RE: [PATCH 1/1] io_uring: clean up io_uring_register_get_file()

[lizetao <lizetao1@huawei.com>]

Hi,

> -----Original Message-----
> From: Pavel Begunkov <asml.silence@gmail.com>
> Sent: Thursday, January 16, 2025 10:53 AM
> To: io-uring@vger.kernel.org
> Cc: asml.silence@gmail.com
> Subject: [PATCH 1/1] io_uring: clean up io_uring_register_get_file()
> 
> Make it always reference the returned file. It's safer, especially with
> unregistrations happening under it. And it makes the api cleaner with no
> conditional clean ups by the caller.
> 
> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
> ---
>  io_uring/register.c | 6 ++++--
>  io_uring/rsrc.c     | 4 ++--
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/io_uring/register.c b/io_uring/register.c index
> 5e48413706ac..a93c979c2f38 100644
> --- a/io_uring/register.c
> +++ b/io_uring/register.c
> @@ -841,6 +841,8 @@ struct file *io_uring_register_get_file(unsigned int fd,
> bool registered)
>  			return ERR_PTR(-EINVAL);
>  		fd = array_index_nospec(fd, IO_RINGFD_REG_MAX);
>  		file = tctx->registered_rings[fd];
> +		if (file)
> +			get_file(file);

Should performance be a priority here?
>  	} else {
>  		file = fget(fd);
>  	}
> @@ -907,7 +909,7 @@ SYSCALL_DEFINE4(io_uring_register, unsigned int, fd,
> unsigned int, opcode,
>  	trace_io_uring_register(ctx, opcode, ctx->file_table.data.nr,
>  				ctx->buf_table.nr, ret);
>  	mutex_unlock(&ctx->uring_lock);
> -	if (!use_registered_ring)
> -		fput(file);
> +
> +	fput(file);
>  	return ret;
>  }
> diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c index
> 964a47c8d85e..792c22b6f2d4 100644
> --- a/io_uring/rsrc.c
> +++ b/io_uring/rsrc.c
> @@ -1073,7 +1073,7 @@ int io_register_clone_buffers(struct io_ring_ctx *ctx,
> void __user *arg)
>  	if (IS_ERR(file))
>  		return PTR_ERR(file);
>  	ret = io_clone_buffers(ctx, file->private_data, &buf);
> -	if (!registered_src)
> -		fput(file);
> +
> +	fput(file);
>  	return ret;
>  }
> --
> 2.47.1
> 


---
Li Zetao