Commit 9a834f9b authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'net-cleanup-datagram-receive-helpers' 



Paolo Abeni says:

====================
net: cleanup datagram receive helpers

Several receive helpers have an optional destructor argument, which uglify
the code a bit and is taxed by retpoline overhead.

This series refactor the code so that we can drop such optional argument,
cleaning the helpers a bit and avoiding an indirect call in fast path.

The first patch refactor a bit the caller, so that the second patch
actually dropping the argument is more straight-forward

v1 -> v2:
 - call scm_stat_del() only when not peeking - Kirill
 - fix build issue with CONFIG_INET_ESPINTCP
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents e9553762 e427cad6

include/linux/skbuff.h

+2 −10
Original line number Diff line number Diff line
@@ -3514,23 +3514,15 @@ int __skb_wait_for_more_packets(struct sock *sk, struct sk_buff_head *queue, 
struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,

					  struct sk_buff_head *queue,

					  unsigned int flags,

					  void (*destructor)(struct sock *sk,

							   struct sk_buff *skb),

					  int *off, int *err,

					  struct sk_buff **last);

struct sk_buff *__skb_try_recv_datagram(struct sock *sk,

					struct sk_buff_head *queue,

					unsigned int flags,

					void (*destructor)(struct sock *sk,

							   struct sk_buff *skb),

					int *off, int *err,

					unsigned int flags, int *off, int *err,

					struct sk_buff **last);

struct sk_buff *__skb_recv_datagram(struct sock *sk,

				    struct sk_buff_head *sk_queue,

				    unsigned int flags,

				    void (*destructor)(struct sock *sk,

						       struct sk_buff *skb),

				    int *off, int *err);

				    unsigned int flags, int *off, int *err);

struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, int noblock,

				  int *err);

__poll_t datagram_poll(struct file *file, struct socket *sock,

include/net/af_unix.h

+1 −1
Original line number Diff line number Diff line
@@ -42,7 +42,7 @@ struct unix_skb_parms { 
} __randomize_layout;



struct scm_stat {

	u32 nr_fds;

	atomic_t nr_fds;

};



#define UNIXCB(skb)	(*(struct unix_skb_parms *)&((skb)->cb))

net/core/datagram.c

+7 −18
Original line number Diff line number Diff line
@@ -166,8 +166,6 @@ done: 
struct sk_buff *__skb_try_recv_from_queue(struct sock *sk,

					  struct sk_buff_head *queue,

					  unsigned int flags,

					  void (*destructor)(struct sock *sk,

							   struct sk_buff *skb),

					  int *off, int *err,

					  struct sk_buff **last)

{
@@ -198,8 +196,6 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 
			refcount_inc(&skb->users);

		} else {

			__skb_unlink(skb, queue);

			if (destructor)

				destructor(sk, skb);

		}

		*off = _off;

		return skb;
@@ -212,7 +208,6 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 
 *	@sk: socket

 *	@queue: socket queue from which to receive

 *	@flags: MSG\_ flags

 *	@destructor: invoked under the receive lock on successful dequeue

 *	@off: an offset in bytes to peek skb from. Returns an offset

 *	      within an skb where data actually starts

 *	@err: error code returned
@@ -245,10 +240,7 @@ struct sk_buff *__skb_try_recv_from_queue(struct sock *sk, 
 */

struct sk_buff *__skb_try_recv_datagram(struct sock *sk,

					struct sk_buff_head *queue,

					unsigned int flags,

					void (*destructor)(struct sock *sk,

							   struct sk_buff *skb),

					int *off, int *err,

					unsigned int flags, int *off, int *err,

					struct sk_buff **last)

{

	struct sk_buff *skb;
@@ -269,8 +261,8 @@ struct sk_buff *__skb_try_recv_datagram(struct sock *sk, 
		 * However, this function was correct in any case. 8)

		 */

		spin_lock_irqsave(&queue->lock, cpu_flags);

		skb = __skb_try_recv_from_queue(sk, queue, flags, destructor,

						off, &error, last);

		skb = __skb_try_recv_from_queue(sk, queue, flags, off, &error,

						last);

		spin_unlock_irqrestore(&queue->lock, cpu_flags);

		if (error)

			goto no_packet;
@@ -293,10 +285,7 @@ EXPORT_SYMBOL(__skb_try_recv_datagram); 


struct sk_buff *__skb_recv_datagram(struct sock *sk,

				    struct sk_buff_head *sk_queue,

				    unsigned int flags,

				    void (*destructor)(struct sock *sk,

						       struct sk_buff *skb),

				    int *off, int *err)

				    unsigned int flags, int *off, int *err)

{

	struct sk_buff *skb, *last;

	long timeo;
@@ -304,8 +293,8 @@ struct sk_buff *__skb_recv_datagram(struct sock *sk, 
	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);



	do {

		skb = __skb_try_recv_datagram(sk, sk_queue, flags, destructor,

					      off, err, &last);

		skb = __skb_try_recv_datagram(sk, sk_queue, flags, off, err,

					      &last);

		if (skb)

			return skb;
@@ -326,7 +315,7 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned int flags, 


	return __skb_recv_datagram(sk, &sk->sk_receive_queue,

				   flags | (noblock ? MSG_DONTWAIT : 0),

				   NULL, &off, err);

