[PATCH net-next 01/10] Drivers: Staging: cxt1e1: use __dev_get_name instead of dev_get_name to find interfaces

Ying Xue
2014-01-14T07:42:26Z

The following call chain denotes that both do_reset() and do_del_chan()
are protected under rtnl_lock. 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 counter.

dev_ioctl()
rtnl_lock()
dev_ifsioc()
c4_ioctl()
do_reset()
do_del_chan()

Signed-off-by: Ying Xue <ying.xue@windriver.com>
---
drivers/staging/cxt1e1/linux.c | 15 +++++++--------
1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/staging/cxt1e1/linux.c b/drivers/staging/cxt1e1/linux.c
index 9b48373..4a08e16 100644
--- a/drivers/staging/cxt1e1/linux.c
+++ b/drivers/staging/cxt1e1/linux.c
@@ -770,9 +770,9 @@ do_del_chan (struct net_device *musycc_dev, void *data)
if (cp.channum > 999)
return -EINVAL;
snprintf (buf, sizeof(buf), CHANNAME "%d", cp.channum);
- if (!(dev = dev_get_by_name (&init_net, buf)))
- return -ENOENT;
- dev_put (dev);
+ dev = __dev_get_by_name(&init_net, buf);
+ if (!dev)
+ return -ENODEV;
ret = do_deluser (dev, 1);
if (ret)
return ret;
@@ -792,19 +792,18 @@ do_reset (struct net_device *musycc_dev, void *data)
char buf[sizeof (CHANNAME) + 3];

sprintf (buf, CHANNAME "%d", i);
- if (!(ndev = dev_get_by_name(&init_net, buf)))
- continue;
+ ndev = __dev_get_by_name(&init_net, buf);
+ if (!ndev)
+ continue;
priv = dev_to_hdlc (ndev)->priv;

if ((unsigned long) (priv->ci) ==
(unsigned long) (netdev_priv(musycc_dev)))
{
ndev->flags &= ~IFF_UP;
- dev_put (ndev);
netif_stop_queue (ndev);
do_deluser (ndev, 1);
- } else
- dev_put (ndev);
+ }
}
return 0;
}
--
1.7.9.5