* [PATCH nf] netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex
@ 2020-12-08 18:01 Pablo Neira Ayuso
2020-12-08 19:29 ` Vladimir Oltean
0 siblings, 1 reply; 2+ messages in thread
From: Pablo Neira Ayuso @ 2020-12-08 18:01 UTC (permalink / raw)
To: netfilter-devel; +Cc: olteanv
Add an explicit comment in the code to describe the indirect
serialization of the holders of the commit_mutex with the rtnl_mutex.
Commit 90d2723c6d4c ("netfilter: nf_tables: do not hold reference on
netdevice from preparation phase") already describes this, but a comment
in this case if better for reference.
Reported-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index c2f59879a48d..9a080767667b 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1723,6 +1723,10 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net,
}
nla_strlcpy(ifname, attr, IFNAMSIZ);
+ /* nf_tables_netdev_event() is called under rtnl_mutex, this is
+ * indirectly serializing all the other holders of the commit_mutex with
+ * the rtnl_mutex.
+ */
dev = __dev_get_by_name(net, ifname);
if (!dev) {
err = -ENOENT;
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH nf] netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex
2020-12-08 18:01 [PATCH nf] netfilter: nftables: comment indirect serialization of commit_mutex with rtnl_mutex Pablo Neira Ayuso
@ 2020-12-08 19:29 ` Vladimir Oltean
0 siblings, 0 replies; 2+ messages in thread
From: Vladimir Oltean @ 2020-12-08 19:29 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: netfilter-devel
On Tue, Dec 08, 2020 at 07:01:01PM +0100, Pablo Neira Ayuso wrote:
> Add an explicit comment in the code to describe the indirect
> serialization of the holders of the commit_mutex with the rtnl_mutex.
> Commit 90d2723c6d4c ("netfilter: nf_tables: do not hold reference on
> netdevice from preparation phase") already describes this, but a comment
> in this case if better for reference.
>
> Reported-by: Vladimir Oltean <olteanv@gmail.com>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> ---
> net/netfilter/nf_tables_api.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
> index c2f59879a48d..9a080767667b 100644
> --- a/net/netfilter/nf_tables_api.c
> +++ b/net/netfilter/nf_tables_api.c
> @@ -1723,6 +1723,10 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net,
> }
>
> nla_strlcpy(ifname, attr, IFNAMSIZ);
> + /* nf_tables_netdev_event() is called under rtnl_mutex, this is
> + * indirectly serializing all the other holders of the commit_mutex with
> + * the rtnl_mutex.
> + */
> dev = __dev_get_by_name(net, ifname);
> if (!dev) {
> err = -ENOENT;
> --
> 2.20.1
>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Thanks!
^ permalink raw reply [flat|nested] 2+ messages in thread
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