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[AF_UNIX]: Make socket locking much less confusing.
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The unix_state_*() locking macros imply that there is some
rwlock kind of thing going on, but the implementation is
actually a spinlock which makes the code more confusing than
it needs to be.

So use plain unix_state_lock and unix_state_unlock.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Jun 4, 2007
1 parent c1a13ff commit 1c92b4e
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Showing 2 changed files with 50 additions and 52 deletions.
8 changes: 3 additions & 5 deletions include/net/af_unix.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,13 +62,11 @@ struct unix_skb_parms {
#define UNIXCREDS(skb) (&UNIXCB((skb)).creds)
#define UNIXSID(skb) (&UNIXCB((skb)).secid)

#define unix_state_rlock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_runlock(s) spin_unlock(&unix_sk(s)->lock)
#define unix_state_wlock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_wlock_nested(s) \
#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock)
#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock)
#define unix_state_lock_nested(s) \
spin_lock_nested(&unix_sk(s)->lock, \
SINGLE_DEPTH_NESTING)
#define unix_state_wunlock(s) spin_unlock(&unix_sk(s)->lock)

#ifdef __KERNEL__
/* The AF_UNIX socket */
Expand Down
94 changes: 47 additions & 47 deletions net/unix/af_unix.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -174,11 +174,11 @@ static struct sock *unix_peer_get(struct sock *s)
{
struct sock *peer;

unix_state_rlock(s);
unix_state_lock(s);
peer = unix_peer(s);
if (peer)
sock_hold(peer);
unix_state_runlock(s);
unix_state_unlock(s);
return peer;
}

Expand Down Expand Up @@ -369,7 +369,7 @@ static int unix_release_sock (struct sock *sk, int embrion)
unix_remove_socket(sk);

/* Clear state */
unix_state_wlock(sk);
unix_state_lock(sk);
sock_orphan(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
dentry = u->dentry;
Expand All @@ -378,20 +378,20 @@ static int unix_release_sock (struct sock *sk, int embrion)
u->mnt = NULL;
state = sk->sk_state;
sk->sk_state = TCP_CLOSE;
unix_state_wunlock(sk);
unix_state_unlock(sk);

wake_up_interruptible_all(&u->peer_wait);

skpair=unix_peer(sk);

if (skpair!=NULL) {
if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) {
unix_state_wlock(skpair);
unix_state_lock(skpair);
/* No more writes */
skpair->sk_shutdown = SHUTDOWN_MASK;
if (!skb_queue_empty(&sk->sk_receive_queue) || embrion)
skpair->sk_err = ECONNRESET;
unix_state_wunlock(skpair);
unix_state_unlock(skpair);
skpair->sk_state_change(skpair);
read_lock(&skpair->sk_callback_lock);
sk_wake_async(skpair,1,POLL_HUP);
Expand Down Expand Up @@ -448,7 +448,7 @@ static int unix_listen(struct socket *sock, int backlog)
err = -EINVAL;
if (!u->addr)
goto out; /* No listens on an unbound socket */
unix_state_wlock(sk);
unix_state_lock(sk);
if (sk->sk_state != TCP_CLOSE && sk->sk_state != TCP_LISTEN)
goto out_unlock;
if (backlog > sk->sk_max_ack_backlog)
Expand All @@ -462,7 +462,7 @@ static int unix_listen(struct socket *sock, int backlog)
err = 0;

out_unlock:
unix_state_wunlock(sk);
unix_state_unlock(sk);
out:
return err;
}
Expand Down Expand Up @@ -881,7 +881,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
if (!other)
goto out;

unix_state_wlock(sk);
unix_state_lock(sk);

err = -EPERM;
if (!unix_may_send(sk, other))
Expand All @@ -896,7 +896,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
* 1003.1g breaking connected state with AF_UNSPEC
*/
other = NULL;
unix_state_wlock(sk);
unix_state_lock(sk);
}

