[PATCH 082/117] Staging: hv: storvsc: Use the newly introduced lock in accessing ext field

K. Y. Srinivasan
2011-07-15T17:38:07Z

Use the newly introduced lock in accessing ext field.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/hyperv_storage.h | 6 ++++++
drivers/staging/hv/storvsc.c | 6 ++++++
2 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/drivers/staging/hv/hyperv_storage.h b/drivers/staging/hv/hyperv_storage.h
index d93bf93..6b20f1d 100644
--- a/drivers/staging/hv/hyperv_storage.h
+++ b/drivers/staging/hv/hyperv_storage.h
@@ -292,12 +292,15 @@ static inline struct storvsc_device *get_out_stor_device(
struct hv_device *device)
{
struct storvsc_device *stor_device;
+ unsigned long flags;

+ spin_lock_irqsave(&device->ext_lock, flags);
stor_device = (struct storvsc_device *)device->ext;
if (stor_device && atomic_read(&stor_device->ref_count) > 1)
atomic_inc(&stor_device->ref_count);
else
stor_device = NULL;
+ spin_unlock_irqrestore(&device->ext_lock, flags);

return stor_device;
}
@@ -306,10 +309,13 @@ static inline struct storvsc_device *get_out_stor_device(
static inline void put_stor_device(struct hv_device *device)
{
struct storvsc_device *stor_device;
+ unsigned long flags;

+ spin_lock_irqsave(&device->ext_lock, flags);
stor_device = (struct storvsc_device *)device->ext;

atomic_dec(&stor_device->ref_count);
+ spin_unlock_irqrestore(&device->ext_lock, flags);
}

static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
diff --git a/drivers/staging/hv/storvsc.c b/drivers/staging/hv/storvsc.c
index 357b08a..d1b6c4e 100644
--- a/drivers/staging/hv/storvsc.c
+++ b/drivers/staging/hv/storvsc.c
@@ -57,12 +57,15 @@ static inline struct storvsc_device *get_in_stor_device(
struct hv_device *device)
{
struct storvsc_device *stor_device;
+ unsigned long flags;

+ spin_lock_irqsave(&device->ext_lock, flags);
stor_device = (struct storvsc_device *)device->ext;
if (stor_device && atomic_read(&stor_device->ref_count))
atomic_inc(&stor_device->ref_count);
else
stor_device = NULL;
+ spin_unlock_irqrestore(&device->ext_lock, flags);

return stor_device;
}
@@ -87,6 +90,7 @@ static inline struct storvsc_device *final_release_stor_device(
struct hv_device *device)
{
struct storvsc_device *stor_device;
+ unsigned long flags;

stor_device = (struct storvsc_device *)device->ext;

@@ -94,7 +98,9 @@ static inline struct storvsc_device *final_release_stor_device(
while (atomic_cmpxchg(&stor_device->ref_count, 1, 0) != 1)
udelay(100);

+ spin_lock_irqsave(&device->ext_lock, flags);
device->ext = NULL;
+ spin_unlock_irqrestore(&device->ext_lock, flags);
return stor_device;
}

--
1.7.4.1