From 1ce0bf50ae2233c7115a18c0c623662d177b434c Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 26 Nov 2015 13:55:39 +0800 Subject: [PATCH] net: Generalise wq_has_sleeper helper The memory barrier in the helper wq_has_sleeper is needed by just about every user of waitqueue_active. This patch generalises it by making it take a wait_queue_head_t directly. The existing helper is renamed to skwq_has_sleeper. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- crypto/algif_aead.c | 4 ++-- crypto/algif_skcipher.c | 4 ++-- include/linux/wait.h | 21 +++++++++++++++++++++ include/net/sock.h | 15 +++++---------- net/atm/common.c | 4 ++-- net/core/sock.c | 8 ++++---- net/core/stream.c | 2 +- net/dccp/output.c | 2 +- net/iucv/af_iucv.c | 2 +- net/rxrpc/af_rxrpc.c | 2 +- net/sctp/socket.c | 2 +- net/tipc/socket.c | 4 ++-- net/unix/af_unix.c | 2 +- 13 files changed, 44 insertions(+), 28 deletions(-) diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c index 0aa6fdfb448a..fb99f30849d2 100644 --- a/crypto/algif_aead.c +++ b/crypto/algif_aead.c @@ -106,7 +106,7 @@ static void aead_wmem_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLRDNORM | POLLRDBAND); @@ -157,7 +157,7 @@ static void aead_data_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | POLLRDNORM | POLLRDBAND); diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c index af31a0ee4057..0e6702e41472 100644 --- a/crypto/algif_skcipher.c +++ b/crypto/algif_skcipher.c @@ -238,7 +238,7 @@ static void skcipher_wmem_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLRDNORM | POLLRDBAND); @@ -288,7 +288,7 @@ static void skcipher_data_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | POLLRDNORM | POLLRDBAND); diff --git a/include/linux/wait.h b/include/linux/wait.h index 1e1bf9f963a9..6aa09a875fbd 100644 --- a/include/linux/wait.h +++ b/include/linux/wait.h @@ -107,6 +107,27 @@ static inline int waitqueue_active(wait_queue_head_t *q) return !list_empty(&q->task_list); } +/** + * wq_has_sleeper - check if there are any waiting processes + * @wq: wait queue head + * + * Returns true if wq has waiting processes + * + * Please refer to the comment for waitqueue_active. + */ +static inline bool wq_has_sleeper(wait_queue_head_t *wq) +{ + /* + * We need to be sure we are in sync with the + * add_wait_queue modifications to the wait queue. + * + * This memory barrier should be paired with one on the + * waiting side. + */ + smp_mb(); + return waitqueue_active(wq); +} + extern void add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); extern void add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t *wait); extern void remove_wait_queue(wait_queue_head_t *q, wait_queue_t *wait); diff --git a/include/net/sock.h b/include/net/sock.h index 7f89e4ba18d1..62d35afcb3ac 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -58,6 +58,7 @@ #include #include #include +#include #include #include @@ -1879,12 +1880,12 @@ static inline bool sk_has_allocations(const struct sock *sk) } /** - * wq_has_sleeper - check if there are any waiting processes + * skwq_has_sleeper - check if there are any waiting processes * @wq: struct socket_wq * * Returns true if socket_wq has waiting processes * - * The purpose of the wq_has_sleeper and sock_poll_wait is to wrap the memory + * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory * barrier call. They were added due to the race found within the tcp code. * * Consider following tcp code paths: @@ -1910,15 +1911,9 @@ static inline bool sk_has_allocations(const struct sock *sk) * data on the socket. * */ -static inline bool wq_has_sleeper(struct socket_wq *wq) +static inline bool skwq_has_sleeper(struct socket_wq *wq) { - /* We need to be sure we are in sync with the - * add_wait_queue modifications to the wait queue. - * - * This memory barrier is paired in the sock_poll_wait. - */ - smp_mb(); - return wq && waitqueue_active(&wq->wait); + return wq && wq_has_sleeper(&wq->wait); } /** diff --git a/net/atm/common.c b/net/atm/common.c index 49a872db7e42..6dc12305799e 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -96,7 +96,7 @@ static void vcc_def_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up(&wq->wait); rcu_read_unlock(); } @@ -117,7 +117,7 @@ static void vcc_write_space(struct sock *sk) if (vcc_writable(sk)) { wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible(&wq->wait); sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); diff --git a/net/core/sock.c b/net/core/sock.c index 1e4dd54bfb5a..2769bd3a4d7c 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2283,7 +2283,7 @@ static void sock_def_wakeup(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_all(&wq->wait); rcu_read_unlock(); } @@ -2294,7 +2294,7 @@ static void sock_def_error_report(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_poll(&wq->wait, POLLERR); sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR); rcu_read_unlock(); @@ -2306,7 +2306,7 @@ static void sock_def_readable(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND); sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); @@ -2324,7 +2324,7 @@ static void sock_def_write_space(struct sock *sk) */ if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) { wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | POLLWRNORM | POLLWRBAND); diff --git a/net/core/stream.c b/net/core/stream.c index d70f77a0c889..8ff9d63b4265 100644 --- a/net/core/stream.c +++ b/net/core/stream.c @@ -35,7 +35,7 @@ void sk_stream_write_space(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_poll(&wq->wait, POLLOUT | POLLWRNORM | POLLWRBAND); if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN)) diff --git a/net/dccp/output.c b/net/dccp/output.c index 4ce912e691d0..b66c84db0766 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -201,7 +201,7 @@ void dccp_write_space(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible(&wq->wait); /* Should agree with poll, otherwise some programs break */ if (sock_writeable(sk)) diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c index fcb2752419c6..4f0aa91470c6 100644 --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -303,7 +303,7 @@ static void iucv_sock_wake_msglim(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_all(&wq->wait); sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); rcu_read_unlock(); diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c index 1f8a144a5dc2..7e2d1057d8bc 100644 --- a/net/rxrpc/af_rxrpc.c +++ b/net/rxrpc/af_rxrpc.c @@ -67,7 +67,7 @@ static void rxrpc_write_space(struct sock *sk) if (rxrpc_writable(sk)) { struct socket_wq *wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible(&wq->wait); sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); } diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 897c01c029ca..ec10b66354b8 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -6978,7 +6978,7 @@ void sctp_data_ready(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLRDNORM | POLLRDBAND); sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 552dbaba9cf3..525acf6dd1c6 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1492,7 +1492,7 @@ static void tipc_write_space(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | POLLWRNORM | POLLWRBAND); rcu_read_unlock(); @@ -1509,7 +1509,7 @@ static void tipc_data_ready(struct sock *sk) rcu_read_lock(); wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLRDNORM | POLLRDBAND); rcu_read_unlock(); diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 955ec152cb71..efb706e1d1c0 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -339,7 +339,7 @@ static void unix_write_space(struct sock *sk) rcu_read_lock(); if (unix_writable(sk)) { wq = rcu_dereference(sk->sk_wq); - if (wq_has_sleeper(wq)) + if (skwq_has_sleeper(wq)) wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | POLLWRNORM | POLLWRBAND); sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); -- 2.30.2