From mboxrd@z Thu Jan 1 00:00:00 1970 From: "K. Y. Srinivasan" Subject: [PATCH 22/40] Staging: hv: netvsc: Further cleanup reference counting of netvsc_device Date: Wed, 29 Jun 2011 07:39:19 -0700 Message-ID: <1309358377-8537-22-git-send-email-kys@microsoft.com> References: <1309358301-8488-1-git-send-email-kys@microsoft.com> <1309358377-8537-1-git-send-email-kys@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1309358377-8537-1-git-send-email-kys@microsoft.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: devel-bounces@linuxdriverproject.org Errors-To: devel-bounces@linuxdriverproject.org To: gregkh@suse.de, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, virtualization@lists.osdl.org Cc: Haiyang Zhang , Abhishek Kane List-Id: virtualization@lists.linuxfoundation.org Signed-off-by: K. Y. Srinivasan Signed-off-by: Haiyang Zhang Signed-off-by: Abhishek Kane Signed-off-by: Hank Janssen --- drivers/staging/hv/netvsc.c | 25 ++++++++++++++++--------- 1 files changed, 16 insertions(+), 9 deletions(-) diff --git a/drivers/staging/hv/netvsc.c b/drivers/staging/hv/netvsc.c index 9ee264c..caca82e 100644 --- a/drivers/staging/hv/netvsc.c +++ b/drivers/staging/hv/netvsc.c @@ -40,8 +40,7 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device) if (!net_device) return NULL; - /* Set to 2 to allow both inbound and outbound traffic */ - net_device->refcnt = 2; + net_device->refcnt = 1; net_device->drain_notify = false; net_device->destroy = false; init_waitqueue_head(&net_device->waiting_to_drain); @@ -52,7 +51,6 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device) return net_device; } -/* Get the net device object iff exists and its refcount > 1 */ static struct netvsc_device *get_outbound_net_device(struct hv_device *device) { struct netvsc_device *net_device; @@ -60,7 +58,7 @@ static struct netvsc_device *get_outbound_net_device(struct hv_device *device) spin_lock_irqsave(&device->ext_lock, flags); net_device = device->ext; - if (net_device && (net_device->refcnt > 1) && + if (net_device && (net_device->refcnt) && !net_device->destroy) net_device->refcnt++; else @@ -70,7 +68,6 @@ static struct netvsc_device *get_outbound_net_device(struct hv_device *device) return net_device; } -/* Get the net device object iff exists and its refcount > 0 */ static struct netvsc_device *get_inbound_net_device(struct hv_device *device) { struct netvsc_device *net_device; @@ -78,11 +75,21 @@ static struct netvsc_device *get_inbound_net_device(struct hv_device *device) spin_lock_irqsave(&device->ext_lock, flags); net_device = device->ext; - if (net_device && net_device->refcnt) - net_device->refcnt++; - else - net_device = NULL; + if (!net_device) + goto cleanup; + + /* + * If the device is being destroyed; allow incoming + * traffic only to cleanup outstanding requests. + */ + if (net_device->destroy && + (atomic_read(&net_device->num_outstanding_sends) == 0)) + goto cleanup; + + net_device->refcnt++; + +cleanup: spin_unlock_irqrestore(&device->ext_lock, flags); return net_device; } -- 1.7.4.1