From ebd93a7daf40d61b994b9928dd7bf26e0dcca10d Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Wed, 15 Jan 2014 10:23:38 +0800 Subject: [PATCH] eql: use __dev_get_by_name instead of dev_get_by_name to find interface The following call chain indicates that eql_ioctl(), eql_enslave(), eql_emancipate(), eql_g_slave_cfg() and eql_s_slave_cfg() are protected under rtnl_lock. So if we use __dev_get_by_name() instead of dev_get_by_name() to find interface handlers in them, this would help us avoid to change interface reference counters. dev_ioctl() rtnl_lock() dev_ifsioc() eql_ioctl() eql_enslave() eql_emancipate() eql_g_slave_cfg() eql_s_slave_cfg() rtnl_unlock() Additionally we also change their return values from -EINVAL to -ENODEV in case that interfaces are no found. Signed-off-by: Ying Xue Signed-off-by: David S. Miller --- drivers/net/eql.c | 87 +++++++++++++++++++++-------------------------- 1 file changed, 38 insertions(+), 49 deletions(-) diff --git a/drivers/net/eql.c b/drivers/net/eql.c index f219d38acf58..7a79b6046879 100644 --- a/drivers/net/eql.c +++ b/drivers/net/eql.c @@ -395,6 +395,7 @@ static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave) if (duplicate_slave) eql_kill_one_slave(queue, duplicate_slave); + dev_hold(slave->dev); list_add(&slave->list, &queue->all_slaves); queue->num_slaves++; slave->dev->flags |= IFF_SLAVE; @@ -413,39 +414,35 @@ static int eql_enslave(struct net_device *master_dev, slaving_request_t __user * if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) return -EFAULT; - slave_dev = dev_get_by_name(&init_net, srq.slave_name); - if (slave_dev) { - if ((master_dev->flags & IFF_UP) == IFF_UP) { - /* slave is not a master & not already a slave: */ - if (!eql_is_master(slave_dev) && - !eql_is_slave(slave_dev)) { - slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL); - equalizer_t *eql = netdev_priv(master_dev); - int ret; + slave_dev = __dev_get_by_name(&init_net, srq.slave_name); + if (!slave_dev) + return -ENODEV; - if (!s) { - dev_put(slave_dev); - return -ENOMEM; - } + if ((master_dev->flags & IFF_UP) == IFF_UP) { + /* slave is not a master & not already a slave: */ + if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) { + slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL); + equalizer_t *eql = netdev_priv(master_dev); + int ret; - memset(s, 0, sizeof(*s)); - s->dev = slave_dev; - s->priority = srq.priority; - s->priority_bps = srq.priority; - s->priority_Bps = srq.priority / 8; + if (!s) + return -ENOMEM; - spin_lock_bh(&eql->queue.lock); - ret = __eql_insert_slave(&eql->queue, s); - if (ret) { - dev_put(slave_dev); - kfree(s); - } - spin_unlock_bh(&eql->queue.lock); + memset(s, 0, sizeof(*s)); + s->dev = slave_dev; + s->priority = srq.priority; + s->priority_bps = srq.priority; + s->priority_Bps = srq.priority / 8; - return ret; - } + spin_lock_bh(&eql->queue.lock); + ret = __eql_insert_slave(&eql->queue, s); + if (ret) + kfree(s); + + spin_unlock_bh(&eql->queue.lock); + + return ret; } - dev_put(slave_dev); } return -EINVAL; @@ -461,24 +458,20 @@ static int eql_emancipate(struct net_device *master_dev, slaving_request_t __use if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) return -EFAULT; - slave_dev = dev_get_by_name(&init_net, srq.slave_name); + slave_dev = __dev_get_by_name(&init_net, srq.slave_name); + if (!slave_dev) + return -ENODEV; + ret = -EINVAL; - if (slave_dev) { - spin_lock_bh(&eql->queue.lock); - - if (eql_is_slave(slave_dev)) { - slave_t *slave = __eql_find_slave_dev(&eql->queue, - slave_dev); - - if (slave) { - eql_kill_one_slave(&eql->queue, slave); - ret = 0; - } + spin_lock_bh(&eql->queue.lock); + if (eql_is_slave(slave_dev)) { + slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev); + if (slave) { + eql_kill_one_slave(&eql->queue, slave); + ret = 0; } - dev_put(slave_dev); - - spin_unlock_bh(&eql->queue.lock); } + spin_unlock_bh(&eql->queue.lock); return ret; } @@ -494,7 +487,7 @@ static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp) if (copy_from_user(&sc, scp, sizeof (slave_config_t))) return -EFAULT; - slave_dev = dev_get_by_name(&init_net, sc.slave_name); + slave_dev = __dev_get_by_name(&init_net, sc.slave_name); if (!slave_dev) return -ENODEV; @@ -510,8 +503,6 @@ static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp) } spin_unlock_bh(&eql->queue.lock); - dev_put(slave_dev); - if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t))) ret = -EFAULT; @@ -529,7 +520,7 @@ static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp) if (copy_from_user(&sc, scp, sizeof (slave_config_t))) return -EFAULT; - slave_dev = dev_get_by_name(&init_net, sc.slave_name); + slave_dev = __dev_get_by_name(&init_net, sc.slave_name); if (!slave_dev) return -ENODEV; @@ -548,8 +539,6 @@ static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp) } spin_unlock_bh(&eql->queue.lock); - dev_put(slave_dev); - return ret; }