[PATCH] Correct return codes during racy destruction.

[Martin Harvey <Martin.Harvey@xxxxxxxxxx>]

Signed-off-by: Martin Harvey <martin.harvey@xxxxxxxxxx>
---
 src/xenbus/driver.c  | 12 ++++++++++++
 src/xenbus/fdo.c     |  2 +-
 src/xenbus/pdo.c     |  2 +-
 src/xenfilt/driver.c | 12 ++++++++++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/xenbus/driver.c b/src/xenbus/driver.c
index e07de55..167dd22 100644
--- 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) {
+            if ((MinorFunction == IRP_MN_SURPRISE_REMOVAL) ||
+               (MinorFunction == IRP_MN_REMOVE_DEVICE)) {
+                /* FDO and PDO deletions can block after being marked deleted, 
but before IoDeleteDevice */
+                status = STATUS_SUCCESS;
+            }
+            BUG_ON((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/xenbus/fdo.c b/src/xenbus/fdo.c
index d08c518..4242f07 100644
--- a/src/xenbus/fdo.c
+++ b/src/xenbus/fdo.c
@@ -4708,7 +4708,7 @@ FdoDispatchPnp(
           MinorFunction, 
           PnpMinorFunctionName(MinorFunction)); 
 
-    switch (StackLocation->MinorFunction) {
+    switch (MinorFunction) {
     case IRP_MN_FILTER_RESOURCE_REQUIREMENTS:
         status = FdoFilterResourceRequirements(Fdo, Irp);
         break;
diff --git a/src/xenbus/pdo.c b/src/xenbus/pdo.c
index efd29dc..fe88d5d 100644
--- a/src/xenbus/pdo.c
+++ b/src/xenbus/pdo.c
@@ -1609,7 +1609,7 @@ PdoDispatchPnp(
           MinorFunction, 
           PnpMinorFunctionName(MinorFunction));
 
-    switch (StackLocation->MinorFunction) {
+    switch (MinorFunction) {
     case IRP_MN_START_DEVICE:
         status = PdoStartDevice(Pdo, Irp);
         break;
diff --git a/src/xenfilt/driver.c b/src/xenfilt/driver.c
index 8a8396e..894fd24 100644
--- 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) {
+            if ((MinorFunction == IRP_MN_SURPRISE_REMOVAL) ||
+               (MinorFunction == IRP_MN_REMOVE_DEVICE)) {
+                /* FDO and PDO deletions can block after being marked deleted, 
but before IoDeleteDevice */
+                status = STATUS_SUCCESS;
+            }
+            BUG_ON((MinorFunction == IRP_MN_CANCEL_REMOVE_DEVICE) || 
(MinorFunction == IRP_MN_CANCEL_STOP_DEVICE));
+        }
+
         Irp->IoStatus.Status = status;
         IoCompleteRequest(Irp, IO_NO_INCREMENT);
         goto done;
-- 
2.25.0.windows.1