Re: [PATCH] RDMA/core: Use fdget() and fdput()

[Leon Romanovsky <leon@kernel.org>]

On Fri, May 05, 2023 at 11:33:57AM +0800, ye.xingchen@zte.com.cn wrote:
> From: Ye Xingchen <ye.xingchen@zte.com.cn>
> 
> convert the fget()/fput() uses to fdget()/fdput().

Why? What is wrong with current implementation?

Thanks

> 
> Signed-off-by: Ye Xingchen <ye.xingchen@zte.com.cn>
> ---
>  drivers/infiniband/core/rdma_core.c | 11 +++++------
>  1 file changed, 5 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
> index 29b1ab1d5f93..c35df0b27e86 100644
> --- a/drivers/infiniband/core/rdma_core.c
> +++ b/drivers/infiniband/core/rdma_core.c
> @@ -335,7 +335,7 @@ lookup_get_fd_uobject(const struct uverbs_api_object *obj,
>  		      enum rdma_lookup_mode mode)
>  {
>  	const struct uverbs_obj_fd_type *fd_type;
> -	struct file *f;
> +	struct fd f = fdget(fdno);
>  	struct ib_uobject *uobject;
>  	int fdno = id;
> 
> @@ -350,18 +350,17 @@ lookup_get_fd_uobject(const struct uverbs_api_object *obj,
>  	fd_type =
>  		container_of(obj->type_attrs, struct uverbs_obj_fd_type, type);
> 
> -	f = fget(fdno);
> -	if (!f)
> +	if (!f.file)
>  		return ERR_PTR(-EBADF);
> 
> -	uobject = f->private_data;
> +	uobject = f.file->private_data;
>  	/*
>  	 * fget(id) ensures we are not currently running
>  	 * uverbs_uobject_fd_release(), and the caller is expected to ensure
>  	 * that release is never done while a call to lookup is possible.
>  	 */
> -	if (f->f_op != fd_type->fops || uobject->ufile != ufile) {
> -		fput(f);
> +	if (f.file->f_op != fd_type->fops || uobject->ufile != ufile) {
> +		fdput(f);
>  		return ERR_PTR(-EBADF);
>  	}
> 
> -- 
> 2.25.1