Re: [net PATCH v3 3/3] net: netprio: fix cgrp create and write priomap race
From: John Fastabend Date: Tue, 14 Aug 2012 15:34:35 -0700 > A race exists where creating cgroups and also updating the priomap > may result in losing a priomap update. This is because priomap > writers are not protected by rtnl_lock. > > Move priority writer into rtnl_lock()/rtnl_unlock(). > > CC: Neil Horman > Reported-by: Al Viro > Signed-off-by: John Fastabend Applied. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [net PATCH v3 3/3] net: netprio: fix cgrp create and write priomap race
On Tue, Aug 14, 2012 at 03:34:35PM -0700, John Fastabend wrote: > A race exists where creating cgroups and also updating the priomap > may result in losing a priomap update. This is because priomap > writers are not protected by rtnl_lock. > > Move priority writer into rtnl_lock()/rtnl_unlock(). > > CC: Neil Horman > Reported-by: Al Viro > Signed-off-by: John Fastabend > --- > > net/core/netprio_cgroup.c |8 +++- > 1 files changed, 3 insertions(+), 5 deletions(-) > > diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c > index f65dba3..c75e3f9 100644 > --- a/net/core/netprio_cgroup.c > +++ b/net/core/netprio_cgroup.c > @@ -101,12 +101,10 @@ static int write_update_netdev_table(struct net_device > *dev) > u32 max_len; > struct netprio_map *map; > > - rtnl_lock(); > max_len = atomic_read(&max_prioidx) + 1; > map = rtnl_dereference(dev->priomap); > if (!map || map->priomap_len < max_len) > ret = extend_netdev_table(dev, max_len); > - rtnl_unlock(); > > return ret; > } > @@ -256,17 +254,17 @@ static int write_priomap(struct cgroup *cgrp, struct > cftype *cft, > if (!dev) > goto out_free_devname; > > + rtnl_lock(); > ret = write_update_netdev_table(dev); > if (ret < 0) > goto out_put_dev; > > - rcu_read_lock(); > - map = rcu_dereference(dev->priomap); > + map = rtnl_dereference(dev->priomap); > if (map) > map->priomap[prioidx] = priority; > - rcu_read_unlock(); > > out_put_dev: > + rtnl_unlock(); > dev_put(dev); > > out_free_devname: > > Acked-by: Neil Horman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[net PATCH v3 3/3] net: netprio: fix cgrp create and write priomap race
A race exists where creating cgroups and also updating the priomap may result in losing a priomap update. This is because priomap writers are not protected by rtnl_lock. Move priority writer into rtnl_lock()/rtnl_unlock(). CC: Neil Horman Reported-by: Al Viro Signed-off-by: John Fastabend --- net/core/netprio_cgroup.c |8 +++- 1 files changed, 3 insertions(+), 5 deletions(-) diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c index f65dba3..c75e3f9 100644 --- a/net/core/netprio_cgroup.c +++ b/net/core/netprio_cgroup.c @@ -101,12 +101,10 @@ static int write_update_netdev_table(struct net_device *dev) u32 max_len; struct netprio_map *map; - rtnl_lock(); max_len = atomic_read(&max_prioidx) + 1; map = rtnl_dereference(dev->priomap); if (!map || map->priomap_len < max_len) ret = extend_netdev_table(dev, max_len); - rtnl_unlock(); return ret; } @@ -256,17 +254,17 @@ static int write_priomap(struct cgroup *cgrp, struct cftype *cft, if (!dev) goto out_free_devname; + rtnl_lock(); ret = write_update_netdev_table(dev); if (ret < 0) goto out_put_dev; - rcu_read_lock(); - map = rcu_dereference(dev->priomap); + map = rtnl_dereference(dev->priomap); if (map) map->priomap[prioidx] = priority; - rcu_read_unlock(); out_put_dev: + rtnl_unlock(); dev_put(dev); out_free_devname: -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
