On Tue, 2013-06-11 at 08:34 +0200, Antonio Quartulli wrote:
From: Matthias Schiffer mschiffer@universe-factory.net
The rtnl_lock in batadv_store_mesh_iface has been converted to a rtnl_trylock some time ago to avoid a possible deadlock between rtnl and s_active on removal of the sysfs nodes.
The behaviour introduced by that was quite confusing as it could lead to the sysfs store to fail, making batman-adv setup scripts unreliable.
I think what you actually wanted was ERESTARTNOINTR. But the real problem is that neither of these error codes is valid unless the system call is aborted due to a signal.
Ben.
As recently the sysfs removal was postponed to a worker not running with the rtnl taken, the deadlock can't occur any more and it is safe to change the trylock back to a lock to make the sysfs store reliable again.
Signed-off-by: Matthias Schiffer mschiffer@universe-factory.net Reviewed-by: Simon Wunderlich siwu@hrz.tu-chemnitz.de Signed-off-by: Marek Lindner lindner_marek@yahoo.de Signed-off-by: Antonio Quartulli ordex@autistici.org
net/batman-adv/sysfs.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/net/batman-adv/sysfs.c b/net/batman-adv/sysfs.c index 15a22ef..929e304 100644 --- a/net/batman-adv/sysfs.c +++ b/net/batman-adv/sysfs.c @@ -582,10 +582,7 @@ static ssize_t batadv_store_mesh_iface(struct kobject *kobj, (strncmp(hard_iface->soft_iface->name, buff, IFNAMSIZ) == 0)) goto out;
- if (!rtnl_trylock()) {
ret = -ERESTARTSYS;goto out;- }
rtnl_lock();
if (status_tmp == BATADV_IF_NOT_IN_USE) { batadv_hardif_disable_interface(hard_iface,