[PATCH 086/117] Staging: hv: storvsc: Leverage the spinlock to manage ref_cnt

K. Y. Srinivasan
2011-07-15T17:39:32Z

Now that we have a spin lock protecting access to the stor device pointer,
use it manage the reference count as well.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/staging/hv/hyperv_storage.h | 8 ++++----
drivers/staging/hv/storvsc.c | 10 +++++-----
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/hv/hyperv_storage.h b/drivers/staging/hv/hyperv_storage.h
index 53b65be..d946211 100644
--- a/drivers/staging/hv/hyperv_storage.h
+++ b/drivers/staging/hv/hyperv_storage.h
@@ -265,7 +265,7 @@ struct storvsc_device {
struct hv_device *device;

/* 0 indicates the device is being destroyed */
- atomic_t ref_count;
+ int ref_count;
bool destroy;
bool drain_notify;
atomic_t num_outstanding_req;
@@ -296,9 +296,9 @@ static inline struct storvsc_device *get_out_stor_device(

spin_lock_irqsave(&device->ext_lock, flags);
stor_device = (struct storvsc_device *)device->ext;
- if (stor_device && (atomic_read(&stor_device->ref_count) > 1) &&
+ if (stor_device && (stor_device->ref_count > 1) &&
!stor_device->destroy)
- atomic_inc(&stor_device->ref_count);
+ stor_device->ref_count++;
else
stor_device = NULL;
spin_unlock_irqrestore(&device->ext_lock, flags);
@@ -315,7 +315,7 @@ static inline void put_stor_device(struct hv_device *device)
spin_lock_irqsave(&device->ext_lock, flags);
stor_device = (struct storvsc_device *)device->ext;

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

diff --git a/drivers/staging/hv/storvsc.c b/drivers/staging/hv/storvsc.c
index c4cb170..a41be2a 100644
--- a/drivers/staging/hv/storvsc.c
+++ b/drivers/staging/hv/storvsc.c
@@ -42,7 +42,7 @@ static inline struct storvsc_device *alloc_stor_device(struct hv_device *device)

/* Set to 2 to allow both inbound and outbound traffics */
/* (ie get_out_stor_device() and get_in_stor_device()) to proceed. */
- atomic_set(&stor_device->ref_count, 2);
+ stor_device->ref_count = 2;
stor_device->destroy = false;
init_waitqueue_head(&stor_device->waiting_to_drain);
stor_device->device = device;
@@ -61,8 +61,8 @@ static inline struct storvsc_device *get_in_stor_device(

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);
+ if (stor_device && stor_device->ref_count)
+ stor_device->ref_count++;
else
stor_device = NULL;
spin_unlock_irqrestore(&device->ext_lock, flags);
@@ -379,7 +379,7 @@ int storvsc_dev_remove(struct hv_device *device)
* pointer.
*/
stor_device = (struct storvsc_device *)device->ext;
- atomic_dec(&stor_device->ref_count);
+
stor_device->destroy = true;

/*
@@ -391,7 +391,7 @@ int storvsc_dev_remove(struct hv_device *device)
storvsc_wait_to_drain(stor_device);

spin_lock_irqsave(&device->ext_lock, flags);
- atomic_set(&stor_device->ref_count, 0);
+ stor_device->ref_count = 0;
device->ext = NULL;
spin_unlock_irqrestore(&device->ext_lock, flags);

--
1.7.4.1