diff options
| author | Sven Eckelmann <sven@narfation.org> | 2011-05-03 13:10:06 +0200 |
|---|---|---|
| committer | Sven Eckelmann <sven@narfation.org> | 2011-05-08 16:10:42 +0200 |
| commit | 3a4375a9f0080e6ae40af63e2e2c1e70a6dcb775 (patch) | |
| tree | a3448104babf921c217a1e94c2e46d5bd7613a2d /net | |
| parent | batman-adv: Remove unnecessary hardif_list_lock (diff) | |
| download | linux-3a4375a9f0080e6ae40af63e2e2c1e70a6dcb775.tar.xz linux-3a4375a9f0080e6ae40af63e2e2c1e70a6dcb775.zip | |
batman-adv: Avoid deadlock between rtnl_lock and s_active
The hard_if_event is called by the notifier with rtnl_lock and tries to
remove sysfs entries when a NETDEV_UNREGISTER event is received. This
will automatically take the s_active lock.
The s_active lock is also used when a new interface is added to a meshif
through sysfs. In that situation we cannot wait for the rntl_lock before
creating the actual batman-adv interface to prevent a deadlock. It is
still possible to try to get the rtnl_lock and immediately abort the
current operation when the trylock call failed.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/bat_sysfs.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/net/batman-adv/bat_sysfs.c b/net/batman-adv/bat_sysfs.c index 85ba20d98a66..497a0700cc3c 100644 --- a/net/batman-adv/bat_sysfs.c +++ b/net/batman-adv/bat_sysfs.c @@ -488,24 +488,24 @@ static ssize_t store_mesh_iface(struct kobject *kobj, struct attribute *attr, (strncmp(hard_iface->soft_iface->name, buff, IFNAMSIZ) == 0)) goto out; + if (!rtnl_trylock()) { + ret = -ERESTARTSYS; + goto out; + } + if (status_tmp == IF_NOT_IN_USE) { - rtnl_lock(); hardif_disable_interface(hard_iface); - rtnl_unlock(); - goto out; + goto unlock; } /* if the interface already is in use */ - if (hard_iface->if_status != IF_NOT_IN_USE) { - rtnl_lock(); + if (hard_iface->if_status != IF_NOT_IN_USE) hardif_disable_interface(hard_iface); - rtnl_unlock(); - } - rtnl_lock(); ret = hardif_enable_interface(hard_iface, buff); - rtnl_unlock(); +unlock: + rtnl_unlock(); out: hardif_free_ref(hard_iface); return ret; |