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

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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: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2020-02-28 12:13:02 -08:00
commit 9a834f9b04
6 changed files with 30 additions and 53 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
include/linux/skbuff.h
View File

@ -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,

2
include/net/af_unix.h
View File

@ -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))

25
net/core/datagram.c
View File

@ -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);

14
net/ipv4/udp.c
View File

@ -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)

28
net/unix/af_unix.c
View File

@ -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);
}

2
net/xfrm/espintcp.c
View File

@ -100,7 +100,7 @@ static int espintcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
flags |= nonblock ? MSG_DONTWAIT : 0;
skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, NULL, &off, &err);
skb = __skb_recv_datagram(sk, &ctx->ike_queue, flags, &off, &err);
if (!skb)
return err;