From: Florian Westphal <fw@strlen•de>
To: <netdev@vger•kernel.org>
Cc: Florian Westphal <fw@strlen•de>
Subject: [PATCH v2 net-next 4/7] rtnetlink: small rtnl lock pushdown
Date: Wed, 9 Aug 2017 20:41:50 +0200 [thread overview]
Message-ID: <20170809184153.16700-5-fw@strlen.de> (raw)
In-Reply-To: <20170809184153.16700-1-fw@strlen.de>
instead of rtnl lock/unload at the top level, push it down
to the called function.
This is just an intermediate step, next commit switches protection
of the rtnl_link ops table to rcu, in which case (for dumps) the
rtnl lock is acquired only by the netlink dumper infrastructure
(current lock/unlock/dump/lock/unlock rtnl sequence becomes
rcu lock/rcu unlock/dump).
Signed-off-by: Florian Westphal <fw@strlen•de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion•org>
---
No changes since v1.
net/core/rtnetlink.c | 19 +++++++++++++------
1 file changed, 13 insertions(+), 6 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index c45a7c5e3232..be01d8e48661 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4178,9 +4178,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
rtnl_dumpit_func dumpit;
u16 min_dump_alloc = 0;
+ rtnl_lock();
+
dumpit = rtnl_get_dumpit(family, type);
if (dumpit == NULL)
- return -EOPNOTSUPP;
+ goto err_unlock;
refcount_inc(&rtnl_msg_handlers_ref[family]);
@@ -4196,23 +4198,28 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
};
err = netlink_dump_start(rtnl, skb, nlh, &c);
}
- rtnl_lock();
refcount_dec(&rtnl_msg_handlers_ref[family]);
return err;
}
+ rtnl_lock();
doit = rtnl_get_doit(family, type);
if (doit == NULL)
- return -EOPNOTSUPP;
+ goto err_unlock;
- return doit(skb, nlh, extack);
+ err = doit(skb, nlh, extack);
+ rtnl_unlock();
+
+ return err;
+
+err_unlock:
+ rtnl_unlock();
+ return -EOPNOTSUPP;
}
static void rtnetlink_rcv(struct sk_buff *skb)
{
- rtnl_lock();
netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
- rtnl_unlock();
}
static int rtnetlink_bind(struct net *net, int group)
--
2.13.0
next prev parent reply other threads:[~2017-08-09 18:41 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-09 18:41 [PATCH v2 net-next 0/7] rtnetlink: allow selected handlers to run without rtnl Florian Westphal
2017-08-09 18:41 ` [PATCH v2 net-next 1/7] rtnetlink: call rtnl_calcit directly Florian Westphal
2017-08-09 18:41 ` [PATCH v2 net-next 2/7] rtnetlink: make rtnl_register accept a flags parameter Florian Westphal
2017-08-09 18:41 ` [PATCH v2 net-next 3/7] rtnetlink: add reference counting to prevent module unload while dump is in progress Florian Westphal
2017-08-09 18:41 ` Florian Westphal [this message]
2017-08-09 18:41 ` [PATCH v2 net-next 5/7] rtnetlink: protect handler table with rcu Florian Westphal
2017-08-10 8:26 ` Ido Schimmel
2017-08-09 18:41 ` [PATCH v2 net-next 6/7] rtnetlink: add RTNL_FLAG_DOIT_UNLOCKED Florian Westphal
2017-08-09 18:41 ` [PATCH v2 net-next 7/7] net: call newid/getid without rtnl mutex held Florian Westphal
2017-08-10 0:21 ` [PATCH v2 net-next 0/7] rtnetlink: allow selected handlers to run without rtnl David Miller
2017-08-10 1:27 ` David Ahern
2017-08-10 11:29 ` Florian Westphal
2017-08-10 16:23 ` David Ahern
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