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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 <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2015-11-26 13:55:39 +08:00 committed by David S. Miller
parent c52fd05a2f
commit 1ce0bf50ae
13 changed files with 44 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
crypto/algif_aead.c
View File

@ -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);

4
crypto/algif_skcipher.c
View File

@ -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);

21
include/linux/wait.h
View File

@ -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);

15
include/net/sock.h
View File

@ -58,6 +58,7 @@
#include <linux/memcontrol.h>
#include <linux/static_key.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/filter.h>
#include <linux/rculist_nulls.h>
@ -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);
}
/**

4
net/atm/common.c
View File

@ -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);

8
net/core/sock.c
View File

@ -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);

2
net/core/stream.c
View File

@ -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))

2
net/dccp/output.c
View File

@ -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))

2
net/iucv/af_iucv.c
View File

@ -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();

2
net/rxrpc/af_rxrpc.c
View File

@ -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);
}

2
net/sctp/socket.c
View File

@ -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);

4
net/tipc/socket.c
View File

@ -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();

2
net/unix/af_unix.c
View File

@ -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);