[PATCH 082/117] Staging: hv: storvsc: 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/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

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