On Tue, May 28, 2013 at 05:32:32PM +0200, Matthias Schiffer wrote:

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. 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

Thanks for posting, Simon

---

sysfs.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/sysfs.c b/sysfs.c index 15a22ef..929e304 100644 --- a/sysfs.c +++ b/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,

-- 1.8.3