net: sock_def_readable() and friends RCU conversion
sk_callback_lock rwlock actually protects sk->sk_sleep pointer, so we
need two atomic operations (and associated dirtying) per incoming
packet.
RCU conversion is pretty much needed :
1) Add a new structure, called "struct socket_wq" to hold all fields
that will need rcu_read_lock() protection (currently: a
wait_queue_head_t and a struct fasync_struct pointer).
[Future patch will add a list anchor for wakeup coalescing]
2) Attach one of such structure to each "struct socket" created in
sock_alloc_inode().
3) Respect RCU grace period when freeing a "struct socket_wq"
4) Change sk_sleep pointer in "struct sock" by sk_wq, pointer to "struct
socket_wq"
5) Change sk_sleep() function to use new sk->sk_wq instead of
sk->sk_sleep
6) Change sk_has_sleeper() to wq_has_sleeper() that must be used inside
a rcu_read_lock() section.
7) Change all sk_has_sleeper() callers to :
- Use rcu_read_lock() instead of read_lock(&sk->sk_callback_lock)
- Use wq_has_sleeper() to eventually wakeup tasks.
- Use rcu_read_unlock() instead of read_unlock(&sk->sk_callback_lock)
8) sock_wake_async() is modified to use rcu protection as well.
9) Exceptions :
macvtap, drivers/net/tun.c, af_unix use integrated "struct socket_wq"
instead of dynamically allocated ones. They dont need rcu freeing.
Some cleanups or followups are probably needed, (possible
sk_callback_lock conversion to a spinlock for example...).
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index d97e1fd..1c4110d 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -37,6 +37,7 @@
struct macvtap_queue {
struct sock sk;
struct socket sock;
+ struct socket_wq wq;
struct macvlan_dev *vlan;
struct file *file;
unsigned int flags;
@@ -242,12 +243,15 @@
static void macvtap_sock_write_space(struct sock *sk)
{
+ wait_queue_head_t *wqueue;
+
if (!sock_writeable(sk) ||
!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
return;
- if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
- wake_up_interruptible_poll(sk_sleep(sk), POLLOUT | POLLWRNORM | POLLWRBAND);
+ wqueue = sk_sleep(sk);
+ if (wqueue && waitqueue_active(wqueue))
+ wake_up_interruptible_poll(wqueue, POLLOUT | POLLWRNORM | POLLWRBAND);
}
static int macvtap_open(struct inode *inode, struct file *file)
@@ -272,7 +276,8 @@
if (!q)
goto out;
- init_waitqueue_head(&q->sock.wait);
+ q->sock.wq = &q->wq;
+ init_waitqueue_head(&q->wq.wait);
q->sock.type = SOCK_RAW;
q->sock.state = SS_CONNECTED;
q->sock.file = file;
@@ -308,7 +313,7 @@
goto out;
mask = 0;
- poll_wait(file, &q->sock.wait, wait);
+ poll_wait(file, &q->wq.wait, wait);
if (!skb_queue_empty(&q->sk.sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 20a1793..e525a6c 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -109,7 +109,7 @@
struct tap_filter txflt;
struct socket socket;
-
+ struct socket_wq wq;
#ifdef TUN_DEBUG
int debug;
#endif
@@ -323,7 +323,7 @@
/* Inform the methods they need to stop using the dev.
