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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-12-05 01:23:53 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-12-08 10:07:24 -0800 |
| commit | 941666c2e3e0f9f6a1cb5808d02352d445bd702c (patch) | |
| tree | 389a773580ef22908391cc71f98982b03de62804 /net/llc/af_llc.c | |
| parent | a2d4b65d477aad1fe8c7218781a031fa9cf5abfc (diff) | |
| download | linux-941666c2e3e0f9f6a1cb5808d02352d445bd702c.tar.gz linux-941666c2e3e0f9f6a1cb5808d02352d445bd702c.tar.bz2 linux-941666c2e3e0f9f6a1cb5808d02352d445bd702c.zip | |
net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()
Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :
> Hmm..
>
> If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> that your patch can be applied.
>
> Right now it is not good, because RTNL wont be necessarly held when you
> are going to call arp_invalidate() ?
While doing this analysis, I found a refcount bug in llc, I'll send a
patch for net-2.6
Meanwhile, here is the patch for net-next-2.6
Your patch then can be applied after mine.
Thanks
[PATCH] net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()
dev_getbyhwaddr() was called under RTNL.
Rename it to dev_getbyhwaddr_rcu() and change all its caller to now use
RCU locking instead of RTNL.
Change arp_ioctl() to use RCU instead of RTNL locking.
Note: this fix a dev refcount bug in llc
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/llc/af_llc.c')
| -rw-r--r-- | net/llc/af_llc.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index 582612998211..dfd3a648a551 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -316,9 +316,9 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) if (unlikely(addr->sllc_family != AF_LLC)) goto out; rc = -ENODEV; - rtnl_lock(); + rcu_read_lock(); if (sk->sk_bound_dev_if) { - llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); + llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); if (llc->dev) { if (!addr->sllc_arphrd) addr->sllc_arphrd = llc->dev->type; @@ -329,14 +329,15 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) !llc_mac_match(addr->sllc_mac, llc->dev->dev_addr)) { rc = -EINVAL; - dev_put(llc->dev); llc->dev = NULL; } } } else - llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd, + llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd, addr->sllc_mac); - rtnl_unlock(); + if (llc->dev) + dev_hold(llc->dev); + rcu_read_unlock(); if (!llc->dev) goto out; if (!addr->sllc_sap) { |