Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

From: Greg Kroah-Hartman <[email-masked]>
Date: Thu, 22 Jun 2023 07:20:48 +0200

On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> Enable io_uring commands on network sockets. Create two new
> SOCKET_URING_OP commands that will operate on sockets. Since these
> commands are similar to ioctl, uses the _IO{R,W} helpers to embedded the
> argument size and operation direction. Also allocates a unused ioctl
> chunk for uring command usage.
> 
> In order to call ioctl on sockets, use the file_operations->uring_cmd
> callbacks, and map it to a uring socket function, which handles the
> SOCKET_URING_OP accordingly, and calls socket ioctls.
> 
> This patches was tested by creating a new test case in liburing.
> Link: https://github.com/leitao/liburing/commit/3340908b742c6a26f662a0679c4ddf9df84ef431
> 
> Signed-off-by: Breno Leitao <[email-masked]>
> ---

Isn't this a new version of an older patch?

>  .../userspace-api/ioctl/ioctl-number.rst      |  1 +
>  include/linux/io_uring.h                      |  6 +++++
>  include/uapi/linux/io_uring.h                 |  6 +++++
>  io_uring/uring_cmd.c                          | 27 +++++++++++++++++++
>  net/socket.c                                  |  2 ++
>  5 files changed, 42 insertions(+)
> 
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 4f7b23faebb9..23348636f2ef 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -361,6 +361,7 @@ Code  Seq#    Include File                                           Comments
>  0xCB  00-1F                                                          CBM serial IEC bus in development:
>                                                                       <mailto:[email-masked]>
>  0xCC  00-0F  drivers/misc/ibmvmc.h                                   pseries VMC driver
> +0xCC  A0-BF  uapi/linux/io_uring.h                                   io_uring cmd subsystem

This change is nice, but not totally related to this specific one,
shouldn't it be separate?

>  0xCD  01     linux/reiserfs_fs.h
>  0xCE  01-02  uapi/linux/cxl_mem.h                                    Compute Express Link Memory Devices
>  0xCF  02     fs/smb/client/cifs_ioctl.h
> diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
> index 7fe31b2cd02f..d1b20e2a9fb0 100644
> --- a/include/linux/io_uring.h
> +++ b/include/linux/io_uring.h
> @@ -71,6 +71,7 @@ static inline void io_uring_free(struct task_struct *tsk)
>  	if (tsk->io_uring)
>  		__io_uring_free(tsk);
>  }
> +int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
>  #else
>  static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
>  			      struct iov_iter *iter, void *ioucmd)
> @@ -102,6 +103,11 @@ static inline const char *io_uring_get_opcode(u8 opcode)
>  {
>  	return "";
>  }
> +static inline int uring_sock_cmd(struct io_uring_cmd *cmd,
> +				 unsigned int issue_flags)
> +{
> +	return -EOPNOTSUPP;
> +}
>  #endif
>  
>  #endif
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 0716cb17e436..e20ba410859d 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -703,6 +703,12 @@ struct io_uring_recvmsg_out {
>  	__u32 flags;
>  };
>  
> +/*
> + * Argument for IORING_OP_URING_CMD when file is a socket
> + */
> +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
> +
>  #ifdef __cplusplus
>  }
>  #endif
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index 5e32db48696d..dcbe6493b03f 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -7,6 +7,7 @@
>  #include <linux/nospec.h>
>  
>  #include <uapi/linux/io_uring.h>
> +#include <uapi/asm-generic/ioctls.h>
>  
>  #include "io_uring.h"
>  #include "rsrc.h"
> @@ -156,3 +157,29 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
>  	return io_import_fixed(rw, iter, req->imu, ubuf, len);
>  }
>  EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
> +
> +int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
> +{
> +	struct socket *sock = cmd->file->private_data;
> +	struct sock *sk = sock->sk;
> +	int ret, arg = 0;
> +
> +	if (!sk->sk_prot || !sk->sk_prot->ioctl)
> +		return -EOPNOTSUPP;
> +
> +	switch (cmd->sqe->cmd_op) {
> +	case SOCKET_URING_OP_SIOCINQ:
> +		ret = sk->sk_prot->ioctl(sk, SIOCINQ, &arg);
> +		if (ret)
> +			return ret;
> +		return arg;
> +	case SOCKET_URING_OP_SIOCOUTQ:
> +		ret = sk->sk_prot->ioctl(sk, SIOCOUTQ, &arg);
> +		if (ret)
> +			return ret;
> +		return arg;
> +	default:
> +		return -EOPNOTSUPP;
> +	}
> +}
> +EXPORT_SYMBOL_GPL(uring_sock_cmd);

Did you forget the "io_" prefix?

thanks,

greg k-h