Linux Virtualization - Feb 2011 - [PATCH 1/4] staging: hv: Fix the code depending on struct vmbus_driver_context data order

The patch fixed the code depending on the exact order of fields in the
struct vmbus_driver_context, so the unused field drv_ctx can be removed,
and drv_obj doesn't have to be the second field in this structure.

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

---
 drivers/staging/hv/blkvsc_drv.c  |    2 ++
 drivers/staging/hv/netvsc_drv.c  |    2 ++
 drivers/staging/hv/storvsc_drv.c |    2 ++
 drivers/staging/hv/vmbus.h       |    2 +-
 drivers/staging/hv/vmbus_drv.c   |   14 +-------------
 5 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/drivers/staging/hv/blkvsc_drv.c b/drivers/staging/hv/blkvsc_drv.c
index 36a0adb..293ab8e 100644
--- a/drivers/staging/hv/blkvsc_drv.c
+++ b/drivers/staging/hv/blkvsc_drv.c
@@ -177,6 +177,8 @@ static int blkvsc_drv_init(int (*drv_init)(struct hv_driver
*drv))
 	struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
 	int ret;
 
+	drv_ctx->hv_drv = &storvsc_drv_obj->base;
+
 	storvsc_drv_obj->ring_buffer_size = blkvsc_ringbuffer_size;
 
 	/* Callback to client driver to complete the initialization */
diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c
index 03f9740..364b6c7 100644
--- a/drivers/staging/hv/netvsc_drv.c
+++ b/drivers/staging/hv/netvsc_drv.c
@@ -500,6 +500,8 @@ static int netvsc_drv_init(int (*drv_init)(struct hv_driver
*drv))
 	struct driver_context *drv_ctx = &g_netvsc_drv.drv_ctx;
 	int ret;
 
+	drv_ctx->hv_drv = &net_drv_obj->base;
+
 	net_drv_obj->ring_buf_size = ring_size * PAGE_SIZE;
 	net_drv_obj->recv_cb = netvsc_recv_callback;
 	net_drv_obj->link_status_change = netvsc_linkstatus_callback;
diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index a8427ff..33acee5 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -140,6 +140,8 @@ static int storvsc_drv_init(int (*drv_init)(struct hv_driver
*drv))
 	struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 	struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 
+	drv_ctx->hv_drv = &storvsc_drv_obj->base;
+
 	storvsc_drv_obj->ring_buffer_size = storvsc_ringbuffer_size;
 
 	/* Callback to client driver to complete the initialization */
diff --git a/drivers/staging/hv/vmbus.h b/drivers/staging/hv/vmbus.h
index 42f2adb..fd9d00f 100644
--- a/drivers/staging/hv/vmbus.h
+++ b/drivers/staging/hv/vmbus.h
@@ -30,8 +30,8 @@
 
 struct driver_context {
 	struct hv_guid class_id;
-
 	struct device_driver driver;
+	struct hv_driver *hv_drv;
 
 	/*
 	 * Use these methods instead of the struct device_driver so 2.6 kernel
diff --git a/drivers/staging/hv/vmbus_drv.c b/drivers/staging/hv/vmbus_drv.c
index 459c707..1f4e46d 100644
--- a/drivers/staging/hv/vmbus_drv.c
+++ b/drivers/staging/hv/vmbus_drv.c
@@ -42,11 +42,6 @@
 
 /* Main vmbus driver data structure */
 struct vmbus_driver_context {
-	/* !! These must be the first 2 fields !! */
-	/* FIXME, this is a bug */
-	/* The driver field is not used in here. Instead, the bus field is */
-	/* used to represent the driver */
-	struct driver_context drv_ctx;
 	struct hv_driver drv_obj;
 
 	struct bus_type bus;
@@ -869,14 +864,7 @@ static int vmbus_match(struct device *device, struct
device_driver *driver)
 	/* We found our driver ? */
 	if (memcmp(&device_ctx->class_id, &driver_ctx->class_id,
 		   sizeof(struct hv_guid)) == 0) {
-		/*
-		 * !! NOTE: The driver_ctx is not a vmbus_drv_ctx. We typecast
-		 * it here to access the struct hv_driver field
-		 */
-		struct vmbus_driver_context *vmbus_drv_ctx -			(struct vmbus_driver_context
*)driver_ctx;
-
-		device_ctx->device_obj.drv = &vmbus_drv_ctx->drv_obj;
+		device_ctx->device_obj.drv = driver_ctx->hv_drv;
 		DPRINT_INFO(VMBUS_DRV,
 			    "device object (%p) set to driver object (%p)",
 			    &device_ctx->device_obj,
-- 
1.6.3.2

The patch fixed the code depending on the exact order of fields in the
struct netvsc_driver_context. Now, we use container_of() instead of type
casting from the first field to the container struct.

