Correct return codes during racy destruction.

Errors in PnP retun codes found when testing under driver
verifier with mixed VM lifecycle operations. Under some
rare cases, it is possible to get more than one PnP
"remove-like" operation. This results in a PnP remove
operation being processed whilst the device is already
in the deleted state.

This patch fixes the immediate cause of the bugfixes,
by fixing the return code. Device destruction is
unchanged. Investigation into the root cause is still
ongoing.

Signed-off-by: Martin Harvey <martin.harvey@citrix.com>
Cosmetic fixes.

Signed-off-by: Paul Durrant <paul@xen.org>

diff --git a/src/xenbus/driver.c b/src/xenbus/driver.c
index e07de5558d70267a8edcad1a30be975c08cfb378..667f8e47d6ce6f560a7c0be51fb5c4af82aa6c3b 100644 (file)
--- a/src/xenbus/driver.c
+++ b/src/xenbus/driver.c
@@ -760,8 +760,20 @@ DriverDispatch(
     ASSERT3P(Dx->DeviceObject, ==, DeviceObject);
 
     if (Dx->DevicePnpState == Deleted) {
+        PIO_STACK_LOCATION  StackLocation = IoGetCurrentIrpStackLocation(Irp);
+        UCHAR               MajorFunction = StackLocation->MajorFunction;
+        UCHAR               MinorFunction = StackLocation->MinorFunction;
+
         status = STATUS_NO_SUCH_DEVICE;
 
+        if (MajorFunction == IRP_MJ_PNP) {
+            /* FDO and PDO deletions can block after being marked deleted, but before IoDeleteDevice */
+            if (MinorFunction == IRP_MN_SURPRISE_REMOVAL || MinorFunction == IRP_MN_REMOVE_DEVICE)
+                status = STATUS_SUCCESS;
+
+            ASSERT((MinorFunction != IRP_MN_CANCEL_REMOVE_DEVICE) && (MinorFunction != IRP_MN_CANCEL_STOP_DEVICE));
+        }
+
         Irp->IoStatus.Status = status;
         IoCompleteRequest(Irp, IO_NO_INCREMENT);
         goto done;

diff --git a/src/xenfilt/driver.c b/src/xenfilt/driver.c
index 8a8396e528b8a093e3edfd53ad14e15facceabff..6801d59aefb4dde8138558a581b814b065a2844e 100644 (file)
--- a/src/xenfilt/driver.c
+++ b/src/xenfilt/driver.c
@@ -862,8 +862,20 @@ DriverDispatch(
     ASSERT3P(Dx->DeviceObject, ==, DeviceObject);
 
     if (Dx->DevicePnpState == Deleted) {
+        PIO_STACK_LOCATION  StackLocation = IoGetCurrentIrpStackLocation(Irp);
+        UCHAR               MajorFunction = StackLocation->MajorFunction;
+        UCHAR               MinorFunction = StackLocation->MinorFunction;
+
         status = STATUS_NO_SUCH_DEVICE;
 
+        if (MajorFunction == IRP_MJ_PNP) {
+            /* FDO and PDO deletions can block after being marked deleted, but before IoDeleteDevice */
+            if (MinorFunction == IRP_MN_SURPRISE_REMOVAL || MinorFunction == IRP_MN_REMOVE_DEVICE)
+                status = STATUS_SUCCESS;
+
+            ASSERT((MinorFunction != IRP_MN_CANCEL_REMOVE_DEVICE) && (MinorFunction != IRP_MN_CANCEL_STOP_DEVICE));
+        }
+
         Irp->IoStatus.Status = status;
         IoCompleteRequest(Irp, IO_NO_INCREMENT);
         goto done;