Re: [PATCH v6 2/9] io_uring: add support for IORING_OP_MKDIRAT

[Pavel Begunkov <asml.silence@gmail.com>]

On 6/24/21 12:14 PM, Dmitry Kadashev wrote:
> IORING_OP_MKDIRAT behaves like mkdirat(2) and takes the same flags
> and arguments.

io_uring part looks good, great finally see it taken.

Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>

> 
> Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
> Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
> ---
>  fs/io_uring.c                 | 59 +++++++++++++++++++++++++++++++++++
>  include/uapi/linux/io_uring.h |  1 +
>  2 files changed, 60 insertions(+)
> 
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index e7997f9bf879..7aa08ed78452 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -673,6 +673,13 @@ struct io_unlink {
>  	struct filename			*filename;
>  };
>  
> +struct io_mkdir {
> +	struct file			*file;
> +	int				dfd;
> +	umode_t				mode;
> +	struct filename			*filename;
> +};
> +
>  struct io_completion {
>  	struct file			*file;
>  	struct list_head		list;
> @@ -825,6 +832,7 @@ struct io_kiocb {
>  		struct io_shutdown	shutdown;
>  		struct io_rename	rename;
>  		struct io_unlink	unlink;
> +		struct io_mkdir		mkdir;
>  		/* use only after cleaning per-op data, see io_clean_op() */
>  		struct io_completion	compl;
>  	};
> @@ -1039,6 +1047,7 @@ static const struct io_op_def io_op_defs[] = {
>  	},
>  	[IORING_OP_RENAMEAT] = {},
>  	[IORING_OP_UNLINKAT] = {},
> +	[IORING_OP_MKDIRAT] = {},
>  };
>  
>  static bool io_disarm_next(struct io_kiocb *req);
> @@ -3548,6 +3557,48 @@ static int io_unlinkat(struct io_kiocb *req, unsigned int issue_flags)
>  	return 0;
>  }
>  
> +static int io_mkdirat_prep(struct io_kiocb *req,
> +			    const struct io_uring_sqe *sqe)
> +{
> +	struct io_mkdir *mkd = &req->mkdir;
> +	const char __user *fname;
> +
> +	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
> +		return -EINVAL;
> +	if (sqe->ioprio || sqe->off || sqe->rw_flags || sqe->buf_index)
> +		return -EINVAL;
> +	if (unlikely(req->flags & REQ_F_FIXED_FILE))
> +		return -EBADF;
> +
> +	mkd->dfd = READ_ONCE(sqe->fd);
> +	mkd->mode = READ_ONCE(sqe->len);
> +
> +	fname = u64_to_user_ptr(READ_ONCE(sqe->addr));
> +	mkd->filename = getname(fname);
> +	if (IS_ERR(mkd->filename))
> +		return PTR_ERR(mkd->filename);
> +
> +	req->flags |= REQ_F_NEED_CLEANUP;
> +	return 0;
> +}
> +
> +static int io_mkdirat(struct io_kiocb *req, int issue_flags)
> +{
> +	struct io_mkdir *mkd = &req->mkdir;
> +	int ret;
> +
> +	if (issue_flags & IO_URING_F_NONBLOCK)
> +		return -EAGAIN;
> +
> +	ret = do_mkdirat(mkd->dfd, mkd->filename, mkd->mode);
> +
> +	req->flags &= ~REQ_F_NEED_CLEANUP;
> +	if (ret < 0)
> +		req_set_fail(req);
> +	io_req_complete(req, ret);
> +	return 0;
> +}
> +
>  static int io_shutdown_prep(struct io_kiocb *req,
>  			    const struct io_uring_sqe *sqe)
>  {
> @@ -5956,6 +6007,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>  		return io_renameat_prep(req, sqe);
>  	case IORING_OP_UNLINKAT:
>  		return io_unlinkat_prep(req, sqe);
> +	case IORING_OP_MKDIRAT:
> +		return io_mkdirat_prep(req, sqe);
>  	}
>  
>  	printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
> @@ -6117,6 +6170,9 @@ static void io_clean_op(struct io_kiocb *req)
>  		case IORING_OP_UNLINKAT:
>  			putname(req->unlink.filename);
>  			break;
> +		case IORING_OP_MKDIRAT:
> +			putname(req->mkdir.filename);
> +			break;
>  		}
>  	}
>  	if ((req->flags & REQ_F_POLLED) && req->apoll) {
> @@ -6245,6 +6301,9 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
>  	case IORING_OP_UNLINKAT:
>  		ret = io_unlinkat(req, issue_flags);
>  		break;
> +	case IORING_OP_MKDIRAT:
> +		ret = io_mkdirat(req, issue_flags);
> +		break;
>  	default:
>  		ret = -EINVAL;
>  		break;
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index f1f9ac114b51..49a24a149eeb 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -137,6 +137,7 @@ enum {
>  	IORING_OP_SHUTDOWN,
>  	IORING_OP_RENAMEAT,
>  	IORING_OP_UNLINKAT,
> +	IORING_OP_MKDIRAT,
>  
>  	/* this goes last, obviously */
>  	IORING_OP_LAST,
> 

-- 
Pavel Begunkov