/*
Expand All @@ -905,19 +905,19 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
if (unix_peer(sk)) {
struct sock *old_peer = unix_peer(sk);
unix_peer(sk)=other;
unix_state_wunlock(sk);
unix_state_unlock(sk);

if (other != old_peer)
unix_dgram_disconnected(sk, old_peer);
sock_put(old_peer);
} else {
unix_peer(sk)=other;
unix_state_wunlock(sk);
unix_state_unlock(sk);
}
return 0;

out_unlock:
unix_state_wunlock(sk);
unix_state_unlock(sk);
sock_put(other);
out:
return err;
Expand All @@ -936,7 +936,7 @@ static long unix_wait_for_peer(struct sock *other, long timeo)
(skb_queue_len(&other->sk_receive_queue) >
other->sk_max_ack_backlog);

unix_state_runlock(other);
unix_state_unlock(other);

if (sched)
timeo = schedule_timeout(timeo);
Expand Down Expand Up @@ -994,11 +994,11 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
goto out;

/* Latch state of peer */
unix_state_rlock(other);
unix_state_lock(other);

/* Apparently VFS overslept socket death. Retry. */
if (sock_flag(other, SOCK_DEAD)) {
unix_state_runlock(other);
unix_state_unlock(other);
sock_put(other);
goto restart;
}
Expand Down Expand Up @@ -1048,18 +1048,18 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
goto out_unlock;
}

unix_state_wlock_nested(sk);
unix_state_lock_nested(sk);

if (sk->sk_state != st) {
unix_state_wunlock(sk);
unix_state_runlock(other);
unix_state_unlock(sk);
unix_state_unlock(other);
sock_put(other);
goto restart;
}

err = security_unix_stream_connect(sock, other->sk_socket, newsk);
if (err) {
unix_state_wunlock(sk);
unix_state_unlock(sk);
goto out_unlock;
}

Expand Down Expand Up @@ -1096,7 +1096,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
smp_mb__after_atomic_inc(); /* sock_hold() does an atomic_inc() */
unix_peer(sk) = newsk;

unix_state_wunlock(sk);
unix_state_unlock(sk);

/* take ten and and send info to listening sock */
spin_lock(&other->sk_receive_queue.lock);
Expand All @@ -1105,14 +1105,14 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
* is installed to listening socket. */
atomic_inc(&newu->inflight);
spin_unlock(&other->sk_receive_queue.lock);
unix_state_runlock(other);
unix_state_unlock(other);
other->sk_data_ready(other, 0);
sock_put(other);
return 0;

out_unlock:
if (other)
unix_state_runlock(other);
unix_state_unlock(other);

out:
if (skb)
Expand Down Expand Up @@ -1178,10 +1178,10 @@ static int unix_accept(struct socket *sock, struct socket *newsock, int flags)
wake_up_interruptible(&unix_sk(sk)->peer_wait);

/* attach accepted sock to socket */
unix_state_wlock(tsk);
unix_state_lock(tsk);
newsock->state = SS_CONNECTED;
sock_graft(tsk, newsock);
unix_state_wunlock(tsk);
unix_state_unlock(tsk);
return 0;

out:
Expand All @@ -1208,7 +1208,7 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_
}

u = unix_sk(sk);
unix_state_rlock(sk);
unix_state_lock(sk);
if (!u->addr) {
sunaddr->sun_family = AF_UNIX;
sunaddr->sun_path[0] = 0;
Expand All @@ -1219,7 +1219,7 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_
*uaddr_len = addr->len;
memcpy(sunaddr, addr->name, *uaddr_len);
}
unix_state_runlock(sk);
unix_state_unlock(sk);
sock_put(sk);
out:
return err;
Expand Down Expand Up @@ -1337,7 +1337,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
goto out_free;
}

unix_state_rlock(other);
unix_state_lock(other);
err = -EPERM;
if (!unix_may_send(sk, other))
goto out_unlock;
Expand All @@ -1347,20 +1347,20 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
* Check with 1003.1g - what should
* datagram error
*/
unix_state_runlock(other);
unix_state_unlock(other);
sock_put(other);

err = 0;
unix_state_wlock(sk);
unix_state_lock(sk);
if (unix_peer(sk) == other) {
unix_peer(sk)=NULL;
unix_state_wunlock(sk);
unix_state_unlock(sk);