*/
if (tfile) {
- wake_up_all(&tun->socket.wait);
+ wake_up_all(&tun->wq.wait);
if (atomic_dec_and_test(&tfile->count))
__tun_detach(tun);
}
@@ -398,7 +398,7 @@
/* Notify and wake up reader process */
if (tun->flags & TUN_FASYNC)
kill_fasync(&tun->fasync, SIGIO, POLL_IN);
- wake_up_interruptible_poll(&tun->socket.wait, POLLIN |
+ wake_up_interruptible_poll(&tun->wq.wait, POLLIN |
POLLRDNORM | POLLRDBAND);
return NETDEV_TX_OK;
@@ -498,7 +498,7 @@
DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
- poll_wait(file, &tun->socket.wait, wait);
+ poll_wait(file, &tun->wq.wait, wait);
if (!skb_queue_empty(&sk->sk_receive_queue))
mask |= POLLIN | POLLRDNORM;
@@ -773,7 +773,7 @@
DBG(KERN_INFO "%s: tun_chr_read\n", tun->dev->name);
- add_wait_queue(&tun->socket.wait, &wait);
+ add_wait_queue(&tun->wq.wait, &wait);
while (len) {
current->state = TASK_INTERRUPTIBLE;
@@ -804,7 +804,7 @@
}
current->state = TASK_RUNNING;
- remove_wait_queue(&tun->socket.wait, &wait);
+ remove_wait_queue(&tun->wq.wait, &wait);
return ret;
}
@@ -861,6 +861,7 @@
static void tun_sock_write_space(struct sock *sk)
{
struct tun_struct *tun;
+ wait_queue_head_t *wqueue;
if (!sock_writeable(sk))
return;
@@ -868,8 +869,9 @@
if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
return;
- if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
- wake_up_interruptible_sync_poll(sk_sleep(sk), POLLOUT |
+ wqueue = sk_sleep(sk);
+ if (wqueue && waitqueue_active(wqueue))
+ wake_up_interruptible_sync_poll(wqueue, POLLOUT |
POLLWRNORM | POLLWRBAND);
tun = tun_sk(sk)->tun;
@@ -1039,7 +1041,8 @@
if (!sk)
goto err_free_dev;
- init_waitqueue_head(&tun->socket.wait);
+ tun->socket.wq = &tun->wq;
+ init_waitqueue_head(&tun->wq.wait);
tun->socket.ops = &tun_socket_ops;
sock_init_data(&tun->socket, sk);
sk->sk_write_space = tun_sock_write_space;
diff --git a/include/linux/net.h b/include/linux/net.h
index 4157b5d..2b4deee 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -59,6 +59,7 @@
#include <linux/wait.h>
#include <linux/fcntl.h> /* For O_CLOEXEC and O_NONBLOCK */
#include <linux/kmemcheck.h>
+#include <linux/rcupdate.h>
struct poll_table_struct;
struct pipe_inode_info;
@@ -116,6 +117,12 @@
SHUT_RDWR = 2,
};
+struct socket_wq {
+ wait_queue_head_t wait;
+ struct fasync_struct *fasync_list;
+ struct rcu_head rcu;
+} ____cacheline_aligned_in_smp;
+
/**
* struct socket - general BSD socket
* @state: socket state (%SS_CONNECTED, etc)
@@ -135,11 +142,8 @@
kmemcheck_bitfield_end(type);
unsigned long flags;
- /*
- * Please keep fasync_list & wait fields in the same cache line
- */
- struct fasync_struct *fasync_list;
- wait_queue_head_t wait;
+
+ struct socket_wq *wq;
struct file *file;
struct sock *sk;
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 1614d78..20725e2 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -30,7 +30,7 @@
#endif
};
-#define UNIXCB(skb) (*(struct unix_skb_parms*)&((skb)->cb))
+#define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb))
#define UNIXCREDS(skb) (&UNIXCB((skb)).creds)
#define UNIXSID(skb) (&UNIXCB((skb)).secid)
@@ -45,21 +45,23 @@
struct unix_sock {
/* WARNING: sk has to be the first member */
struct sock sk;
- struct unix_address *addr;
- struct dentry *dentry;
- struct vfsmount *mnt;
+ struct unix_address *addr;
+ struct dentry *dentry;
+ struct vfsmount *mnt;
struct mutex readlock;
- struct sock *peer;
- struct sock *other;
+ struct sock *peer;
+ struct sock *other;
struct list_head link;
- atomic_long_t inflight;
- spinlock_t lock;
+ atomic_long_t inflight;
+ spinlock_t lock;
unsigned int gc_candidate : 1;
unsigned int gc_maybe_cycle : 1;
- wait_queue_head_t peer_wait;
+ struct socket_wq peer_wq;
};
#define unix_sk(__sk) ((struct unix_sock *)__sk)
+#define peer_wait peer_wq.wait
+
#ifdef CONFIG_SYSCTL
extern int unix_sysctl_register(struct net *net);
extern void unix_sysctl_unregister(struct net *net);
diff --git a/include/net/sock.h b/include/net/sock.h
index e1777db..cc7f91e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -159,7 +159,7 @@
* @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
* @sk_lock: synchronizer
* @sk_rcvbuf: size of receive buffer in bytes
- * @sk_sleep: sock wait queue
+ * @sk_wq: sock wait queue and async head
* @sk_dst_cache: destination cache
* @sk_dst_lock: destination cache lock
* @sk_policy: flow policy
@@ -257,7 +257,7 @@
struct sk_buff *tail;
int len;
} sk_backlog;
- wait_queue_head_t *sk_sleep;
+ struct socket_wq *sk_wq;
struct dst_entry *sk_dst_cache;
#ifdef CONFIG_XFRM
struct xfrm_policy *sk_policy[2];
@@ -1219,7 +1219,7 @@
static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
- return sk->sk_sleep;
+ return &sk->sk_wq->wait;
}
/* Detach socket from process context.
