Commit 128aaa98 authored by Kirill Tkhai's avatar Kirill Tkhai Committed by David S. Miller
Browse files

net: Revert "ipv4: fix a deadlock in ip_ra_control" 



This reverts commit 1215e51e.
Since raw_close() is used on every RAW socket destruction,
the changes made by 1215e51e scale sadly. This clearly
seen on endless unshare(CLONE_NEWNET) test, and cleanup_net()
kwork spends a lot of time waiting for rtnl_lock() introduced
by this commit.

Previous patch moved IP_ROUTER_ALERT out of rtnl_lock(),
so we revert this patch.

Signed-off-by: default avatarKirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0526947f

net/ipv4/ip_sockglue.c

+0 −1
Original line number Diff line number Diff line
@@ -594,7 +594,6 @@ static bool setsockopt_needs_rtnl(int optname) 
	case MCAST_LEAVE_GROUP:

	case MCAST_LEAVE_SOURCE_GROUP:

	case MCAST_UNBLOCK_SOURCE:

	case IP_ROUTER_ALERT:

		return true;

	}

	return false;

net/ipv4/ipmr.c

+9 −2
Original line number Diff line number Diff line
@@ -1399,7 +1399,7 @@ static void mrtsock_destruct(struct sock *sk) 
	struct net *net = sock_net(sk);

	struct mr_table *mrt;



	ASSERT_RTNL();

	rtnl_lock();

	ipmr_for_each_table(mrt, net) {

		if (sk == rtnl_dereference(mrt->mroute_sk)) {

			IPV4_DEVCONF_ALL(net, MC_FORWARDING)--;
@@ -1411,6 +1411,7 @@ static void mrtsock_destruct(struct sock *sk) 
			mroute_clean_tables(mrt, false);

		}

	}

	rtnl_unlock();

}



/* Socket options and virtual interface manipulation. The whole
@@ -1475,8 +1476,13 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, 
		if (sk != rcu_access_pointer(mrt->mroute_sk)) {

			ret = -EACCES;

		} else {

			/* We need to unlock here because mrtsock_destruct takes

			 * care of rtnl itself and we can't change that due to

			 * the IP_ROUTER_ALERT setsockopt which runs without it.

			 */

			rtnl_unlock();

			ret = ip_ra_control(sk, 0, NULL);

			goto out_unlock;

			goto out;

		}

		break;

	case MRT_ADD_VIF:
@@ -1588,6 +1594,7 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, 
	}

out_unlock:

	rtnl_unlock();

out:

	return ret;

}

net/ipv4/raw.c

+0 −2
Original line number Diff line number Diff line
@@ -711,9 +711,7 @@ static void raw_close(struct sock *sk, long timeout) 
	/*

	 * Raw sockets may have direct kernel references. Kill them.

	 */

	rtnl_lock();

	ip_ra_control(sk, 0, NULL);

	rtnl_unlock();



	sk_common_release(sk);

}

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