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

---
 drivers/staging/hv/netvsc_drv.c |   14 ++++++--------
 1 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c
index 364b6c7..c78624c 100644
--- a/drivers/staging/hv/netvsc_drv.c
+++ b/drivers/staging/hv/netvsc_drv.c
@@ -49,8 +49,6 @@ struct net_device_context {
 };
 
 struct netvsc_driver_context {
-	/* !! These must be the first 2 fields !! */
-	/* Which is a bug FIXME! */
 	struct driver_context drv_ctx;
 	struct netvsc_driver drv_obj;
 };
@@ -137,8 +135,8 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct
net_device *net)
 	struct net_device_context *net_device_ctx = netdev_priv(net);
 	struct driver_context *driver_ctx  	   
driver_to_driver_context(net_device_ctx->device_ctx->device.driver);
-	struct netvsc_driver_context *net_drv_ctx -		(struct netvsc_driver_context
*)driver_ctx;
+	struct netvsc_driver_context *net_drv_ctx = container_of(driver_ctx,
+		struct netvsc_driver_context, drv_ctx);
 	struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 	struct hv_netvsc_packet *packet;
 	int ret;
@@ -342,8 +340,8 @@ static int netvsc_probe(struct device *device)
 {
 	struct driver_context *driver_ctx  	
driver_to_driver_context(device->driver);
-	struct netvsc_driver_context *net_drv_ctx -		(struct netvsc_driver_context
*)driver_ctx;
+	struct netvsc_driver_context *net_drv_ctx = container_of(driver_ctx,
+		struct netvsc_driver_context, drv_ctx);
 	struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
 	struct hv_device *device_obj = &device_ctx->device_obj;
@@ -414,8 +412,8 @@ static int netvsc_remove(struct device *device)
 {
 	struct driver_context *driver_ctx  	
driver_to_driver_context(device->driver);
-	struct netvsc_driver_context *net_drv_ctx -		(struct netvsc_driver_context
*)driver_ctx;
+	struct netvsc_driver_context *net_drv_ctx = container_of(driver_ctx,
+		struct netvsc_driver_context, drv_ctx);
 	struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
 	struct net_device *net = dev_get_drvdata(&device_ctx->device);
-- 
1.6.3.2

The patch fixed the code depending on the exact order of fields in the
struct blkvsc_driver_context. Now, we use container_of() instead of type
casting from the first field to the container struct.

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

---
 drivers/staging/hv/blkvsc_drv.c |    8 +++-----
 1 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/hv/blkvsc_drv.c b/drivers/staging/hv/blkvsc_drv.c
index 293ab8e..8f38895 100644
--- a/drivers/staging/hv/blkvsc_drv.c
+++ b/drivers/staging/hv/blkvsc_drv.c
@@ -117,8 +117,6 @@ struct block_device_context {
 
 /* Per driver */
 struct blkvsc_driver_context {
-	/* !! These must be the first 2 fields !! */
-	/* FIXME this is a bug! */
 	struct driver_context drv_ctx;
 	struct storvsc_driver_object drv_obj;
 };
@@ -248,7 +246,7 @@ static int blkvsc_probe(struct device *device)
 	struct driver_context *driver_ctx  			
driver_to_driver_context(device->driver);
 	struct blkvsc_driver_context *blkvsc_drv_ctx -				(struct
blkvsc_driver_context *)driver_ctx;
+		container_of(driver_ctx, struct blkvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  			
&blkvsc_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
@@ -733,7 +731,7 @@ static int blkvsc_remove(struct device *device)
 	struct driver_context *driver_ctx  			
driver_to_driver_context(device->driver);
 	struct blkvsc_driver_context *blkvsc_drv_ctx -				(struct
blkvsc_driver_context *)driver_ctx;
+		container_of(driver_ctx, struct blkvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  			
&blkvsc_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
@@ -856,7 +854,7 @@ static int blkvsc_submit_request(struct blkvsc_request
*blkvsc_req,
 	struct driver_context *driver_ctx  		
driver_to_driver_context(device_ctx->device.driver);
 	struct blkvsc_driver_context *blkvsc_drv_ctx -			(struct blkvsc_driver_context
*)driver_ctx;
+		container_of(driver_ctx, struct blkvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  		
&blkvsc_drv_ctx->drv_obj;
 	struct hv_storvsc_request *storvsc_req;
-- 
1.6.3.2