* Announce socket dead, detach it from wait queue and inode.
@@ -1233,14 +1233,14 @@
write_lock_bh(&sk->sk_callback_lock);
sock_set_flag(sk, SOCK_DEAD);
sk_set_socket(sk, NULL);
- sk->sk_sleep = NULL;
+ sk->sk_wq = NULL;
write_unlock_bh(&sk->sk_callback_lock);
}
static inline void sock_graft(struct sock *sk, struct socket *parent)
{
write_lock_bh(&sk->sk_callback_lock);
- sk->sk_sleep = &parent->wait;
+ rcu_assign_pointer(sk->sk_wq, parent->wq);
parent->sk = sk;
sk_set_socket(sk, parent);
security_sock_graft(sk, parent);
@@ -1392,12 +1392,12 @@
}
/**
- * sk_has_sleeper - check if there are any waiting processes
- * @sk: socket
+ * wq_has_sleeper - check if there are any waiting processes
+ * @sk: struct socket_wq
*
- * Returns true if socket has waiting processes
+ * Returns true if socket_wq has waiting processes
*
- * The purpose of the sk_has_sleeper and sock_poll_wait is to wrap the memory
+ * The purpose of the wq_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:
@@ -1410,9 +1410,10 @@
* ... ...
* tp->rcv_nxt check sock_def_readable
* ... {
- * schedule ...
- * if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
- * wake_up_interruptible(sk_sleep(sk))
+ * schedule rcu_read_lock();
+ * wq = rcu_dereference(sk->sk_wq);
+ * if (wq && waitqueue_active(&wq->wait))
+ * wake_up_interruptible(&wq->wait)
* ...
* }
*
@@ -1421,19 +1422,18 @@
* could then endup calling schedule and sleep forever if there are no more
* data on the socket.
*
- * The sk_has_sleeper is always called right after a call to read_lock, so we
- * can use smp_mb__after_lock barrier.
*/
-static inline int sk_has_sleeper(struct sock *sk)
+static inline bool wq_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__after_lock();
- return sk_sleep(sk) && waitqueue_active(sk_sleep(sk));
+ smp_mb();
+ return wq && waitqueue_active(&wq->wait);
}
/**
@@ -1442,7 +1442,7 @@
* @wait_address: socket wait queue
* @p: poll_table
*
- * See the comments in the sk_has_sleeper function.
+ * 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)
@@ -1453,7 +1453,7 @@
* We need to be sure we are in sync with the
* socket flags modification.
*
- * This memory barrier is paired in the sk_has_sleeper.
+ * This memory barrier is paired in the wq_has_sleeper.
