Re: [PATCH 1/6] [net] drop 'size' argument of sock_recvmsg()

[Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>]

On Sat, 2016-04-09 at 21:50 +0100, Al Viro wrote:
> all callers have it equal to msg_data_left(msg).
> 
> Signed-off-by: Al Viro <viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org>
> ---
>  drivers/target/iscsi/iscsi_target_util.c |  5 ++---
>  include/linux/net.h                      |  3 +--
>  net/socket.c                             | 23 ++++++++++-------------
>  3 files changed, 13 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
> index 428b0d9..5772038 100644
> --- a/drivers/target/iscsi/iscsi_target_util.c
> +++ b/drivers/target/iscsi/iscsi_target_util.c
> @@ -1283,9 +1283,8 @@ static int iscsit_do_rx_data(
>  	iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
>  		      count->iov, count->iov_count, data);
>  
> -	while (total_rx < data) {
> -		rx_loop = sock_recvmsg(conn->sock, &msg,
> -				      (data - total_rx), MSG_WAITALL);
> +	while (msg_data_left(&msg)) {
> +		rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
>  		if (rx_loop <= 0) {
>  			pr_debug("rx_loop: %d total_rx: %d\n",
>  				rx_loop, total_rx);
> diff --git a/include/linux/net.h b/include/linux/net.h
> index 49175e4..72c1e06 100644
> --- a/include/linux/net.h
> +++ b/include/linux/net.h
> @@ -218,8 +218,7 @@ int sock_create_lite(int family, int type, int proto, struct socket **res);
>  struct socket *sock_alloc(void);
>  void sock_release(struct socket *sock);
>  int sock_sendmsg(struct socket *sock, struct msghdr *msg);
> -int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
> -		 int flags);
> +int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
>  struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
>  struct socket *sockfd_lookup(int fd, int *err);
>  struct socket *sock_from_file(struct file *file, int *err);
> diff --git a/net/socket.c b/net/socket.c
> index 5f77a8e..956426e3 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -709,17 +709,16 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
>  EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);
>  
>  static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
> -				     size_t size, int flags)
> +				     int flags)
>  {
> -	return sock->ops->recvmsg(sock, msg, size, flags);
> +	return sock->ops->recvmsg(sock, msg, msg_data_left(msg), flags);
>  }
>  
> -int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
> -		 int flags)
> +int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
>  {
> -	int err = security_socket_recvmsg(sock, msg, size, flags);
> +	int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);
>  
> -	return err ?: sock_recvmsg_nosec(sock, msg, size, flags);
> +	return err ?: sock_recvmsg_nosec(sock, msg, flags);
>  }
>  EXPORT_SYMBOL(sock_recvmsg);
>  
> @@ -746,7 +745,7 @@ int kernel_recvmsg(struct socket *sock, struct msghdr *msg,
>  
>  	iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
>  	set_fs(KERNEL_DS);
> -	result = sock_recvmsg(sock, msg, size, flags);
> +	result = sock_recvmsg(sock, msg, flags);
>  	set_fs(oldfs);
>  	return result;
>  }
> @@ -796,7 +795,7 @@ static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
>  	if (!iov_iter_count(to))	/* Match SYS5 behaviour */
>  		return 0;
>  
> -	res = sock_recvmsg(sock, &msg, iov_iter_count(to), msg.msg_flags);
> +	res = sock_recvmsg(sock, &msg, msg.msg_flags);
>  	*to = msg.msg_iter;
>  	return res;
>  }
> @@ -1696,7 +1695,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
>  	msg.msg_iocb = NULL;
>  	if (sock->file->f_flags & O_NONBLOCK)
>  		flags |= MSG_DONTWAIT;
> -	err = sock_recvmsg(sock, &msg, iov_iter_count(&msg.msg_iter), flags);
> +	err = sock_recvmsg(sock, &msg, flags);
>  
>  	if (err >= 0 && addr != NULL) {
>  		err2 = move_addr_to_user(&address,
> @@ -2073,7 +2072,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
>  	struct iovec iovstack[UIO_FASTIOV];
>  	struct iovec *iov = iovstack;
>  	unsigned long cmsg_ptr;
> -	int total_len, len;
> +	int len;
>  	ssize_t err;
>  
>  	/* kernel mode address */
> @@ -2091,7 +2090,6 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
>  		err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
>  	if (err < 0)
>  		return err;
> -	total_len = iov_iter_count(&msg_sys->msg_iter);
>  
>  	cmsg_ptr = (unsigned long)msg_sys->msg_control;
>  	msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
> @@ -2101,8 +2099,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
>  
>  	if (sock->file->f_flags & O_NONBLOCK)
>  		flags |= MSG_DONTWAIT;
> -	err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys,
> -							  total_len, flags);
> +	err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, flags);
>  	if (err < 0)
>  		goto out_freeiov;
>  	len = err;

Looks good. Assuming that the corresponding change to sock_recvmsg is
merged.

Reviewed-by: Jeff Layton <jlayton-vpEMnDpepFuMZCB2o+C8xQ@public.gmane.org>