net-sysfs: Use rtnl_trylock in sysfs methods.

The earlier patch to fix the deadlock between a network device going
away and writing to sysfs attributes was incomplete.
- It did not set signal_pending so we would leak ERSTARTSYS to user space.
- It used ERESTARTSYS which only restarts if sigaction configures it to.
- It did not cover store and show for ifalias.

So fix all of these up and use the new helper restart_syscall so we get
the details correct on what it takes.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric W. Biederman 2009-05-13 16:57:25 +00:00 committed by David S. Miller
parent 690cc3ffe3
commit 336ca57c3b

View File

@ -78,7 +78,7 @@ static ssize_t netdev_store(struct device *dev, struct device_attribute *attr,
goto err;
if (!rtnl_trylock())
return -ERESTARTSYS;
return restart_syscall();
if (dev_isalive(net)) {
if ((ret = (*set)(net, new)) == 0)
@ -225,7 +225,8 @@ static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr,
if (len > 0 && buf[len - 1] == '\n')
--count;
rtnl_lock();
if (!rtnl_trylock())
return restart_syscall();
ret = dev_set_alias(netdev, buf, count);
rtnl_unlock();
@ -238,7 +239,8 @@ static ssize_t show_ifalias(struct device *dev,
const struct net_device *netdev = to_net_dev(dev);
ssize_t ret = 0;
rtnl_lock();
if (!rtnl_trylock())
return restart_syscall();
if (netdev->ifalias)
ret = sprintf(buf, "%s\n", netdev->ifalias);
rtnl_unlock();