[PATCH 2/7] netprio_cgroup: simplify write_priomap()

Tejun Heo
2012-11-20T07:06:46Z

sscanf() doesn't bite.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
---
net/core/netprio_cgroup.c | 56 ++++++++++-------------------------------------
1 file changed, 11 insertions(+), 45 deletions(-)

diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index f0b6b0d..66d98da 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -176,66 +176,32 @@ static int read_priomap(struct cgroup *cont, struct cftype *cft,
static int write_priomap(struct cgroup *cgrp, struct cftype *cft,
const char *buffer)
{
- char *devname = kstrdup(buffer, GFP_KERNEL);
- int ret = -EINVAL;
u32 prioidx = cgrp_netprio_state(cgrp)->prioidx;
- unsigned long priority;
- char *priostr;
+ char devname[IFNAMSIZ + 1];
struct net_device *dev;
struct netprio_map *map;
+ u32 prio;
+ int ret;

- if (!devname)
- return -ENOMEM;
-
- /*
- * Minimally sized valid priomap string
- */
- if (strlen(devname) < 3)
- goto out_free_devname;
-
- priostr = strstr(devname, " ");
- if (!priostr)
- goto out_free_devname;
-
- /*
- *Separate the devname from the associated priority
- *and advance the priostr pointer to the priority value
- */
- *priostr = '\0';
- priostr++;
-
- /*
- * If the priostr points to NULL, we're at the end of the passed
- * in string, and its not a valid write
- */
- if (*priostr == '\0')
- goto out_free_devname;
-
- ret = kstrtoul(priostr, 10, &priority);
- if (ret < 0)
- goto out_free_devname;
-
- ret = -ENODEV;
+ if (sscanf(buffer, "%"__stringify(IFNAMSIZ)"s %u", devname, &prio) != 2)
+ return -EINVAL;

dev = dev_get_by_name(&init_net, devname);
if (!dev)
- goto out_free_devname;
+ return -ENODEV;

rtnl_lock();
+
ret = write_update_netdev_table(dev);
- if (ret < 0)
- goto out_put_dev;
+ if (ret)
+ goto out_unlock;

map = rtnl_dereference(dev->priomap);
if (map)
- map->priomap[prioidx] = priority;
-
-out_put_dev:
+ map->priomap[prioidx] = prio;
+out_unlock:
rtnl_unlock();
dev_put(dev);
-
-out_free_devname:
- kfree(devname);
return ret;
}

--
1.7.11.7