Staging: hv: Embed struct storvsc_request_extension into hv_storvsc_request

Embed struct storvsc_request_extension into hv_storvsc_request.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Abhishek Kane <v-abkane@microsoft.com>
Signed-off-by: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/blkvsc_drv.c

@@ -84,12 +84,6 @@ struct blkvsc_request {
 	unsigned char cmnd[MAX_COMMAND_SIZE];
 
 	struct hv_storvsc_request request;
-	/*
-	 * !!!DO NOT ADD ANYTHING BELOW HERE!!! Otherwise, memory can overlap,
-	 * because - The extension buffer falls right here and is pointed to by
-	 * request.Extension;
-	 * Which sounds like a horrible idea, who designed this?
-	 */
 };
 
 /* Per device structure */
@@ -944,8 +938,6 @@ static int blkvsc_submit_request(struct blkvsc_request *blkvsc_req,
 #endif
 
 	storvsc_req = &blkvsc_req->request;
-	storvsc_req->extension = (void *)((unsigned long)blkvsc_req +
-					  sizeof(struct blkvsc_request));
 
 	storvsc_req->type = blkvsc_req->write ? WRITE_TYPE : READ_TYPE;
 

drivers/staging/hv/storvsc.c

@@ -533,8 +533,7 @@ int stor_vsc_on_io_request(struct hv_device *device,
 	struct vstor_packet *vstor_packet;
 	int ret = 0;
 
-	request_extension =
-		(struct storvsc_request_extension *)request->extension;
+	request_extension = &request->extension;
 	vstor_packet = &request_extension->vstor_packet;
 	stor_device = get_stor_device(device);
 

drivers/staging/hv/storvsc_api.h

@@ -83,8 +83,7 @@ struct hv_storvsc_request {
 
 	void (*on_io_completion)(struct hv_storvsc_request *request);
 
-	/* This points to the memory after DataBuffer */
-	void *extension;
+	struct storvsc_request_extension extension;
 
 	struct hv_multipage_buffer data_buffer;
 };

drivers/staging/hv/storvsc_drv.c

@@ -69,10 +69,6 @@ struct storvsc_cmd_request {
 	struct scatterlist *bounce_sgl;
 
 	struct hv_storvsc_request request;
-	/* !!!DO NOT ADD ANYTHING BELOW HERE!!! */
-	/* The extension buffer falls right here and is pointed to by
-	 * request.Extension;
-	 * Which sounds like a very bad design... */
 };
 
 
@@ -763,8 +759,6 @@ static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 
 	request = &cmd_request->request;
 
-	request->extension =
-		(void *)((unsigned long)cmd_request + request_size);
 	DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 		   storvsc_drv_obj->request_ext_size);