount(current);
             KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
+            KeReleaseGuardedMutex(&ViewLock);
             KeWaitForSingleObject(&current->Mutex,
                                   Executive,
                                   KernelMode,
@@ -470,7 +477,10 @@
         }
         current_entry = current_entry->Flink;
     }
+
     KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
+    KeReleaseGuardedMutex(&ViewLock);
+
     return(NULL);
 }

@@ -490,29 +500,28 @@
     {
       KeBugCheck(CACHE_MANAGER);
     }
+
+  KeAcquireGuardedMutex(&ViewLock);
+  KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
+
   if (!CacheSeg->Dirty)
-    {
-      KeAcquireGuardedMutex(&ViewLock);
+  {
       InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
       DirtyPageCount += Bcb->CacheSegmentSize / PAGE_SIZE;
-      KeReleaseGuardedMutex(&ViewLock);
-    }
+  }
   else
   {
-     KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
-     CcRosCacheSegmentDecRefCount(CacheSeg);
-     KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
-  }
-
-  KeAcquireGuardedMutex(&ViewLock);
+      CcRosCacheSegmentDecRefCount(CacheSeg);
+  }

/* Move to the tail of the LRU list */
   RemoveEntryList(&CacheSeg->CacheSegmentLRUListEntry);
   InsertTailList(&CacheSegmentLRUListHead, &CacheSeg->CacheSegmentLRUListEntry);

+  CacheSeg->Dirty = TRUE;
+
+  KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
   KeReleaseGuardedMutex(&ViewLock);
-
-  CacheSeg->Dirty = TRUE;
   KeReleaseMutex(&CacheSeg->Mutex, 0);

return(STATUS_SUCCESS);
@@ -537,6 +546,9 @@
       return(STATUS_UNSUCCESSFUL);
     }

+  KeAcquireGuardedMutex(&ViewLock);
+  KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
+
   WasDirty = CacheSeg->Dirty;
   CacheSeg->Dirty = CacheSeg->Dirty || NowDirty;

@@ -544,13 +556,10 @@

if (!WasDirty && NowDirty)
   {
-     KeAcquireGuardedMutex(&ViewLock);
      InsertTailList(&DirtySegmentListHead, &CacheSeg->DirtySegmentListEntry);
      DirtyPageCount += Bcb->CacheSegmentSize / PAGE_SIZE;
-     KeReleaseGuardedMutex(&ViewLock);
-  }
-
-  KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
+  }
+
   CcRosCacheSegmentDecRefCount(CacheSeg);
   if (!WasDirty && NowDirty)
   {
@@ -560,8 +569,9 @@
   {
      CcRosCacheSegmentDecRefCount(CacheSeg);
   }
+
   KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
-
+  KeReleaseGuardedMutex(&ViewLock);
   KeReleaseMutex(&CacheSeg->Mutex, 0);

return(STATUS_SUCCESS);
@@ -1039,9 +1049,12 @@
                     }
                 }
                 KeReleaseMutex(&current->Mutex, 0);
+                
+                KeAcquireGuardedMutex(&ViewLock);
                 KeAcquireSpinLock(&Bcb->BcbLock, &oldIrql);
                 CcRosCacheSegmentDecRefCount(current);
                 KeReleaseSpinLock(&Bcb->BcbLock, oldIrql);
+                KeReleaseGuardedMutex(&ViewLock);
             }

Offset.QuadPart += Bcb->CacheSegmentSize;