[PATCH 091/117] Staging: hv: netvsc: Use the newly introduced lock in accessing ext field

[K. Y. Srinivasan]

Use the newly introduced lock in accessing ext field.

Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
Signed-off-by: Haiyang Zhang <haiya...@microsoft.com>
---
 drivers/staging/hv/netvsc.c |   33 ++++++++++++++++++++++++++++++---
 1 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/hv/netvsc.c b/drivers/staging/hv/netvsc.c
index 67cf7fb..c38c669 100644
--- a/drivers/staging/hv/netvsc.c
+++ b/drivers/staging/hv/netvsc.c
@@ -54,12 +54,15 @@ static struct netvsc_device *alloc_net_device(struct 
hv_device *device)
 static struct netvsc_device *get_outbound_net_device(struct hv_device *device)
 {
        struct netvsc_device *net_device;
+       unsigned long flags;
 
+       spin_lock_irqsave(&device->ext_lock, flags);
        net_device = device->ext;
        if (net_device && atomic_read(&net_device->refcnt) > 1)
                atomic_inc(&net_device->refcnt);
        else
                net_device = NULL;
+       spin_unlock_irqrestore(&device->ext_lock, flags);
 
        return net_device;
 }
@@ -68,33 +71,46 @@ static struct netvsc_device *get_outbound_net_device(struct 
hv_device *device)
 static struct netvsc_device *get_inbound_net_device(struct hv_device *device)
 {
        struct netvsc_device *net_device;
+       unsigned long flags;
 
+       spin_lock_irqsave(&device->ext_lock, flags);
        net_device = device->ext;
        if (net_device && atomic_read(&net_device->refcnt))
                atomic_inc(&net_device->refcnt);
        else
                net_device = NULL;
 
+       spin_unlock_irqrestore(&device->ext_lock, flags);
        return net_device;
 }
 
 static void put_net_device(struct hv_device *device)
 {
        struct netvsc_device *net_device;
+       unsigned long flags;
+
+       spin_lock_irqsave(&device->ext_lock, flags);
 
        net_device = device->ext;
 
        atomic_dec(&net_device->refcnt);
+       spin_unlock_irqrestore(&device->ext_lock, flags);
 }
 
 static struct netvsc_device *release_outbound_net_device(
                struct hv_device *device)
 {
        struct netvsc_device *net_device;
+       unsigned long flags;
 
+       spin_lock_irqsave(&device->ext_lock, flags);
        net_device = device->ext;
-       if (net_device == NULL)
+       if (net_device == NULL) {
+               spin_unlock_irqrestore(&device->ext_lock, flags);
                return NULL;
+       }
+
+       spin_unlock_irqrestore(&device->ext_lock, flags);
 
        /* Busy wait until the ref drop to 2, then set it to 1 */
        while (atomic_cmpxchg(&net_device->refcnt, 2, 1) != 2)
@@ -107,16 +123,23 @@ static struct netvsc_device *release_inbound_net_device(
                struct hv_device *device)
 {
        struct netvsc_device *net_device;
+       unsigned long flags;
 
+       spin_lock_irqsave(&device->ext_lock, flags);
        net_device = device->ext;
-       if (net_device == NULL)
+       if (net_device == NULL) {
+               spin_unlock_irqrestore(&device->ext_lock, flags);
                return NULL;
+       }
 
+       spin_unlock_irqrestore(&device->ext_lock, flags);
        /* Busy wait until the ref drop to 1, then set it to 0 */
        while (atomic_cmpxchg(&net_device->refcnt, 1, 0) != 1)
                udelay(100);
 
+       spin_lock_irqsave(&device->ext_lock, flags);
        device->ext = NULL;
+       spin_unlock_irqrestore(&device->ext_lock, flags);
        return net_device;
 }
 
@@ -397,6 +420,8 @@ int netvsc_device_remove(struct hv_device *device)
 {
        struct netvsc_device *net_device;
        struct hv_netvsc_packet *netvsc_packet, *pos;
+       unsigned long flags;
+
 
        /* Stop outbound traffic ie sends and receives completions */
        net_device = release_outbound_net_device(device);
@@ -404,8 +429,10 @@ int netvsc_device_remove(struct hv_device *device)
                dev_err(&device->device, "No net device present!!");
                return -ENODEV;
        }
-
+       spin_lock_irqsave(&device->ext_lock, flags);
        net_device->destroy = true;
+       spin_unlock_irqrestore(&device->ext_lock, flags);
+
 
        /* Wait for all send completions */
        while (atomic_read(&net_device->num_outstanding_sends)) {
-- 
1.7.4.1

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