[0.4.9] cherry-pick [FASTFAT] Lock DirResource when modifying an entry on disk.

Likely not optimal, but fixes some races conditions where
the directory is uninit in the middle of the write.

(cherry picked from commit fc788cf)

Author: HeisSpiter

drivers/filesystems/fastfat/finfo.c

@@ -1552,6 +1552,7 @@ VfatSetInformation(
     PVFATFCB FCB;
     NTSTATUS Status = STATUS_SUCCESS;
     PVOID SystemBuffer;
+    BOOLEAN LockDir;
 
     /* PRECONDITION */
     ASSERT(IrpContext);
@@ -1593,7 +1594,14 @@ VfatSetInformation(
         DPRINT("Can set file size\n");
     }
 
-    if (FileInformationClass == FileRenameInformation)
+    LockDir = FALSE;
+    if (FileInformationClass == FileRenameInformation || FileInformationClass == FileAllocationInformation ||
+        FileInformationClass == FileEndOfFileInformation || FileInformationClass == FileBasicInformation)
+    {
+        LockDir = TRUE;
+    }
+
+    if (LockDir)
     {
         if (!ExAcquireResourceExclusiveLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource,
                                             BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_CANWAIT)))
@@ -1607,7 +1615,7 @@ VfatSetInformation(
         if (!ExAcquireResourceExclusiveLite(&FCB->MainResource,
                                             BooleanFlagOn(IrpContext->Flags, IRPCONTEXT_CANWAIT)))
         {
-            if (FileInformationClass == FileRenameInformation)
+            if (LockDir)
             {
                 ExReleaseResourceLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource);
             }
@@ -1662,7 +1670,7 @@ VfatSetInformation(
         ExReleaseResourceLite(&FCB->MainResource);
     }
 
-    if (FileInformationClass == FileRenameInformation)
+    if (LockDir)
     {
         ExReleaseResourceLite(&((PDEVICE_EXTENSION)IrpContext->DeviceObject->DeviceExtension)->DirResource);
     }