[PATCH 4.19 56/79] net: use skb_queue_empty_lockless() in poll() handlers

From: Greg Kroah-Hartman
Date: Fri Nov 08 2019 - 14:03:03 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

[ Upstream commit 3ef7cf57c72f32f61e97f8fa401bc39ea1f1a5d4 ]

Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/isdn/capi/capi.c | 2 +-
net/atm/common.c | 2 +-
net/bluetooth/af_bluetooth.c | 4 ++--
net/caif/caif_socket.c | 2 +-
net/core/datagram.c | 4 ++--
net/decnet/af_decnet.c | 2 +-
net/ipv4/tcp.c | 2 +-
net/ipv4/udp.c | 2 +-
net/nfc/llcp_sock.c | 4 ++--
net/phonet/socket.c | 4 ++--
net/sctp/socket.c | 4 ++--
net/tipc/socket.c | 4 ++--
net/unix/af_unix.c | 6 +++---
net/vmw_vsock/af_vsock.c | 2 +-
14 files changed, 22 insertions(+), 22 deletions(-)

--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -744,7 +744,7 @@ capi_poll(struct file *file, poll_table

poll_wait(file, &(cdev->recvwait), wait);
mask = EPOLLOUT | EPOLLWRNORM;
- if (!skb_queue_empty(&cdev->recvqueue))
+ if (!skb_queue_empty_lockless(&cdev->recvqueue))
mask |= EPOLLIN | EPOLLRDNORM;
return mask;
}
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -667,7 +667,7 @@ __poll_t vcc_poll(struct file *file, str
mask |= EPOLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* writable? */
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -460,7 +460,7 @@ __poll_t bt_sock_poll(struct file *file,
if (sk->sk_state == BT_LISTEN)
return bt_accept_poll(sk);

- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);

@@ -470,7 +470,7 @@ __poll_t bt_sock_poll(struct file *file,
if (sk->sk_shutdown == SHUTDOWN_MASK)
mask |= EPOLLHUP;

- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

if (sk->sk_state == BT_CLOSED)
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -953,7 +953,7 @@ static __poll_t caif_poll(struct file *f
mask |= EPOLLRDHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue) ||
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN))
mask |= EPOLLIN | EPOLLRDNORM;

--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -842,7 +842,7 @@ __poll_t datagram_poll(struct file *file
mask = 0;

/* exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);

@@ -852,7 +852,7 @@ __poll_t datagram_poll(struct file *file
mask |= EPOLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* Connection-based need to check for termination and startup */
--- a/net/decnet/af_decnet.c
+++ b/net/decnet/af_decnet.c
@@ -1213,7 +1213,7 @@ static __poll_t dn_poll(struct file *fil
struct dn_scp *scp = DN_SK(sk);
__poll_t mask = datagram_poll(file, sock, wait);

- if (!skb_queue_empty(&scp->other_receive_queue))
+ if (!skb_queue_empty_lockless(&scp->other_receive_queue))
mask |= EPOLLRDBAND;

return mask;
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -595,7 +595,7 @@ __poll_t tcp_poll(struct file *file, str
}
/* This barrier is coupled with smp_wmb() in tcp_reset() */
smp_rmb();
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR;

return mask;
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -2651,7 +2651,7 @@ __poll_t udp_poll(struct file *file, str
__poll_t mask = datagram_poll(file, sock, wait);
struct sock *sk = sock->sk;

- if (!skb_queue_empty(&udp_sk(sk)->reader_queue))
+ if (!skb_queue_empty_lockless(&udp_sk(sk)->reader_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* Check for false positives due to checksum errors */
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -566,11 +566,11 @@ static __poll_t llcp_sock_poll(struct fi
if (sk->sk_state == LLCP_LISTEN)
return llcp_accept_poll(sk);

- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);

- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

if (sk->sk_state == LLCP_CLOSED)
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -351,9 +351,9 @@ static __poll_t pn_socket_poll(struct fi

if (sk->sk_state == TCP_CLOSE)
return EPOLLERR;
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;
- if (!skb_queue_empty(&pn->ctrlreq_queue))
+ if (!skb_queue_empty_lockless(&pn->ctrlreq_queue))
mask |= EPOLLPRI;
if (!mask && sk->sk_state == TCP_CLOSE_WAIT)
return EPOLLHUP;
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -7939,7 +7939,7 @@ __poll_t sctp_poll(struct file *file, st
mask = 0;

/* Is there any exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);
if (sk->sk_shutdown & RCV_SHUTDOWN)
@@ -7948,7 +7948,7 @@ __poll_t sctp_poll(struct file *file, st
mask |= EPOLLHUP;

/* Is it readable? Reconsider this code with TCP-style support. */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* The association is either gone or not ready. */
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -731,7 +731,7 @@ static __poll_t tipc_poll(struct file *f
/* fall thru' */
case TIPC_LISTEN:
case TIPC_CONNECTING:
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
revents |= EPOLLIN | EPOLLRDNORM;
break;
case TIPC_OPEN:
@@ -739,7 +739,7 @@ static __poll_t tipc_poll(struct file *f
revents |= EPOLLOUT;
if (!tipc_sk_type_connectionless(sk))
break;
- if (skb_queue_empty(&sk->sk_receive_queue))
+ if (skb_queue_empty_lockless(&sk->sk_receive_queue))
break;
revents |= EPOLLIN | EPOLLRDNORM;
break;
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2661,7 +2661,7 @@ static __poll_t unix_poll(struct file *f
mask |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* Connection-based need to check for termination and startup */
@@ -2690,7 +2690,7 @@ static __poll_t unix_dgram_poll(struct f
mask = 0;

/* exceptional events? */
- if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+ if (sk->sk_err || !skb_queue_empty_lockless(&sk->sk_error_queue))
mask |= EPOLLERR |
(sock_flag(sk, SOCK_SELECT_ERR_QUEUE) ? EPOLLPRI : 0);

@@ -2700,7 +2700,7 @@ static __poll_t unix_dgram_poll(struct f
mask |= EPOLLHUP;

/* readable? */
- if (!skb_queue_empty(&sk->sk_receive_queue))
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
mask |= EPOLLIN | EPOLLRDNORM;

/* Connection-based need to check for termination and startup */
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -873,7 +873,7 @@ static __poll_t vsock_poll(struct file *
* the queue and write as long as the socket isn't shutdown for
* sending.
*/
- if (!skb_queue_empty(&sk->sk_receive_queue) ||
+ if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN)) {
mask |= EPOLLIN | EPOLLRDNORM;
}