From dd979b4df817e9976f18fb6f9d134d6bc4a3c317 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 30 Jul 2018 09:42:10 +0200 Subject: [PATCH 1/4] net: simplify sock_poll_wait The wait_address argument is always directly derived from the filp argument, so remove it. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller --- crypto/af_alg.c | 2 +- include/net/sock.h | 11 ++++++----- net/atm/common.c | 2 +- net/caif/caif_socket.c | 2 +- net/core/datagram.c | 2 +- net/dccp/proto.c | 2 +- net/ipv4/tcp.c | 2 +- net/iucv/af_iucv.c | 2 +- net/nfc/llcp_sock.c | 2 +- net/rxrpc/af_rxrpc.c | 2 +- net/smc/af_smc.c | 2 +- net/tipc/socket.c | 2 +- net/unix/af_unix.c | 4 ++-- 13 files changed, 19 insertions(+), 18 deletions(-) diff --git a/crypto/af_alg.c b/crypto/af_alg.c index c166f424871c8..b053179e0bc53 100644 --- a/crypto/af_alg.c +++ b/crypto/af_alg.c @@ -1071,7 +1071,7 @@ __poll_t af_alg_poll(struct file *file, struct socket *sock, struct af_alg_ctx *ctx = ask->private; __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; if (!ctx->more || ctx->used) diff --git a/include/net/sock.h b/include/net/sock.h index 83b747538bd0d..0518f61926ecb 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2057,16 +2057,17 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq) /** * sock_poll_wait - place memory barrier behind the poll_wait call. * @filp: file - * @wait_address: socket wait queue * @p: poll_table * * See the comments in the wq_has_sleeper function. */ -static inline void sock_poll_wait(struct file *filp, - wait_queue_head_t *wait_address, poll_table *p) +static inline void sock_poll_wait(struct file *filp, poll_table *p) { - if (!poll_does_not_wait(p) && wait_address) { - poll_wait(filp, wait_address, p); + struct socket *sock = filp->private_data; + wait_queue_head_t *wq = sk_sleep(sock->sk); + + if (!poll_does_not_wait(p) && wq) { + poll_wait(filp, wq, p); /* We need to be sure we are in sync with the * socket flags modification. * diff --git a/net/atm/common.c b/net/atm/common.c index a7a68e5096288..9f8cb0d2e71ef 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -653,7 +653,7 @@ __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait) struct atm_vcc *vcc; __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; vcc = ATM_SD(sock); diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index a6fb1b3bcad9b..d18965f3291f3 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -941,7 +941,7 @@ static __poll_t caif_poll(struct file *file, __poll_t mask; struct caifsock *cf_sk = container_of(sk, struct caifsock, sk); - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; /* exceptional events? */ diff --git a/net/core/datagram.c b/net/core/datagram.c index 9938952c5c78f..9aac0d63d53eb 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -837,7 +837,7 @@ __poll_t datagram_poll(struct file *file, struct socket *sock, struct sock *sk = sock->sk; __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; /* exceptional events? */ diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 0d56e36a6db7b..875858c8b0592 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -325,7 +325,7 @@ __poll_t dccp_poll(struct file *file, struct socket *sock, __poll_t mask; struct sock *sk = sock->sk; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); if (sk->sk_state == DCCP_LISTEN) return inet_csk_listen_poll(sk); diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 514aaac1626fc..f3bfb9f295209 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -507,7 +507,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait) const struct tcp_sock *tp = tcp_sk(sk); int state; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); state = inet_sk_state_load(sk); if (state == TCP_LISTEN) diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index 8d1c43f8fed41..92ee91e343959 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -1494,7 +1494,7 @@ __poll_t iucv_sock_poll(struct file *file, struct socket *sock, struct sock *sk = sock->sk; __poll_t mask = 0; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); if (sk->sk_state == IUCV_LISTEN) return iucv_accept_poll(sk); diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index ea0c0c6f18742..dd4adf8b1167e 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -556,7 +556,7 @@ static __poll_t llcp_sock_poll(struct file *file, struct socket *sock, pr_debug("%p\n", sk); - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); if (sk->sk_state == LLCP_LISTEN) return llcp_accept_poll(sk); diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 2b463047dd7ba..ac44d8afffb11 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -741,7 +741,7 @@ static __poll_t rxrpc_poll(struct file *file, struct socket *sock, struct rxrpc_sock *rx = rxrpc_sk(sk); __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; /* the socket is readable if there are any messages waiting on the Rx diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index fce7e47511516..0fc94f296e541 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1535,7 +1535,7 @@ static __poll_t smc_poll(struct file *file, struct socket *sock, mask |= EPOLLERR; } else { if (sk->sk_state != SMC_CLOSED) - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); if (sk->sk_err) mask |= EPOLLERR; if ((sk->sk_shutdown == SHUTDOWN_MASK) || diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 3d21414ba357d..3763bedecf5fd 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -716,7 +716,7 @@ static __poll_t tipc_poll(struct file *file, struct socket *sock, struct tipc_sock *tsk = tipc_sk(sk); __poll_t revents = 0; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); if (sk->sk_shutdown & RCV_SHUTDOWN) revents |= EPOLLRDHUP | EPOLLIN | EPOLLRDNORM; diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index e5473c03d667a..1772a0e326654 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2635,7 +2635,7 @@ static __poll_t unix_poll(struct file *file, struct socket *sock, poll_table *wa struct sock *sk = sock->sk; __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; /* exceptional events? */ @@ -2672,7 +2672,7 @@ static __poll_t unix_dgram_poll(struct file *file, struct socket *sock, unsigned int writable; __poll_t mask; - sock_poll_wait(file, sk_sleep(sk), wait); + sock_poll_wait(file, wait); mask = 0; /* exceptional events? */ From d8bbd13beeaacd6494954bf5b945b54ccb2af309 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 30 Jul 2018 09:42:11 +0200 Subject: [PATCH 2/4] net: don not detour through struct sock to find the poll waitqueue For any open socket file descriptor sock->sk->sk_wq->wait will always point to sock->wq->wait. That means we can do the shorter dereference and removal a NULL check and don't have to not worry about any RCU protection. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller --- include/net/sock.h | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 0518f61926ecb..2afea5d1bdfe9 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -2064,10 +2064,9 @@ static inline bool skwq_has_sleeper(struct socket_wq *wq) static inline void sock_poll_wait(struct file *filp, poll_table *p) { struct socket *sock = filp->private_data; - wait_queue_head_t *wq = sk_sleep(sock->sk); - if (!poll_does_not_wait(p) && wq) { - poll_wait(filp, wq, p); + if (!poll_does_not_wait(p)) { + poll_wait(filp, &sock->wq->wait, p); /* We need to be sure we are in sync with the * socket flags modification. * From f641f13b992979b97e595b761a9ba1a64fed7c4e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 30 Jul 2018 09:42:12 +0200 Subject: [PATCH 3/4] net: remove sock_poll_busy_loop There is no point in hiding this logic in a helper. Also remove the useless events != 0 check and only busy loop once we know we actually have a poll method. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller --- include/net/busy_poll.h | 9 --------- net/socket.c | 5 ++++- 2 files changed, 4 insertions(+), 10 deletions(-) diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h index 9e36fda652b7e..85777e68f738a 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -121,15 +121,6 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock) #endif } -static inline void sock_poll_busy_loop(struct socket *sock, __poll_t events) -{ - if (sk_can_busy_loop(sock->sk) && - events && (events & POLL_BUSY_LOOP)) { - /* once, only if requested by syscall */ - sk_busy_loop(sock->sk, 1); - } -} - /* if this socket can poll_ll, tell the system call */ static inline __poll_t sock_poll_busy_flag(struct socket *sock) { diff --git a/net/socket.c b/net/socket.c index 85633622c94d0..674434127b3ad 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1132,9 +1132,12 @@ static __poll_t sock_poll(struct file *file, poll_table *wait) struct socket *sock = file->private_data; __poll_t events = poll_requested_events(wait); - sock_poll_busy_loop(sock, events); if (!sock->ops->poll) return 0; + + /* poll once if requested by the syscall */ + if (sk_can_busy_loop(sock->sk) && (events & POLL_BUSY_LOOP)) + sk_busy_loop(sock->sk, 1); return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock); } From a331de3bf0e66ab2437fc8c5b99bd3c0d9da3088 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 30 Jul 2018 09:42:13 +0200 Subject: [PATCH 4/4] net: remove sock_poll_busy_flag Fold it into the only caller to make the code simpler and easier to read. Signed-off-by: Christoph Hellwig Signed-off-by: David S. Miller --- include/net/busy_poll.h | 6 ------ net/socket.c | 16 +++++++++++----- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h index 85777e68f738a..ba61cdd09eaa8 100644 --- a/include/net/busy_poll.h +++ b/include/net/busy_poll.h @@ -121,12 +121,6 @@ static inline void sk_busy_loop(struct sock *sk, int nonblock) #endif } -/* if this socket can poll_ll, tell the system call */ -static inline __poll_t sock_poll_busy_flag(struct socket *sock) -{ - return sk_can_busy_loop(sock->sk) ? POLL_BUSY_LOOP : 0; -} - /* used in the NIC receive handler to mark the skb */ static inline void skb_mark_napi_id(struct sk_buff *skb, struct napi_struct *napi) diff --git a/net/socket.c b/net/socket.c index 674434127b3ad..5b7df6695f4f1 100644 --- a/net/socket.c +++ b/net/socket.c @@ -1130,15 +1130,21 @@ EXPORT_SYMBOL(sock_create_lite); static __poll_t sock_poll(struct file *file, poll_table *wait) { struct socket *sock = file->private_data; - __poll_t events = poll_requested_events(wait); + __poll_t events = poll_requested_events(wait), flag = 0; if (!sock->ops->poll) return 0; - /* poll once if requested by the syscall */ - if (sk_can_busy_loop(sock->sk) && (events & POLL_BUSY_LOOP)) - sk_busy_loop(sock->sk, 1); - return sock->ops->poll(file, sock, wait) | sock_poll_busy_flag(sock); + if (sk_can_busy_loop(sock->sk)) { + /* poll once if requested by the syscall */ + if (events & POLL_BUSY_LOOP) + sk_busy_loop(sock->sk, 1); + + /* if this socket can poll_ll, tell the system call */ + flag = POLL_BUSY_LOOP; + } + + return sock->ops->poll(file, sock, wait) | flag; } static int sock_mmap(struct file *file, struct vm_area_struct *vma)