The patch fixed the code depending on the exact order of fields in the
struct storvsc_driver_context. Now, we use container_of() instead of type
casting from the first field to the container struct.

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

---
 drivers/staging/hv/storvsc_drv.c |   14 ++++++--------
 1 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c
index 33acee5..a364627 100644
--- a/drivers/staging/hv/storvsc_drv.c
+++ b/drivers/staging/hv/storvsc_drv.c
@@ -64,8 +64,6 @@ struct storvsc_cmd_request {
 };
 
 struct storvsc_driver_context {
-	/* !! These must be the first 2 fields !! */
-	/* FIXME this is a bug... */
 	struct driver_context drv_ctx;
 	struct storvsc_driver_object drv_obj;
 };
@@ -223,8 +221,8 @@ static int storvsc_probe(struct device *device)
 	int ret;
 	struct driver_context *driver_ctx  			
driver_to_driver_context(device->driver);
-	struct storvsc_driver_context *storvsc_drv_ctx -				(struct
storvsc_driver_context *)driver_ctx;
+	struct storvsc_driver_context *storvsc_drv_ctx = container_of(
+		driver_ctx, struct storvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  			
&storvsc_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
@@ -308,8 +306,8 @@ static int storvsc_remove(struct device *device)
 	int ret;
 	struct driver_context *driver_ctx  		
driver_to_driver_context(device->driver);
-	struct storvsc_driver_context *storvsc_drv_ctx -			(struct
storvsc_driver_context *)driver_ctx;
+	struct storvsc_driver_context *storvsc_drv_ctx = container_of(
+		driver_ctx, struct storvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  		
&storvsc_drv_ctx->drv_obj;
 	struct vm_device *device_ctx = device_to_vm_device(device);
@@ -606,8 +604,8 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 	struct vm_device *device_ctx = host_device_ctx->device_ctx;
 	struct driver_context *driver_ctx  	
driver_to_driver_context(device_ctx->device.driver);
-	struct storvsc_driver_context *storvsc_drv_ctx -		(struct
storvsc_driver_context *)driver_ctx;
+	struct storvsc_driver_context *storvsc_drv_ctx = container_of(
+		driver_ctx, struct storvsc_driver_context, drv_ctx);
 	struct storvsc_driver_object *storvsc_drv_obj  	
&storvsc_drv_ctx->drv_obj;
 	struct hv_storvsc_request *request;
-- 
1.6.3.2

