RDMA/uverbs: Make write() handlers return 0 on success

Currently they return the command length, while all other handlers return
0. This makes the write path closer to the write_ex and ioctl path.

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

drivers/infiniband/core/rdma_core.c

@@ -245,13 +245,11 @@ struct ib_uobject *__uobj_get_destroy(const struct uverbs_api_object *obj,
 }
 
 /*
- * Does both uobj_get_destroy() and uobj_put_destroy().  Returns success_res
- * on success (negative errno on failure). For use by callers that do not need
- * the uobj.
+ * Does both uobj_get_destroy() and uobj_put_destroy().  Returns 0 on success
+ * (negative errno on failure). For use by callers that do not need the uobj.
  */
 int __uobj_perform_destroy(const struct uverbs_api_object *obj, u32 id,
-			   const struct uverbs_attr_bundle *attrs,
-			   int success_res)
+			   const struct uverbs_attr_bundle *attrs)
 {
 	struct ib_uobject *uobj;
 
@@ -260,7 +258,7 @@ int __uobj_perform_destroy(const struct uverbs_api_object *obj, u32 id,
 		return PTR_ERR(uobj);
 
 	rdma_lookup_put_uobject(uobj, UVERBS_LOOKUP_WRITE);
-	return success_res;
+	return 0;
 }
 
 /* alloc_uobj must be undone by uverbs_destroy_uobject() */

drivers/infiniband/core/rdma_core.h

@@ -137,8 +137,8 @@ struct uverbs_api_ioctl_method {
 };
 
 struct uverbs_api_write_method {
-	ssize_t (*handler)(struct uverbs_attr_bundle *attrs,
-			   const char __user *buf, int in_len, int out_len);
+	int (*handler)(struct uverbs_attr_bundle *attrs, const char __user *buf,
+		       int in_len, int out_len);
 	int (*handler_ex)(struct uverbs_attr_bundle *attrs,
 			  struct ib_udata *ucore, struct ib_udata *uhw);
 	u8 disabled:1;