*/
smp_mb();
}
diff --git a/net/atm/common.c b/net/atm/common.c
index e3e10e6..b43feb1 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -90,10 +90,13 @@
static void vcc_def_wakeup(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
- if (sk_has_sleeper(sk))
- wake_up(sk_sleep(sk));
- read_unlock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up(&wq->wait);
+ rcu_read_unlock();
}
static inline int vcc_writable(struct sock *sk)
@@ -106,16 +109,19 @@
static void vcc_write_space(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
if (vcc_writable(sk)) {
- if (sk_has_sleeper(sk))
- wake_up_interruptible(sk_sleep(sk));
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible(&wq->wait);
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
static struct proto vcc_proto = {
diff --git a/net/core/sock.c b/net/core/sock.c
index 5104175..94c4aff 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1211,7 +1211,7 @@
*/
sk_refcnt_debug_inc(newsk);
sk_set_socket(newsk, NULL);
- newsk->sk_sleep = NULL;
+ newsk->sk_wq = NULL;
if (newsk->sk_prot->sockets_allocated)
percpu_counter_inc(newsk->sk_prot->sockets_allocated);
@@ -1800,41 +1800,53 @@
static void sock_def_wakeup(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
- if (sk_has_sleeper(sk))
- wake_up_interruptible_all(sk_sleep(sk));
- read_unlock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_all(&wq->wait);
+ rcu_read_unlock();
}
static void sock_def_error_report(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
- if (sk_has_sleeper(sk))
- wake_up_interruptible_poll(sk_sleep(sk), POLLERR);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_poll(&wq->wait, POLLERR);
sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
static void sock_def_readable(struct sock *sk, int len)
{
- read_lock(&sk->sk_callback_lock);
- if (sk_has_sleeper(sk))
- wake_up_interruptible_sync_poll(sk_sleep(sk), POLLIN |
+ struct socket_wq *wq;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLIN |
POLLRDNORM | POLLRDBAND);
sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
static void sock_def_write_space(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
/* Do not wake up a writer until he can make "significant"
* progress. --DaveM
*/
if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
- if (sk_has_sleeper(sk))
- wake_up_interruptible_sync_poll(sk_sleep(sk), POLLOUT |
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
POLLWRNORM | POLLWRBAND);
/* Should agree with poll, otherwise some programs break */
@@ -1842,7 +1854,7 @@
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
static void sock_def_destruct(struct sock *sk)
@@ -1896,10 +1908,10 @@
if (sock) {
sk->sk_type = sock->type;
- sk->sk_sleep = &sock->wait;
+ sk->sk_wq = sock->wq;
sock->sk = sk;
} else
- sk->sk_sleep = NULL;
+ sk->sk_wq = NULL;
spin_lock_init(&sk->sk_dst_lock);
rwlock_init(&sk->sk_callback_lock);
diff --git a/net/core/stream.c b/net/core/stream.c
index 7b3c3f3..cc196f4 100644
--- a/net/core/stream.c
+++ b/net/core/stream.c
@@ -28,15 +28,19 @@
void sk_stream_write_space(struct sock *sk)
{
struct socket *sock = sk->sk_socket;
+ struct socket_wq *wq;
if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) && sock) {
clear_bit(SOCK_NOSPACE, &sock->flags);
- if (sk_sleep(sk) && waitqueue_active(sk_sleep(sk)))
- wake_up_interruptible_poll(sk_sleep(sk), POLLOUT |
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_poll(&wq->wait, POLLOUT |
POLLWRNORM | POLLWRBAND);
- if (sock->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
+ if (wq && wq->fasync_list && !(sk->sk_shutdown & SEND_SHUTDOWN))
sock_wake_async(sock, SOCK_WAKE_SPACE, POLL_OUT);