On Wed, Feb 23, 2011 at 12:19:55PM -0800, Haiyang Zhang
wrote:
> The patch fixed the code depending on the exact order of fields in the
> struct vmbus_driver_context, so the unused field drv_ctx can be removed,
> and drv_obj doesn't have to be the second field in this structure.
> 
> Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
> Signed-off-by: Hank Janssen <hjanssen at microsoft.com>
> 
> ---
>  drivers/staging/hv/blkvsc_drv.c  |    2 ++
>  drivers/staging/hv/netvsc_drv.c  |    2 ++
>  drivers/staging/hv/storvsc_drv.c |    2 ++
>  drivers/staging/hv/vmbus.h       |    2 +-
>  drivers/staging/hv/vmbus_drv.c   |   14 +-------------
>  5 files changed, 8 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/staging/hv/blkvsc_drv.c
b/drivers/staging/hv/blkvsc_drv.c
> index 36a0adb..293ab8e 100644
> --- a/drivers/staging/hv/blkvsc_drv.c
> +++ b/drivers/staging/hv/blkvsc_drv.c
> @@ -177,6 +177,8 @@ static int blkvsc_drv_init(int (*drv_init)(struct
hv_driver *drv))
>  	struct driver_context *drv_ctx = &g_blkvsc_drv.drv_ctx;
>  	int ret;
>  
> +	drv_ctx->hv_drv = &storvsc_drv_obj->base;
> +
>  	storvsc_drv_obj->ring_buffer_size = blkvsc_ringbuffer_size;
>  
>  	/* Callback to client driver to complete the initialization */
> diff --git a/drivers/staging/hv/netvsc_drv.c
b/drivers/staging/hv/netvsc_drv.c
> index 03f9740..364b6c7 100644
> --- a/drivers/staging/hv/netvsc_drv.c
> +++ b/drivers/staging/hv/netvsc_drv.c
> @@ -500,6 +500,8 @@ static int netvsc_drv_init(int (*drv_init)(struct
hv_driver *drv))
>  	struct driver_context *drv_ctx = &g_netvsc_drv.drv_ctx;
>  	int ret;
>  
> +	drv_ctx->hv_drv = &net_drv_obj->base;
> +
>  	net_drv_obj->ring_buf_size = ring_size * PAGE_SIZE;
>  	net_drv_obj->recv_cb = netvsc_recv_callback;
>  	net_drv_obj->link_status_change = netvsc_linkstatus_callback;
> diff --git a/drivers/staging/hv/storvsc_drv.c
b/drivers/staging/hv/storvsc_drv.c
> index a8427ff..33acee5 100644
> --- a/drivers/staging/hv/storvsc_drv.c
> +++ b/drivers/staging/hv/storvsc_drv.c
> @@ -140,6 +140,8 @@ static int storvsc_drv_init(int (*drv_init)(struct
hv_driver *drv))
>  	struct storvsc_driver_object *storvsc_drv_obj =
&g_storvsc_drv.drv_obj;
>  	struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
>  
> +	drv_ctx->hv_drv = &storvsc_drv_obj->base;
> +
>  	storvsc_drv_obj->ring_buffer_size = storvsc_ringbuffer_size;
>  
>  	/* Callback to client driver to complete the initialization */
> diff --git a/drivers/staging/hv/vmbus.h b/drivers/staging/hv/vmbus.h
> index 42f2adb..fd9d00f 100644
> --- a/drivers/staging/hv/vmbus.h
> +++ b/drivers/staging/hv/vmbus.h
> @@ -30,8 +30,8 @@
>  
>  struct driver_context {
>  	struct hv_guid class_id;
> -
>  	struct device_driver driver;
> +	struct hv_driver *hv_drv;
If you have a pointer to hv_driver, why do you need a full 'struct
device_driver' here?  That sounds really wrong.

Actually, having 'struct device_driver' within a structure called
"driver_context" seems wrong, this should be what 'struct
hv_driver'
really is, right?

So no, I can't take this patch, as it isn't solving the root problem
here.

thanks,

greg k-h

On Wed, Feb 23, 2011 at 12:19:56PM -0800, Haiyang Zhang
wrote:
> The patch fixed the code depending on the exact order of fields in the
> struct netvsc_driver_context. Now, we use container_of() instead of type
> casting from the first field to the container struct.
> 
> Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
> Signed-off-by: Hank Janssen <hjanssen at microsoft.com>
> 
> ---
>  drivers/staging/hv/netvsc_drv.c |   14 ++++++--------
>  1 files changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/hv/netvsc_drv.c
b/drivers/staging/hv/netvsc_drv.c
> index 364b6c7..c78624c 100644
> --- a/drivers/staging/hv/netvsc_drv.c
> +++ b/drivers/staging/hv/netvsc_drv.c
> @@ -49,8 +49,6 @@ struct net_device_context {
>  };
>  
>  struct netvsc_driver_context {
> -	/* !! These must be the first 2 fields !! */
> -	/* Which is a bug FIXME! */
>  	struct driver_context drv_ctx;
>  	struct netvsc_driver drv_obj;
>  };
> @@ -137,8 +135,8 @@ static int netvsc_start_xmit(struct sk_buff *skb,
struct net_device *net)
>  	struct net_device_context *net_device_ctx = netdev_priv(net);
>  	struct driver_context *driver_ctx >  	   
driver_to_driver_context(net_device_ctx->device_ctx->device.driver);
> -	struct netvsc_driver_context *net_drv_ctx > -		(struct
netvsc_driver_context *)driver_ctx;
> +	struct netvsc_driver_context *net_drv_ctx = container_of(driver_ctx,
> +		struct netvsc_driver_context, drv_ctx);
>  	struct netvsc_driver *net_drv_obj = &net_drv_ctx->drv_obj;
>  	struct hv_netvsc_packet *packet;
>  	int ret;
> @@ -342,8 +340,8 @@ static int netvsc_probe(struct device *device)
>  {
>  	struct driver_context *driver_ctx >  	
driver_to_driver_context(device->driver);
> -	struct netvsc_driver_context *net_drv_ctx > -		(struct
netvsc_driver_context *)driver_ctx;
> +	struct netvsc_driver_context *net_drv_ctx = container_of(driver_ctx,
> +		struct netvsc_driver_context, drv_ctx);
container_of calls should be turned into either a macro, or an inline
function, to make them smaller and easier to understand what is going
on.  Do that and you will solve the line-length problems as well.

