[patch 1/1] Convert the semaphore to a mutex in net/tipc/socket.c

From: Kevin Winchester
Date: Sun Dec 09 2007 - 20:26:03 EST


To: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Per Liden <per.liden@xxxxxxxxxxxx>
Cc: Jon Maloy <jon.maloy@xxxxxxxxxxxx>
Cc: Allan Stephens <allan.stephens@xxxxxxxxxxxxx>
Cc: tipc-discussion@xxxxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Note also that in the release method, down_interruptible() was being called
without checking the return value. I converted it to mutex_lock_interruptible()
and made the interrupted case return -ERESTARTSYS, as was done for all other
calls to down_interruptible() in the file.

Signed-off-by: Kevin Winchester <kjwinchester@xxxxxxxxx>

---
net/tipc/socket.c | 56 +++++++++++++++++++++++++++---------------------------
1 file changed, 28 insertions(+), 28 deletions(-)

Index: v2.6.24-rc4/net/tipc/socket.c
===================================================================
--- v2.6.24-rc4.orig/net/tipc/socket.c
+++ v2.6.24-rc4/net/tipc/socket.c
@@ -63,7 +63,7 @@
struct tipc_sock {
struct sock sk;
struct tipc_port *p;
- struct semaphore sem;
+ struct mutex lock;
};

#define tipc_sk(sk) ((struct tipc_sock*)sk)
@@ -217,7 +217,7 @@ static int tipc_create(struct net *net,
tsock->p = port;
port->usr_handle = tsock;

- init_MUTEX(&tsock->sem);
+ mutex_init(&tsock->lock);

dbg("sock_create: %x\n",tsock);

@@ -253,9 +253,10 @@ static int release(struct socket *sock)
dbg("sock_delete: %x\n",tsock);
if (!tsock)
return 0;
- down_interruptible(&tsock->sem);
+ if (mutex_lock_interruptible(&tsock->lock))
+ return -ERESTARTSYS;
if (!sock->sk) {
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return 0;
}

@@ -288,7 +289,7 @@ static int release(struct socket *sock)
atomic_dec(&tipc_queue_size);
}

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);

sock_put(sk);

@@ -315,7 +316,7 @@ static int bind(struct socket *sock, str
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
int res;

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

if (unlikely(!uaddr_len)) {
@@ -346,7 +347,7 @@ static int bind(struct socket *sock, str
res = tipc_withdraw(tsock->p->ref, -addr->scope,
&addr->addr.nameseq);
exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -367,7 +368,7 @@ static int get_name(struct socket *sock,
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
u32 res;

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

*uaddr_len = sizeof(*addr);
@@ -380,7 +381,7 @@ static int get_name(struct socket *sock,
res = tipc_ownidentity(tsock->p->ref, &addr->addr.id);
addr->addr.name.domain = 0;

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -477,7 +478,7 @@ static int send_msg(struct kiocb *iocb,
}
}

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

if (needs_conn) {
@@ -523,7 +524,7 @@ static int send_msg(struct kiocb *iocb,
}
if (likely(res != -ELINKCONG)) {
exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}
if (m->msg_flags & MSG_DONTWAIT) {
@@ -562,9 +563,8 @@ static int send_packet(struct kiocb *ioc
if (unlikely(dest))
return send_msg(iocb, sock, m, total_len);

- if (down_interruptible(&tsock->sem)) {
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;
- }

do {
if (unlikely(sock->state != SS_CONNECTED)) {
@@ -578,7 +578,7 @@ static int send_packet(struct kiocb *ioc
res = tipc_send(tsock->p->ref, m->msg_iovlen, m->msg_iov);
if (likely(res != -ELINKCONG)) {
exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}
if (m->msg_flags & MSG_DONTWAIT) {
@@ -846,7 +846,7 @@ static int recv_msg(struct kiocb *iocb,

/* Look for a message in receive queue; wait if necessary */

- if (unlikely(down_interruptible(&tsock->sem)))
+ if (unlikely(mutex_lock_interruptible(&tsock->lock)))
return -ERESTARTSYS;

restart:
@@ -930,7 +930,7 @@ restart:
advance_queue(tsock);
}
exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -981,7 +981,7 @@ static int recv_stream(struct kiocb *ioc

/* Look for a message in receive queue; wait if necessary */

- if (unlikely(down_interruptible(&tsock->sem)))
+ if (unlikely(mutex_lock_interruptible(&tsock->lock)))
return -ERESTARTSYS;

restart:
@@ -1077,7 +1077,7 @@ restart:
goto restart;

exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return sz_copied ? sz_copied : res;
}

@@ -1293,7 +1293,7 @@ static int connect(struct socket *sock,
return res;
}

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

/* Wait for destination's 'ACK' response */
@@ -1317,7 +1317,7 @@ static int connect(struct socket *sock,
sock->state = SS_DISCONNECTING;
}

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -1365,7 +1365,7 @@ static int accept(struct socket *sock, s
(flags & O_NONBLOCK)))
return -EWOULDBLOCK;

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

if (wait_event_interruptible(*sock->sk->sk_sleep,
@@ -1412,7 +1412,7 @@ static int accept(struct socket *sock, s
}
}
exit:
- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -1434,7 +1434,7 @@ static int shutdown(struct socket *sock,

/* Could return -EINVAL for an invalid "how", but why bother? */

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

sock_lock(tsock);
@@ -1484,7 +1484,7 @@ restart:

sock_unlock(tsock);

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -1518,7 +1518,7 @@ static int setsockopt(struct socket *soc
if ((res = get_user(value, (u32 __user *)ov)))
return res;

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

switch (opt) {
@@ -1541,7 +1541,7 @@ static int setsockopt(struct socket *soc
res = -EINVAL;
}

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}

@@ -1574,7 +1574,7 @@ static int getsockopt(struct socket *soc
if ((res = get_user(len, ol)))
return res;

- if (down_interruptible(&tsock->sem))
+ if (mutex_lock_interruptible(&tsock->lock))
return -ERESTARTSYS;

switch (opt) {
@@ -1607,7 +1607,7 @@ static int getsockopt(struct socket *soc
res = put_user(sizeof(value), ol);
}

- up(&tsock->sem);
+ mutex_unlock(&tsock->lock);
return res;
}


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