+ rcu_read_unlock();
}
}
diff --git a/net/dccp/output.c b/net/dccp/output.c
index 2d3dcb3..aadbdb5 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -195,15 +195,17 @@
void dccp_write_space(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
- if (sk_has_sleeper(sk))
- wake_up_interruptible(sk_sleep(sk));
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible(&wq->wait);
/* Should agree with poll, otherwise some programs break */
if (sock_writeable(sk))
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
/**
diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c
index 9636b7d..8be324f 100644
--- a/net/iucv/af_iucv.c
+++ b/net/iucv/af_iucv.c
@@ -305,11 +305,14 @@
*/
static void iucv_sock_wake_msglim(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
- if (sk_has_sleeper(sk))
- wake_up_interruptible_all(sk_sleep(sk));
+ struct socket_wq *wq;
+
+ rcu_read_lock();
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_all(&wq->wait);
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
/* Timers */
diff --git a/net/phonet/pep.c b/net/phonet/pep.c
index e2a9576..af4d38b 100644
--- a/net/phonet/pep.c
+++ b/net/phonet/pep.c
@@ -664,12 +664,12 @@
if (signal_pending(tsk))
return sock_intr_errno(timeo);
- prepare_to_wait_exclusive(&sk->sk_socket->wait, &wait,
+ prepare_to_wait_exclusive(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
- finish_wait(&sk->sk_socket->wait, &wait);
+ finish_wait(sk_sleep(sk), &wait);
}
return 0;
@@ -910,10 +910,10 @@
goto out;
}
- prepare_to_wait(&sk->sk_socket->wait, &wait,
+ prepare_to_wait(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
done = sk_wait_event(sk, &timeo, atomic_read(&pn->tx_credits));
- finish_wait(&sk->sk_socket->wait, &wait);
+ finish_wait(sk_sleep(sk), &wait);
if (sk->sk_state != TCP_ESTABLISHED)
goto disabled;
diff --git a/net/phonet/socket.c b/net/phonet/socket.c
index c785bfd..6e9848bf 100644
--- a/net/phonet/socket.c
+++ b/net/phonet/socket.c
@@ -265,7 +265,7 @@
struct pep_sock *pn = pep_sk(sk);
unsigned int mask = 0;
- poll_wait(file, &sock->wait, wait);
+ poll_wait(file, sk_sleep(sk), wait);
switch (sk->sk_state) {
case TCP_LISTEN:
diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index c432d76..0b9bb20 100644
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -62,13 +62,15 @@
static void rxrpc_write_space(struct sock *sk)
{
_enter("%p", sk);
- read_lock(&sk->sk_callback_lock);
+ rcu_read_lock();
if (rxrpc_writable(sk)) {
- if (sk_has_sleeper(sk))
- wake_up_interruptible(sk_sleep(sk));
+ struct socket_wq *wq = rcu_dereference(sk->sk_wq);
+
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible(&wq->wait);
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
/*
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 13d8229..d54700a 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -6065,7 +6065,7 @@
* here by modeling from the current TCP/UDP code.
* We have not tested with it yet.
*/
- if (sock->fasync_list &&
+ if (sock->wq->fasync_list &&
!(sk->sk_shutdown & SEND_SHUTDOWN))
sock_wake_async(sock,
SOCK_WAKE_SPACE, POLL_OUT);
diff --git a/net/socket.c b/net/socket.c
index cb7c1f6..dae8c6b 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -252,9 +252,14 @@
ei = kmem_cache_alloc(sock_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
- init_waitqueue_head(&ei->socket.wait);
+ ei->socket.wq = kmalloc(sizeof(struct socket_wq), GFP_KERNEL);
+ if (!ei->socket.wq) {
+ kmem_cache_free(sock_inode_cachep, ei);
+ return NULL;
+ }
+ init_waitqueue_head(&ei->socket.wq->wait);
+ ei->socket.wq->fasync_list = NULL;
- ei->socket.fasync_list = NULL;
ei->socket.state = SS_UNCONNECTED;
