Please apply these tiny, 4-month-old patches.

Michael Witten
2018-02-06T01:08:08Z

Strictly speaking, these patches streamline the code at both
compile-time and run-time, and seem to face no technical
objection of note.

The strongest objection was a dubious *potential* refactoring of
similar code, a refactoring which is clearly vaporware, and which
I myself would have tried to complete if only this initial foray
had been applied.

If this is considered "new" code (it isn't) and if this email is
received outside of an appropriate merge window, then save this
email for later consideration---this isn't a real-time conversation;
this is email, so it doesn't matter when you receive it.

Sincerely,
Michael Witten

On Sun, 01 Oct 2017 22:19:02 -0000, Michael Witten wrote:

> The following patch series is an ad hoc "cleanup" that I made
> while perusing the code (I'm not well versed in this code, so I
> would not be surprised if there were objections to the changes):
>
> [1] net: __sock_cmsg_send(): Remove unused parameter `msg'
> [2] net: inet_recvmsg(): Remove unnecessary bitwise operation
> [3] net: skb_queue_purge(): lock/unlock the queue only once
>
> Each patch will be sent as an individual reply to this email;
> the total diff is appended below for your convenience.
>
> You may also fetch these patches from GitHub:
>
> git checkout --detach 5969d1bb3082b41eba8fd2c826559abe38ccb6df
> git pull https://github.com/mfwitten/linux.git net/tcp-ip/01-cleanup/02
>
> Overall:
>
> include/net/sock.h | 2 +-
> net/core/skbuff.c | 26 ++++++++++++++++++--------
> net/core/sock.c | 4 ++--
> net/ipv4/af_inet.c | 2 +-
> net/ipv4/ip_sockglue.c | 2 +-
> net/ipv6/datagram.c | 2 +-
> 6 files changed, 24 insertions(+), 14 deletions(-)
>
> Sincerly,
> Michael Witten
>
> diff --git a/include/net/sock.h b/include/net/sock.h
> index 03a362568357..83373d7148a9 100644
> --- a/include/net/sock.h
> +++ b/include/net/sock.h
> @@ -1562,7 +1562,7 @@ struct sockcm_cookie {
> u16 tsflags;
> };
>
> -int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
> +int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
> struct sockcm_cookie *sockc);
> int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
> struct sockcm_cookie *sockc);
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 9b7b6bbb2a23..425e03fe1c56 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -2091,7 +2091,7 @@ struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
> }
> EXPORT_SYMBOL(sock_alloc_send_skb);
>
> -int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
> +int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg,
> struct sockcm_cookie *sockc)
> {
> u32 tsflags;
> @@ -2137,7 +2137,7 @@ int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
> return -EINVAL;
> if (cmsg->cmsg_level != SOL_SOCKET)
> continue;
> - ret = __sock_cmsg_send(sk, msg, cmsg, sockc);
> + ret = __sock_cmsg_send(sk, cmsg, sockc);
> if (ret)
> return ret;
> }
> diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
> index e558e4f9597b..c79b7822b0b9 100644
> --- a/net/ipv4/ip_sockglue.c
> +++ b/net/ipv4/ip_sockglue.c
> @@ -263,7 +263,7 @@ int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc,
> }
> #endif
> if (cmsg->cmsg_level == SOL_SOCKET) {
> - err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc);
> + err = __sock_cmsg_send(sk, cmsg, &ipc->sockc);
> if (err)
> return err;
> continue;
> diff --git a/net/ipv6/datagram.c b/net/ipv6/datagram.c
> index a1f918713006..1d1926a4cbe2 100644
> --- a/net/ipv6/datagram.c
> +++ b/net/ipv6/datagram.c
> @@ -756,7 +756,7 @@ int ip6_datagram_send_ctl(struct net *net, struct sock *sk,
> }
>
> if (cmsg->cmsg_level == SOL_SOCKET) {
> - err = __sock_cmsg_send(sk, msg, cmsg, sockc);
> + err = __sock_cmsg_send(sk, cmsg, sockc);
> if (err)
> return err;
> continue;
> diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
> index e31108e5ef79..2dbed042a412 100644
> --- a/net/ipv4/af_inet.c
> +++ b/net/ipv4/af_inet.c
> @@ -791,7 +791,7 @@ int inet_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
> sock_rps_record_flow(sk);
>
> err = sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
> - flags & ~MSG_DONTWAIT, &addr_len);
> + flags, &addr_len);
> if (err >= 0)
> msg->msg_namelen = addr_len;
> return err;
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 68065d7d383f..bd26b0bde784 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -2825,18 +2825,28 @@
> EXPORT_SYMBOL(skb_dequeue_tail);
>
> /**
> - * skb_queue_purge - empty a list
> - * @list: list to empty
> + * skb_queue_purge - empty a queue
> + * @q: the queue to empty
> *
> - * Delete all buffers on an &sk_buff list. Each buffer is removed from
> - * the list and one reference dropped. This function takes the list
> - * lock and is atomic with respect to other list locking functions.
> + * Dequeue and free each socket buffer that is in @q.
> + *
> + * This function is atomic with respect to other queue-locking functions.
> */
> -void skb_queue_purge(struct sk_buff_head *list)
> +void skb_queue_purge(struct sk_buff_head *q)
> {
> - struct sk_buff *skb;
> - while ((skb = skb_dequeue(list)) != NULL)
> + unsigned long flags;
> + struct sk_buff *skb, *next, *head = (struct sk_buff *)q;
> +
> + spin_lock_irqsave(&q->lock, flags);
> + skb = q->next;
> + __skb_queue_head_init(q);
> + spin_unlock_irqrestore(&q->lock, flags);
> +
> + while (skb != head) {
> + next = skb->next;
> kfree_skb(skb);
> + skb = next;
> + }
> }
> EXPORT_SYMBOL(skb_queue_purge);
>
> --
> 2.14.1
>