---

yaml
---
r: 249463
b: refs/heads/master
c: 604df37
h: refs/heads/master
i:
  249461: 10bfb50
  249459: dd7f611
  249455: e0f7e15
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 43c51f7dd13c75962eebc4c28667d1b0162543ed
+refs/heads/master: 604df37dc3ba185b1017f6ca5e497fbfb68da8d8

trunk/drivers/staging/hv/storvsc.c

@@ -47,6 +47,7 @@ static inline struct storvsc_device *alloc_stor_device(struct hv_device *device)
 	/* (ie get_stor_device() and must_get_stor_device()) to proceed. */
 	atomic_cmpxchg(&stor_device->ref_count, 0, 2);
 
+	init_waitqueue_head(&stor_device->waiting_to_drain);
 	stor_device->device = device;
 	device->ext = stor_device;
 
@@ -332,7 +333,10 @@ static void stor_vsc_on_io_completion(struct hv_device *device,
 
 	request->on_io_completion(request);
 
-	atomic_dec(&stor_device->num_outstanding_req);
+	if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
+		stor_device->drain_notify)
+		wake_up(&stor_device->waiting_to_drain);
+
 
 	put_stor_device(device);
 }

trunk/drivers/staging/hv/storvsc_api.h

@@ -26,6 +26,7 @@
 #define _STORVSC_API_H_
 
 #include <linux/kernel.h>
+#include <linux/wait.h>
 #include "vstorage.h"
 #include "vmbus_api.h"
 #include "vmbus.h"
@@ -108,8 +109,11 @@ struct storvsc_device {
 	/* 0 indicates the device is being destroyed */
 	atomic_t ref_count;
 
+	bool	 drain_notify;
 	atomic_t num_outstanding_req;
 
+	wait_queue_head_t waiting_to_drain;
+
 	/*
 	 * Each unique Port/Path/Target represents 1 channel ie scsi
 	 * controller. In reality, the pathid, targetid is always 0
@@ -161,6 +165,14 @@ struct storvsc_driver *drv_to_stordrv(struct device_driver *d)
 	return hvdr_to_stordr(hvdrv);
 }
 
+static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
+{
+	dev->drain_notify = true;
+	wait_event(dev->waiting_to_drain,
+		   atomic_read(&dev->num_outstanding_req) == 0);
+	dev->drain_notify = false;
+}
+
 /* Interface */
 
 int storvsc_dev_add(struct hv_device *device,