Ignore attempts to remove device usage types that were not added.

ASSERTing on this condition is not particularly helpful as other buggy
software causes BSODs. We should be able to safely ignore and succeed
such IRPs.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>

diff --git a/src/xenbus/fdo.c b/src/xenbus/fdo.c
index f6ae1f1a3bf022814b4ccb596efc0526ed9b5d47..2805d85dafc2562c3331e1b26acfb5c573576db8 100644 (file)
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -2539,12 +2539,12 @@ FdoDeviceUsageNotification(
              DeviceUsageTypeName(Type));
         Fdo->Usage[Type]++;
     } else {
-        ASSERT(Fdo->Usage[Type] != 0);
-
-        Info("%s: REMOVING %s\n",
-             __FdoGetName(Fdo),
-             DeviceUsageTypeName(Type));
-        --Fdo->Usage[Type];
+        if (Fdo->Usage[Type] != 0) {
+            Info("%s: REMOVING %s\n",
+                 __FdoGetName(Fdo),
+                 DeviceUsageTypeName(Type));
+            --Fdo->Usage[Type];
+        }
     }
 
     status = FdoForwardIrpSynchronously(Fdo, Irp);