				   &off, err);

}

EXPORT_SYMBOL(skb_recv_datagram);

net/ipv4/udp.c

+8 −6
Original line number Diff line number Diff line
@@ -1671,10 +1671,11 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 
		error = -EAGAIN;

		do {

			spin_lock_bh(&queue->lock);

			skb = __skb_try_recv_from_queue(sk, queue, flags,

							udp_skb_destructor,

							off, err, &last);

			skb = __skb_try_recv_from_queue(sk, queue, flags, off,

							err, &last);

			if (skb) {

				if (!(flags & MSG_PEEK))

					udp_skb_destructor(sk, skb);

				spin_unlock_bh(&queue->lock);

				return skb;

			}
@@ -1692,9 +1693,10 @@ struct sk_buff *__skb_recv_udp(struct sock *sk, unsigned int flags, 
			spin_lock(&sk_queue->lock);

			skb_queue_splice_tail_init(sk_queue, queue);



			skb = __skb_try_recv_from_queue(sk, queue, flags,

							udp_skb_dtor_locked,

							off, err, &last);

			skb = __skb_try_recv_from_queue(sk, queue, flags, off,

							err, &last);

			if (skb && !(flags & MSG_PEEK))

				udp_skb_dtor_locked(sk, skb);

			spin_unlock(&sk_queue->lock);

			spin_unlock_bh(&queue->lock);

			if (skb)

net/unix/af_unix.c

+11 −17
Original line number Diff line number Diff line
@@ -690,7 +690,8 @@ static void unix_show_fdinfo(struct seq_file *m, struct socket *sock) 


	if (sk) {

		u = unix_sk(sock->sk);

		seq_printf(m, "scm_fds: %u\n", READ_ONCE(u->scm_stat.nr_fds));

		seq_printf(m, "scm_fds: %u\n",

			   atomic_read(&u->scm_stat.nr_fds));

	}

}

#else
@@ -1602,10 +1603,8 @@ static void scm_stat_add(struct sock *sk, struct sk_buff *skb) 
	struct scm_fp_list *fp = UNIXCB(skb).fp;

	struct unix_sock *u = unix_sk(sk);



	lockdep_assert_held(&sk->sk_receive_queue.lock);



	if (unlikely(fp && fp->count))

		u->scm_stat.nr_fds += fp->count;

		atomic_add(fp->count, &u->scm_stat.nr_fds);

}



static void scm_stat_del(struct sock *sk, struct sk_buff *skb)
@@ -1613,10 +1612,8 @@ static void scm_stat_del(struct sock *sk, struct sk_buff *skb) 
	struct scm_fp_list *fp = UNIXCB(skb).fp;

	struct unix_sock *u = unix_sk(sk);



	lockdep_assert_held(&sk->sk_receive_queue.lock);



	if (unlikely(fp && fp->count))

		u->scm_stat.nr_fds -= fp->count;

		atomic_sub(fp->count, &u->scm_stat.nr_fds);

}



/*
@@ -1805,10 +1802,8 @@ restart_locked: 
	if (sock_flag(other, SOCK_RCVTSTAMP))

		__net_timestamp(skb);

	maybe_add_creds(skb, sock, other);

	spin_lock(&other->sk_receive_queue.lock);

	scm_stat_add(other, skb);

	__skb_queue_tail(&other->sk_receive_queue, skb);

	spin_unlock(&other->sk_receive_queue.lock);

	skb_queue_tail(&other->sk_receive_queue, skb);

	unix_state_unlock(other);

	other->sk_data_ready(other);

	sock_put(other);
@@ -1910,10 +1905,8 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, 
			goto pipe_err_free;



		maybe_add_creds(skb, sock, other);

		spin_lock(&other->sk_receive_queue.lock);

		scm_stat_add(other, skb);

		__skb_queue_tail(&other->sk_receive_queue, skb);

		spin_unlock(&other->sk_receive_queue.lock);

		skb_queue_tail(&other->sk_receive_queue, skb);

		unix_state_unlock(other);

		other->sk_data_ready(other);

		sent += size;
@@ -2113,9 +2106,12 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, 


		skip = sk_peek_offset(sk, flags);

		skb = __skb_try_recv_datagram(sk, &sk->sk_receive_queue, flags,

					      scm_stat_del, &skip, &err, &last);

		if (skb)

					      &skip, &err, &last);

		if (skb) {

			if (!(flags & MSG_PEEK))

				scm_stat_del(sk, skb);

			break;

		}



		mutex_unlock(&u->iolock);
@@ -2409,9 +2405,7 @@ unlock: 
			sk_peek_offset_bwd(sk, chunk);



			if (UNIXCB(skb).fp) {

				spin_lock(&sk->sk_receive_queue.lock);

				scm_stat_del(sk, skb);

				spin_unlock(&sk->sk_receive_queue.lock);

				unix_detach_fds(&scm, skb);

			}

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