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

K. Y. Srinivasan
Fri, 15 Jul 2011 17:47:10 -0000

Use the newly introduced lock in accessing ext field.

Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz at 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