Re: [PATCH] io_uring: remove io_remove_personalities()

[Stefano Garzarella]

On Wed, Dec 23, 2020 at 11:27:05AM +0800, Yejune Deng wrote:
> The function io_remove_personalities() is very similar to
> io_unregister_personality(),but the latter has a more reasonable
> return value.
>
> Signed-off-by: Yejune Deng <yejune.deng@xxxxxxxxx>
> ---
> fs/io_uring.c | 25 ++++++-------------------
> 1 file changed, 6 insertions(+), 19 deletions(-)

The patch LGTM, maybe as an alternative you can leave 
io_remove_personality() with the interface needed by idr_for_each() and 
implement io_unregister_personality() calling io_remove_personality() 
with the right parameters.

Just an idea, but I'm also fine with this patch, so:

Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>

> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index b749578..000ea9a 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -8608,7 +8608,7 @@ static int io_uring_fasync(int fd, struct file *file, int on)
> 	return fasync_helper(fd, file, on, &ctx->cq_fasync);
> }
>
> -static int io_remove_personalities(int id, void *p, void *data)
> +static int io_unregister_personality(int id, void *p, void *data)
> {
> 	struct io_ring_ctx *ctx = data;
> 	struct io_identity *iod;
> @@ -8618,8 +8618,10 @@ static int io_remove_personalities(int id, void *p, void *data)
> 		put_cred(iod->creds);
> 		if (refcount_dec_and_test(&iod->count))
> 			kfree(iod);
> +		return 0;
> 	}
> -	return 0;
> +
> +	return -EINVAL;
> }
>
> static void io_ring_exit_work(struct work_struct *work)
> @@ -8657,7 +8659,7 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
>
> 	/* if we failed setting up the ctx, we might not have any rings */
> 	io_iopoll_try_reap_events(ctx);
> -	idr_for_each(&ctx->personality_idr, io_remove_personalities, ctx);
> +	idr_for_each(&ctx->personality_idr, io_unregister_personality, ctx);
>
> 	/*
> 	 * Do this upfront, so we won't have a grace period where the ring
> @@ -9679,21 +9681,6 @@ static int io_register_personality(struct io_ring_ctx *ctx)
> 	return ret;
> }
>
> -static int io_unregister_personality(struct io_ring_ctx *ctx, unsigned id)
> -{
> -	struct io_identity *iod;
> -
> -	iod = idr_remove(&ctx->personality_idr, id);
> -	if (iod) {
> -		put_cred(iod->creds);
> -		if (refcount_dec_and_test(&iod->count))
> -			kfree(iod);
> -		return 0;
> -	}
> -
> -	return -EINVAL;
> -}
> -
> static int io_register_restrictions(struct io_ring_ctx *ctx, void __user *arg,
> 				    unsigned int nr_args)
> {
> @@ -9906,7 +9893,7 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
> 		ret = -EINVAL;
> 		if (arg)
> 			break;
> -		ret = io_unregister_personality(ctx, nr_args);
> +		ret = io_unregister_personality(nr_args, NULL, ctx);
> 		break;
> 	case IORING_REGISTER_ENABLE_RINGS:
> 		ret = -EINVAL;
> --
> 1.9.1