ei->socket.flags = 0;
ei->socket.ops = NULL;
@@ -264,10 +269,21 @@
return &ei->vfs_inode;
}
+
+static void wq_free_rcu(struct rcu_head *head)
+{
+ struct socket_wq *wq = container_of(head, struct socket_wq, rcu);
+
+ kfree(wq);
+}
+
static void sock_destroy_inode(struct inode *inode)
{
- kmem_cache_free(sock_inode_cachep,
- container_of(inode, struct socket_alloc, vfs_inode));
+ struct socket_alloc *ei;
+
+ ei = container_of(inode, struct socket_alloc, vfs_inode);
+ call_rcu(&ei->socket.wq->rcu, wq_free_rcu);
+ kmem_cache_free(sock_inode_cachep, ei);
}
static void init_once(void *foo)
@@ -513,7 +529,7 @@
module_put(owner);
}
- if (sock->fasync_list)
+ if (sock->wq->fasync_list)
printk(KERN_ERR "sock_release: fasync list not empty!\n");
percpu_sub(sockets_in_use, 1);
@@ -1080,9 +1096,9 @@
lock_sock(sk);
- fasync_helper(fd, filp, on, &sock->fasync_list);
+ fasync_helper(fd, filp, on, &sock->wq->fasync_list);
- if (!sock->fasync_list)
+ if (!sock->wq->fasync_list)
sock_reset_flag(sk, SOCK_FASYNC);
else
sock_set_flag(sk, SOCK_FASYNC);
@@ -1091,12 +1107,20 @@
return 0;
}
-/* This function may be called only under socket lock or callback_lock */
+/* This function may be called only under socket lock or callback_lock or rcu_lock */
int sock_wake_async(struct socket *sock, int how, int band)
{
- if (!sock || !sock->fasync_list)
+ struct socket_wq *wq;
+
+ if (!sock)
return -1;
+ rcu_read_lock();
+ wq = rcu_dereference(sock->wq);
+ if (!wq || !wq->fasync_list) {
+ rcu_read_unlock();
+ return -1;
+ }
switch (how) {
case SOCK_WAKE_WAITD:
if (test_bit(SOCK_ASYNC_WAITDATA, &sock->flags))
@@ -1108,11 +1132,12 @@
/* fall through */
case SOCK_WAKE_IO:
call_kill:
- kill_fasync(&sock->fasync_list, SIGIO, band);
+ kill_fasync(&wq->fasync_list, SIGIO, band);
break;
case SOCK_WAKE_URG:
- kill_fasync(&sock->fasync_list, SIGURG, band);
+ kill_fasync(&wq->fasync_list, SIGURG, band);
}
+ rcu_read_unlock();
return 0;
}
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 87c0360..fef2cc5 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -313,13 +313,16 @@
static void unix_write_space(struct sock *sk)
{
- read_lock(&sk->sk_callback_lock);
+ struct socket_wq *wq;
+
+ rcu_read_lock();
if (unix_writable(sk)) {
- if (sk_has_sleeper(sk))
- wake_up_interruptible_sync(sk_sleep(sk));
+ wq = rcu_dereference(sk->sk_wq);
+ if (wq_has_sleeper(wq))
+ wake_up_interruptible_sync(&wq->wait);
sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
}
- read_unlock(&sk->sk_callback_lock);
+ rcu_read_unlock();
}
/* When dgram socket disconnects (or changes its peer), we clear its receive
@@ -406,9 +409,7 @@
skpair->sk_err = ECONNRESET;
unix_state_unlock(skpair);
skpair->sk_state_change(skpair);
- read_lock(&skpair->sk_callback_lock);
sk_wake_async(skpair, SOCK_WAKE_WAITD, POLL_HUP);
- read_unlock(&skpair->sk_callback_lock);
}
sock_put(skpair); /* It may now die */
unix_peer(sk) = NULL;
@@ -1142,7 +1143,7 @@
newsk->sk_peercred.pid = task_tgid_vnr(current);
current_euid_egid(&newsk->sk_peercred.uid, &newsk->sk_peercred.gid);
newu = unix_sk(newsk);
- newsk->sk_sleep = &newu->peer_wait;
+ newsk->sk_wq = &newu->peer_wq;
otheru = unix_sk(other);
/* copy address information from listening to new sock*/
@@ -1931,12 +1932,10 @@
other->sk_shutdown |= peer_mode;
unix_state_unlock(other);
other->sk_state_change(other);
- read_lock(&other->sk_callback_lock);
if (peer_mode == SHUTDOWN_MASK)
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
else if (peer_mode & RCV_SHUTDOWN)
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
- read_unlock(&other->sk_callback_lock);
}
if (other)
sock_put(other);