unix_dgram_disconnected(sk, other);
sock_put(other);
err = -ECONNREFUSED;
} else {
unix_state_wunlock(sk);
unix_state_unlock(sk);
}

other = NULL;
Expand Down Expand Up @@ -1397,14 +1397,14 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
}

skb_queue_tail(&other->sk_receive_queue, skb);
unix_state_runlock(other);
unix_state_unlock(other);
other->sk_data_ready(other, len);
sock_put(other);
scm_destroy(siocb->scm);
return len;

out_unlock:
unix_state_runlock(other);
unix_state_unlock(other);
out_free:
kfree_skb(skb);
out:
Expand Down Expand Up @@ -1494,14 +1494,14 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
goto out_err;
}

unix_state_rlock(other);
unix_state_lock(other);

if (sock_flag(other, SOCK_DEAD) ||
(other->sk_shutdown & RCV_SHUTDOWN))
goto pipe_err_free;

skb_queue_tail(&other->sk_receive_queue, skb);
unix_state_runlock(other);
unix_state_unlock(other);
other->sk_data_ready(other, size);
sent+=size;
}
Expand All @@ -1512,7 +1512,7 @@ static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
return sent;

pipe_err_free:
unix_state_runlock(other);
unix_state_unlock(other);
kfree_skb(skb);
pipe_err:
if (sent==0 && !(msg->msg_flags&MSG_NOSIGNAL))
Expand Down Expand Up @@ -1641,7 +1641,7 @@ static long unix_stream_data_wait(struct sock * sk, long timeo)
{
DEFINE_WAIT(wait);

unix_state_rlock(sk);
unix_state_lock(sk);

for (;;) {
prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
Expand All @@ -1654,14 +1654,14 @@ static long unix_stream_data_wait(struct sock * sk, long timeo)
break;

set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
unix_state_runlock(sk);
unix_state_unlock(sk);
timeo = schedule_timeout(timeo);
unix_state_rlock(sk);
unix_state_lock(sk);
clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
}

finish_wait(sk->sk_sleep, &wait);
unix_state_runlock(sk);
unix_state_unlock(sk);
return timeo;
}

Expand Down Expand Up @@ -1816,12 +1816,12 @@ static int unix_shutdown(struct socket *sock, int mode)
mode = (mode+1)&(RCV_SHUTDOWN|SEND_SHUTDOWN);

if (mode) {
unix_state_wlock(sk);
unix_state_lock(sk);
sk->sk_shutdown |= mode;
other=unix_peer(sk);
if (other)
sock_hold(other);
unix_state_wunlock(sk);
unix_state_unlock(sk);
sk->sk_state_change(sk);

if (other &&
Expand All @@ -1833,9 +1833,9 @@ static int unix_shutdown(struct socket *sock, int mode)
peer_mode |= SEND_SHUTDOWN;
if (mode&SEND_SHUTDOWN)
peer_mode |= RCV_SHUTDOWN;
unix_state_wlock(other);
unix_state_lock(other);
other->sk_shutdown |= peer_mode;
unix_state_wunlock(other);
unix_state_unlock(other);
other->sk_state_change(other);
read_lock(&other->sk_callback_lock);
if (peer_mode == SHUTDOWN_MASK)
Expand Down Expand Up @@ -1973,7 +1973,7 @@ static int unix_seq_show(struct seq_file *seq, void *v)
else {
struct sock *s = v;
struct unix_sock *u = unix_sk(s);
unix_state_rlock(s);
unix_state_lock(s);

seq_printf(seq, "%p: %08X %08X %08X %04X %02X %5lu",
s,
Expand Down Expand Up @@ -2001,7 +2001,7 @@ static int unix_seq_show(struct seq_file *seq, void *v)
for ( ; i < len; i++)
seq_putc(seq, u->addr->name->sun_path[i]);
}
unix_state_runlock(s);
unix_state_unlock(s);
seq_putc(seq, '\n');
}

Expand Down

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