Please do that here.

thanks,

greg k-h

On Wed, Feb 23, 2011 at 12:19:57PM -0800, Haiyang Zhang
wrote:
> The patch fixed the code depending on the exact order of fields in the
> struct blkvsc_driver_context. Now, we use container_of() instead of type
> casting from the first field to the container struct.
> 
> Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
> Signed-off-by: Hank Janssen <hjanssen at microsoft.com>
> 
> ---
>  drivers/staging/hv/blkvsc_drv.c |    8 +++-----
>  1 files changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/staging/hv/blkvsc_drv.c
b/drivers/staging/hv/blkvsc_drv.c
> index 293ab8e..8f38895 100644
> --- a/drivers/staging/hv/blkvsc_drv.c
> +++ b/drivers/staging/hv/blkvsc_drv.c
> @@ -117,8 +117,6 @@ struct block_device_context {
>  
>  /* Per driver */
>  struct blkvsc_driver_context {
> -	/* !! These must be the first 2 fields !! */
> -	/* FIXME this is a bug! */
>  	struct driver_context drv_ctx;
>  	struct storvsc_driver_object drv_obj;
>  };
> @@ -248,7 +246,7 @@ static int blkvsc_probe(struct device *device)
>  	struct driver_context *driver_ctx >  			
driver_to_driver_context(device->driver);
>  	struct blkvsc_driver_context *blkvsc_drv_ctx > -				(struct
blkvsc_driver_context *)driver_ctx;
> +		container_of(driver_ctx, struct blkvsc_driver_context, drv_ctx);
Same container_of() complaint here, make it a macro or inline function.

thanks,

greg k-h

On Wed, Feb 23, 2011 at 12:19:58PM -0800, Haiyang Zhang
wrote:
> The patch fixed the code depending on the exact order of fields in the
> struct storvsc_driver_context. Now, we use container_of() instead of type
> casting from the first field to the container struct.
> 
> Signed-off-by: Haiyang Zhang <haiyangz at microsoft.com>
> Signed-off-by: K. Y. Srinivasan <kys at microsoft.com>
> Signed-off-by: Hank Janssen <hjanssen at microsoft.com>
> 
> ---
>  drivers/staging/hv/storvsc_drv.c |   14 ++++++--------
>  1 files changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/staging/hv/storvsc_drv.c
b/drivers/staging/hv/storvsc_drv.c
> index 33acee5..a364627 100644
> --- a/drivers/staging/hv/storvsc_drv.c
> +++ b/drivers/staging/hv/storvsc_drv.c
> @@ -64,8 +64,6 @@ struct storvsc_cmd_request {
>  };
>  
>  struct storvsc_driver_context {
> -	/* !! These must be the first 2 fields !! */
> -	/* FIXME this is a bug... */
>  	struct driver_context drv_ctx;
>  	struct storvsc_driver_object drv_obj;
>  };
> @@ -223,8 +221,8 @@ static int storvsc_probe(struct device *device)
>  	int ret;
>  	struct driver_context *driver_ctx >  			
driver_to_driver_context(device->driver);
> -	struct storvsc_driver_context *storvsc_drv_ctx > -				(struct
storvsc_driver_context *)driver_ctx;
> +	struct storvsc_driver_context *storvsc_drv_ctx = container_of(
> +		driver_ctx, struct storvsc_driver_context, drv_ctx);
Same container_of() macro/inline function issue.

thanks,

greg k-h