RE: [PATCH 086/117] Staging: hv: storvsc: Leverage the spinlock to manage ref_cnt

-----Original Message-----
From: Greg KH [mailto:greg@kroah.com]
Sent: Tuesday, August 23, 2011 7:10 PM
To: KY Srinivasan
Cc: gregkh@suse.de; linux-kernel@vger.kernel.org;
devel@linuxdriverproject.org; virtualization@lists.osdl.org; Haiyang Zhang
Subject: Re: [PATCH 086/117] Staging: hv: storvsc: Leverage the spinlock to
manage ref_cnt

On Fri, Jul 15, 2011 at 10:47:14AM -0700, K. Y. Srinivasan wrote:

quoted

Now that we have a spin lock protecting access to the stor device pointer,
use it manage the reference count as well.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
 drivers/staging/hv/hyperv_storage.h |    8 ++++----
 drivers/staging/hv/storvsc.c        |   10 +++++-----
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/hv/hyperv_storage.h

b/drivers/staging/hv/hyperv_storage.h

quoted

index 53b65be..d946211 100644

--- a/drivers/staging/hv/hyperv_storage.h
+++ b/drivers/staging/hv/hyperv_storage.h

@@ -265,7 +265,7 @@ struct storvsc_device {
 	struct hv_device *device;

 	/* 0 indicates the device is being destroyed */
-	atomic_t ref_count;
+	int	 ref_count;

Is this really needed?  Can't you rely on the reference count of the
hv_device itself?

We don't have a reference count on the hv_device and this count is taken
to deal with racing unloads and incoming traffic on the channel from the 
host. 

Regards,

K. Y