Re: [PATCH] Modify the return value ret to EOPNOTSUPP when initialized to reduce repeated assignment of errno

[Stefano Garzarella]

On Thu, Aug 11, 2022 at 03:56:38PM +0800, Zhang chunchao wrote:
> Remove unnecessary initialization assignments.
>
> Signed-off-by: Zhang chunchao <chunchao@xxxxxxxxxxxx>
> ---
> io_uring/io_uring.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index b54218da075c..8c267af06401 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -3859,14 +3859,13 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
> 		void __user *, arg, unsigned int, nr_args)
> {
> 	struct io_ring_ctx *ctx;
> -	long ret = -EBADF;
> +	long ret = -EOPNOTSUPP;
> 	struct fd f;
>
> 	f = fdget(fd);
> 	if (!f.file)
> 		return -EBADF;
>
> -	ret = -EOPNOTSUPP;
> 	if (!io_is_uring_fops(f.file))
> 		goto out_fput;

What about remove the initialization and assign it in the if branch?
I find it a bit easier to read.

I mean something like this:

--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3859,16 +3859,17 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd, unsigned int, opcode,
                void __user *, arg, unsigned int, nr_args)
 {
        struct io_ring_ctx *ctx;
-       long ret = -EBADF;
+       long ret;
        struct fd f;

        f = fdget(fd);
        if (!f.file)
                return -EBADF;

-       ret = -EOPNOTSUPP;
-       if (!io_is_uring_fops(f.file))
+       if (!io_is_uring_fops(f.file)) {
+               ret = -EOPNOTSUPP;
                goto out_fput;
+       }

        ctx = f.file->private_data;


Otherwise remove the initialization, but leave the assignment as it is 
now.

Thanks,
Stefano